milk borne disease 2 (eng)-2012

7/31/2019 Milk Borne Disease 2 (Eng)-2012

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MILK BORNE DISEASES


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Review


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Milk and DairyProducts


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Milk and Dairy Products

Raw Milk

Pathogens associated:

E. coli O157:H7 Salmonella typhimurium

Campylobacter jejuni Listeria monocytogenes

Staphylococcus aureus (mastitis)


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Why is raw milk consumed?

Easy access to raw but less access topasteurized

Drinking raw milk has been practiced

over time A notion that raw milk is better thanpasteurized


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Spoilage bacteria

Bacteria that limits the shelf life:

Total Psychrotrophic counts in raw milk

Needs to be


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Post-Pasteurization Contamination

Pseudomonas spp.

Bacillus cereus

Lactic acid bacteria


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Standards for Pasteurized Milk and Milk Products

Temperature cooled to 10o

C or less Bacterial counts < 20, 000 cfu/ml

Coliform counts < 10 cfu/ml

Antibiotic presence: negative

Phosphatase < 1 g


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Dried Milk

Low water activity prevents growth of pathogensand spoilage bacteria

Largest foodborne illness outbreak associated withStaphylococcus aureus was in Japan 2000, 13,000cases

The incident was the result of post-pasteurizationcontamination with Staph aureus toxin that is notdestroyed by drying


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Fermented milk products : produced by bacterial orfungal transformation for carbohydrate (lactose-lactate)

Fermented products are preserved by acidsand alcohol produced by the beneficialbacteria that inhibits spoilage bacteria and

pathogens


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Cheese

Product made from the curd of the milk of cowsor other animals

Casein coagulated by rennin and acid

Subsequent heating, salting, pressing, aging


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SalmonellaSalmonella : two distinct species : Salmonella enterica and Salmonella bongori .

S. enterica subspecies I contains 1367 serotypes, is mainlyisolated from warm-blooded animals (mammals and birds),and accounts for _99% of all clinical isolates.

The remaining subspecies (II, IIIa, IIIb, IV, VI, and VII) aremainly isolated from coldblooded animals and account for

_1% of clinical isolates.


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Salmonella continues to be a majorcause of food poisoning throughoutthe world. Salmonellosis sickens asmany as 3.84 million Americansand costs billions of dollars in lostproductivity and medical costs peryear


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DISEASE

the most prevalent recognized communicable diseasescaused by bacteria in the United States today.transmitted from animals to humans through food andoccasionally from person to person through the fecal-

oral routeSalmonellosis in the human occurs in a variety of forms,presenting a broad clinical spectrum.


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A. Gastroenteritis

The incubation period 6 72 hours. There isabdominal pain and loose, watery diarrhea,occasionally with mucous or blood. Nausea andvomiting are frequentFever of 38 39C is common, and there may be aninitial chill. Abdominal pain is frequent and may causemild to severe discomfort. In uncomplicated cases,the acute stage usually resolves within 48 hours.However, illness is occasionally more protracted, with

persistent diarrhea and low-grade fever for 10 14days. In severe cases, dehydration may lead tohypotension, cramps, oliguria, and uremia. Symptomsare likely to be more severe in infants and older adults(>60 years


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Bacteremia

Salmonella enterica serotypes :prolonged fever and a positive bloodculture, Gastroenteritis + / - ,sweats, anorexia, and weight loss.The characteristic symptoms of

typhoid fever, which include rosespots, leukopenia, and sustainedfever, are absent.


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Enteric or Paratyphoid Fever S. cholerae-suis and S. enterica serotypesparatyphi A and paratyphi B. have symprom liketyphoid Fever : prolonged fever, rose spots,splenomegaly, leukopenia, gastrointestinalsymptoms, and positive blood and stool cultureMilder than S. typhi infections, but differentiationon clinical grounds is not possible in the individualcase.


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Local Infections Meningeal localization of infections is common innewborns and infantsPolyarthritis


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Escherichia coli In 1945, Bray and other researchersdemonstrated that E.coli involvement ingastroenteritis. E. coli involve in gastroenteritiscategorized into five major groups according totheir virulence mechanisms:enteropathogenic (EPEC), enterotoxigenic(ETEC), enteroinvasive (EIEC),enterohemorrhagic (EHEC), andenteroaggregative (EAEC). Other strains, namelydiffusely adherent E. Coli (DAEC), are less wellestablished as pathogens


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Enterotoxigenic E. coli ETEC produces a watery diarrhea, cramps and alow-grade or no fever,has a lot in common with cholera; both result

from ingestion of large inocula of bacteria, whichthen colonize the small intestine and producetoxins that cause net secretion into intestinallumen.


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Enteroinvasive E. coli EIEC infection produces a disease similar to thatcaused by Shigella .The diarrhea is initially acute and watery,accompanied by fever and abdominal cramps,and then may progress to a colonic phase withbloody and mucoid stools.EIEC infection has been traced to contaminatedfoods and water also spread from person toperson.


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Enterohemorrhagic E. coli The EHEC group causes severe bloody diarrhea(hemorrhagic colitis), hemolytic uremic syndrome(HUS), and thrombotic thrombocytopenic purpurasometimes the infection causes only diarrhea or

no symptoms.In the United States, hemolytic uremic syndromeis the principal cause of acute kidney failure inchildren.


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Enteroaggregative E. coli

Acute, persistent, and bloody diarrhea disease inchildren and nosocomial and communityoutbreaks worldwide

EAEC as the causative agent of diarrhealdisease in HIV-infected adults in the developedworld


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Enterobacter sakazakii

Fam. Enterobacteriaceae, genus Enterobacter .In the past as a yellow-pigmented Enterobacter cloacae .In 1980 E. sakazakii was designated as aunique species, based on differences from E.cloacae in DNA relatedness, pigmentproduction, and biochemical reactions.A mortality rate of 40 80%, in many casesneonates die within days of birth. In survivingpatients severe neurological sequelae such ashydrocephalus, quadraplegia,Contaminated dry infant formulas as the sourceof E. sakazakii


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E. sakazakii has been isolated from insects collectedat a dairy farm. Could not isolate from surface water,soil, mud, rotting wood, grain, bird faeces, rodents,domestic animals, cattle, or raw cow s milk.E. sakazakii strains have been isolated from clinicalsources, blood, or cerebrospinal fluid.


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DISEASES Enterobacter spp. ( E. Sakazakii) are frequentlythe cause of nosocomial diseases, E. sakazakii is usually a rare opportunistic pathogen causingsevere meningitis in neonates and prematurebabies, the most common gastrointestinalemergency in newborns.In a few cases the symptoms were limited to

septicemia only.


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E. sakazakii overcomes the gastrointestinal barrier,gaining access to the blood stream and finally to the

cerebrospinal fluid. Severe symptoms of the diseasesuch as ventriculitis, brain abscess, infarction, and cystformationThe mortality rate is usually high, E. sakazakii seems

to be more susceptible to commonly used antibacterialagents than other Enterobacteriaceae, and treatmentwith ampicillin/gentamicin is effective in most cases


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Risk comes from the list of pathogens possiblein the raw milk:

Enterotoxigenic Staphylococcus aureus Campylobacter jejuni Salmonella species E. coli (EHEC) (ETEC)

Listeria monocytogenes Mycobacterium tuberculosis Mycobacterium bovis Brucella species (abortus cattle) (melitensis- goats)Coxiella burnetii Yersinia enterocolitica

(Sheehan, 2005)


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Salmonella

Several forms

Symptoms include:Diarrhea, fever, abdominal cramps

May cause hospitalization

Death can occur if not treated

(CDC, 2008)


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E. Coli 0157:H7Symptoms include:Bloody diarrhea, severe abdominal cramps,

vomiting

Potentially fatal

Can cause hemolytic uremic syndrome(HUS)

Sensitive to heatKilled by cooking and proper pasteurization

(Vasavada, 1988) , (Karns et al., 2007)

Camp lobacter jej ni


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Campylobacter jejuni

Gram-negative, nonsporeforming bacteriumSymptoms include:

Mild enteritis or severe enterocolitis, nausea,abdominal cramps, bloody diarrhea

Sensitive to heat, oxygen, drying, and acidic pHKilled with normal pasteurization

(Vasavada, 1988)


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Listeria monocytogenes Gram-positive, nonsporeformingFound in:

Soil, manure, unpasteurized raw milk

Symptoms include:Meningitis, infectious abortion, perinatalsepticemia, encephalitisCan cause stillbirths or deaths of infants

Sensitive to heat / pasteurization

(Vasavada, 1988)


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StudiesPrevalence of Foodborne Pathogens in BulkTank Milk

Of dairy producers consuming raw milk:21 of 79 (26.6%) had 1 or more pathogenic bacteria inmilk

35 of 131 (26.7%) bulk tank samplesFound:

Campylobacter jejuni (9.2%)Shiga-toxin producing E. coli (3.8%)

Listeria monocytogenes (4.6%)Salmonella spp. (6.1%)Yersinia enterocolitica (6.1%)

(Jayarao et al., 2001)


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StudiesPrevalance of Salmonellae, Listeria monocytogenes , and Fecal Coliforms in BulkTank Milk on US Dairies

861 samples collected, 21 statesColiforms detected in 95% of samplesFound:

Salmonella (2.6%)Listeria monocytogenes (6.5%)

(Kessel et al., 2003)


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Bulk Tank Sample

Tests used:TSA tests for bacterial growthBlood agar tests for bacterial growth

Violet Red Bile Glucose (VRBG) agar used fornumerating coliform organisms in dairy productsMacConkey (MAC) agar used for isolating anddifferentiating coliforms based on fermentation

Xylose Lysine Deoxycoagulate (XLD) agar usedfor isolating and differentiating gram-negative andenteric bacteria from the gut


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Who are affected the most?Children

Rely on us for guidance and protectionEducate children about the bad bugs

Immunocompromised

Elderly

Pregnant Women

(Bren, 2004)


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OutbreaksAccording to the USFDA:

Outbreaks differ depending on type of pathogen,geographic location, and species of milk

Not all outbreaks are recognized

Not all get reported to the Centers for DiseaseControl (CDC)

(Sheehan, 2005)


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OutbreaksE. coli O157:H7

September 28, 2006

Washington dairy causes illness in 2 unrelatedchildren8 year-old boy5 year-old girl

Hospitalized

(Sheehan, 2005)


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OutbreaksSalmonella typhimurium

2002-2003

62 people infected40 - IL, IN, OH, TN

After investigation:Raw milk only product associated with illnesses

(Sheehan, 2005)


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OutbreaksSalmonella dublin

1971 1975CA infections increased 5 times

44 of 113 from raw milk exposure35 from 1 single dairy

89 of 113 hospitalized

22 died

(Sheehan, 2005)


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OutbreaksListeria monocytogenes

Cause of 2500 illnesses each year

~500 die

Only 0.02% of foodborne illnesses, but 27.6%of deaths from foodborne infection

(Sheehan, 2005)

Disease Outbreaks From Milk


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Disease Outbreaks From MilkProducts


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milk borne disease 2 (eng)-2012

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