Submitted to: US-Japan Coop Pgm on Dev and Util of Natural Products Abstracts Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/21/1996
Publication Date: N/A
Technical Abstract: Campylobacter jejuni and C. coli are major causes of human foodborne illness and account for approximately 2.1 million cases annually at a toll of $1 billion. Listeria monocytogenes is a human foodborne pathogen with a mortality rate of 25%. Because of the "zero tolerance" for L. monocytogenes in ready-to-eat foods and the financial loss of recalling a contaminated product, a reliable and rapid method to distinguish L. monocytogenes from other Listeria is needed. We evaluated a multiplex PCR to distinguish C. jejuni from C. coli colonies present on modified charcoal-cefazolin-sodium deoxycholate agar (mCCDA) supplemented with 0.01% amphotericin B. Livestock feces was streaked onto mCCDA. After incubation (48 h in 5% 02, 10% C02, 85% N2) colonies were processed directly for PCR. Initial studies demonstrated that C. jejuni yielded two PCR products (450 bp and 160 bp); C. coli generated a single PCR product (450 bp). Of 1,057 pig fecal samples examined, 69% were positive for C. coli and 0.28% were positive for C. jejuni. Of 1,334 cattle fecal samples processed on mCCDA, 43% were positive for C. jejuni and 1.57% were positive for C. coli. These results indicate that performing a multiplex PCR on colonies on selective agar provides an efficient method for screening large numbers of livestock for potential human foodborne pathogens. We designed a multiplex PCR to distinguish L. monocytogenes from other Listeria species. L. monocytogenes yielded two PCR products (938 bp and 174 bp); other Listeria species generated a single PCR product (938 bp). The PCR assay correctly distinguished L. monocytogenes (n=79 isolates) from L. innocua (n=8), L. welshimerii (n=2), L. grayii (n=2), and L. seeligeri (n=2).