Background: We investigated the prevalence of various pathogens (13 enteric bacteria and 5 viruses) which cause diarrhea using multiplex PCR of stool specimens and compared two multiplex PCR methods for detecting diarrheagenic Escherichia coli.

Methods: A total of 405 stool specimens submitted between November 2010 to February 2011 for routine culture of enteric pathogens were included and screened for five viruses (astrovirus, Group A rotavirus, enteric adenovirus, norovirus G1/G2) and eight bacteria (Salmonella spp., Shigella spp., Campylobacter spp., Vibrio spp., C. difficile Toxin B, C. perfringens, Y. enterolytica, Aeromonas spp.) using the SeeplexⓇ Diarrhea ACE detection kit (Seegene). In addition, virulence-associated genes of enteropathogenic E. coli, (EPEC), enterohemorrhagic E. coli (EHEC), enteroinvasive E. coli, (EIEC), enterotoxigenic E. coli (ETEC), and enteroaggressive E. coli (EAEC) were detected using 16-plex PCR and a commercial diarrheagenic E. coli detection (DEC) PCR kit (SSI Diagnostica).

Results: Overall, 138 (34.1%) of 405 samples was positive for pathogen. The positive rate for virus was 18.5%. norovirus G2, Group A rotavirus, enteric adenovirus, astrovirus and norovirus G1 were detected in 40, 23, 8, 3 and 1 samples, respectively. The positive rate for bacteria was 24.4% (99/405). C. difficile toxin B was the most frequently detected, followed by C. perfringens, EPEC, and EAEC. The agreements of the two multiplex PCR methods for detecting EPEC and EHEC were 99.3% and 100%, respectively.

Conclusion: The detection rate was high (34.1%) including various diarrheagenic E. coli (6.2%) and C. perfringens (5.2%). Multiplex PCR is thus useful for detecting various pathogens. (Ann Clin Microbiol 2013; 16:33-38)