Detection of Enterotoxigenic Clostridium perfringens Type A Isolates in American Retail Foods

Abstract

Currently there is only limited understanding of the reservoirs for Clostridium perfringens type A food poisoning. A recent survey (Y.-T. Lin and R. Labbe, Appl. Environ. Microbiol. 69:1642-1646, 2003) of nonoutbreak American retail foods did not identify the presence of a single C. perfringens isolate carrying the enterotoxin gene (cpe) necessary for causing food poisoning. The present study revisited this issue, using revised methodology and food sampling strategies. In our survey, cpe-positive C. perfringens isolates were detected in ϳ1.4% of ϳ900 surveyed non-outbreak American retail foods. Interestingly, those enterotoxigenic isolates in non-outbreak foods appear indistinguishable from C. perfringens isolates known to cause food poisoning outbreaks: i.e., the enterotoxigenic retail food isolates all carry a chromosomal cpe gene, are classified as type A, and exhibit exceptional heat resistance. Collectively, these findings indicate that some American foods are contaminated, at the time of retail purchase, with C. perfringens isolates having full potential to cause food poisoning. Furthermore, demonstrating that type A isolates carrying a chromosomal cpe gene are the enterotoxigenic isolates most commonly present in foods helps to explain why these isolates (rather than type A isolates carrying a plasmid cpe gene or cpe-positive type C or D isolates) are strongly associated with food poisoning outbreaks. Finally, since type A chromosomal cpe isolates present in the surveyed raw foods exhibited strong heat resistance, it appears that exceptional heat resistance is not a survivor trait selected for by cooking but is instead an intrinsic trait possessed by many type A chromosomal cpe isolates.

Prevalence and molecular typing of Clostridium perfringens isolates from edible offal of broiler

“…In another study, 37% of the meat and poultry samples were detected as positive for C. perfringens but different from our results 17% of the isolates were carrying cpe gene (27). Similarly Wen and McClane (2004) reported that 56 of 147 (38%) chicken meat were contaminated with C. perfringens and only one isolate was positive for cpe.…”

“…Epidemiological studies showed that more than 90% of C. perfringens outbreaks were associated with only meat and poultry products. (14,25,27,32). In various studies type A was reported to be the dominant type of C. perfringens isolated in poultry diseases (especially in necrotic enteritis) and from industry, processing line, products and environment worldwide (6,17,21,32).…”

Distribution of Enterotoxin Gene-positive <i>Clostridium perfringens</i> Spores among Human and Livestock Samples and its Potential as a Human Fecal Source Tracking Indicator

“…In particular, although C. perfringens was detected in 142 of 200 samples (beef, chicken, and pork), only two from beef and one from chicken were cpe-positive [26]. In another study of 887 food samples, 278 were positive for C. perfringens but only 10 were also cpe-positive [27]. The type A strain of C. perfringens was detected in 22 of 180 turkey meat samples and most were cpe-negative [28].…”

Toxinotyping and antimicrobial susceptibility of enterotoxigenic Clostridium perfringens isolates from mutton, beef and chicken meat

“…Diluted meat samples (1 ml) were inoculated into FTM broth and the tubes were incubated for 24 h at 37°C in an anaerobic jar HP-11 (Oxoid, Hampshire, UK) containing AnaeroGen TM Sacchet AN35 (Oxoid, Hampshire, UK) (Wen and McClane 2004). Enrichment culture (0.1 ml) thus obtained was spread over the tryptose sulfite cycloserine (TSC) agar (Himedia Labs, Mumbai, India) plates using a sterile glass rod and incubated anaerobically for 24 h at 37°C.…”