2/16/2016 Infectious Dose C.perfringens Food Poisoning Most cells are killed by stomach acid heatacthoadspore Toxicoinfection develops when heavily The mal treaterts contaminated food (>106 C.perfringens) Spores is consumed Toxin is produced in the victim Sporulation occurs in the intestines Enterotoxin binds to C Previous exposure provides no immunity Cells multiply The Organism INCLUSION BODY Gram-positive,rod-shaped,encapsulated,non- motile bacterium Causes a broad spectrum of human and animal diseases Facultative anaerobe that can be plated at the bench that is subsequently incubated anaerobically Produces numerous toxins of which two are active in the human GI tract Grows rapidly:doubles in number in 10 min with optimal growth conditions Forms heat-resistant spores that survive incompletely cooked or reheated food. 2/16/2016 4 Under optimal growth conditions, C. perfringens can double in number every 10 min Large number of bacteria are consumed Temperature abuse stimulate vegetative growth Enterotoxin binds to and damages intestinal epithelial cells Cells multiply sporulate and release enterotoxin Infectious Dose • Most cells are killed by stomach acid • Toxicoinfection develops when heavily contaminated food (> 106 C. perfringens) is consumed • Toxin is produced in the victim • Sporulation occurs in the intestines • Previous exposure provides no immunity The Organism • Gram-positive, rod-shaped, encapsulated, non￾motile bacterium • Causes a broad spectrum of human and animal diseases • Facultative anaerobe that can be plated at the bench that is subsequently incubated anaerobically • Produces numerous toxins of which two are active in the human GI tract • Grows rapidly; doubles in number in < 10 min with optimal growth conditions • Forms heat-resistant spores that survive incompletely cooked or reheated food