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SVN-Congress, 18 March 2016 1

Biofilms

–

The World‘s First Community

Dr. Johannes Lenz Chemische Fabrik Dr. Weigert

Hamburg, Germany


Topics

• What are Biofilms?

• Where do Biofilms exist?

• Biofilm formation

• Biofilms in endoscopes

• conclusions


What are Biofilms?

• Microbiological communities, attached on surfaces (bacteria,

fungi, algae)

• Consist of 2 components:

• microorganisms (approx. 20 %)

• extracellular polymeric substances (EPS) (approx. 80 %)

• A Biofilm can consist of one, of various or multiple species

• The eldest community on earth (approx. 3 billion years)

• Can be formed on nearly all wet surfaces


Where do

Biofilms exist?


Biofilms in nature


Unwanted Biofilms


Dangerous Biofilms


Useful Biofilms


Biofilm Formation


Biofilm Formation in 5 Phases

(1)reversible adhesion of single bacteria

(Stoodley et al., 2002)



(2) irreversible adhesion and production of EPS




(3) Increase of mircroorgansims and first layer




(4) maturation of the biofilm matrix




(5) Plateau phase, release of microorganisms in environment



Sections of a Biofilm

aerobe and anaerobe sections


• Protection of microbial cells

• increased stability by adherence (increased life time, lower metabolism)

• increased adaptation against environmental influences (dehydration, protozoa , biocidal products,

antibiotics)

Which meaning have Biofilms for Microorganisms?


Communication in biofilms

Quorum sensing: communication via pheromones


How to remove Biofilms?

• Most important is good cleaning

– 80 % of biofilms are EPS, which has to be opened, to release microorganisms

• Additional disinfection is necessary, in order to inactivate released microorganisms

• A single disinfection for inactivating microorganisms in biofilms is not sufficient

• „dirt is not disinfectable“


Biofilms

in flexible Endoscopes


Application of flexible endoscopy in the medical field:

Gastroenterology e.g. • Gastroscopy • Colonoscopy • ERCP (Endoscopic retrograde

Cholangio-Pancreaticography): Examination of the bile duct (gall) and the pancreas (x-ray contrast

media)


air/water channel suction channel

biopsy channel

jet channel

water

air

ligth source suction

flushing bottle

Construction of a flexible endoscope


The role of flexible endocopes associated with outbreaks of health-care infections

• Widely used in diagnostic and therapeutic procedures

• Become contamiated with organic soiling (e.g. blood, secretions)

• Difficult to reprocess

• Easy to damage (they are expensive!)

• Mostly no steam sterilisation possible


Reprocessing of flexible endoscopes European Society of Gastrointestinal Endoscopy (ESGE) - European Society of Gastroenterology and Endoscopy Nurses and Associates (ESGENA)

Automated reprocessing is recommended: • standardisation •documentation


Cleaning: Cleaning is a process that removes foreign material (e.g. soil, organic material, microorganisms) from an object. Disinfection: Disinfection is a process that reduces the number of pathogenic microorganisms, from inanimate objects or skin, to a level which is not harmful to health. Sterilisation: Sterilisation is a process that destroys all microorganisms including bacterial spores.

International Federation of Infection Control (IFIC):


Biofilms in endoscopes?

There is lots of literature about it:

Kovaleva J. et al., Mimicking disinfection and drying of biofilms in contaminated endoscopes, J Hosp Infect. 2010 Dec;76(4):345-50 (generation of biofilms in 96-well plates)

Pineau L. et al., Comparison of the fixative properties of five disinfectant solutions, J Hosp Infect. 2008 Feb;68(2):171-7 (generation of biofilm according to EN ISO 15883-5 in teflon tubes)

Vicker M. et al., Removal of biofilms from endoscopes: Evaluation of detergent efficiency, Am J Infect Control. 2004 May 32(3) (mono culture biofilm (E.coli) in teflon + PVC tube)


Biofilm removal is investigated with artifical biofilms:

- generation of biofilms in 96-well plates - generation of biofilm according to EN ISO 15883-5 in teflon tubes - mono culture biofilm (E.coli) in teflon + PVC tube

These biofilms grow under optimal conditions:

high number of microorganisms, temperature, humidity, nutrients

these conditions are impossible in

correct reprocessed endoscopes!

Biofilms in endoscopes?


How could biofilms arise in endoscopes?

insufficient

reprocessing


• wipe with lint-free disposable cloth

=> lint can block channels

• repeatedly rinse all accessible channels with a CE-labelled cleaning solution => No “Fairy” washing-up liquid

• transport in a closed container to

the reprocessing room

(Pre-) Cleaning

How could Biofilms arise in endoscopes?



Insufficient disinfection

• Only use of high level disinfectants , e.g. peracetic acid or glutardialdehyde (eleminates all vegetative bacteria,

mycobacteria, fungi, viruses)

• Concentration, exposure time and temperature according to manufacturers recommendation

• Efficacy tests according to „the state of the art“ (EN standards according to EN 14885)



Rinsing with contaminated water

- Remaining disinfectants with bacterium-free water

- using sterile water according to the Guideline of ESGE/ESGENA (tap water is has not to be free of

microorganisms!)

- Optional: final rinse with 70-90% alcohol



Insufficient drying

- should be done mechanical or manual with compressed air


Study of compliance regarding reprocessing steps

45

Regarded performance of reprocessing steps: (figures in %, n=69) 1. Leakage test in clear water 77 2. Full disassembly of the endoscope 100 3. Brushing of all channels and accessories 43 4. Complete immerse in cleaning solution 99 5. Complete immerse of accessories in cleaning solution 99 6. Flushing of endoscope with cleaner 96 7. Flushing of endoscope with water 96 8. Flushing of endoscope with air 84 9. Complete automated high level disinfection 100 10.Rinsing with alcohol 86 11.Compressed air for drying 45 12.Wiping of external sufaces before hanging 90


How could biofilms arise in endoscopes?

Wrong storage

• Optimal drying within drying cabinet

• hanging storage

• Protected against contamination

• Regular cleaning & disinfection of contact surfaces

• Distance too long until next use (in case they are

not really dry): there are different requirements in each country

Hanging storage

Photos: Sylacon, Petra Labonte

Drying cabinet


United Kingdom

- Storage in drying cabinets

- Disinfection after 3h

The Netherlands

- Complete reprocessing after 4h, if storage not in drying

cabinets (drying insufficient)

France

Disinfection after 12h

Storage time of flexible endoscopes – Requirements in different countries


Sweden

- Reprocessing every morning

Australia

- max. storage time of 72h for gastroscopes/ colonoscopes

- max 12 h for duodenoscopes, enteroscopes, bronchoscopes

Germany

- intensive drying before storage, no defined storage time

Storage time of flexible endoscopes – Requirements in different countries



Damaged endoscopes

– wrinkles/crack in biopsy channel

– damage of bending cuff

– spalling in coating of fiberoptic light

damage of surface in endoscopy channel

wrinkles in bending cuff damage to the leading edge


Study - Biofilms in 13 endoscopes of an Australian clinic

Is biofilm accumulation on Endoskop tubing a contributor to the failure of cleaning and decontamination? Pajkos, Vickery, Cossart; J Hosp Infect (2004)

Biofilms in biopsy or air/water channel detected but all endoscopes were damaged (wrinkles or cracks)


Fault interpretation of different soiling types

• Results of IR-spectroscopy: Mixture of protein with glutardialdeyhyde, no biofilm

Source: M. Kamer


Conclusion

• Biofilms are natural source

• They are everywhere because it is the preferred

life form of microorganisms

• Microorganisms need optimal living conditions to form a biofilm (temperature, humidity, nutrient etc.)


Conclusion

• Biofilms in „intact“ endoscopes are not proofed so far

• No biofilms in endoscopes when reprocessed correctly

• Fault interpretation of other soilings

• Good cleaning is essential in order to remove biofilms

• „dirt is not disinfectable“


Thanks for your attention !!!


Principle of Quorum Sensing

high concentration of autoinduction molecules (blue) → synthesis of bacterial products (red)

Low concentration of autoinduction molecules (blue) → no reaction

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