Dr. H. Gh. Safaei 04/21/23
Over eating Nutritional deficiency Allergy Chemical poisioning Bacterial contamination
Dr. H. Gh. Safaei 04/21/23
two primary types◦ food-borne infections◦ food intoxications
Dr. H. Gh. Safaei 04/21/23
•Food infections (microbes are transferred to consumer)•Food poisoning (results from the toxin consumption)
Dr. H. Gh. Safaei 04/21/23
• Ingestion of toxins in foods in which microbes have grown
• Exotoxin • Neurotoxin• Enterotoxin• Metabolite • Staphylococcal food poisoning,• botulism, • Clostridium perfringens food poisoning,• Bacillus cereus food poisoning
Dr. H. Gh. Safaei 04/21/23
ergotism◦ toxic condition caused by growth of a fungus in
grains aflatoxins
◦ carcinogens produced in fungus-infected grains and nut products
fumonisins◦ carcinogens produced in fungus-infected corn
Dr. H. Gh. Safaei 04/21/23
Neurtoxin ( Bacteriophage ) A-G Heat labile Nutrient content ( Glucose , Maltose ) Aw, PH, O-R, NaCl, Temp, Time IP 12-36 h Canned food
Dr. H. Gh. Safaei 04/21/23
Neurological signsVisual disturbances, vertigo, tingling
sensation & paralysis
Clostridium botulinum
Dr. H. Gh. Safaei 04/21/23
Enterotoxin S.aureus , heat stable 4-46 C PH 4.8- 8 Aw 0.86-0.9 IP 2-4 hour
Dr. H. Gh. Safaei 04/21/23
Upper GIT signsNausea, retching, vomiting, abdominal
pain, diarrhoea S. aureus and its toxins B. cereus and its toxin
Dr. H. Gh. Safaei 04/21/23
• C. botulinum, C. perfringens - Soil, hide, faecal material
• Staphylococcus aureus toxin - Human (nostrils and hands)
• Listeria monocytogenes- Soil, hide, faecal material
• Campylobacter spp. - GIT (esp. poultry)
• E. coli O157:H7 - GIT
• Salmonella spp. - GIT / Hide
• Yersinia enterocolitica - GIT
Dr. H. Gh. Safaei 04/21/23
Dr. H. Gh. Safaei 04/21/23
Upper GIT – nausea & vomiting
Lower GIT – cramps & diarrhoea
Neurological signs
General symptoms
Dr. H. Gh. Safaei 04/21/23
Lower GIT signsLower abdominal cramps & diarrhoea
Clostridium perfringens, Bacillus cereus Salmonella, Shigella, ET E. coli, Yersinia
enterocolitica, Campylobacter jejuni, Vibrio cholera
Dr. H. Gh. Safaei 04/21/23
Lower GIT signs, continuedLower abdominal cramps &
diarrhoea
Giardia intestinalis Cryptosporidium parvum
Dr. H. Gh. Safaei 04/21/23
General symptomsFever, chills, malaise, prostration, aches,
swollen lymph nodes
• S. typhi, L. monocytogenes, C. jejuni• Hepatitis A
Dr. H. Gh. Safaei 04/21/23
Dr. H. Gh. Safaei 04/21/23
Cause enteritis Occasionally systemic infection
C. jejuni & C. coli infections indistinguishable
2 million case / year in USA
Dr. H. Gh. Safaei 04/21/23
• Gram negative Gram negative • Curved or spiral , comma, S , gull wing Curved or spiral , comma, S , gull wing • Motile single polar flagellum Motile single polar flagellum • Thermophile Thermophile
Dr. H. Gh. Safaei 04/21/23
1. Temperatures > 55 deg. C destroy
2. Sensitive to desiccation3. Salt, ascorbic acid4. Disinfectants, chlorinated water5. UV radiation
Dr. H. Gh. Safaei 04/21/23
EndotoxinCytopathic extracellular toxin
Enter toxin
Dr. H. Gh. Safaei 04/21/23
Oral route , food , drink , contact infected animals, sexual activity
Sensitive to gastric acid 104 organism should ingested Multiply in small intestine ----invade
epithelial ----inflammation ----white & red blood cell in stool
Occasionally blood stream is invaded Enteritis
Dr. H. Gh. Safaei 04/21/23
Sources - human – faecal-oral person-to-person - animal – cats, dogs, flies,chickenschickens, ,
cattle, cattle, sheepsheep
Transmitted milk meat productsPublic health control
Dr. H. Gh. Safaei 04/21/23
Dr. H. Gh. Safaei 04/21/23
consumption of undercooked meat products, unpasteurized
milk, water contaminated by the bacteria. Usually, someone with an infection caused
by Yersinia bacteria recovers within a few days without medical treatment (in some cases, doctors prescribe antibiotics
Dr. H. Gh. Safaei 04/21/23
4 to 7 days after exposure and can last up to 3 weeks
fever, stomach pain, nausea, vomiting, and bloody diarrhea. Sometimes, older kids also get pain in the lower right side of the abdomen, which can mimic appendicitis.
Dr. H. Gh. Safaei 04/21/23
1. Avoid eating raw or undercooked pork. 2. Consume only pasteurized milk 3. Wash hands with soap and water 4. Prevent cross-contamination in the
kitchen: -Use separate cutting boards for meat and other foods. -Carefully clean all cutting boards, counter-tops, and utensils with soap and hot water after preparing raw meat.
5. Dispose of animal feces in a sanitary manner.
Dr. H. Gh. Safaei 04/21/23
is a bacterium in the same family as those that cause cholera.
gastrointestinal illness in humans. V. parahaemolyticus naturally inhabits
coastal waters is present in higher concentrations during summer;
it is a halophilic, or salt-requiring organism.
Dr. H. Gh. Safaei 04/21/23
watery diarrhea often with abdominal cramping, nausea, vomiting, fever and chills. Usually these symptoms occur within 24 hours of ingestion. Illness is usually self-limited and lasts 3 days.
Dr. H. Gh. Safaei 04/21/23
Most people become infected by eating raw or undercooked shellfish, particularly oysters. Less commonly, this organism can cause an infection in the skin when an open wound is exposed to warm seawater.
Dr. H. Gh. Safaei 04/21/23
Most people become infected by eating raw or undercooked shellfish, particularly oysters. Less commonly, this organism can cause an infection in the skin when an open wound is exposed to warm seawater.
Dr. H. Gh. Safaei 04/21/23
•incubation 2 to 5 days •Abdominal painAbdominal pain• DiarrheaDiarrhea• Malaise, fever, headacheMalaise, fever, headache•Usually self-limiting 5-8 days 5-8 days • Antibiotics erythromycin
SymptomsSymptoms
Dr. H. Gh. Safaei 04/21/23
Micro-organisms – part of nature Chemicals – many are man-made Micro-organisms change numbers Uneven distribution in food Clinical symptoms – acute Variable consumer susceptibility
Dr. H. Gh. Safaei 04/21/23
Contamination with undesirable micro-organisms
Unacceptable levels of micro-organisms
Treatment did not result in inactivation
Dr. H. Gh. Safaei 04/21/23
Preventing/limiting contamination Preventing/limiting spread Preventing growth Preventing survival of organisms &
persistence of metabolites
Dr. H. Gh. Safaei 04/21/23
No contact between raw & cooked Wash hands Keep food preparation surfaces
clean Protect from pests Use potable water
Dr. H. Gh. Safaei 04/21/23
?Dr. H. Gh. Safaei 04/21/23