Food and Water Borne Pathogens Text questions: Chap 12: Crit Think 2; Self-Quiz #s 8-10, 12, 13, 16 Roles of Micro

1. Food and Water Borne Pathogens Text questions: Chap 12: Crit Think 2; Self-Quiz #s 8-10, 12, 13, 16 Roles of Microbiologists in the Food Industry 1) Monitoring and controlling contamination 2) Developing control methodologies 3) Using microbes in food production Types of food-borne diseases Food borne intoxicationsFood/water borne infections Botulism E. coli (e.g., O157:H7) Perfringens Salmonellosis Staphylococcal Campylobacteriosis Mycotoxins Cholera rapid onsetslower onset Incidence (/100,000) in 2005 from CDC Food and Water Borne Pathogens

2. Food Intoxications: Perfringens Agent: Clostridium perfringens obligate anaerobe Reservoir: animal digestive systems endospores common Toxin: Enterotoxin -- heat-labile Institutional steam tables notorious bulk food Cook to at least 140OF Chill rapidly Symptoms within 8-14 hours pain, diarrhea no nausea and vomiting pass within 24 hour Food and Water Borne Pathogens

3. Staphylococcal Agent: Staphylococus aureus Reservoir: Humans and animals Toxin: enterotoxins 7 types identified (genes often on plasmids) heat-stable 50% inactivation at 100OC Foods: inadequately refrigerated -- custards and pastries -- poultry and egg salads -- creamy salad dressings -- etc symptoms onset 1-6 hours nausea, vomiting, diarrhea pass within a few hours What about the chicken & potato salads? It’s not the mayo! Dateline: Modesto CA, 1983 Cook prepared 3600 eggs for Easter hunt boiled, dyed, and left at room temperature for 3 days 300 children were afflicted CDC investigation revealed: cook had sores on his hands dyed eggs with vinegar, which softens & permeates shells Don’t leave cooked eggs unrefrigerated! Food and Water Borne Pathogens

4. Mycotoxins • Produceed by fungi • Ergot – Claviceps • Aflatoxins – Aspergillus flavus • -- heat stable • Foods typically affected • cereal grains, oilseeds, spices, tree nuts, fruits • Toxicity: LD50 = 0.5 - 10 mg/kg • -- endocrine effects • -- digestion • Acute: liver necrosis • Chronic: • -- suspected hepatic carcinogen • -- metabolites intercalate into DNA 1960 - UK 100,000 turkeys die “Turkey X disease” Contaminated peanut meal 1974 - NW India ~400 people affected (~110 died) Traced to infested corn -- unseasonable rains, -- poor storage -- poverty Estimated 2-6 mg/d consumed for weeks Food and Water Borne Pathogens

5. Food infections: E. coli Transmission: food and water “Traveler’ diarrhea” “Montezuma’s revenge” “delhi belly” “Don’t drink the water” Reservoir: warm-blooded animals including humans Plasmid-borne enterotoxins Hemolytic toxins can lead to hemorrhagic colitis, kidney failure, etc. Symptoms diarrhea; cramping, bloody stools Surface antigens -- ‘O’ (lipopolysaccharide) & ‘H’ (flagellar) (173) (56) E. coli O157:H7 extremely virulent 5 cells enough Dateline: Jan 1993, Pacific Northwest. Jack-the-the-box restaurants serve O157:H7 tainted hamburgers; over 500 people become ill, 3 die; $30 M awarded in lawsuits Dateline: June 11-12, 1998, Marietta, GA 30 children swimming in a kiddie pool contract O157:H7. Conditions were listed from fair to critical. Food and Water Borne Pathogens

6. Salmonellosis Agent:Salmonella enteritidis Reservoir: animal digestive systems Foods: inadequately cooked poultry & eggs meats & dairy products shellfood (raw!) Symptoms within 1-2 days fever, nausea, diarrhea, vomiting, headache convalescence in ~ a week Typhoid fever Salmonella typhi What about those baby turtles? illegal to sell since 1975 Food and Water Borne Pathogens

7. Campylobacteriosis Agent: Campylobacter jejuni microaerophile reservoir: poultry Symptoms 2-5 day incubation diarrhea (bloody stool) abdominal cramping high fever (>104O) Transmission: Foods (usually) & water undercooked meats contaminated milks and water (farm runoff) Very common 104 cases per year possibly 2 x 106 go unreported estimated 500 deaths/year Food and Water Borne Pathogens

8. 1O Water Borne: Cholera Agent: Vibrio cholorae reservoir: humans Transmission: usually water Symptoms toxin effects large intestine SEVERE diarrhea untreated, mortality rates > 70% Worldwide pandemic Oral rehydration therapy Oral Rehydration Therapy Oral rehydration solution can be approximated by adding to 1 L of water 8 tsp of table sugar 1/2 tsp of salt 1/2 tsp of sodium bicarbonate (baking soda) 1/3 tsp of potassium chloride Food and Water Borne Pathogens

9. Probiotics: Consuming bacteria to improve intestinal flora Estimated > 500 types of bacteria present How might digestive tract bacteria benefit health? 1) improve intestinal tract function -- food digestion; lactose intolerance; reduce flatulence -- replace microbes lost during antimicrobial therapy -- e.g., lactinex -- replace harmful denizens 2) improve immune function -- reduce allergies “Hygiene hypothesis” -- modulate immune response -- protective immune responses 3) Reduces cancer risk?? (colon, bladder) -- mutagen binding & detoxification -- immune modulation Probiotic bacteria Lactobacillus, Bifidobacterium yogurt; dietary supplements Does it work? Maybe, sometimes… Normal microflora is relatively stable In children not breast fed Food and Water Borne Pathogens