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DAFM NRL Newsletter Volume 7, Issue 1.
Page 1
NRL Contacts
Antimicrobial Resistance
Zoonoses (Salmonella)
Dr R Slowey
Listeria
Staphylococci
Milk & Milk Products
Ms B Hickey
E. coli (STEC)
Dr M Gutierrez
TSE’s
Dr M McElroy
Residues/Chemical Elements
Dr S Earley
Pesticide Residues
Dr J Garvey
Campylobacter, TB & Johnes Disease
Dr J Egan
Animal Proteins
Dr S Nolan
Exotic Animal Viral Diseases
Dr R O’Neill & Dr E Ryan
Parasites
Dr W Byrne
Contagious equine metritis
Mr J Moriarty & Dr E Ryan
Bovine Viral Diarrhoea
Dr Jose Maria Lozano
Volume 7, Issue 1 2016
BACKWESTON
DAFM LABORATORIES
BACKWESTON
Newsletter
Activities of National Reference Laboratories Introduction In 2006, following the designation of a number of additional European Union Reference Laboratories (EURL’s), Member States were required under Article 33 of Regulation 882 / 2004 to designate one or more National Reference Laboratory (NRL) for each EURL. The Departments of Health and Children and Agriculture, Food and the Marine (DAFM), as the Irish Competent Authorities, assigned these NRL functions to a number of laboratories including those within the Backweston Laboratory Campus. The DAFM laboratories also host a number of NRL established under EU or national legislation focusing specifically on animal health. In this issue reports on:
10th Workshop of the EURL for Listeria monocytogenes
21st Workshop of the EURL for Antimicrobial and Dye Residues in Food
Euroresidue VIII
10th Workshop of the EURL Coagulase Positive Staphylococci
19th Workshop of the EURL for Milk and Milk Products
Annual Workshop of the EURL for Chemical Elements in food of animal origin.
11th Workshop of the EURL Campylobacter
11th Workshop of the EURL Escherichia coli
10th Workshop of the EURL Animal Protein
Also included a note on the Food Health and the Role of National Reference Laboratories Conference

DAFM NRL Newsletter Volume 7, Issue 1.
Page 2
Abbreviations: PT- Proficiency Test MS- Member States NGS- Next Generation Sequencing WGS- Whole Genome Sequencing FBO- Food Business Operator CA- Competent Authority CRM- Certified Reference Material
10th
Workshop of the EURL for Listeria monocytogenes, ANSES, Paris, March 15-17
th 2016
NRL Representative: Bernadette Hickey (DSL)
Participants from 27 MS, Norway and Macedonia attended the meeting. Pamina Mika SUZUKI, DG Santé was present on 15
th and 16
th March. Invited
guests were Valentina Rizzi- EFSA, Johanna Takkinen -ECDC and Yi Chen, FDA.
A wide range of topics were discussed including Listeria monocytogenes outbreaks, updates on EFSA and ECDC activities, results on subsampling project and the temperature profile at retail from the EU baseline study on Listeria monocytogenes. Typing methods including the experience of MS in using WGS were also discussed. The meeting participants were briefed on the progress of the establishment of the database for Listeria monocytogenes using PFGE profiles from non-human sources. An update on ISO working groups relating to Listeria was provided.
Epidemiological Context
Valentina Rizzi (EFSA) and Johanna Takkinen(ECDC) presented data from the EFSA and ECDC 2014 Reports. In 2014 there were >2000 confirmed cases. This was an increase of 16% over 2013. The EU notification rate was 0.52 per 100,000 of the population. This increase is of great concern as the infection is acquired from consumption of contaminated RTE foods. Despite the rise in listerosis, Listeria monocytogenes was seldom detected above the levels set in the Regulation (EC) 2073/2005. RTE fishery products, mainly smoked fish are most frequently associated with non-compliances with 4.7% of single samples and 10.6% of batches non-compliant. There were 15 food borne outbreaks in 2015.
The highest rate of fatality was in the male population aged over 65. The relative risk is 100 for women over 65 and 160 for men over 65. There appears to be a higher incidence in the summer months. There is concern over the increasing level
of listerosis as the population is aging: in 2012, 17% of the population were over 65 but by 2060, 30% of the population will be over 65.
EFSA and ECDC have developed databases for the collection of typing information on Salmonella, Listeria monocytogenes and STEC. The ECDC will collect data from clinical isolates and the EFSA database from non-human isolates. The EFSA database will be piloted during 2016. Currently the database is designed to collect PFGE profiles and not sequence data from WGS. EFSA has urged MS moving towards WGS to continue to do PFGE during the transition phase so that data from MS can be compared.
Franceso Pomilio (NRL Italy) presented the use of WGS in tracking an outbreak in Italy. The Italians identified an epidemic PFGE pulsotype. Through the use of epidemiological data including questionnaires some risky foods were identified. WGS was performed on the human isolates and they contained 4 specific genomic islands, all the strains clustered closely and there was practically no differences in the accessory genes. A fast PCR targeting 2 of the genomic islands was developed and used to target isolates for WGS and PFGE typing.
Yi Chen (US FDA) gave an overview of the use of WGS in surveillance in the US. In the US, CDC and the FDA have developed a partnership to sequence every human isolate (CDC) and isolates from food, feed and the environment (FDA). They have a network of Genome TRACKR laboratories feeding sequences to the NCBI website. The kmer tree is updated daily and weekly discussions on clusters takes place between CDC and FDA. The US are using Single Nucleotide Polymorphisms (SNP’s) Cluster Analysis to analyse the data using freely available software. There were >30,000 sequences in the Genome TRACKR database by the end of quarter 2 in 2015 and the numbers are increasing rapidly. Approximately 4,000 are sequences from Listeria monocytogenes. When Listeria monocytogenes is detected, isolates obtained from premises before and after the cleaning are sequenced by FDA, and if the strains after clean-up match the strains obtained prior to clean-up the FDA takes action as cleaning is considered not effective.
Detection/ Enumeration
Lena Barre (EURL) presented results of trials carried out on the effect of the quantity of sample used for the primary dilution and its effect on reducing the measurement of uncertainty. The distribution of microorganisms is heterogeneous in solid matrices.

DAFM NRL Newsletter Volume 7, Issue 1.
Page 3
The EURL asked for assistance from NRL’s to evaluate the results using 10g and 25g portions of naturally contaminated results. Two NRL’s returned results and the data were evaluated on 12 sets of results. The result obtained from this data set did not support that 25g gave a lower MU than 10g sample portion.
The recommendation is to take sub-samples at different places of the sample to cover heterogeneity; it seems to be more important than test portion size. In this regard the use of a larger subsample i.e. 25g would allow more subsampling from different portions of the product.
Shelf Life Studies
Helen Bergis (EURL) evaluated the temperature data collected from retail during the baseline study to see the temperature distribution in the MS. More than 10,000 temperature measurements were collected during the survey. The temperature of the retail cabinet and the surface temperature were recorded. The products checked in the survey were soft and semi soft cheese, packaged heat treated meat and packaged smoked or gravid fish. The results of the analysis showed that the mean temperature was 4.1°C for cheese and 3.5°C for fish and 3.7°C for meat. There was a 0.2% chance that the product would be outside 12°C. There was no difference in seasonality or geographic location. This analysis of the data was very beneficial and hopefully it can be used to amend the default temperatures in the “EURL Lm Technical guidance document for conducting shelf-life studies relating to Lm”
Characterisation and Epidemiology
This session was mainly devoted to presentations on EU funded projects to assess WGS that are currently on-going and the experience of the Austrian NRL in implementing WGS. Three projects currently in progress were presented. The purpose of all the projects is to harmonise protocols and interpretation.
Ariane Pietzka (AGES, NRL Austria) delivered a presentation on the approach to WGS taken in AGES in Austria. AGES with the cooperation of Munster University have developed and evaluated a typing scheme for Listeria monocytogenes based on core genome MLST (cgMLST). The genome wide gene by gene comparison is carried out on 1,700 core MLST targets. This typing scheme improves outbreak investigations and due to the availability
of cgMLST nomenclature interlaboratory exchange of data is possible.
ISO Updates
Updates on ISO working groups that the EURL are involved in and relating to Listeria monocytogenes were presented:
ISO 11290-1 and -2 Detection and
Enumeration of Listeria spp. including Listeria
monocytogenes. Draft under preparation for
final vote.
Working group on the revision of the ISO
21807:2004 on the Determination of Water
Activity in Foodstuffs.
Working group on Shelf life Studies. In 2014 a
working group under ISO/TC34/SC9/WG19
was set up to establish an ISO Guideline for
conducting challenge tests
A working group on Whole Genome
sequencing for typing and genomic
characterisation under ISO/TC34/SC9/WG25
was set up. The working group is focusing on
DNA and not RNA. The priority is for food
borne bacteria such as Salmonella spp,
Listeria monocytogenes, Shiga-toxin producing
strains of Escherichia coli, Campylobacter
jejuni and C. coli, Vibrio cholerae, V.
parahemolyticus and Chronobacter sazakii
21
st Workshop of the EURL for Antimicrobial and
Dye Residues in Food - Advances in LC-MS/MS
Methods for Screening and Confirming Antibiotics,
Fougeres, France October 6th
and 7th
2016
NRL Representative: Seán Earley (VPHRL)
Pascal Sanders (EURL - ANSES) welcomed
participants to the annual EURL workshop. The 2-
day workshop was attended by 49 participants; 46
from EU member states, two from candidate

DAFM NRL Newsletter Volume 7, Issue 1.
Page 4
countries and one from an EFTA country. Frank
Swartenbroux (DG SANTE) sent his apologies for his
absence.
Eric Verdon (EURL) gave an overview of the EURL
2015 and 2016 activities including:
Screening Methods
A survey update on micro/immunological
methods (Discussed in the 2015 Workshop in
detail).
2015 evaluation of the ‘Explorer' test in eggs.
The biosensor technology / high throughput
screening survey, which is ongoing. This was
partly presented at the 2015 Workshop.
Evaluation of new techniques for rapid
screening of Antibiotics in food -
immunoreceptor / electrochemical biosensors
this includes the Vantix potentiometric
method and an amperometric sensor
developed by Madrid University.
Evaluation of a new multiplex method -
Infiniplex in milk products.
Four rapid method kits for nitrofurans banned
in aquaculture products
Physicochemical Methods
Meat and fish: 70+ multi-analyte antibiotic
screen.
Meat and milk: aminoglycosides in kidney,
muscle and milk - discussed at the 2014
workshop.
Poultry: LC-HRMS for critically important
antibiotics - C3G and C4G cephalosporins -
metabolic profiling of residues conducted in
poultry and eggs - presentation at the 2016 by
Murielle GAUGAIN.
Aquaculture multi-dye LCMS Method, 10 - 15
compounds plus LC-HRMS metabolic profiling
of contaminants in farmed fish.
Proficiency Tests
2015 and 2016 PTs - 2016 Honey and Shrimp.
Training
2016 Workshop on the new multi-residue
screening method presented by Estelle
Dubreille.
2017 Planned Visits
The EURL Anses representatives plan to visit the 3
NRLs in Ireland in 2017. Formal notification is
expected in December 2016.
Other Updates
Latest publications/posters/presentations
Updated Anses website was discussed/
presented. Any registered members of the old
website will have to re-register for the new
site (see the Closing Session also).
Publications/presentations/posters etc. from
the 2016 workshop will be available from the
member’s area of the Anses website.
Eric Verdon (EURL – ANSES) presented news from
the commission (in the absence of Frank
Swartenbroux (DG SANTE)) including discussion of
the Repeal of 96/23/EC and new Official Controls
Regulation. Note that the original annexes remain
valid until replaced by updated versions. For
Veterinary Medicinal Products (VMP) residues new
provisions are expected in 3-6 years with updates
to include MS residue monitoring and Third Country
import conditions. Technical discussion in this area
is to start as soon as possible.
Review of 2002/657: Discussion/feedback
conducted at EURL WS in 2016/17 (Berlin, Rome &
Fougères) Member States/Competent Authorities
via NRL expert groups.
Reference Points for Action (RPAs): EFSA general
opinion in 2013; Opinion on Chloramphenicol (CAP)
in 2014; Opinion on Nitrofurans (NF) and Malachite
green (MG) in 2015/16. NFs marker residues to
include DNSH (for Nifursol) - AOZ, AND and DNSH ~
1ppb - health concerns unlikely. Note that Anses
has published articles on analysis of
Nitrofursol/DNSH. RPAs currently confirmed for
CAP 0.3µg/kg; MG 2.0 µg/kg (Sum of
MG/LeucoMG); NFs 1.0 µg/kg (for each AOZ, AMOZ
AHD, SEM and DNSH). Stakeholder consultation etc.
to be carried out before adoption.
Cascade Maximum Residues Levels (MRL):
Discussion on the draft proposal completed.
Although honey bees/honey production remain
sensitive, exclusion of honey from cascade/cascade
MRLs is not legally possible.

DAFM NRL Newsletter Volume 7, Issue 1.
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Eric Verdon (EURL - ANSES) presented an update on
revision of 2002/657/EC giving a summary of the
timelines/work to date on the review. Also
discussed was the EURL Fougères questionnaire on
the fitness for purpose of the 2010 EURL Guidelines
for the Validation of Screening for Residues of
VMPs – Any simplification or additions deems
necessary by the NRL network? The outcome of the
questionnaire on the EURL 2010 guidelines was
summarized in the presentation - the majority of
the member states replies were in agreement with
the VPHRL opinion.
The inclusion of guidelines for Physicochemical
Methods and trends in LC-MS/MS, LC-HRMS for
screening was flagged. Additionally the use of a
‘Confirmatory-Only’ approach for screening of
samples was considered (e.g. LC-MS/MS approach)
for inclusion in the screening guidelines. The use of
Global Approaches (POD / Accuracy Profile) was
also considered in the questionnaire although the
majority of responses indicated no comment or no
expertise in applying these.
The following points were made with regard to the
2010 CRL Screening Guidelines:
It will be maintained as a separate guidance
document.
Physico-chemical screening methods should
be included in the guidelines.
Revision every 3-4 years to include/address
new approaches & techniques.
Suggestions for simplification to be
considered.
The following points were made with regard to
Commission Decision/2002/657:
Main performance criteria will be kept, with a
more accurate definition of CCβ and reference
to the CRL guideline.
The possible inclusion of a list of suitable
screening methods – most likely to be in the
guideline as opposed to the CD.
Inclusion of ‘Global Approaches’ to be further
discussed.
A workshop dedicated to consideration of
screening is proposed for 2017 to look at
simplification, the use of global approaches
and any other topics raised by the lab
network.
Jens Hinge Andersen (National Food Institute, DTU
Food, Denmark) presented the building of Standard
Sample Description No . 2 explaining the origin and
overview of Standard Sample Description 2.0 (SSD
2.0). EFSA propose the use of data in the context of
Risk Management and Risk Assessment; this will
require a significant increase in the amount of data
required from laboratories/Competent Authorities.
The SSD 2.0 system is in an XML format and aims to
standardize the analytical data gathered in member
states to allow data mining for trends and potential
risks – the current data submissions are limited and
provide minimal information to EFSA e.g. Compliant
/ Non-Compliant. SSD 2.0 will expand this to looking
at the analysed levels of veterinary residues across
the EU, along with the inclusion of various other
sample data.
EFSA has been liaising with CAs with regard to
approaches to collecting the expanded lab
data and converting to the SSD 2.0 format.
The most common approach to generating the
required data from labs is to utilize LIMS
databases to export the detailed sample
information – there may be requirement to
modify LIMS to incorporate the required
information as per the SSD 2.0 format.
The experience of Denmark in producing lab
data for SSD 2.0 included the inclusion of
additional sample information at LIMS login
and in the sample results: differentiating
between screening/confirmatory LC-MS
methods, inclusion of various limits etc.
The possibility of demands for further sample
information by EFSA in future was also raised.
Eric Verdon (EURL - ANSES) presented a discussion
on possible changes to analytical methods in
response to SSD 2.0.
Current challenges include:
No LIMS in use in some labs – burden of
producing required sample data without LIMS.

DAFM NRL Newsletter Volume 7, Issue 1.
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Need to include further sample information in
existing LIMS environments e.g. location,
sample size etc.
A spreadsheet should be made available to
CAs to collect data from LIMS and allow data-
mapping into the XML SSD 2.0 database.
SSD 2.0 will require the inclusion of the LOQ –
additional requirement in validation of
methods (typically CCα and CCβ required as
per 2002/657).
Only Negative Screening results will be
accepted in SSD 2.0, i.e. Positive Screens will
not be entered – the corresponding
confirmatory test results will be required for
any samples that screen positive.
There may be the possibility of amendments
to MRLs based on the data collated by SSD 2.0
with the possible need to extend the
validation from an MRL centered approach to
ALARA levels of detection – this may require
revalidation of methods.
Note that 2017 has been flagged as the
deadline for the inclusion of some results for
SSD 2.0 with 2019 being the target for full
rollout of the SSD 2.0 requirements.
Estelle Dubreille (EURL - ANSES) presented an LC-
MS/MS method for screening 70+ antibiotics in
meat and fish. A Workshop and lab tour were
conducted as part of this presentation. Note that
the screening method excludes aminoglycosides
which is performed using a separate method. A
single extraction approach with the same mobile
phase as the aminoglycosides method is used. The
Internal Standard used is sulfaphenazole; Extraction
entails - 2g of sample into ACN; LC acquisition time
= 15 min/sample; meat validated on AB-Sciex 4000
LC-MS/MS (Fish on ABN-Sciex 5500).
2 QC Spikes are used – Groups A & B; a 2 point
calibration is used (0 and Spike); Positive Criteria as
follows: MRM, S/N >3 and the estimated level of
analyte is > ¼ of the target MRL.
Regine Fuselier (EURL - ANSES) presented an
overview of PT programs 2015 – 2016 discussing
the outcomes from previous PT schemes and the
upcoming 2016 PT for Dyes, Nitroimidazoles and
Chloramphenicol in Prawn (Banned Substance sin
Aquaculture Products). The updated EURL website
and PT portal was also presented and an overview
given of the resources currently on the website –
information on PT schemes, methods, workshops,
standards etc.
Anton Kaufmann (Official Food Control Authority of
the Canton of Zurich, Switzerland) presented
ION_MOBILITY-HRMS based screening of residues
which introduced the radical approaches to
confirmatory analysis of veterinary residues
including the proposed elimination of the use of
physical reference standards in combination with
LC-HRMS methods – represents a significant cost
saving and overcomes difficulty of sourcing certain
standards!
Positive ID by accurate mass, relative retention time
predicted by Quantitative Structure Retentive
Activity software – ACD/ChromGenius and the use
of fragmentation patterns with prediction using ‘in-
silico’ approach (computer-based models).
The presentation highlights the approach to this
method using a Waters LC-IMS-Q-TOF (Vion
system). Note that the approach described in this
presentation is at an early stage and improvements
are needed before it can be used as a routine
technique (some issues observed with false
positives for large ions – high m/z ratio).
Andreia Freitas (INIAV, Instituto Nacional De
Investigacao Agraria e Veterinaria, Portugal)
presented screening of antibiotics in milk & muscle
by LC-TOF-MS describing a multiclass method for 36
antibiotics across the classes of Beta-Lactams,
Tetracyclines, Quinolones, Macrolides,
Trimethoprim and Sulphonamides. The method
uses a UHPLC system with AB Sciex Triple Time of
Flight 5600 mass spectrometer. The same
extraction solvent is used for milk and muscle with
an additional defatting step for milk following
extraction. The analysis utilises exact mass and
relative retention time for identification of
compounds with a semi-quantitative approach and
is used as a high throughput screening method.
Further confirmatory analysis is performed using
LC-MS/MS.

DAFM NRL Newsletter Volume 7, Issue 1.
Page 7
Dominique Pessel (EURL - ANSES) presented a
proposal for a collaborative study on criteria for
screening/confirmatory residue control by HRMS
with NRLS equipped with LC-HRMS instruments
which will involve the following:
An inter-laboratory study for screening
veterinary drugs with high-resolution mass
spectrometry.
The focus will be on targeted screening.
State-of-the art of HRMS screening methods
to be developed by NRLs.
The study will evaluate the False Negative and
False Positives rates, evaluate Detection Limits
and evaluate applied criteria using exact mass
data. The aim is to also identify/evaluate
trends or difficulties experienced during the
study. The following guidelines were given for
the participant labs:
1. Use your own LCHRMS method whatever the
acquisition mode.
2. Analysis of a set of extracted samples
3. Report the results
4. Report your acquisition method, criteria, and
automatic identification treatment.
The survey will start in December 2016 with
analysis of the samples in May-June 2017, Data
Evaluation over the following 2 months with results
& reports anticipated in November-December
2017.
Estelle Dubriel (EURL - ANSES) presented
occurrence of dye residues in aquaculture products
giving a general overview of issues with dyes in
aquaculture, approaches to regulatory controls,
analytical challenges and development and
optimisation of the method. A targeted screening
method using an AB-Sciex 5500 Q-Trap instrument
and the extraction method were detailed in the
presentation. Furthermore a non-selective
metabolomic study for compounds associated with
dye residues, using an LTQ-Orbitrap instrument was
described in the presentation. Work is ongoing in
identifying suitable biomarkers.
Rebecca Moffat (Marine Institute, Ireland)
presented minimizing analytical contamination of
dyes giving a brief introduction to dyes and use in
aquaculture. This presentation focused on a
contamination issue with Victoria Blue in the
Marine Institute and detailed the systematic
approaches used to eliminate the contamination
problem including steps to identify the
contamination source, changes to general lab
housekeeping and management of labcoat use, a
systematic approach to sample and standard
preparation and standardizing the associated
protocols, creating separate/ segregated work and
storage areas. Overall the contamination issue was
resolved using the approaches described above.
Murielle Gaugain (EURL - ANSES) presented non-
targeted analysis for search of biomarkers of 3G/4G
cephalosporins in poultry which looked at a non-
targeted metabolomic approach to determining
biomarkers for Cephalosporins (ceftiofur and
cefquinome) in dosed poultry (laying hens) versus a
negative group. This involved analysis of liver, eggs
and droppings. A generic method was utilised to
extract metabolites from the 3 matrices and the
samples were analysed using full scan high
resolution mass spectrometry. The presentation
detailed the scale of the chemometric and
predictive model approaches to analysis of data
from the control group and the dosed group in
identifying appropriate biomarkers (extracted
metabolites were in the order of 1398 from
droppings, 1734 from liver and 3633 from eggs).
Appropriate biomarkers were identified for
cefquinome and ceftiofur in droppings; however it
was only possible to identify suitable biomarkers for
cefquinome in eggs and liver. In discussion on the
biomarker approach a number of important
considerations were highlighted such as the lifetime
of metabolites following treatment in biological
systems and in test samples; the effect of
metabolites associated with other
antibiotics/veterinary drugs on the biomarkers of
interest; the importance of the matrix in the
availability of suitable biomarkers i.e. different
matrices can have different biomarkers associated
with a particular drug of interest; the need for a
rigorous approach that ensures the robustness of
the selected biomarkers and consider the above
issues in the approach and analysis of data.

DAFM NRL Newsletter Volume 7, Issue 1.
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Sophie Mompelat (EURL - ANSES) presented honey
control for specific antimicrobial residues from
biosensors to LC-HRMS. This presentation dealt
with the analysis of the source of false positives for
quinolones seen with cross-reaction on
immunoassay screening by a quinolone-like
compound in the honey of chestnuts and of floral
origin. A large number of positive screens for
quinolones using the immunoassay were found to
be negative on confirmatory analysis by LC-MS,
leading to an investigation to characterize what
may be leading to this phenomenon.
The use of LC-HRMS and a non-targeted analytical
workflow to isolate and identify the compound of
interest in tandem was described. A quinolone
specific extraction method from honey was devised
to ensure extraction of the compound of interest
(the routine generic extraction was not effective in
extracting the compound of interest). Using
fingerprinting and metabolomics methodology, the
ions of interest were identified and the structure of
the candidate compound of interest was elucidated
and predicted to be Kyenuric Acid. Further
validation work involving samples spiked with
kyenuric acid is to be conducted in addition to
confirming the association of this compound with
chestnut or multifloral honeys.
Gitte Geertsen (Danish Veterinary and Food
Administration) presented multi antibiotic analysis
in honey by LC-MS/MS, describing a Multi-Class
Screening method. The scope of analytes covers 45
compounds in total and covers the following
antibiotic classes: Lincosamides, Quinolones,
Macrolides, Tetracyclines, Pleuoromutilins and
Sulphonamides. A specific route is used for
Sulphonamides (Acidic Extraction) and another for
the remaining antibiotic classes (McIlvaine Buffer).
The 2 extracts are combined on an Oasis HLB SPE
cartridge before washing & elution. The scope of
analytes covers 45 analytes in total and covers the
following classes: Lincosamides, Quinolones,
Macrolides, Tetracyclines, Pleuoromutilins and
Sulphonamides. LC-MS/MS analysis is conducted
with a Waters Acquity with TQD MS/MS.
The validation results were documented as part of
the presentation, including information on Cut-Offs
and proficiency test performance and the
prescribed other screening criteria: RT, RRT, Ion
ratio were demonstrated. Confirmatory analysis of
the analytes is performed using standard addition
with a compound/class specific method; this
approach is currently undergoing validation.
Eric Verdon (EURL - ANSES) Closing session and
updated EURL Anses-Fougères website & workshop
conclusions. The closing session involved discussion
of the updated Anses website and reminded of the
need to re-register if previously registered with the
old website.
A mini tutorial for registration to Anses Fougeres
EU-RL New Website and an overview of the new
website were presented. The new website URL is:
https://eurl-fougeres-veterinaryresidues.anses.fr/
A summary of conferences in 2015/2016 and
upcoming conferences/workshops was presented
to the attendees with upcoming events highlighted
as follows:
Metabolomics
SMMAP 2017 (Spectrométrie de Masse,
Métabolomique et Analyse Protéomique 2017,
congrès), 2-5 October 2017, l’Hôtel New-York®,
(Disneyland® Paris, Marne-la-Vallée-Chessy),
https://smmap2017.sciencesconf.org/
Metabolomics 2017, 26-29 June, Brisbane,
Australia, http://metabolomics2017.org
Conference on Personalized Food and Nutritional
Metabolomics for Health, May 17& 18, 2017, The
Ohio Union, The Ohio State University
https://discovery.osu.edu/focus-areas/foods-
forhealth/events/conference-2017.html
Miscellaneous
IHC (International Honey Commission 2016)
Antalya, Turkey - October 2016 postponed April
2017
International Dairy Federation analytical week (IDF
2016) Madison (Wisconsin, USA) May 2017
Biosensors
5th International Conference on Biosensing
Technology Riva del Garda May 2017
7th Euro Biosensors & Bioelectronics Conference
Berlin July 10-12, 2017

DAFM NRL Newsletter Volume 7, Issue 1.
Page 9
Other
AOAC-Europe section symposium Barcelona (Spain)
postponed to 2-3 March 2017
EURACHEM / AOAC-Europe symposium:
“Uncertainty in Qualitative and Quantitative
Analysis” Nicosia (Cyprus) 29-30 May 2017
131st AOAC Int. Annual Meeting Atlanta (USA) 24-
27 September 2017
Eurachem 9th International Workshop on
Proficiency Testing Slovenia October 2017
8th International Symposium on Recent Advances
in Food Analysis (RAFA 2017) Prague November
2017
Euroresidue VIII, Hotel Zuiderduin, Egmond aan
Zee, The Netherlands 22-25th
May 2016
NRL Representative: Seán Earley (VPHRL)
There was a large international attendance at the
Euroresidue VIII meeting (over 300 delegates) with
growing numbers of attendees from non-EU
countries/regions including The Philippines,
Thailand, Malaysia, Korea, the Middle East, New
Zealand, Australia and South America.
Overall there were 28 Oral Presentations and 6
Keynote lectures with an additional 206 Posters on
display over the course of the conference.
Presentations and Posters are available at the
Euroresidue website: www.euroresidue.nl
Introductory Workshop –presented by Dr Gaud
Dervilly-Pinel and Prof Dr Bruno Le Bizec.
This was designed as a practical session and
opportunity to get to know other attendees. It
included discussion of particular areas of interest at
the Euroresidue meeting and what attendees
hoped to gain from attendance.
The workshop covered the following topics:
Introduction to regulatory bodies, Food &
Feed Safety regulations.
EURL/NRL network.
Discussion of common analytical techniques
and emerging analytical strategies -
advantages & pitfalls and of new analytical
approaches (LC-TOF, HRMS, OMICS-
biomarkers as an alternative/complementary
approach to analysing for specific drug
residues).
Discussion of 2002/657 - current form and
points for review - proposed changes to RRT,
Spectrometric Criteria (SN & ID points) and
consideration for multi-residue methods.
Future Challenges in the area of residues analysis
were also discussed, these include:
New Natural Hormones.
Low Dose remedies - need for increasing
analytical sensitivity
Designer Drugs (compounds analogous to the
recently observed Novel Psychoactive
Substances/ 'Headshop Drugs' used for
recreational purposes).
Genetically Modified animals/feed.
Day 1 - Conference Presentations
The Sessions on Day One were:
S1. Antibiotics, Residues and Resistance
S2. Residues and the Environment
The potential analytical requirements and
expansion of matrices in light of these issues were
explored. There was some discussion on the
potential contribution of biocides and heavy metals
(arsenic, copper, silver) in the environment to
antibacterial (AB) resistance. Note that
tetracyclines were a recurring topic of discussion as
they are frequently detected in residues analysis.
Several studies were presented involving LC-MS
analysis of manure to determine AB levels and the
most effective approaches to reduction of ABs in
manure/waste, for example devising new
approaches to fermentation of waste.
Also presented was the potential use of High
Resolution Mass Spectrometry techniques to
replace current screening approaches i.e. 6 Plate
Test for antibacterials. The need for a harmonised
global approach to AB control was raised on several
occasions.
Day 1 - Presentations of Note:
Keynote lecture 1: Prof Dr Dan Andersson, Uppsala
University Sweden - Evolution of antibiotic
resistance at very low antibiotic concentrations.

DAFM NRL Newsletter Volume 7, Issue 1.
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Keynote lecture 4: Dr Jin-Wook Kwon -
Management of antimicrobials in the environment:
What have we learned and what should we prepare
for the future?
Oral 2: Dr Brigitte Roudaut – Contribution of
LC‐MS/MS methods to detection and identification
of antibiotic residues in meat – Application in
official control in France.
Oral 4: Dr A. Cannavan - Global perspectives on
antimicrobial resistance in the food chain.
Oral 7: Dr Steven Crooks - An investigation into the
sources of contamination of cattle with the
veterinary drug phenylbutazone.
Oral 8: Dr Tina Van Den Meersche - Quantification
of five different classes of veterinary antibiotics in
(processed) swine manure using a validated UHPLC-
MS/MS method.
Day 2 - Conference Presentations
The Sessions on Day Two were:
S3. New Analytical Techniques, Confirmatory
Analysis
S4. Alternative Matrices
S5. Validation and Criteria Approaches
Presentations and discussion of several newer
approaches in the area of LC-MS were conducted
including - Supercritical Fluid Chromatography, Ion
Mobility/MS, DESI, Paper Spray and miniaturisation
of LC-MS instruments for field testing. Also
discussed were approaches to non-targeted
screening with the use of databases such as
Chemspider (www.chemspider.com) as a resource
to support non-targeted approach.
With regard to new matrices, the potential use of
hair and feathers for official controls was discussed.
This is due to presence of residues for significant
timeframes following withdrawal and these may be
of particularly use in the context of banned
substances. Also explored was the possibility of
insects as a growing protein source and the
potential regulatory/analytical implications. Also
discussed was the analysis of saliva for ABs and
chicken feet for tetracyclines.
On the subject of Validation and Criteria
approaches Keynote 6: Update to 2002/657/EC -
the Rikilt Collaborative Project, suggested changes
to 2002/657/EC to address multi-residue
approaches to include changes to Resolution, RRT
and Ion ratio criteria. It was also proposed that
2002/657/EC becomes a 'living' document with
regular updates (~biannual) to reflect analytical
trends.
Also of particular interest was Oral 19: Discussion
on Chloramphenicol PT 02256 - CAP stereoisomers
& ELISA method, which suggested an approach to
overcome issues observed with stereoisomers of
chloramphenicol.
Day 2 ended with a Workshop/Panel Discussion on
Risk Based Approaches to Monitoring, the main
points being:
Possible criteria for Risk Analysis approaches
to monitoring based on production numbers;
quantities of imported food/feed; substances
for inclusion in control approach; sampling
frequency; screening approaches and future
testing programmes; consideration for imports
from third countries and developing countries;
changing/developing markets; consider
possible alternatives to using a ‘percentage’ of
production volume.
It was noted that a consensus needs to be
reached on the definition of a risk-based
approach and proper assessment of the
perceived risks.
Euroresidue will publish an article arising from
the Risk Assessment workshop.
Day 2 - Presentations of Note:
Keynote lecture 5: Prof. Dr Bruno Le Bizec, Laberca, Nantes, France - An overview of latest advanced technological options for residue analysis.
Keynote lecture 6: Dr Bjorn Berendsen, Rikilt Wageningen, the Netherlands - Time for an update! A unique collaborative study to assess confirmatory analysis performance criteria in veterinary drug residue analysis.
Oral 9: Dr Anton Kauffman, Zurich, Switzerland - Ion mobility coupled to high resolution mass spectrometry: The possibilities, the limitations.
Oral 11: Dr Roberta Galarini, Italy - Confirmatory multiclass method for residues of antimicrobials in milk by LC-HRMS/MS.

DAFM NRL Newsletter Volume 7, Issue 1.
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Oral 12: Robin Wegh Msc, Rikilt Wageningen, the Netherlands - Hair and feathers: the matrix of choice for antedating the use of antibiotics, beta-agonists and steroid-esters?
Oral 13: Dr Wim Reybroeck - Testing of Saliva as ante-mortem screening for antimicrobials in pigs.
Oral 14: Dr Eline Kowalski – Insects on your plate: monitoring chemical contaminants and residues.
Oral 15: Dr Javiera Cornejo - Depletion study of oxytetracycline (OTC) and 4-epi-oxytetracycline (4-epi-OTC) residues in claws of broiler chickens by liquid chromatography tandem mass spectrometry.
Oral 18: Dr Katrin Kittler - Investigations on the influence of hydrolysis on the total amount of marker residue and the consequences.
Oral 19: Dr Mark Sykes - Chloramphenicol Proficiency Tests on a Global Scale – Unforeseen Consequences.
Day 3 - Conference Presentations
S6. & S7 – Both sessions covered the area of Broad
Screening with topics in the areas of:
Screening, Un-Targeted Screening and
OMICS/biomarker detection approaches.
Histopathological approaches to monitoring
growth promoters.
Approaches, challenges and a number of examples
of new screening applications were discussed over
the course of the oral presentations. The use of
accurate mass/full scan spectrometry technology
was highlighted as the main tool in untargeted
screening and OMICS/biomarker research. OMICS
approaches aim to identify unique biological
markers that are associated with the application of
banned or controlled veterinary
residues/medicines. These can include metabolites
of the compound or biological molecules/ markers
that are associated with exposure to the veterinary
residue, such as proteins, lipids or peptides.
Challenges associated with this approach include
the identification and isolation of these biomarkers
amongst the many chemical entities observed in
biological matrices and ascertaining that they are
uniquely linked to the veterinary residues in
question. The development of an appropriate
sample preparation procedure is also one of the
main challenges - an example includes enzymatic
hydrolysis of the sample followed by solid phase
extraction techniques to remove any interfering
components.
The use of histopathology (Dr Mario Botta) as a
complementary tool to monitor the use of growth
promoted was discussed, indicating the approach
and histological criteria that may be associated with
administration of growth promoters an example of
which is an increased presence of lesions, i.e.
induced squamous metaplasia of glandular tissue
on administration of sex hormones (Estrogen,
Androgen and 17β-E2 + Androgen).
Of particular practical interest was the presentation
by Lieven Van Meulebroek on the use of a
biomarker to discriminate between semi-
endogenous and exogenous thiouracil (TU) in cattle,
which identified 4 potential biomarkers for
endogenous TU in calves and 2 potential
biomarkers in calves – note that further
investigation and validation is required with this
approach. In future this may prove useful for
overcoming the issue of discrimination of low levels
of TU (< 10ppb) observed in some samples that may
or may not be associated with the consumption of
rapeseed/cruciferous plants as opposed the illegal
administration of TU.
Day 3 - Presentations of Note:
Oral 21: Dr Kathrin Schmidt - Application of LC-QTOF technology for screening for hormonally active substances in matrices of animal origin.
Oral 22: Dr Roberto Stella - Targeted proteomics for
dexamethasone treatment in bovines.
Oral 23: Dr Mario Botta - The histopathological
approach for the monitoring of the illegal
administration of growth promoters in food
producing animals.
Oral 24: Dr Pilar Marco, Spain - Site-encoded DNA
strategies for residue analysis.
Oral 25: Jérémy Marchand, Laberca, Nantes, France
- Lipidomics: an alternative and complementary
tool to highlight biomarkers of growth promoting
practices.
Oral 26: Dr Marco H. Blokland, Rikilt, Wageningen,
the Netherlands - The Dutch approach for the
detection of (synthetic) natural steroids in the
Netherlands: A retrospective overview.

DAFM NRL Newsletter Volume 7, Issue 1.
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Oral 27: Dr Gaud Dervilly-Pinel, Laberca, Nantes,
France - Are biomarkers universal and transferable?
Oral 28: Lieven Van Meulebroek - Discovery of a
urinary biomarker to discriminate between semi-
endogenous and exogenous thiouracil in cattle.
Parting Comments:
The International Symposium on Hormone and
Veterinary Drug Residue Analysis is to be held in
Ghent, Belgium was announced for May 2018.
A preliminary announcement for The 4th
Saskval
International Workshop on Validation and
Regulatory Analysis of Residues in Foods in
Saskatoon, Canada was made for 2019.
10th
Workshop of the EURL Coagulase Positive Staphylococci (CPS) dedicated to Staphylococcal Enterotoxins (SEs), ANSES Paris, France, 25
th-27
th
May 2016
NRL Representative: Regina Heslin (DSL)
43 participants from 27 NRLs were represented at
the workshop, including the members of the
working group on the use of Next Generation
Sequencing for bacterial/CPS typing and of Maldi-
tof for bacterial/CPS characterization and
identification. The DG SANTE representative Sylvie
Coulon was unable to attend. The workshop was
divided into sections by the following topics;
General, Recent Staphylococcal Food Poisoning
Outbreaks (SFPO’s), NRL Network and Analytical
works on Staphylococcal Enterotoxins (SE’s).
Recent Staphylococcal Food Poisoning Outbreaks
Table 1 Summary of the outbreaks presented by 4 MS Country
No. people ill/exposed population
Event where food served
Implicated Food
CPS/g SE Detected VIDAS/ Rida-screen
Genes Encoding for SE detected
Cyprus 2/10 Take away
Sandwich
2.7x10
8
SEA 2.15ng/g
Sea, seh
Cyprus 13/26
School
Pasta dish
8.3x10
4
SEA & SEB <LOQ
Sea, seh
France School
Pork chop
1.1x10
8
SEA
suey
Ireland 44 Flight Mousse dessert
>105 SEA
1.928ng/g
Sea,sed, seh,ser,seg,seisej
Bulgaria
2 Street vendor
Roasted chicken legs
SEA 0.033ng/g
sea
Giusi Amore EFSA also gave a presentation on
SFBOs and noted that a large proportion of them
are due to foods other than dairy products. EFSA
will start a discussion with the BIOHAZ panel on risk
assessment of CPS/SE’s in foods other than dairy
products.
New Technologies
A working group met in advance of the workshop to
discuss new technologies for CPS characterisation
and identification. A summary of the advantages
and disadvantages of the NGS and Maldi TOF
technologies is presented in Table 2.
Table 2 Advantages and disadvantages of new technologies for CPS characterisation and identification
Technology Advantage Disadvantage
NGS Multiple results derived on a single experiment (AMR, Virulence genes, etc.)
Need of technical facilities, expertise and skilled personnel
Epidemiology (outbreak investigations, strains similarity, same origin)
DNA extraction (food samples)
Increased typing resolution & range of data
Data analysis: Need of standardization of data analysis protocols.
Access to "all" genomic data
Current lack of reference sequences.
Retrospective analysis for new targets
Storage (costly)
Portability of results Need of criteria to be used for differentiation of strains (outbreak investigation)
Comparison of data by different labs. Robustness and standardization of laboratory workflow
Only genotype available. Conventional microbiology still necessary => phenotype (e.g. biochemical properties, data on gene expression)
Maldi TOF Useful and accurate for strain identification (species)
Limitation of reference database (not all bacteria yet, some only

DAFM NRL Newsletter Volume 7, Issue 1.
Page 13
to genus level, difficulties with rare species)
Good alternative when failure of identification with other techniques (biochemical galleries)
Expensive equipment (with dedicated room)
Time saving and Cost efficient analysis (when the instrument is available)
Skills for the sample prep (extraction step => standardization)
Possibility to process a large amount of samples
CPS Characterisation
The EURL CPS developed a multiplex real-time PCR
scheme for the detection of 11 se genes and a
target gene specific to S. aureus (nuc) and carried
out an in house validation and an interlaboratory
validation study in 2015. This method is very useful
for the investigation of SFPOs, as it is often
necessary to detect the presence of se genes in CPS
strains, in addition to SE detection in the suspected
food, in order to confirm the identity of the food
responsible for SFPO. However, a large variability
between the 16 participating labs was observed. As
unsatisfactory results were obtained for several
labs for control DNA samples & strains, the method
could not be validated.
Optimisation of the test method is required for
different manufacturers of instruments.
Another interlaboratory validation study will be
organised following training and test optimisation.
Study on the Prevalence of SE genes
Bacterial toxins are ranked after Salmonella as the
leading cause of food borne illness. Results of
studies from Italy and Poland were presented.
Italy
481 milk & cheese samples were studied in Italy.
SEA toxin was the toxin most frequently observed
followed by SED.
The most frequent SE gene found in the isolates
was SER, together with SED and SEJ, as these are
carried on the same plasmid. SEG together with SEI
were observed in 18% of isolates.
Poland
115 samples of raw milk were collected between
2009 and 2013 from 15 dairy farms and 15 dairies
located in the eastern part of Poland. CPS were
found in 71 of 115 (62%) analysed milk samples.
29% strains had enterotoxigenic properties with the
following genes identified in order of prevalence:
sed, ser, sej, sei, seg, sep, seh, sec and sea. The
genes encoding SEB and SEE toxins were not
identified.
57% isolates were susceptible to all 10
antimicrobial agents studied. The highest resistance
rate was found to Penicillin. No MRSA positive
strains were identified.
CPS Enumeration
Overview of recent PT trials for CPS
The EURL CPS organised an inter-laboratory trial on
CPS enumeration for evaluation of the ability of the
NRLs to apply satisfactorily the reference methods
for the analyses performed in the frame of controls
prescribed by EC Regulation 2073/2005.
The PT trial was performed according to the EURL
quality management system and allows them to
comply with ISO 13528 for statistical analyses.
There are conflicting requirements between
standards EN ISO 6888-1 maximum number of
colonies per plate is 150, while it is 100 in the
general Standard EN ISO 7218. The EURL will refer
this to the project leader for ISO 6888-1.
Update on ISO Standardisation
An amendment to ISO 6888-1 to permit the use of
RPFA for confirmation has progressed to DIS vote.
A query arose as to whether the target of EN ISO
6888 series is CPS or S. aureus. It was favoured to
maintain CPS as a hygienic parameter in Regulation
2073/2005 as confirmation for S. aureus would
involve PCR or Maldi TOF.
Detection of STAPHYLOCOCCAL ENTEROTOXINS IN
FOOD
Overview of recent PT trials
NRLs have to implement the EURL Screening
method for the detection of SE’s in food matrices
and participate to the ILPT organized by EURL. A
total of 31 (29 in 2016) NRLs participated to 4 ILPTs
and analysed eight food matrices contaminated

DAFM NRL Newsletter Volume 7, Issue 1.
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with four types of SE (SEA, SEC, SED, and SEE) at
different concentrations.
The rates of discrepancies identified decreased
from 2013 to 2016: NRL network for SE detection is
competent. 100% satisfactory results were
obtained in the last 2 PT’s.
EN ISO 19020 detection of SE in Food Matrices
Jacques Antoine Hennekinne (EURL CPS) was the
project leader on the development of a CEN / ISO
standard method for the Detection of SE in food
matrices. NRLs participated in interlaboratory
studies for the development of the method.
The Standard is expected to be published in June
2017.
Data was generated for 3 kits Vidas, Ridascreen and
Tecra. 3M have stopped the marketing of the Tecra
kit that was included in the studies.
Certified Reference Materials.
Certified reference material (CRM.s) are now
commercially available for Staphylococcal
Entertoxins from IRMM
Work Programme for 2017
The work programmes are now decided biannually
and EURL unsure if changes can be made to include
optimisation of real time PCR for the detection of
SE and optimisation of PFGE for CPS typing.
19
th workshop of the EURL for Milk and Milk
Products (EURL MMP) ANSES Laboratory for Food Safety, Maisons-Alfort, Paris 5-7
th October 2016
NRL Representative: Eoin O Brien (DSL)
General information
NRL’s from 27 Member States (MS) were
represented, Norway and Switzerland also
attended. 3 experts, Luisa Pellegrino (IT), Vesela
Tzeneva (NL) attended for sections. Sylvie Coulon
DG SANTE attended on the final day.
A wide range of topics were discussed including
updates on Irish Dairy Federation (IDF) / ISO
activities relating to the workshop, activities on
topics relating to total bacterial count and somatic
cell count in raw milk, and phosphatase activity.
Working group on a single European conversion equation for TBC in raw milk
Nathalie Gnanou-Besse
(ANSES) gave a presentation on the ANSES report
on the assessment of a unified European
conversion equation for TBC in raw milk.
To date most European countries have
implemented national equations for the conversion
of IBC readings from instrumental methods to TBC
(cfu/ml) for assessment of compliance with the
regulatory requirements for raw milk set down in
Regulation (EC) No 853/2004.
At the 2011 workshop it was agreed to form a WG
to look at the possibility of introducing a
harmonised European equation for the conversion
of IBC to TBC. Data was collected from MSs to allow
the comparison to take place and the EURL
produced a Technical Report on the outcome of the
study. A statistical analysis of all data by the EURL
lead them to conclude that a unified conversion
equation could be derived at EU level for cow’s
milk, irrespective of the type of flow cytometer.
Prior to the workshop MSs were asked to carry out
an assessment of the impact of the harmonised
European equation on the regulatory limits
established by Regulation (EC) No 853/2004 and
also its impact on the payment systems in
operation in MSs.
Switzerland and Italy made detailed presentations
on the impact at national level; Switzerland found
that there was not a big impact for them but noted
that payments were affected slightly. Italy noted
that the big impact was that at the higher levels but
no big difference at the legal limits.
Belgium noted big differences between the national
and harmonised European equations and predicted
a big impact at all levels. They made the point that
the impact of the use of preservatives by some MSs
needs to be fully evaluated.
Denmark concluded that it would have little impact
and commented that following consultation with
their largest milk purchaser (Arla) that company
would be implementing the harmonised equation
across all its operations to facilitate and simplify
trade.
Ireland noted increases of approximately 8 and 14%
for the BactoScan and Bactocount respectively at
around the legal limit of 100,000 cfu/ml. At high
levels there would be reduction in values using the

DAFM NRL Newsletter Volume 7, Issue 1.
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harmonised equation. Based on the limited
information on milk payment systems available to
the NRL is could be seen that some milk producers
would move to higher penalty bands if the new
system was to be implemented. The NRL does not
have information on the quality (TBC) of Irish milk
and it is therefore difficult to make a detailed
assessment.
It was agreed by the WG that the report could be
improved and the EURL are to circulate a corrected
version of the report to NRLs that will include a new
calculation tool to assist NRLs in examining the
impact of the harmonised equation.
Overall it was felt that given the feedback from MSs
and the fact that some MSs don’t have a single
national conversion factor it would be difficult to
require MSs to use the harmonised equation,
instead it could be implemented on a voluntary
basis.
ANSES opinion on French draft decree concerning the labelling requirements for raw milk intended for human consumption.
Pauline Kooh (ANSES) gave a presentation on an
ANSES opinion on a French draft decree concerning
the labelling requirements for raw milk intended for
human consumption.
In France the sale of raw milk for direct
consumption is possible only after authorisation by
the CA. The draft decree has set the following
criteria for milk:
Listeria monocytogenes – absent
Salmonella – absent
E. coli as process hygiene criteria
TBC < 50,000 cfu/ml
Max 4oC storage temperature
Shelf life maximum of 3 days
Boil before consumption for the at risk groups
The draft decree proposes the following labelling
statement: "Boil before consumption for children
under five years of age, pregnant women and
people whose immune system is weakened".
Information was provided that the latest EFSA
opinion on raw milk identifies that Campylobacter is
responsible for the highest number of outbreaks
concerning raw milk.
Overall ANSES concluded that the burden is difficult
to estimate but can be considered low, and while
severity can be high for at risk groups adequate
labelling can reduce the risk.
Therefore, the Agency considers it necessary to
inform consumers about the need to boil raw milk,
especially for vulnerable populations.
EURL presentation on the critical points for the
reference method for Somatic Cell Counts (SCC) /
SCC Reference methods critical points
EURL gave an update on a study of the critical
points that can affect the implementation of the
standard reference method EN ISO 13366-1
(Microscopic method), this followed on from a
request for such a study at the 2014 workshop.
The finding is that there is no significant deviation
where using 40X or 50X magnification. The use of
40X will be allowed in the next PT.
There will be no changes to the ISO method but
rather clarifications will be made on different
points. The conclusions regarding the magnification
levels will be transmitted to the IDF/ISO WG that
looks at this.
Vesela Tzeneva, QLIP Netherlands, Microval certification of flow cytometers for Total Flora and SCC in raw milk
There are two EURL guidelines on the validation of
the above instruments as the EN ISO 16140
protocol was unsuitable for evaluating these
instruments. Microval validations for total flora
were carried out on both the Bactoscan from FOSS
and Bactocount from Bently and comply with the
EURL documents and were awarded certification.
Microval validations for SCC instruments started in
2015 and it’s expected that certification will be
awarded at the beginning of 2017.
Reinhart Zeleny, IRMM, provided an update on the
project to develop certified reference materials
(CRM) for SCC in milk on behalf of the Institute for
Reference Materials and Measurements (IRMM)
Geel, Belgium. The Institute is still carrying out
studies on the best way to produce the material.
The main use of the CRMs will be to calibrate
secondary reference materials. Good progress is
being made and the freeze dried milk based

DAFM NRL Newsletter Volume 7, Issue 1.
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materials developed so far have been found to be
stable over 17 months.
The goal of the project is to:
Enable calibration of measurements within range 50,000 – 1,000,000 cells/mL (cow milk) by making available two milks, 50,000 cells/mL (L) and 1,000,000 cells/mL (H), sufficient quantity to prepare calibration line samples by mixing L and H accordingly to provide 9 calibration levels
Improve comparability of measurement results
Link fluoro-opto-electronic results with microscopy results
Cross-calibrate secondary materials to the CRM
IRMM are in discussion with NIZO and Acatalia on
the best methods for producing large batches of the
reference material by spray drying and freeze
drying.
Hanene Ghezzal (EURL) on phosphatase in cheese and the publication of ISO 11816-2
The new ISO standard 11816-2 on alkaline
phosphatase in cheeses was published in August
2016, it is planned that EURL will now write to DG
SANTE and recommend the establishment of a legal
limit of 10 MU/g for ALP in cheese. DSL participated
in the inter laboratory trials related to the
establishment of this limit.
Luisa Pellegrino (University of Milan) on ALP in
cream
An update was given on the work carried out to try
to optimise the flourophos method for use in
determining ALP in cream following on from a
request from DG SANTE raised by Ireland.
The experimental plan looked at the following areas
The ALP levels in different types of cream on the Italian market
Evaluation of some critical steps in ISO 11816-1/IDF 155-1 when applied to cream
Evaluation of ALP reactivation in cream during storage.
The following graphs were presented to the
meeting and show big increases in ALP levels during
storage at room temperature and at temperature
as low as 8 degrees C.
Graph of APL level vs. days to expiration
Graph of ALP level against holding time (H) at room
temperature after storage initially at 4 and 8oC
Due the reactivation issues encountered the
feasibility of this project is now in question and
EURL are to discuss the future of this work item
with DG SANTE.
Validation of an ALP Flourometric Microwell Assay
Thomas Berger of Agroscope Switzerland gave a presentation on the validation of a Flourometric Microwell method for the determination of alkaline phosphatase in milk and milk products.
The current reference method ISO 11816-1 is based on a proprietary method with the instrument and reagents supplied by Advanced Instruments.
This method has the following requirements:
Equipment:
Fluorescence microplate reader (e.g. Molecular Device, Biotek, Labtech, Millipore…) capable of temperature control (37°C) and running kinetic analysis mode.
Excitation 365 nm and emission wavelength of 450 nm.
Black 96 well plates

DAFM NRL Newsletter Volume 7, Issue 1.
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Solutions
Substrate 4-methylumbelliferone-phosphate (4-MUP) dissolution in diethanolamine (DEA) buffer, pH 9.2
Standard 4-methylumbelliferone (4-MU) dissolution in 2-amino-2-methyl-1-propanol buffer (AMP), pH 10.1
Both the EURL and Agroscope are reporting good comparisons between the reference method and the microplate method
Activity Fluorophos = 0.5 x Activity Microtiter Assay
It is expected that a draft protocol will be available by end of 2016 and the EURL will seek expression from NRLs with the necessary equipment to participate in an inter laboratory trial.
Annual Workshop of the EURL for Chemical
Elements in Food of Animal Origin (EURL-CEFAO),
Rome, Italy, 28th September 2016
NRL Representative: Josephine Coloe (VPHRL)
Laura Ciaralli (Director of the EURL-CEFAO in
Rome) opened the 2016 workshop by welcoming all
participants, including the invited guest speakers.
The workshop was attended by 39 participants
which included 30 representatives of EU NRLs from
26 MSs, 6 representatives from laboratories outside
the EURL-CEFAO network, 9 staff from the EURL-
CEFAO, and 4 invited speakers, including a
representative from the European Commission. This
workshop covered a range of relevant topics
including developments in EU legislation, current
and future proficiency testing (PTs), selection and
use of reference materials, critical points in mercury
determination by Direct Mercury Analysis,
METROFOOD-RI for promoting metrology in food
and nutrition, determination of inorganic arsenic in
mussel tissues by HPLC-ICP-MS and a working group
on CD 2002/657 Revision led by Andrea Colabucci
(EURL-CEFAO in Rome).
Frank Swartenbroux, European Commission
There are ongoing discussions related to certain
heavy metals. The first is Chromium. The current
scientific opinion from EFSA on the risks to public
health from the presence of chromium in drinking
water concludes that overall the calculated MOEs
(Margin of Exposure) indicate low concern
regarding Cr(VI) intake via drinking water (water
intended for human consumption and natural
mineral waters) for all age groups when considering
the mean chronic exposure values with the
exception of infants at the upper bound (UB)
exposure estimates. No action is needed at the
moment for chromium in food due to
environmental contamination.
The second heavy metal discussed was Nickel.
Overall the CONTAM Panel (EFSA Panel on
Contaminants in the Food Chain) concluded that at
the current levels of acute dietary exposure to Ni,
there is a concern that Ni-sensitized individuals may
develop eczematous flare-up skin reactions. There
are discussions with MSs with regard to the
monitoring recommendation (EU) 2016/11 with a
potential time frame 2016-2018 to propose
possible risk management measures. The main food
groups that are recommended to be monitored for
Ni are cereals and cereal based products, infant
formula and baby food, food supplements,
legumes, oils and seeds, milk and dairy products,
alcoholic and non-alcoholic beverages, sugar and
confectionary, fruits and vegetables, dry tea leaves
and bivalve molluscs.
The third heavy metal discussed was Mercury. The
current scientific opinion from EFSA on the risks to
public health from the presence of mercury and
methylmercury in food is that high fish consumers,
which might include pregnant women, may exceed
the TWI (total weekly intake) by up to
approximately six-fold. Unborn children constitute
the most vulnerable group. Biomonitoring data

DAFM NRL Newsletter Volume 7, Issue 1.
Page 18
from blood and hair indicate that methylmercury
exposure is generally below the TWI in Europe.
There may be changes to legislation on mercury in
the future to concentrate all legal standards in
mercury in a single legislative act. Current ML’s for
fish are 0.5mg/kg and 1mg/kg for predatory fish but
maybe changed to 0.3mg/kg for fish and 2mg/kg for
swordfish and shark. Food supplements are
maintained at 0.1mg/kg. The current state of play
with regard to mercury is technical discussions with
MSs and stakeholder consultations are finished and
this has been well received. Internal consultation
will start soon with some legal issues to be checked.
There is a current review of Commission Decision
(CD) 2002/657/EC and NRL input is via EURL
workshop circuit and Member States competent
authorities input via residues expert group.
With regard to the Official Controls Regulation (EC
882/2004) there is a political agreement with
adoption expected by end 2016, with a repeal of
96/23/EC with the timeframe for this expected to
be between 3 – 6 years.
Timo Kapp (Federal Office of Consumer Protection
and Food Safety, Berlin) Do we need fresh samples
for proficiency testing? Report on two PTs with pig
liver
Timo Kapp discussed two PTs performed with pig
liver: The first exercise was done in 2011 with a
lyophilised sample, while in 2016 a deep-frozen
fresh material was used. While the first material
was easy to store and to work with, the second one
was assumed to be more representative for routine
work.
The fresh material was prepared at the NRL from
liver of four individual animals. For some elements
(Cd, Cu, Hg, Mn, Mo, Se, Zn) the natural contents
were left unchanged, while for other elements (Ag,
As, Co, Pb, Tl, U) spiking was necessary to achieve
analytically reasonable values. The resulting
concentrations were between 0.020 mg/kg for U
and 42.7 mg/kg for Zn.
Twenty-two German official laboratories took part
in this PT. As only As, Cd, Hg and Pb were
mandatory analytes there were between 16 (for Ag)
and 22 (for Hg and Cd) data sets for statistical
evaluation. Reporting was done according to ISO
13528 using the participants’ data for calculating
the robust mean and the robust standard deviation.
The correlation with the standard deviation
calculated from the Horwitz equation (modified by
Thompson) showed HorRat-values between 0.28
for Co and 0.62 for Zn. The overall rate receiving a
satisfying score was nearly 95%, with no laboratory
producing clear outlier results.
Therefore the fresh material did not pose problems
to the participants. The ratios of repeatability to
reproducibility were between 1.9 (for Cu) and 3.8
(for Ag).
It is often stated that lyophilised materials are
easier to handle than fresh materials. Hence, the
recent data was compared to the data generated
with lyophilised pig liver in the same network in
2011. The data were normalised to lyophilised liver
and compared: For Pb and Se, the contents were
nearly identical. For Pb, the laboratory performance
expressed in terms of the reported standard
deviation was comparable, while for Se the recent
PT showed a significantly lower standard deviation
(8.5% vs. 16.3%). Even though for As, Cd, Hg and Zn
the concentrations in the recent PT were
significantly lower, the standard deviation was
nearly the same (for As) or even lower. The only
element with a higher content in the recent PT was
Cu. There the standard deviation was lower with
the higher content.
Even though some participants stated more
difficulties working with fresh material, the data did
not suggest a higher level of difficulty compared to
lyophilised material. Therefore, the use of
lyophilised materials as reference material is to be
preferred because of the better long-term stability.
However, fresh material could be a good alternative
in cases of matrices without stable lyophilisates,
e.g. fruit materials.
Angela Sorbo (EURL-CEFAO) 24th
Proficiency
Testing on Honey: Overview of Statistical analysis
and comments on Results

DAFM NRL Newsletter Volume 7, Issue 1.
Page 19
The monitoring performed annually at national
level on the content of chemical elements in
different categories of food has highlighted the
presence of Pb in honey, sometimes at rather high
concentrations. In order to ensure the protection of
the EU market on one hand and the health of the
consumers on the other, the European Commission
published CR (EU) 2015/1005, which sets a
harmonized Maximum Level (ML) for Pb in honey.
The introduction of this new analyte/matrix
combination in the EU legislation forces the official
control laboratories to have adequate analytical
methods. Moreover, the methods performance
needs to be satisfactory and as uniform as possible
amongst the laboratories.
In view of providing suitable means for assessing
the performance of these methods and of assisting
laboratories in their improvement, the EURL-CEFAO
based the 24th
PT on the determination of Cd, total
Hg and Pb in honey. The analytes included in the
exercise had been selected on the basis of the
regulation in force, the possible inclusion in new or
existing regulations and analytical considerations.
All the NRLs belonging to the EURL-CEFAO network
joined the PT.
The statistical evaluation of the results was
performed in accordance with ISO 13528:2015. As
for Cd and Pb, the statistical analysis was
straightforward: data distribution was roughly
symmetric and unimodal without significant
differences between results obtained by different
analytical techniques. Robust mean was set as the
assigned value for both analytes (0.0072 mg/kg and
0.140 mg/kg for Cd and Pb, respectively).
With regard to Hg, the criteria on robust standard
deviation and uncertainty of the assigned value
were not fulfilled. This was due to the wide data
dispersion. The general performance of the
network was extremely satisfactory: almost all NRLs
obtained a z-score lower than 2 for all analytes.
Laura Ciaralli (EURL-CEFAO) Planning of 2017 PTs
PTs are provided using combinations of matrices
and elements of interest in order to check the
general performance of the network and maintain
this at a steady level. The 2017 PTs have been
planned with this specific view. In particular, the
26th
PT will be based on the determination of Cd,
Cu, Pb and total Hg in freeze dried meat.
The 27th
PT will be based on the determination of
total As, Cd and Pb in powdered and liquid Infant
Formula based on animal proteins. This choice was
influenced by the publication of CR EU 2015/1005,
amending Regulation 1881/2006, as regards
maximum levels of lead in certain foodstuffs, which
entered in force on 1 January 2016.
Marina Patriarca (Department of Food Safety and
Veterinary Public Health, Istituto Superiore di
Sanità, Rome, Italy) TrainMic - Selection and use of
Reference Materials
TrainMiC is based on national TrainMiC teams
sharing common training materials (lectures,
examples, and exercises) and in turn contributing to
its production. TrainMiC material covers all aspects
of the technical requirements of ISO/IEC 17025.
Over the last few years, a process of revision,
update and extension of the guidance from
ISO/REMCO on reference materials has been in
place, aiming to cover quality control materials
prepared in-house as well as setting the basis for
formal accreditation of reference material
producers. However, using a reference material
does not automatically provides better results and
it is of the utmost importance that the criticalities
associated with appropriate selection and use of
reference materials are fully understood by all
those involved.
Reference materials are materials sufficiently
homogenous and stable with reference to its
specific properties which have been established to
be fit for its intended use. A CRM is a reference
material characterized by a metrologically valid
procedure for one or more specified properties,
accompanied by a certificate that provides the
value of the specified property, its associated
uncertainty, and a statement of metrological
traceability. A CRM should state traceability,
provide uncertainty and demonstrate traceability of
certified value. The main types of CRM are – Pure

DAFM NRL Newsletter Volume 7, Issue 1.
Page 20
substances for calibration, pure substances for
matrix matching, matrix CRM, and physic-chemical
standards. CRM can be used for calibration as part
of a measurement procedure, validation of
measurement procedure, quality control, and
comparison with in house materials. The
preparation of CRM is described in general in ISO
Guide 34 and in more detail in ISO Guide 35.
General steps required in production of a certified
reference material typically include:
Collection or synthesis of material
Sample preparation (including homogenization,
stabilization, bottling etc.)
Homogeneity testing
Stability assessment
Value assignment
Maria Ciprotti (EURL-CEFAO) Critical Points in
Mercury Determination by Direct Mercury Analysis
Maria Ciprotti spoke on the characteristics of
mercury including its high volatility, absorption on
container walls and suspended particles and
colloids, and inclusion in stable complex and
amalgams.
Methods for determination are neutron activation,
Cold Vapour Atomic Absorption Spectroscopy, Cold
Vapour Atomic Fluorescence Spectroscopy, and ICP-
MS plus direct mercury analysis (COMB-AAS).
The main advantages of direct mercury analysis are:
No sample treatment
Time saving
No purchase of high purity acid
No acid wasted
Reduced possibility of sample contamination
Increased stability of calibration curve
The main disadvantages of direct mercury analysis
are:
Tools contamination
Environmental contamination
Time consuming calibration curve
Correction for dry weight
Claudia Zoani (Italian National Agency for New
Technologies, Energy and Sustainable Economic
Development, ENEA - C.R. Casaccia, Rome, Italy)
Metrofood-Ri: A New Pan-EU Research
Infrastructure for Promoting Metrology in Food
and Nutrition
METROFOOD-RI “Infrastructure for promoting
Metrology in Food and Nutrition” is a European
Research Infrastructure project listed as “Emerging”
on the 2016 ESFRI Roadmap aiming to carry out
different activities supporting data collection and
measurement reliability, as well as basic and
frontier research in food and nutrition. Its general
objective is to enhance scientific cooperation and
encourage interaction between the various
stakeholders, as well as the creation of a common
and shared base of data, information and
knowledge.
A network of plants, laboratories and experimental
fields/farms will be realized (Physical-RI) and an e-RI
will be developed. The Physical-RI will enable to
carry out different research activities supporting
data collection and measurement reliability; quality
& safety and traceability of food production, as well
as basic and frontier research in food and nutrition.
The e-RI will provide a new useful, free access web
platform to share and integrate information and
data on availability of metrological tools for food
analysis. It will deal with integration of existing
databases on food, focusing on emerging needs and
collection of data on food composition, nutritional
contents and levels of contaminants in foods
produced in different geographic regions by
applying to different technologies.
METROFOOD-RI is supported by the economic
endorsement of 3 MSs and the political
endorsement of 13 countries. Currently, 35
partners from 17 countries, together with an
international partner (FAO) are involved. Ireland is
not involved in this. Each partner brings its wide
and consolidated network of international
collaboration, which will ensure a very broad range
of action, open also to developing countries and
new markets and able to meet the needs of the
scientific community and all stakeholders at a
global level.

DAFM NRL Newsletter Volume 7, Issue 1.
Page 21
Andrea Colabucci (EURL-CEFAO) Annual update
As announced in 2015 EURL-CEFAO annual
workshop, the PT results submission has changed.
As for the 24th
PT on honey, an intermediate
procedure has been chosen: participants were
required to submit the official results by e-mail, as
usual, but also to test the online submission system.
Starting from the 25th
PT on milk, results are
submitted only in the on-line restricted area.
The second issue is related to changes in the
European legislation. In fact, the entering into force
of the Commission Regulation (CR) 582/2016
amending CR 333/2007 has changed the definitions
of Limit of Detection and Limit of Quantification. In
particular, one of the main issues he highlighted is
that not all the EU MSs take into account the
Maximum Residue Limits set for Hg and Cu in the
pesticides legislation (Regulation 396/2005).
National Monitoring Residues Programs (NRCPs)
results for 2015 were also discussed. The high
number of non-compliant samples found in some
specific matrix/element combinations (e.g. Cd in
kidney) was highlighted as well as the relevant
follow-up action reported by the MSs in the
“Questionnaire on the actions taken as a
consequence of non-compliant results”. Finally, the
representatives of the NRLs were reminded of the
opportunity to include As and Ni in their 2016-2018
NRCPs at least for the matrices prescribed in the
Commission Recommendations 1381/2015 and
1111/2016.
Andrea Colabucci (EURL for Chemical Elements in
Food of Animal Origin) Applicability of the CD
2002/657 to the Analysis of Chemical Elements in
Food of Animal Origin
The urgent need for a review of the CD
2002/657/EC was highlighted in the expert
committee on residues of veterinary medicinal
products meeting, held in June 2015. For this
purpose, the four EURLs for residues (BVL, RIKILT,
ANSES, and ISS) were asked by the European
Commission for technical assistance including the
revision of CD 2002/657/EC in their work
programmes for 2016/2017.
In July 2015, a questionnaire was prepared by the
three “organic residue” EURLs (BVL, ANSES and
RIKILT) asking their NRLs network to rate for each
article of the Decision the need for changing from 0
(no changes required) to 5 (changes urgently
needed).
For group B3c (Chemical Elements), the field of
competence of the EURL-CEFAO, more specific
provisions are reported in the Commission
Regulation (CR) 333/2007 that, however, does not
indicate any mandatory document to be preferred
for method validation.
The EURL-CEFAO sent a questionnaire to the NRLs
of its network asking them whether and how this
decision is applied. 23 out of 31 were collected. The
main outcome from the questionnaires was that
there is a need for revision of validation
procedures, to simplify the classification of
analytical methods by performance characteristics,
and more detailed information should be given on
whether CRMs are available or not.
The review could lead to – full CD 2002/657 revision
or ‘light’ version plus technical guidance in EURL
documents.
Marilena D’Amato, EURL-CEFAO Determination of
Inorganic Arsenic in Mussel Tissues by HPLC-ICP-
MS
Marilena D’Amato presented on how analytical
methods for arsenic speciation in food of animal
origin can still be demanding for implementation as
a part of the routine activities of those laboratories
not primarily focused on research. Most works
reported in the literature deal with the
identification of the variety of As species typically
found in marine samples, whereas the interest in
developing robust analytical methods focusing on
inorganic As as the most toxic fraction has
increased only recently. Therefore, the
implementation of a relatively cheap, fast, and
easy-to-use method directly applicable to incurred
samples can represent an added value for routine
laboratories.
Due to the rising interest in As speciation at the
level of control laboratories and in compliance with

DAFM NRL Newsletter Volume 7, Issue 1.
Page 22
its tasks, the EURL-CEFAO has developed a method
for inorganic As determination in fresh mussels
using water bath extraction and anion exchange
chromatography-inductively coupled plasma mass
spectrometry (HPLC-ICP-MS). This method might be
applicable to incurred samples of animal origin. In
particular, an effective procedure for extracting,
separating and quantifying inorganic As was
developed in order to reduce sample preparation,
e.g. avoiding freeze-drying. The proposed method
will be considered only as a general guideline for
inorganic As determination in fresh mussels and as
a support to NRLs when approaching analytical
issues related to inorganic arsenic speciation.
During the method development, the optimization
of an HPLC-ICP-MS method for selective inorganic
As determination was investigated and the results
obtained with anion-exchange chromatography by
using different extraction mixtures and columns
were compared and evaluated. The method
consists of extraction with a HNO3/H2O2 mixture in
a shaking water bath and elution with ammonium
phosphate and ammonium nitrate in 2% methanol
(pH=5.5) on Hamilton PRPX-100 column. Following
good preliminary results obtained, the method was
considered for validation.
The method was validated using samples of
Mediterranean mussels containing roughly 3.8
mg/kg of total As. With the proposed extraction
procedure using HNO3/H2O2 mixture, the complete
oxidation of As(III) into As(V) was achieved, which
resulted in a well-separated peak in the anion
exchange HPLC-ICP-MS chromatogram. Then, the
inorganic arsenic was easily quantified as As(V). In
the validation procedure LoD, LoQ, repeatability,
within-laboratory reproducibility and accuracy were
assessed. A provisional value of expanded
uncertainty was also estimated.
11th
Workshop EURL Campylobacter, Uppsala,
Sweden, 4th
-5th
October 2016
NRL Representative: Tony O’Brien (Bacteriology
and Parasitology Division)
The workshop was opened by Dr Hanna Skarin of
EURL Campylobacter who outlined the topics to be
covered in the workshop and reviewed the work
carried out by the EURL in 2016
The main issues to be covered in the workshop
were
Campylobacter activities at EU level
Molecular typing and surveillance
Epidemiology of Campylobacter
Quality controls and standards for WGS
National presentations
PT results and performance
ISO updates
Group discussions on three topics ( subtyping,
detection and enumeration and MALDI-TOF )
Networking
The 2016 work program for EURL Campylobacter
included the following
PT17 and PT18 sent out in March
Two questionnaires
Update of website, new learning materials
Training courses (detection, enumeration and
PCR)
Tests of analytical methods ( detection of
Campylobacter in water, freeze drying of
Campylobacter, tested PCR’s, comparisons of
WGS subtyping methods and pipelines )
Participation in revision of ISO for
Campylobacter
Participation in meetings / conferences
The presentation on subtyping focussed on the
various methods used by the different labs. These
were mainly PFGE, MLST, PCR-based and WGS-
based. Most labs used subtyping for research
reasons followed by outbreak investigations and
then surveillance. Very few laboratories had
embarked on WGS. Those that had were using the
Illumina equipment with the MiSeq being the most
popular. Some countries (including Ireland) had
purchased equipment and were ready to proceed
to training and implementation of protocols. There
was a consensus that it would be very helpful if the
various EURLs could coordinate training and give
advice on the best protocols and pipelines available
to laboratories about to embark on WGS. There was
also discussion on the creation of a Campylobacter
WGS-network which will be considered at a later
date.

DAFM NRL Newsletter Volume 7, Issue 1.
Page 23
Some laboratories expressed an interest in
obtaining training in the use of MLST subtyping.
This is being planned to occur in late 2017 and it is
hoped that an analyst from NRL-IRE will attend this
course.
The presentation on PTs for WGS discussed the
objectives of any future PT. The preference would
be to include two components, one would be using
lyophilised culture and the other using purified
DNA. The aim would be to quantify differences
among laboratories in order to facilitate the
development of reliable laboratory results of
consistently good quality within the areas of DNA
preparation, sequencing and analysis. Also to
facilitate harmonisation and standardisation in WGS
and data analysis. On the latter point the
participants were agreed that this is crucial as the
various labs take the steps to implement WGS as a
diagnostic and research tool.
Global Microbial Identifier is involved in setting up
PTs in these areas with the support of Compare,
Genome Trakr and Microbiologics.
www.globalmicrobialidentifier.org
www.compare-europe.eu
Ingrid Hansson and Ann Nyman (EURL-
Campylobacter) proficiency tests update
PT 17 included detection and enumeration of
Campylobacter in 10 samples consisting of broiler
carcass skin. The skin was analysed together with
10 vials each containing one capsule with or
without Campylobacter.
PT 18 involved detection and species identification
of Campylobacter in avian caeca samples. 18 caeca
samples from a Campylobacter negative flock were
inoculated with Campylobacter of various species
and concentrations. Some caeca were inoculated
with non-Campylobacter organisms.
Results among participants (%)
Excellent Good Acceptable
PT 17
Detection
95 4 4
PT 17
Enumeration
74 17 3
PT 17
Identification
88 8 4
PT 18
Detection
67 30 3
PT 18
Identification
60 23 10
NRL-IRL achieved excellent results in all
components of PT17 and PT18. Overall both PT17
and PT18 showed improved results compared to
the previous two PTs.
Ingrid Hansson (EURL) led a discussion on drying
times of mCCDA selective agar plates. This was
based on feedback from a questionnaire circulated
to the NRL’s by EURL.
Campylobacter has a tendency to swarm over agar
particularly when it is wet. This means it is very
difficult to enumerate the colonies. Most
laboratories either dry out the plates at room
temperature for several days or for a few hours in
an incubator prior to use. It is the practice in the
NRL-IRL to dry the plates at room temperature for
up to three days. This is essential to achieve
accurate and reproducible enumeration of
Campylobacter.
Elisabeth Reperant (NRL-FR) gave a presentation
on whether using different selective media
influence Campylobacter detection. They carried
out comparisons of four commercially available
selective agars with the mandatory mCCDA.
The summary was that two of the agars were more
efficient than mCCDA in detecting Campylobacter
and more selective for negative samples.
Also mCCDA was less efficient in detecting samples
in cross contaminated samples. It was mentioned
that NRL-IRL had done some work examining the

DAFM NRL Newsletter Volume 7, Issue 1.
Page 24
effect of adding tazobactam to mCCDA based on
work done by colleagues in UCD which showed a
decrease in the amount of background flora
growing in the presence of the Campylobacter.
Miriam Koene (NRL-NL) gave a very comprehensive
presentation on the use of MALDI-TOF in
identification of Campylobacter species. They use
the Bruker instrument. All of the NRLs using MALDI-
TOF (including NRL-IRL) use the Bruker. Miriam
described the principles and practicalities of using
the instrument and also went into detail on how
they validated the test prior to accreditation. This
was particularly interesting for NRL-IRL as we are in
the process of validating MALDI-TOF in our
laboratory.
Miriam concluded that although the instrument
was very expensive, it produced fast and accurate
results and the cost per tests were very low.
Hanna Skarin and Ingrid Hansson (EURL) gave an
update on the proposed changes to ISO 10272:
Horizontal Method for the Detection and
Enumeration of Campylobacter Species. Although
the preparation and discussion of the changes to
the ISO method have been going on for several
years, it is envisaged that they will be implemented
in 2017.
The main changes to the detection method include
Samples from the primary production stage
have been added to the scope
Option of using another enrichment broth
(Preston), primarily to overcome problems
with background flora resistant to 3rd
generation beta lactams
Option of direct plating onto mCCDA agar
The use of closed containers with a reduced
headspace as an alternative to incubation in a
microaerobic environment has been deleted
Confirmation tests on based on microaerobic
growth at 25oC and aerobic growth at 41.5
oC,
will be replaced by the study of aerobic
growth at 25oC
Performance testing for the quality assurance
of the culture media has been added to Annex
B
Performance characteristics have been added
to Annex C
The main changes to the enumeration method
include
Samples from the primary production stage
have been added to the scope
Serial dilutions will be plated singularly rather
than in duplicate, to be comparable with ISO
7218
Confirmation tests on based on microaerobic
growth at 25oC and aerobic growth at 41.5
oC,
will be replaced by the study of aerobic
growth at 25oC
Publication of the final standards is expected in
March 2017.
11th
Workshop EURL E. coli, Rome, Italy, 10-11th
November 2016
NRL Representative: Regina Heslin (DSL)
The 11th
EURL E. coli workshop was attended by 33
NRLs representing 24 EU countries, plus the NRLs of
Norway, Iceland, Switzerland, FYROM, Serbia,
Turkey and Russia; Commission, EFSA, ECDC and
WHO Collaborating Centre for Reference and
Research on Escherichia and Klebsiella
Session 1: Update of surveillance and monitoring
activities on STEC in the EU and the development
of a database on molecular typing of foodborne
pathogens
1. Karin Johansson from ECDC spoke on the role of
EPIS -FWD (Epidemic Intelligence Information
System for Food and waterborne diseases). It has
been updated to manage non-clinical and joint
clinical/non clinical clusters that can be detected
through the joint ECDC- EFSA molecular typing
database. This updated version is due for release in
early Dec 2016. Training for the nominated users
from the food safety and veterinary sector is being
planned with dates to be confirmed and invitations
to be sent out by EFSA.
The importance of data being referred to them was
stressed. The main EPIS-FWD features discussed
were Molecular Typing Cluster Investigation (MTCI)
and Urgent Inquiry (UI). MTCI is a forum for
exchange of information about a specific cluster /
molecular type. This can only be assessed by MS
that have isolates in the cluster. UI is a forum for

DAFM NRL Newsletter Volume 7, Issue 1.
Page 25
exchange of information about an unusual event
with the potential for international spread and is
accessible to representatives of all MS and
international partners. If the information provided
in the MTCI leads to suspect that more countries
may be involved, and/or there is value in informing
both the food safety and veterinary expert
networks, the MTCI can be escalated to an Urgent
Inquiry (UI).
2. Valentina Rizzi, EFSA, gave an update on the
annual reporting of STEC in the EU and on EFSA
activities for molecular typing data collection for
food and animal isolates. The EU summary report of
2014 includes the different analytical methods used
as well as data reported for certain food categories
and animal species. In total 12 MSs provided
information on STEC serogroups in 226 STEC
isolates. In food the main serogroups are ranked as
follows and are also the most commonly reported
serogroups in human infections in the EU/EEA.
Serogroup Frequency %
Main source
VTEC O157 33.5 Bovine meat, raw milk
O26 8.7 Milk & dairy products
O103 6.9 Meat and Milk & dairy products
O113 6.4 Meat Products
O146 4.6 Meat Products
O174 4.6 Meat Products
O91 4.0 Meat Products
O145 2.9 Meat and Milk & dairy products
An increasing trend of reporting in food was
observed for STEC O26 and STEC O103 two
serogroups strongly associated with severe human
infections in the EU. Contamination was rare in
ready-to-eat food of vegetable origin. No STEC
positive samples reported for spices and herbs or
for sprouted seeds, the sole food category for
which microbiological criteria for STEC have been
established in the EU.
3. Antonella Maugliani gave an update on the STEC
Network preparedness for molecular typing data
collection. The EURLs for STEC, L. monocytogenes
and Salmonella have all produced PFGE SOPs for
the production, interpretation and curation of PFGE
profiles. The STEC EURL has distributed EQAs on
PFGE annually between 2012 and 2015. They have
also provided training sessions on PFGE (9 courses
to date) and basic courses on BioNumerics software
(2 courses to date). Training on the 3rd
edition of
BioNumerics will be organised jointly by all 3 EURLs
in 2017 with the 4th
expected to be organised by
the EURL Salmonella in 2018 in the Netherlands.
EQAs on PFGE are valuable in assessing the labs
ability to produce good quality profiles. An outline
on the NRLs performance in PTs showed vast
improvement year on year. The main areas labs
have problems with are image acquisition and
staining and compressed central or fuzzy bands.
42% of NRLs improved their performance after
attending training. The EURL will focus training on
the areas that proved problematic for the
participants.
Session 2: E. coli Genomics.
1. Valeria Michelacci EURL gave a talk on
preparedness towards the use of NGS for
characterization and typing of pathogenic E. coli. In
2014 all NRLs expressed the need for training in
genomics data analysis. 8 NRLs had access to
bench-top sequencers with 8 planning to outsource
NGS data production. The EURL has provided
training on Bioinfomatics for NGS since 2015. ARIES,
a Galaxy based workspace for intensive data
analyses was demonstrated.
2. Federica Gigliucci EURL presented the use of
metagenomics to study STEC infections. The
metagenomics approach was used to investigate
the changes in the microbiota in patients with STEC
infections as compared to healthy individuals. The
cases were from an O26:H11 outbreak in Rome. 10
faecal samples were analysed: 3 from patients (1
bloody diarrhoea, 2 diarrhoea), 3 from recovered
patients and 4 from healthy individuals. DNA was
extracted from 0.20g of faecal sample. Sequencing
was by Ion Torrent and Illumina Miseq platforms.
Bioinfomatics analysis was through ARIES and
MEGAN software. A comparision of the E. coli
virulence genes was made from the three groups
with 20% more genes present in the group with
diarrohea than the other two groups. In terms of

DAFM NRL Newsletter Volume 7, Issue 1.
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Taxonomic abundance, Clostridia were more
abundant in negative samples while Bacilli
predominated in recovered or clinical cases,
particularly Bifidobacteria. This different
microbiological distribution between cases and
healthy controls may be related to the clinical
demonstration of the patient. Prevalence of
Clostridia may indicate a protective role in the gut.
When colonisation by STEC occurs the reduction in
Clostridia allows Bacilli to increase. Faecal samples
from patients with Crohns disease (with and
without evidence of infection) were also studied.
Two of three samples had genes associated with
aEPEC (escV), and the third with stx2f gene (STEC).
In summary, on STEC infection, the balance
between species composing the intestinal
microflora is altered.
3. Sabine Schlager, NRL Austria presented on a
study of STEC O26:H11/HNM isolated in Austria in
2009-2014 by NGS analysis. Incidence of STEC
cases are increasing year on year. Human isolates in
order of occurrence O157 (22%): O26 (14%): O103,
O111, O145 (<10%), others (44%). In terms of HUS
cases the occurrence is as follows: O157 (22%),
other (22%), O26 (18%), no isolate (16%), O145
(9%), O111 (7%), O103 & O104 (3%). Of 109 E. coli
O26 strains studied (MLST) 11% belonged to ST29
with the remaining belonging to ST21, ST591 and
ST1566. However geographically throughout
Austria ST21 predominates. In clinical outcomes,
42% stx2a genes from ST21 caused HUS versus 18%
from ST29.
4. Invited speaker Flemming Scheutz from the
International Escherichia Centre of the WHO talked
on the EQA schemes for Public Health laboratories.
The results of the 7th
EQA scheme for typing of STEC
in 2015-2016 were presented. EQA-7 includes the
following methods:
Molecular typing: PFGE
Serotyping O and H
Virulence determination: genotyping of STEC
virulence genes: vtx1, vtx2, eae, aaiC and aggR
& subtyping of vtx1 (vtx1a, vtx1c and vtx1d)
and vtx2 (vtx2a to vtx2g)
Phenotypic testing: production of:
Verocytotoxin/Shiga toxin, Extended Spectrum
Beta Lactamases (ESBL), β-glucuronidase,
Enterohaemolysin & fermentation of sorbitol.
30 participants took part. Over 90% of participants
submitted results for serotyping, genotyping and
Phenotyping while PFGE were submitted by 63% of
participants.
Session 3: Laboratory methods and Proficiency
Testing
Rosangela Tozzoli EURL discussed the results of
recent Proficiency Tests: PT 16, detection of STEC in
sprout irrigation water and PT17, the inter-
laboratory study on the detection of STEC in ground
beef. The objective of PT 16 was to allow the
evaluation of a procedure for the pre-treatment of
spent irrigation water to be added to ISO/TS 13136:
2012. The water used had been obtained from a
sprout producer. 3 samples were spiked with STEC
O157 (vtx1+, vtx2+, eae+) at high (500cfu/ml), low
(200cfu/ml) and 0 levels. 50 labs responded. 44/50
successfully isolated the high sample and 42/50 the
low sample. The results confirmed the suitability of
the added centrifugation step for processing spent
irrigation water. 36 labs reported results for PT 17
on ground beef. The strain used to spike samples
was ED 76, STEC O91 (vtx1+, vtx2+, eae-) at high
(50cfu/g) sample C, low (5cfu/g) sample B and 0
levels sample A. 35 labs (97%) correctly identified
STEC O91 virulence genes in both samples. Four
labs picked up O26 in sample B and six labs picked
up eae in sample C. However these were not
considered penalties as the raw material may have
been naturally contaminated with these genes. At
isolation stage 4/25 labs did not determine the O91
serogroup (ONT). However isolation was correctly
achieved by 78% of labs. In conclusion ISO/TS
13136:2012 method is suitable for the detection of
all the serogroups analysed so far in foods most
regarded as vehicles of human infection.
2. Rosangela Tozzoli EURL gave an update of
Revision of ISO/TS 13136:2012. There are 8 main
areas for revision. (i) Enrichment: data from EURL
shows that most non-O157 STEC of the top 5 O-
groups show inhibition when grown in the presence
of supplements. Therefore BPW is considered the
most reliable enrichment media. (ii) Revision of stx-
gene sub types detected: possibility of adding stx2f.

DAFM NRL Newsletter Volume 7, Issue 1.
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NRLs for E. coli in the EU were surveyed on the
presence of this stx sub type in E. coli isolated from
food. 3 MSs perform routine testing of stx2f. No
positive findings so far. Therefore it is unlikely that
this will be added to the revised standard. (iii)
Inclusion of Enteroaggregative E. coli (EAEC)
virulence genes: EFSA opinion “Current evidence
indicates that in EU MSs EAEC are primarily non
zoonotic in origin and that transmission mainly
occurs by person to person spread and by the
contamination of foods by asymptomatic carriers”
Points (iv-vii) Inclusion of protocol for spent
irrigation water, Reconsideration of serogroups,
Expression of results and Performance
characteristics will be adopted as per evaluation of
data from EU-RL PT programs 2009-2015. (viii)
Isolation: Acid treatment (pH 2 for 1h) to reduce
background flora without addition of supplements.
Not going to be added to the revision as it is a
complex procedure and not verified for all STEC
types. Dilution of the enrichment broth before
plating is recommended instead of acid wash.
Lina Cavaco EURL AMR: Overview of activities.
Information can be obtained at www.eurl-ar.eu
Session 4: Presentations from the NRLs and other
participants
1. Pathogenic E. coli in Czech Republic overview by
Ivana Kolackova. Reported occurrence of
STEC/EHEC in humans in the Czech Republic is rare
with O26 as the dominant serogroup and stx2
subtype A as the most often identified virulence
factor. Monitoring of STEC in carcasses at
slaughterhouses shows higher prevalence of STEC
in cattle (8.3%) than in pigs (2.8%). O91, O146 &
O157 predominate in pig swabs while O91 and
O113 predominate in cattle swabs. 90% of STEC in
pigs carry the gene for stx2 subtype E (42% in
cattle). The spectrum of detected O- serogroups is
varied but the O26 was not detected in any of
them.
2. Estelle Loukadis Enterohaemorrhagic E. coli
Hybrid Pathotype O80:H2 an emerging clone in
France. In 2012 an atypical EHEC O80:H2 was
isolated from a HUS patients’ blood culture. From
2005 to 2015 five foodborne outbreaks leading to
HUS were detected with O157:H7 & O177:H25
found in frozen and fresh beef, O104:H4 in
Fenugreek and O26:H1& O80:H2 found in raw milk
cheese. There appears to be a shift in STEC
serogroups causing HUS in France. Clinical cases of
O157 have gone from 66% in 2005 to 23% in 2015.
O26 has remained stable at 13% and 11% in the
same time period. O80 has risen from 3% in 2010 to
35% in 2015 from stools of paediatric HUS cases.
3. Shona Neal from UK NRL spoke on their activities
and responsibilities regarding UK –NRL structure,
dissemination of information and training for
Official Control labs and NRL colleagues. She
focused on how they handled the implementation
of regulation 208/2013.
4. Rosangela Tozzoli EURL presented a study of
Stx2f-producing E. coli and HUS from a
collaboration with NRLs in Austria, The Netherlands
and the Faculty of Veterinary Medicine, Garmsar,
Iran. Pigeons are known to carry STEC producing
stx2f. Prior to 2004 few human infections were
related to stxf2. From 2008 it has been identified in
human diarrhoeagenic E. coli strains formally
classified as atypical EPEC. In 2013 the first HUS
associated cases implicating stx2f emerged. The
majority of human cases caused by stxf2 have been
reported as uncomplicated diarrhoea and may
therefore have been overlooked. Stxf2 in HUS cases
are different from those isolated from the pigeon
reservoir and from other diarrohea cases leading to
the conclusion that stxf2 toxin can move from
pigeon strains to E. coli strains with a genetic
background of aEPEC (not found in pigeons).
Therefore stxf2 is a fully functional toxin and its
ability to cause HUS depends on the strains genetic
receptor for host colonisation.
Session 5: Investigation of a multistate outbreak of
STEC O26 infections
1. Ciupescu Laurentiu NRL Romania presented a
Romanian O26 STEC outbreak in February 2016
involving pasteurised cow’s milk cheese and 15
paediatric cases, resulting in three deaths. The
common STEC genotype was stx2+, eae+ O26. Initial
food consumption surveys of the cases involved did
not target one food in particular leading to 574
different suspect food samples being tested, 40% of
which were dairy products, by the ISO method. Milk
fat caused interference requiring two to three extra
washing steps at the extraction stage. The results

DAFM NRL Newsletter Volume 7, Issue 1.
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showed that from 16 types of food (five dairy
products, ten poultry and one mixed meat (beef
and pork), 86 samples were positive by RT-PCR for
one or more of the investigated genes (stx1, stx2,
eae, wzx-O26). The target genes were detected in a
batch of soft cheese linked to the cases so the
investigation focused on this product. O26 culture
could not be isolated.
2. Valentina Rizzi, EFSA spoke on the assessment of
this outbreak and general background of O26
involvement in STEC infections. Among STEC,
serogroup O26 is the second most commonly
reported in Europe after O157. In the period 2010-
2014, 19 EU/EEA reported 2,356 confirmed cases of
STEC O26 with most cases during this period being
reported from Ireland (32%) followed by Germany
(15%) and Sweden (12%). These cases were
predominantly in young children; the median age
two years. Symptom onset for STEC O26 cases was
distributed over the year with a peak during the
period June-September. 88% of the cases were
acquired within the reporting country. An increase
in STEC O26 cases has been reported from 2012
onwards, most likely due to the increased use of
methods capable of identifying serogroups other
than O157. As of 23 March 2016, 463 cases of STEC
O26 have been reported to the European
Surveillance System (TESSy) for 2015. Since
November 2012, ECDC has been collecting PFGE
molecular typing data for STEC isolates from MSs
on a voluntary basis. As of 23 March 2016, 1,610
STEC isolates have been submitted to TESSy, 167 of
them reported to be of O26. Of these, 130 isolates
from eight MSs have approved and curated PFGE
profiles, involving 106 PFGE pulsotypes, 13 of which
are represented in the database by more than one
isolate. Two of these 13 patterns include isolates
from more than one country. Similar to the data for
human infections, O26 was the second most
frequently reported serogroup in food and animal
samples in Europe from 2005, with an increasing
trend between 2011 and 2014. Overall, a wide
range of STEC serogroups was reported, with STEC
O157 being the most frequent in food and animal
samples. However, many of the MS surveillance and
monitoring programmes are focused on STEC O157,
potentially biasing the estimates of the frequency
of non-O157 serogroups. An analysis of the 2014
STEC data indicated that serogroups O26 and O103
were reported more frequently than O157 in the
food samples (mainly from bovine meat, raw milk
and dairy products) tested using the ISO/TS
13136:2012 standard method which is able to
detect STEC regardless of its serogroup.
3. The story was taken up by Gaia Scavia of the
EURL who initially became aware of the outbreak
from the TV and newspapers. The information
relayed from EPIS FWD described it as an Urgent
Inquiry: unusual cluster of severe diarrhoea with
HUS. In March a HUS case was reported through
the Early Warning and Response System (EWRS) in
Italy from a Romanian child living in Tuscany. The
same cheese as in the Romanian RASFF had been
consumed. STEC O26 isolated from the cheese
upgrading the RASFF to an ALERT. There were a
further 10 epidemic cases, 5 HUS, caused by STEC
O26 in Italy from April to August 2016 with a link to
Romania, both food and travel related. Person to
person contact as well as consuming the Romanian
cheese were the cause of illness. Romanian
nationals are one of the highest immigration
populations in Italy. PFGE was performed for five
STEC O26 isolates obtained from confirmed cases.
Two showed indistinguishable PFGE patterns
whereas the other three all showed non-identical
PFGE profiles (86-93% similarity). The three cases
with non-identical PFGE patterns are from different
districts, had onset of symptoms in early to mid-
February and all have different virulence gene
profiles (one case is PCR-positive to both stx1 and
stx2, one case is PCR positive only to stx1 and one
case is PCR positive only to stx2). The two cases
with indistinguishable PFGE patterns are from the
same district, had onset of symptoms in late
February to early March and share the same
virulence gene profile (PCR-positive to both stx1
and stx2). PFGE data from more cases would be
highly desirable to be able to further characterise
the outbreak strain(s). WGS is awaited on the
isolates from the Romanian outbreak.
4. Details of a recent outbreak, August 2016,
associated with rucola in Helsinki, Finland was also
presented. The rucola was supplied to a catering
company and wholesalers. The product was grown
in Denmark and packaged in Sweden. 200 people

DAFM NRL Newsletter Volume 7, Issue 1.
Page 29
were reported ill. Of 80 hospitalised cases STEC was
isolated in 30 cases and EPEC in 50. No HUS were
reported. Chicken salad where rucola was used as a
garnish was analysed. 1 out of 5 samples was stx2,
eae and O111 positive. The laboratory carried out
acid treatment for 1h following IMS isolation. They
found that the selective agars did not grow the
outbreak strains and used culture from non-
selective TBX and SHIBAM (STEC Heart Infusion
blood agar with Mitomycin).
10th
Annual EURL-Animal Protein Workshop,
Namur, Belgium September 2016
NRL Representative: Oliver Burke and PJ Conway
1. Introduction
This meeting is held every year to inform the
National Reference Laboratories for Animal Protein
(NRL-AP) network of developments in the area of
feedingstuff analysis and to discuss issues such as
new or revised scientific protocols. The meeting
also celebrated the 10th
anniversary of the EURL-AP.
The meeting was attended by 50 delegates from 27
countries. Ireland was represented by Oliver Burke
(AAI) and PJ Conway (Lab Analyst).
2. Presentations
As with other workshops in recent years, the
programme was dominatd by the implementation
of PCR for the detection and differentiation of
animal protein from different species in
feedingstuffs.The newest item on the agenda was
insect meal detection: possible methods.
EURL-AP activity report 2015
The activities of the EURL-AP were outlined with
reference to its functions as detailed in legislation.
Among the activities highlighted were:
ISO17043 accreditation and conformity
assessment;
NRL proficiency for qualitative testing –
Network performance;
Preparation for legal extension to feed ban
( Pig- Poultry);
Transfer of the EURL-AP micrograph
collection to the public site;
Parameters around Official Lab interaction
with EURL-AP;
PAP detection in liquid samples;
Training in light microscopy and PCR;
Effect of grinding on bone detection by
light microscopy- Study Results;
Production of pDNA calibrants for the
detection of poultry in processed animal
proteins; and
Implementation study for pig PCR
Production of pDNA calibrants for the detection of
poultry in processed animal proteins
The production of a poultry calibrant was initiated
in 2015 by the JRC in Geel with a validation study of
a chicken/turkey PCR method. Currently, the short-
term stability study and the determination of the
copy numbers by chamber and droplet digital PCR
are finalised. The long-term stability study to obtain
a certified reference material is still pending and
will end in January 2017. A report and the ERM-
AD484 should be available in February 2017.
The EURL- AP concluded that the short term
stability studies already highlighted the high
susceptibility of the poultry plasmid to
frozen/thawing cycles. For that reason, it was
recommended to thaw only once and to store it at
4°C during the few days of the cut-off
determination of the PCR platform.
Implementation study for pig PCR
An interlaboratory study was organised to run
jointly with the proficiency test 2015 to assess the
use of the validated pig PCR assay by the NRLs. The
implementation of the method was already

DAFM NRL Newsletter Volume 7, Issue 1.
Page 30
initiated in August 2015 with the distribution of all
necessary information and material. The DNA
extraction protocol to use is the same as for the
ruminant DNA detection currently being operated
by the NRL network. A dedicated Excel file has to be
used for the determination of the cut-off at 5
copies and a PCR protocol was distributed by EURL-
AP. The sample set was composed of a total of 9
samples (3 samples in triplicate). The method can
now be considered as validated including the DNA
extraction step and successfully implemented in the
majority of the NRLs. Four labs did not submitted
results in time and are asked to continue the
implementation. The implementation study
attracted detailed discussion among the attendees.
Some of the points raised by the representatives
included; the report for the implementation of the
test pig PCR which is not yet available, the
sensitivity of the test?. The pig PCR method is less
sensitive than the ruminant method. The
mitochondrial target is present in a lower copy
number. For that reason, the cut-off was adapted
to be determined at a level of 5 copies and the
dedicated Excel file must be used. The Danish NRL
observed high differences between CT values when
the dilution steps are repeated. No other NRL
observed this. EURL-AP will investigate the
repeatability of the test.
New NRL: Republic of Serbia - Control of feed for
the presence of PAPs in Serbia (by Ksenija Nesic,
Serbian NRL)
Mrs Ksenija Nesic presented the activities of the
different departments of the Institute of Veterinary
Medicine of Serbia. She drew attention on the
difference between European and Serbian
legislation. A total feed ban has been applied in
Serbia since 2011.
Ksenija also presented the results of their 10 years
monitoring. Since 2005, the number of positive
samples has decreased significantly.
Combined proficiency test 2015 “Microscopy + PCR
(by O. Fumière and P. Veys EURL-AP )
For the first time, EURL-AP organised a proficiency
test combining microscopy and PCR. Moreover, the
study was conducted in agreement with ISO 17043
standard. The sample set was constituted of 12
samples: 4 to analyse by microscopy, 5 to analyse
by PCR and the 3 remaining samples to analyse by
both methods. The performances of the NRL
network was reported as good whatever the
method. The cases of underperformances (1 NRL
for both methods) were resolved and corrective
action completed.
Results of the study were presented; no special
remarks or comments were brought up by the
audience. The performance of the Irish NRL was
good and in line with the other NRL participants.
Mass spectrometry – updates (by M.C. Lecrenier
EURL-AP)
The transfer of the mass spectrometry method to
routine testing was presented. This transfer is firstly
focused on the haemoglobin powder and blood
meal detection using the haemoglobin peptides
biomarkers identified in high resolution mass
spectrometry (Q-TOF). After collision energy
optimisation and best transitions selection,
retention times for each MRM transitions were
determined. The limit of detection was evaluated in
various matrices using blood meal or haemoglobin
powder. The first estimation of the LOD for bovine
and porcine blood detection is around 0.05 % w/w
which is below the LOD imposed by the European
commission. A prospective study also started on
aquafeed known to contain porcine blood derived
products. Using PCR, all samples gave positive
results for porcine DNA but one gave a positive
result for ruminant DNA. The Porcine biomarker
was clearly detected. Regarding the bovine
biomarkers, a weak signal was detected for the
positive aquafeed for ruminant DNA though it was
below the internal threshold. Additional feeds and
bloods samples will be analysed. Secondly, the
suggestion to analysis milk powders and whey
powder was made. Evaluation of milk biomarkers is
underway is already underway in the EURL-AP
laboratory.

DAFM NRL Newsletter Volume 7, Issue 1.
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Insect meal detection: possible methods (by
P.Veys, A.Marien, M.C. Lecrenier EURL-AP)
A review of the preliminary test on different
analytical methods was presented: light
microscopy, PCR and mass spectrometry.
Requirements for future insect PAP detection were
highlighted (modification of existing protocols, new
target development). The possible methods for
insect meal detection were discussed in detail with
the NRL representatives. Points raised included the
possibility of natural insect contamination of feed.
The EURL- AP responded by stating that the
implementation of the methods is not yet fully
developed. Regarding the setting of a specific
concentration procedure for microscopic
observation, it is reminded to look at the work
performed in the STRATFEED and SAFEED-PAP
projects where different procedures were tested to
concentrate muscles in the light fraction of the
sample being tested. As for some tested procedure,
the fraction of sample taken into account is low
(c.200 mg), therefore the sample preparation will
be a key issue. The protocol will need to take into
account the sampling of the material. Some of the
legislation surrounding this has yet to be clarified by
the Commission. The final point raised on this topic
was asking about the perspective offered by
fluorescence microscopy and immunology.
Effect of sample grinding on PAPs detection by
light microscopy (by P. Veys EURL-AP)
This study was completed by the Irish NRL. The
study demonstrated that the different grinding
process used did not significantly impact the bone
detection at level of 0.01% and 0.05% PAP in the
feed matrix used. Although variations were
observed in bone numbers those variations (on the
exception of a combined grinding with a rotor mill
operating with a 5 mm sieve and an Alizarin red
colouring) were negligible. Unexpectedly no
correlation could be found between the amount of
sediment used and the number of bones found.
Update on DG SANTE’s TSE activities (by L.
Carrouée, DG-Sante)
The lecture started with a presentation of the EFSA
recent reports and opinions: Zoonotic potential of
scrapie, Croatia's BSE monitoring regime and
Insects as food and feed. The ongoing and future
mandates of EFSA were also listed. The second
point presented by L. Carrouee, was about the
regulatory updates regarding the feed ban
(reintroduction of non- ruminant PAPs in aquafeed,
use of starfish, export of PAPs and use of insect PAP
in aquafeed) and the SRM. Last point presented
was about a retrospective exercise on BSE
surveillance and CWD. Items discussed in response
to the presentation were the clarification between
feed and substrate. Substrate has to be considered
as feed. PAP detection by light microscopy should
probably not be affected by the presence of insect
material. Light microscopy has some potential to
detect the presence of illegal addition of insect
material. The method still need some development
and has to be widely tested.
Pig feed and poultry feed survey (by P Veys EURL-AP) Based on commercial samples being collected and analysed by the EURL-AP, the lecture attempted to inform the delegates on the risk of authorising terrestrial PAP (other than prohibited ruminant PAPs) to be added to pig feed and to poultry feed. The key point is to sort the source of ruminant and pork DNA signals in presence of those authorised terrestrial PAPs. For poultry feed it seems that casein could likely cause issues since it is used in the composition of feed additives. There was a discussion on the test results presented. Positive PCR results for poultry feed are clearly below the cut-off value. It is mentioned that casein is used as carrier. Combination of PCR and ELISA results should be able to conclude if the positive result is coming from the use of an additive. This has to be investigated by EULR-AP and will be reported at a future date.

DAFM NRL Newsletter Volume 7, Issue 1.
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Food Health and the Role of National Reference
Laboratories Conference Backweston 3-4th
February 2016
A national NRL conference was organised in
February 2016, entitled “Food, Health and the Role
of National Reference Laboratories”. The
conference was attended by 140 delegates and
included representatives from all of Ireland’s NRLs,
policy makers and academics.
The conference was addressed by a range of
international and national speakers. This report
details the presentations given and presents
conclusions on future actions to support Ireland’s
NRL network.
Among the speakers were:
Pamela Byrne, CEO, FSAI - The role of NRLs in
ensuring safe and trustworthy food for
everyone
Jan Von Kietzell, Head of Sector, Pesticides
and Import Controls, FVO - FVO perspective on
official laboratories and NRLs
Lucie Carrouée-Pook, Legislative Officer, Food
Safety & Zoonoses EURLs, DG-Sante -The EU
approach to reference laboratories
Leen Van Ginkel, Director EURL for Residues,
RIKILT, Wageningen - A view on the changing
role of EURLs
Bertrand Lombard, L. monocytogenes,
Staphylococci and Milk EURL, ANSES -
Experiences and potential of food
microbiology laboratories – Illustration with
EURLs/NRL networks for L. monocytogenes,
Staphylococci, Milk & Milk Products
Donald King, Foot and Mouth Disease EURL,
The Pirbright Institute - Examples of the
coordination, advice, training and surveillance
activities undertaken by the EURL for foot and
mouth disease
Enikő Varga, Scientific Officer, Evidence
Management Unit, EFSA - Usage of data in
EFSA’s work and risk assessments
Gail Carroll, Services Contract Manger, FSAI -
Impact of the new Official Controls Regulation
on laboratories.
Adrienne Duff, Director of Irish National
Accreditation Board - Accreditation of Flexible
Scopes
Martin Maiden, Prof Molecular Epidemiology,
University of Oxford - Whole genome data for
the analysis of food borne Infections
Baldissera Giovanni, Co-ordinator, European
Plant Health Research Co-ordination, EPPO -
EUPHRESCO and plant health research
David Butler, Director of Sustainable Food
Systems Ireland - Applying Ireland’s agri-food
expertise in international markets
Lance O’Brien Head of Strategy and
International Relations, Teagasc -Teagasc
Technology Foresight 2035
Richard Howell, Head of Research and Codex
Division, DAFM - DAFM strategic planning and
competitive funding for research; and role in
Codex Alimentarius Commission
A full report on this conference can be read at Food Health and the Role of NRL's, Final Report