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Foodborne pathogens Gabriella Kiskó, PhD Corvinus University of Budapest, Department of Microbiology and Biotechnology ERASMUS IP Maribor, 2011 Food safety issues such as E. coli O157, Listeria are never far from the newspaper headlines, becoming grounds for increasing public concern ERASMUS IP Maribor, 2011 Foodborne illness term used to describe the adverse health effects associated with the consumption of biological, (including parasites) chemical and physical hazards in food. More than 200 diseases are spread through food ERASMUS IP Maribor, 2011 Foodborne hazards Microbiological Parasitic Bacterial Viral Prion Genes (resistant) Chemical Drug residues Antibiotics, Pesticides, Disinfectants Environmental contaminants (dioxins, PCBs, heavy metals, radioactive isotopes, Physical Foreign bodies (needles, fragments of glass, pieces of plastic or metal, etc.) ERASMUS IP Maribor, 2011 Food borne hazards microbiological chemical physical ERASMUS IP Maribor, 2011 Don’t count on these to test for food safety! Sight Smell Taste ERASMUS IP Maribor, 2011 Estimated Annual Incidence of Foodborne Illness with Other Illnesses in U.S. Illness Bronchitis Flu Common cold Foodborne disease No. of Cases 12 million 50 million 62 million 76 million CDC estimates (2000) ERASMUS IP Maribor, 2011 The infections we see are only the tip of the iceberg…..or the eyes of the hippo! ERASMUS IP Maribor, 2011 Foodborne Diseases Pyramid Reported to health department Culture-confirmed case Lab tests for organism Specimen obtained Person seeks care Person becomes ill Population exposures ERASMUS IP Maribor, 2011 Why does it take so long? ERASMUS IP Maribor, 2011 Food borne outbreaks 250 200 150 Unknown Suspected Confirmed 100 50 0 1999 2000 2001 2002 2003 2004 ERASMUS IP Maribor, 2011 Are you at Risk? YES, you are! Foodborne disease each year Total 76 million cases (estimated), 325,000 hospitalizations, and 5000 deaths from acute foodborne infections (Mead et al, 1999) ↔ illnesses, 60,000 hospitalizations, 1,800 deaths Known pathogens 14 million Most cases without defined agent 1 in four Americans gets a foodborne illness each year 1 in 1000 Americans is hospitalized each year At least $56.5 billion annually in medical and associated costs due to foodborne illness 1400 foodborne outbreaks reported annually In 2005 1.8 million people died from diarrhoeal diseases. A great proportion of these cases can be attributed to contamination of food and drinking water 3.5 million cases, 33,000 hospitalizations and 1,600 deaths are caused by 5 pathogens Salmonella, E. coli O157:H7 and other STEC, Campylobacter, Listeria monocytogenes, Toxoplasmosa ERASMUS IP Maribor, 2011 Additional impact of foodborne illness - Cost U.S. - $6.9 billion/yr. South Korea - $16-$28 million/yr. Australia - $1.7 billion in 1999 Economic losses from foodborne diseases estimated annualy $ billion Pathogen Emerging foodborne diseaeses estimated annually Cases No. of No. of Illnesses Deaths Campylobacter spp. 1,963,141 10,539 99 1.2 Salmonella non-typhoidal 1,341,873 15,608 553 2.4 E. coli O157:H7 62,458 1,843 52 0.7 E. coli non-O157-STEC 31,229 921 26 0.3 L. monocytogenes 2,493 2,298 499 2.3 Total 3,401,194 31,209 1,229 6.9 ERASMUS IP Maribor, 2011 Cost of Foodborne Illness in the Food Service Industry ERASMUS IP Maribor, 2011 Categories of foodborne illnesses Food infection Result from the growth of microorganisms in the body, which are carried by food or water into the host e.g. Salmonella sp., Campylobacter sp., Listeria monocytogenes , Yersinia enterocolitica, Hepatitis A, norovirus, rotavirus, Trichinella spiralis, Giaria duodenalis, Toxoplasma gondii, Cryptosporidium parvum Food intoxication (poisoning) Results from the action of microbial toxins, that contaminat food, toxins are ingested e.g. Staphylococcus aureus, Clostridium perfigens, Clostridium botulinum Infection-mediated intoxication (toxicoinfection) Results from the consumption of food containing harmful bacteria, which in the intestinal tract produce toxins that cause illness e.g. Shigella spp., Shiga toxin-producing Escherichia coli ERASMUS IP Maribor, 2011 Foodborne infections vs intoxication Infections Bacterial / Viral / parasite Invade and or multiply in lining of intestine Incubation period - longer, hours to days Intoxications toxins ( natural / preformed bacterial / chemical) No invasion or multiplication Incubation period – shorter, minutes to hours Symptoms – vomitting , nausea, diarrhea , diplopia, weakness, resp. failure , numbness, sensory/motor dysfunction Not spreads from person to person Spreads from person to person Factors-inadequate cooking , improper Factors-inadequate cooking, cross handling temperatures contamination , poor personal hygiene, bare hand contact Symptoms – diarrhoea , nausea, vomitting , abdominal cramps, fever ERASMUS IP Maribor, 2011 Is the food safe for everyone at the table? Some people have a greater risk for foodborne illnesses. A food you safely eat might make others sick. ERASMUS IP Maribor, 2011 Highly Susceptible Populations Young e.g. Salmonella, Shigella, E. coli O157:H7 Old e.g. Salmonella, Shigella, E. coli O157:H7 Pregnant e.g. Listeria, Toxoplasma, Hepatits E Immuno-compromised e.g. Salmonella, Listeria ERASMUS IP Maribor, 2011 Major Identified Foodborne Pathogens, United States – circa 1920 Bacterial Brucella Clostridium botulinum Salmonella typhi Salmonella non-typhoidal Streptococcus Parasitic Trichinella spiralis Taenia saginata Taenia solinum ERASMUS IP Maribor, 2011 Major identified foodborne pathogens, United States – circa 2002 Bacterial: Bacillus cereus Brucella Campylobacter* Clostridium botulinum Clostridium perfringens E. coli O157:H7* E. coli, non-O157 STEC* E. coli, other diarrheagenic* Listeria monocytogenes* Salmonella Typhi Salmonella non-typhoidal Shigella Staphylococcus Streptococcus Vibrio cholerae, toxigenic* Bacterial (continued) Vibrio vulnificus* Vibrio, other* Yersinia enterocolitica* Parasitic Cryptosporidium* Cyclospora* Giardia* Taenia Toxoplasma* Trichinella Prions Viral Norwalk-like viruses* Rotavirus* Astrovirus* ERASMUS IP Hepatitis A * Recognized as foodborne in last 30 years Maribor, 2011 Estimated Number of Cases of Foodborne Illness Annually in US Cases from Foodborne Transmission Norwalk-like viruses Campylobacter spp. Salmonella (nontyphoid) Clostridium perfringens Giardia lamblia Staphylococcus food poisoning Toxoplasma gondii Shigella spp. Yersinia enterocolitica Escherichia coli O157:H7 Enterotoxigenic E. coli Streptococcus Astrovirus Rotavirus Shiga-toxin producing E. coli (nonO157) Bacillus cereus E. coli (other diarrheic) Cyclospora cayetanensis Vibrio parahaemolyticus Hepatitis A Listeria monocytogenes Brucella sp. Botulism Trichinella spiralis Vibrio cholerae Vibrio vulnificus 9, 200,000 1,963,000 1,332,000 248,500 200,000 185,000 112,500 90,000 86,800 62,500 55,600 51,000 39,000 39,000 31,000 27,400 23,900 14,600 5,000 4,200 2,500 780 60 50 50 50 ERASMUS IP Maribor, 2011 P. S. Mead et al. Emerging Infect. Dis. 5:607 (1999) Trends and Sources of Zoonoses, Zoonotic Agents, Antimicrobial Resistance and Foodborne Outbreaks in the European Union in 2006 Incidence = case/100˙000 inhabitant/year Source: The Community Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents, Antimicrobial Resistance and Foodborne Outbreaks in the European Union in 2006, The EFSA Journal (2007) 130 ERASMUS IP Maribor, 2011 Foodborne outbreaks in 2008 - EU Causes of illness in outbreaks, 2003–2008 - USA ERASMUS IP Maribor, 2011 ERASMUS IP Maribor, 2011 Main Reasons for Foodborne deseases Food prepared too far in advance and stored at room temperature. Inproper cooling Cross-contamination. Storing hot food below 63ºC Inadequate reheating Undercooking Low level of hygiene Infected food handlers Use of leftovers ERASMUS IP Maribor, 2011 Hours Minutes bacteria/ml Number of 0 00 1 0 0 0 0 0 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 10 20 30 40 50 00 10 20 30 40 50 00 10 20 30 40 50 00 10 20 2 4 8 16 32 64 128 256 512 1024 2048 4096 8192 16834 32768 65536 131072 262174 524288 1048578 ERASMUS IP Maribor, 2011 Transmission of foodborne pathogens SOME GENERAL PATHWAYS OF CONTAMINATION UNWASHED HANDS CROSS-CONTAMINATION. FOOD HANDLERS POOR HYGIENE FOOD CONTACT SURFACES WATER, IRRIGATION WATER VERMIN PACKAGING SOIL INGREDIENTS AIR SLAUGHTER STORAGE AT INCORRECT TEMPERATURE INSUFFICIENT COOKING ERASMUS IP Maribor, 2011 Fecal–oral routes of transmission of foodborne intestinal pathogens ERASMUS IP Maribor, 2011 Foodborne Enteric Microbial Contamination Transmission: Fecal contamination prior to harvest or collection Animal foods contaminated naturally by infection (e.g., salmonella) Surface contamination (e.g., feces on fur, feathers, hooves, etc.) Shellfish and other fish contaminated in their environment Fecal (sewage) contamination of water → pathogen uptake by filter-feeding on waterborne particles Fish and shellfish naturally colonized by aquatic pathogens Vibrio cholerae in copepods, fish and shellfish Produce contaminated by irrigation with sewage or contaminated water or fertilization with nightsoil (feces) or animal feces. Soil contaminating plants and animals with bacteria, fungi, etc. ERASMUS IP Maribor, 2011 Foodborne Enteric Microbial Contamination Transmission: Foods Implicated in Foodborne Illness: Meats Red Meats High contamination in comminuted and processed meats (e.g., ground beef, sausage) – High surface area, increased contact with processing equipment; increased handling; variety of sources from the animal (organs, trimmings, etc.). Ex., E. coli O157:H7 outbreaks due to undercooked hamburger Poultry High contamination levels in cut-up poultry Increased handling, processing and contact with common equipment Salmonella and campylobacters are prevalent in some poultry flocks – can contaminate an entire processing plant via equipment and process baths (e.g., chiller tank) Eggs Endogenous contamination by Salmonella enteritidis in some flocks – Time and temperature abuse leads to proliferation in the egg Raw/undercooked eggs a source of exposure and infection ERASMUS IP Maribor, 2011 Foodborne Enteric Microbial Contamination Transmission: Foods Implicated in Foodborne Illness: Fish Contamination depends on type of seafood,quality of harvest water and amount of processing, handling and storage. Bivalve mollusks (oysters, clams, mussels, etc.); filter feeders Accumulate enteric pathogens from fecally contaminated waters Acquire high levels of vibrios from their environmental waters Crustaceans (e.g., crabs) Acquire some pathogens by feeding on mollusks Acquire high levels of vibrios from their water environment Vibrio levels can increase during handling, processing and storage, especially if temperatures are too high. Fin fish Outer surface and epithelial lining (e.g., gut) contamination by enteric microbes in fecally contaminated waters; Contamination during processing (e.g., filleting). Endogenous contamination: ERASMUS IP Ex:: Diphyllobothrium latum; fish tapeworm; anemia; undercooking Maribor, 2011 Foodborne Enteric Microbial Contamination Transmission: Other Foods Implicated in Foodborne Illness Produce (fruits and vegetables) fecal contamination in irrigation water and other fecal sources (animal droppings, birds, etc.) inadequate or unsanitary picking, washing or processing. Dairy Products In developed countries milk and related dairy products are usually made from pasteurized milk. Raw milk and products (e.g., cheeses) made from unpasteurized milk are high risk of bacteria contamination – salmonella, campylobacter, brucella, yersinia, listeria,). Unpasteurized fruit juices and other beverages fecal contamination from animal and human sources Deli, "Fast" and Restaurant Foods salads, sandwiches, other fast, deli or restaurant foods become fecally contaminated during preparation and handling Cereal and Grain: inadequate storage of cooked rice/grain ERASMUS IP Maribor, 2011 Some virulence factors of pathogens The ability to: 1. Adherence (examples) eg. fimbriae - Escherichia coli 2. Avoid phagocytosis eg. capsules - prevent phagocytosis and help with attachment (adherence) eg. Streptococcus pneumoniae 3. Penetrate get into host and spread eg. coagulase Staphylococcus aureus - coagulate blood 4. Produce Enzymes spread, prevent host defenses and cause damage at or near site of infection – eg. collagense Clostridium perfringens 5. Produce Toxins cause damage at distant site ERASMUS IP Maribor, 2011 Toxins Provide properties to spread and cause damage to the host. Endotoxins from inside the cell. Released upon cell lysis. Exotoxins are secreted out of the cell during cell life. ERASMUS IP Maribor, 2011 Exotoxin Exotoxin Source Metabolic product Chemistry Fever? Neutralized by antitoxin LD50 Mostly Gram + By-products of growing cell Protein Water soluble No Yes Small - Very potent 1 mg of Clostridium botulinum toxin can kill 1 million guinea pigs ERASMUS IP Maribor, 2011 Exotoxins - three types 1. Cytotoxins kill cells Streptococcus pyogenes toxin 2. Neurotoxins interfere with normal nerve impulses Clostridium botulinum – botulin toxin prevents impulse from nerve cell to muscle cell results in muscle paralysis 3. Enterotoxins effect cells lining the G.I. Tract Vibrio cholerae cholera toxin ERASMUS IP Maribor, 2011 Exotoxins Exotoxin • Corynebacterium diphtheriae • Streptococcus pyogenes • Clostridium botulinum • C. tetani • Vibrio cholerae • Staphylococcus aureus Inhibits protein synthesis Membrane-disrupting Neurotoxin - paralysis Botox Neurotoxin - paralysis Enterotoxin - cause severe diarrhea Enterotoxin ERASMUS IP Maribor, 2011 Endotoxin ERASMUS IP Maribor, 2011 Endotoxins Source Gram– Metabolic product Present in LPS of outer membrane Chemistry Lipid Fever? Yes Neutralized by antitoxin No LD50 Relatively large ERASMUS IP Maribor, 2011 Type of bacterial pathogens Obligate pathogens: organisms that will always cause infection and disease whenever and wherever they are encountered e.g. Yersinia pestis – plague, Bacillus anthracis - antrax, Salmonella Typhimurium - salmonellosis Opportunistic pathogens: organisms that can only cause disease in an immuno-suppressed person or under unusual circumstances e.g. skin infections e.g. Staphylococcus aureus, Listeria monocytogenes ERASMUS IP Maribor, 2011 Gram-negative pathogenic bacteria ERASMUS IP Maribor, 2011 Campylobacter jejuni Characteristics: no growth at <30 °C, microaerophilic, grow with 10% CO2 / 5% O2 . sensitive to drying, heat, acidic conditions, and disinfectants Infection, campylobacteriosis The most commonly identified bacterial cause of diarrheal illness in the world Infective dose: 500 -10,000 bacteria /ml Incubation: 2-5 days Symptoms: watery diarrhea, vomiting, headache, fever, muscle pain, Guillian-Barre Syndrome, death (rare) Children are at an increased risk of infection Foods: poultry, dairy products, water Reservoir: wild/ domestic animals, most commonly cattle and poultry Transmisson: intestinal tracts of wild/ domestic animals, fecal contamination of skin during grow out and processing, fecal-oral, person-to-person Prevention: Proper pasteuriation and cooking can prevent the infection ERASMUS IP Maribor, 2011 Campylobacteriosis cases ERASMUS IP Maribor, 2011 Some Important Campylobacter Outbreaks in the World Year Country Food No. of cases 2000 U.K & Wales Raw milk 333 2001-2002 Australia Chicken 601 2005 Denmark Chicken salad 4 2005 Scotland Chicken pate 82 2005-2006 U.S.A Water 32 2007 U.S.A Cheese (from unpasteurized milk) 67 2007 Denmark Water 16 ERASMUS IP Maribor, 2011 Salmonella Enteriditis Named named after Daniel Elmer Salmon, an American veterinary scientist Characteristics: enteric bacterium; all strains are pathogenic; Colonization of intestinal epithelium Infection Symptoms: Two diseases type: – Enterocolitis - salmonellosis (most commonly by S. enterica serovar Typhimurium): disease onset within 8 - 48 hrs; headaches, chills, vomiting, diarrhea and fever (23 days); death (rare) - YOPI continuous shading of organism for months/years; treatment - none – Typhoid fever (Salmonella enterica serovar Typhi ): Septicemia leading to high fever that can last for several weeks; mortality is 15% if untreated; treatment - antibioticsERASMUS IP Maribor, 2011 Salmonella Enteriditis Infective dose: 100 – 1.000.000 bacteria/ml Reservoir: domestic and wild animals, it colonize ovarian tissue of poultry, Foods: poultry, meat, eggs and egg products, sliced melons, vegetables, chocolate Transmission: water, soil, insects, animals, and humans, internal contents of eggs, contact with infected animals, or by fecal-oral person to person contact Temporary carrier state can continue for months, especially in infants. ERASMUS IP Maribor, 2011 Salmonella Enteriditis Children, elderly, immunocomcpormised - increased risk of infection Amphibians and reptiles are colonized Turtles, salamanders, and lizards ~74,000 Salmonella infections annually in the US Prevention: proper cooking (70 °C for 10 min), improved sanitation, adequate personal hygiene, monitor for carrier state among food handlers and exclusion of infected individuals as food-handlers and health care providers, restriction of sale of pet turtles and reptiles, proper sewage treatment No under age of 5 ERASMUS IP Maribor, 2011 Some Important Salmonella Outbreaks in the World Year Country Food Serotype/Phage type No. of cases No. of deaths 1991 Germany Orange cream S. Enteritidis PT4 109 4 1991 Germany Puding (egg) S. Enteritidis 87 10 1994 U.S.A Ice cream S. Enteritidis 224000 - 2003 U.S.A Chicken S. Typhimurium 38 - 2005 Spain Processed chicken S. Hadar 2138 1 2006 Norway Salami S. Kedougou 54 1 2008 Ireland&U.K Beef, chicken S. Agona 119 - ERASMUS IP Maribor, 2011 Escherichia coli O157:H7 Characteristics: produce Shiga-like toxins (verotoxin), - colonize small intestine , verotoxin production Infection based intoxication Incubation: 2-8 days Infective dose: 10 -100 bacteria/ml Symptoms: dehydration, bloody diarrhea, nausea, vomiting, kidney failure – HUS, death (<5% - 50%) Primary cause of HUS in children in the US Reservoir: cattle and deer (humans - reservoir for person-to-person transmission) ERASMUS IP Maribor, 2011 Hemolytic Uremic Syndrome (HUS) HUS - destruction of red blood vessels, impairment of renal function Most HUS in the United States results from E. coli O157:H7 infections Children and the elderly are at the greatest risk for progressing to HUS Usually need for dialysis and other invasive treatments Long-term complications in 15% of HUS cases Renal impairment, hypertension, stroke ERASMUS IP Maribor, 2011 Transmission of E.coli O157 Transmission: • fecal-oral route, • direct or indirect contact with cattle; • manure contaminate food, • contaminated water, • polluted irrigation water, • swimming in, inadequately chlorinated pools and outdoor water sources ERASMUS IP Maribor, 2011 E. coli O157:H7 transmission model – 2003 Sheep, Caribou, other ungulates? Cow Meat Cow Contact Milk Water Human Human Water Manure Deer Fruits and vegetables ERASMUS IP Maribor, 2011 Escherichia coli O157:H7 Foods: ground beef, yogurt, and lettuce, contaminated fruits and vegetables, unpasteurized milk and juice Prevention: Hygiene and proper cooking, improved sanitation, adequate personal hygiene and avoiding consumption of undercooked ground beef and unpasteurized dairy and fruit juice products, proper food handling techniques, consumption of potable water, avoiding farm animal contact ERASMUS IP Maribor, 2011 E. coli O157 Visiting Farms „Zoo” Camps ERASMUS IP Maribor, 2011 Some important E. coli O157:H7 Outbreaks in the World Country Year No of cases(age) Complications Infection source Japan 1996 >10000 (students) 12 deaths Alfalfa U.S.A 1999 321 - Beef Canada 2000 27 5 deaths Water Sweden 2002 39 - Fermented sausage U.S.A 2002 34 5 HUS Ground beef Netherlands 2005 32 - Steak tartare U.S.A 2006 376 3 deaths Fresh spinach ERASMUS IP Maribor, 2011 Shigella dysenteria Genus is named after Kiyoshi Shiga, Shigellosis or bacillary dysentery Incubation: 1 to 7 days Infective dose: 10-100 bacteria/ml Symptoms: diarrhea, abdominal pain, fever, blood in feces (ulcers on the intestinal wall) bloody , nausea, dehydration, prostration and vomiting shiga toxin (verotoxin) - cytotoxin, causes severe diarrhea, massive tissue inflammation and destruction (blood and pus), HUS, death (rare, but high in developing countries) Foods: salads and seafood Reservoir: infected humans and higher primates Transmission: 4F, y ingestion of contaminated food or water or by fecal-oral person-to-person contact. Secondary household cases are common Children are at an increased risk of infection Prevention: improved hygiene and waste-handling practice and personal hygiene ERASMUS IP Maribor, 2011 Yersinia enterocolitica Characteristics: capable of growth at 2 °C Infection Incubation: 4-7 days Infective dose: 108-109 bacteria/ml Symptoms: severe abdominal pain, diarrhea, fever, vomiting, arthritis in adults, pseudoappendicitis, death (rare), sporadic Reservoir: major reservoir pigs, others: rodents, rabbits, horses, sheep, cattle , dogs , cat Foods: Contaminated raw pork or beef, drinking water, milk products, tofu Yersiniasis is more common in Northern Europe, Scandinavia, and Japan Prevention: Avoid to contamination of porcine wastes and fecal contamination ERASMUS IP Maribor, 2011 Gram-positive pathogenic bacteria ERASMUS IP Maribor, 2011 Staphylococcus aureus Characteristics: coccoid, fakultative anaerob meaning the "golden grape-cluster berry high NaCl tolerance (7-10 %, some strains at 20 %) aw min 0,83-0,99 ! enterotoxin production min - 0,86 aw ↓ capable of growth at low aw Heat stable enterotoxin, heat may kill bacateria but not eliminate toxin D100=1-3 hours, D120=10-40 minutes Toxin production, if S. aureus > 104/g Coagulase-positiv strains are important ERASMUS IP Maribor, 2011 Staphylococcus aureus Range of illnesses: eg. from impetigo, furuncles, scalded skinsyndrom, to eg. pneumonia, meningitis, endocarditis, sepsis Bacterial intoxication Symptoms: vomiting, diarrhea, prostration, abdominal cramps, death (rare) Incubation: 3- 8 hours Infective dose: 105-106 bacteria/ml Reservoir: human, animals Food: Meat and meat products, milk and dairy products, custard or cream-filled pastries, egg foods, cheese, prawns and salads containing potato, pasta Source: skin, hair, nose, persons with skin injuries or surgical wounds or with piercings and fresh tattoos, pus, soil, dust, air Transmission: foods by infected food-handlers Prevention: proper cooking and chilling, adequate personal hygiene, keep ingradients under 7 °C to avoid toxin production, exclusion of skin infected individuals as food-handlers ERASMUS IP Maribor, 2011 Listeria monocytogenes Characteristic: named for Joseph Liser, capable of growth at refrigeration temperatures (! 0,5 °C-45 °C), salt tolerant (at pH 6 16 % NaCl) Incubation: 3-70 days Infective dose: 103?, YOPI Symptoms: 3 type of deseases: ♦ Adult listeriosis: fever, muscle/head aches, nausea or diarrhea,meningitis, encephalitis, meningoencephalitis, bacteremia, if nervous system is infected, stiff neck, confusion, loss of balance, or convulsions, death ♦ Listeriosis in pregnancy/neonatan listeriosis: acquired transplacentally or during or after delivery, listeriosis of a newborn, neonatal sepsis/meningitis, mothers flulike, stillbirths, spontaneous abortion, death ♦ Listeria gastroenteritis - Febrile gastroenteritis : in normal hosts, fever, diarrhea, vomitting, self-limited, ingestion high numbers of organisms, no death High mortality (10-30 %, or even higher in risk groups) Carrier state: among healthy adults 1%-21% ERASMUS IP Maribor, 2011 Listeria monocytogenes Foods: unpasteurized milk and fruit juices, soft cheese, raw meat, ice cream, ready-to-eat, lunchmeats, vegetables Sources: soil, water, damp environments, domestic/ wild animals (esp. poultry) Reservoir: silage, infected animals (cattle, poultry, sheep), humans; environmental - soil, forage, water,mud Transmission: by ingestion of contaminated food Prevention: wash uncooked vegetables thoroughly, consume refrigerated, perishable items as soon as possible or freeze ERASMUS IP Maribor, 2011 Listeria monocytogenes Prevention Some special recommendations for pregnant woman Do not eat hot dogs, deli meats, or luncheon meats unless they are reheated until steaming hot Do not eat soft cheeses unless they have labels that clearly state they are made from pasteurized milk Do not drink unpasteurized (raw) milk and do not eat foods that contain unpasteurized milk Do not eat refrigerated pâtés or meat spreads. Do not eat refrigerated smoked seafood unless it is an ingredient in a cooked dish, such as a casserole.ERASMUS IP Maribor, 2011 Listeriosis outbreaks Death/cases/letality Nova Scotia, Canada 1981 Massachusetts, 1983 17 / 41 / 41 14 / 32 / 43 Cole slaw mix Pasterurized milk Switzerland, 1983-1987 31 / 122 / 25 Cheese Los Angeles, CA 1985 48 / 142 / 34 Jalisco soft cheese Philadelphia, PA 1986-1987 United Kingdom, 1988-1989 16 / 36 / 44 94 / 355 / 26 Icecream Paté Illinois, 1994 USA, 1998-1999 North Carolina, 2000-2001 USA, 2000 USA, 2002 0 / 45 / 0 21 5 7 7 / / / / 101 12 / 29 / 63 / / 21 42 24 11 Food Chocolate milk Hot dog Mexican cheese Ready-to-eat turkey Sliced meat products ERASMUS IP Maribor, 2011 ERASMUS IP Maribor, 2011 Bacillus cereus Characteristic: spore-forming microorganism Intoxication Infective dose min. 105/g Symptoms: Diarrheal desease: watery diarrhea, abdominal cramps and pain; heat-sensitive enterotoxin produced during vegetative growth in small intestine Emetic desease: nausea and vomiting; heat-stable enterotoxin produced by growing cells in the food, death (rare) Incubation: 6 to 15 hours (diarrheal), 30 min. to 6 hours (emetic) Foods: diarrheal - meats, milk, vegetables, fish emetic - rice products, starchy foods, casseroles, puddings, soups Source: soil, dust, cereal crops, spices Prevention: holding food >60˚C or <10˚C ERASMUS IP Maribor, 2011 Clostridium botulinum Characteristic: obligate anaerobic, spores are highly heat – resistant (survival at 100 °C for several hours, but 120 °C for 30 min. kill spores) production of botulinum neurotoxin, toxin easily destroyed by heat (cooking at 80 °C for 30 min) Named after botulus, latin: sausage, 7 serotype: A, B, C, D, E, F, and G pH: 4,6-9 - food pH < 4.5 → pasteurization food pH > 4.5 → sterilization Target organism of industrial heat treatments Symptoms: Botulism occur in 3 forms: foodborne, wound and infant botulism ♦ Foodborne: weariness, weakness, dizziness, doublevision, difficulty swallowing and speaking, paralisis, death; toxin produced in contaminated food is eaten ♦ Wound and infant: neurotoxin is produced in infected tissue and in the GI tract, death may occure Incubation (foodborne): 12 – 72 hours ERASMUS IP Maribor, 2011 Agent LD50(μ/kg ) Source 0.001 Bacterium Shiga toxin 0.002 Bacterium Tetanus toxin 0.002 Bacterium Diphtheria toxin 0.10 Bacterium Maitotoxin 0.10 Alga Ciguatoxin 0.40 Fish C. perfringens toxinok 0.1-5.0 Bacterium Batrachotoxin 2.0 Frog Ricin 3.0 Castor oil bean Taipoxin 5.0 Snake venom Tetrodotoxin 8.0 Fish Tityustoxin 9.0 Scorpio Sarin (GB) 100.0 Chemical agent T – 2 toxin 1,210.0 Mycotoxin * Botulinum toxin ERASMUS IP Maribor, 2011 Clostridium botulinum Food: home-made cannes, home-made meat products (black pudding, sausages), baked potatoes, sous vide, garlic/ oil mixtures, lowacid canned foods, honey (infant botulism) Source: soil, water, soil contaminated foods Prevention: destruction of the spores through processing or prevention of growth through formulation, temperature control, or a combination of these factors, proper heat treatment, addition of nitrite prevents the growth of Cl. botulinum ERASMUS IP Maribor, 2011 Clostridium perfringens Characteristic: spore-forming, obligate anaerob Toxicoinfection: caused by sporulation of bacterial cell in the intestine Incubation: 10- 12 hours Infective dose: dose >106/g Symptoms: abdominal pain, nausea, diarrhea, fever, headache, vomiting usually absent, death (rare) Foods: stews, gravies, beans, meat, poultry, fish Sources: meat and poultry, soil, animal and human intestinal tracts Prevention: adequate reheating (toxin inactivated at 100 °C for 1 hour) ERASMUS IP Maribor, 2011 How are foodborne illnesses prevented? 1. COOK. 2. SEPARATE. 3. CHILL. 4. CLEAN. 5. REPORT. ERASMUS IP Maribor, 2011 COOK • • • • • Thoroughly cook meat (63 –74ºC), poultry (74ºC), and eggs (63ºC). Use a thermometer to measure internal temperature of meat. Cooked food should be reheated to 74ºC. Hot foods should be kept hot at 57ºC or above. Cook food immediately after defrosting. ERASMUS IP Maribor, 2011 CLEAN • • • • • • Wash produce under running water. Remove and discard outer leaves from lettuce or cabbage. Wash hands before preparing food, between types of food, and after preparation. The single most important method of preventing infectious diseases is to wash your hands. Regularly clean and disinfect the refrigerator and freezer. Clean and disinfect countertops regularly. ERASMUS IP Maribor, 2011 When should you wash your hands? Before Preparing or eating food Treating a cut or wound Tending to someone who is sick After Using the bathroom Changing a diaper or helping a child in the bathroom Handling raw meats, poultry or eggs Touching pets Sneezing or blowing your nose Tending to someone who is sick or injured ERASMUS IP Maribor, 2011 SEPARATE • • • • Do not cross-contaminate Wash hands, utensils, and cutting boards after they have been in contact with raw meat or poultry and before they touch another food. Put cooked meat on a clean platter. Use different dishes and utensils for raw and cooked foods. 75 ERASMUS IP Maribor, 2011 CHILL • • • • • • Refrigerate leftovers promptly. Set refrigerator temperature at 4ºC. Set freezer temperature at -18ºC. Separate large volumes of food so they will cool more quickly. Cold foods should be kept at a temperature of 5ºC or below. Keep purchased food chilled until you get home from the store. ERASMUS IP Maribor, 2011 REPORT Report suspected foodborne illnesses to your local health department. ERASMUS IP Maribor, 2011 Thank you for your attention! ERASMUS IP Maribor, 2011