2/16/2016 Reservoirs for C.perfringens Type A Reservoirs for C.perfringens Type A Natural environments Wide spread distribution is linked to its Soil 103-104 CFU per gram frequent occurrence in foodborne illness Foods,contained in 50%of raw or ·However,‘5%of all isolates contain the frozen meat cpe gene,which encodes the entertoxin -Dust required for illness -Intestinal tracts of humans and Thus,the ubiquitous nature of this domestic animals microbe is not relevant for understanding -Human feces contains 104-106 CFU per the reservoir of C.perfringens gram Many questions are still to be answered Virulence Factors Contributing to C. Virulence Factors Contributing to C perfringens perfringens Foodborne Illness Foodborne Illness ·Heat Resistance ·Enterotoxin -Most Cperfringens toxicoinfections are caused by isolates carrying a Induces loss of fluid from the chromosomal cpe gene intestinal tract -Isolates carrying chromosomal or plasmid cpe genes make the same amount of toxin Oddly,strains carrying a chromosomal hpeehn ran 2/16/2016 6 Reservoirs for C. perfringens Type A • Natural environments S il 103 – - Soil 103 – 104 CFU p m CFU per gram - Foods, contained in 50% of raw or frozen meat - Dust - Intestinal tracts of humans and domestic animals - Human feces contains 104 – 106 CFU per gram Reservoirs for C. perfringens Type A • Wide spread distribution is linked to its frequent occurrence in foodborne illness • However, < 5% of all isolates contain the cpe gene, which encodes the entertoxin required for illness • Thus, the ub hus, the ub qu tous nature of th s iquitous nature of this microbe is not relevant for understanding the reservoir of C. perfringens • Many questions are still to be answered Virulence Factors Contributing to C. perfringens Foodborne Illness • Heat Resistance - Most C perfringens C. perfringens toxicoinfections toxicoinfections are caused by isolates carrying a chromosomal cpe gene - Isolates carrying chromosomal or plasmid cpe genes make the same amount of toxin - Oddly, strains carrying a chromosomal cpe gene are more heat resistant than those with a plasmid-based gene Virulence Factors Contributing to C. perfringens Foodborne Illness • Enterotoxin - Induces loss of fluid from the intestinal tract