A beef cattle liver and swine liver were collected between July to November 2013 in Japan. Campylobacterjejuni and C. coli were isolated from 21.6% (109/505) of beef cattle liver and from 14.8% (74/500) of swine liver. A total of 184 Campylobacter isolates (109 beef cattle liver isolates and 75 swine liver isolates) were subjected to antimicrobial resistance profiling against eight different antimicrobials. Regarding antimicrobial resistance, C. jejuni (beef cattle liver isolates) and C. coli (swine liver isolates) showed resistance against 1 to 5 and 1 to 6 antimicrobial agent, respectively. For C. jejuni isolates, antimicrobial resistance rates were observed in 2.0% of EM and CP to 58.6% of TC. And for C. coli isolates, these were observed in 8.3% of CP to 84.7% of TC. Pulsed-field gel electrophoresis (PFGE) patterns were examined in Ciprofloxacin (CPFX) resistant strains. CPFX resistant C. jejuni and C. coli were classified into 17 different PFGE patterns and 19 patterns, respectively.
Enterohemorrhagic E. coli (EHEC) or Shiga toxin-producing E. coli is known as an important food-borne pathogen, and O157 is the most frequently reported O serogroups of EHEC strains associated with bloody diarrhea and hemolytic-uremic syndrome worldwide. Subsequently O26, O111, O103, O145, O121 and O165 serogroups of EHEC were also frequently isolated from patients with severe diseases in Japan. The O serogrouping of EHEC is essential in outbreak investigations and surveillance. In a previous study, we developed a comprehensive and practical platform for molecular O-serogrouping of E. coli strains, named as E. coli O-genotyping PCR (Iguchi, A., et al.: J. Clin. Microbiol., in press), targeting unique sequences on each O-antigen biosynthesis gene cluster. Based on the PCR system, we now developed an EHEC-specific multiplex PCR system, named as “MP-1 plus,” targeting seven major EHEC O serogroups and three virulence genes, stx1, stx2 and eae. This primer set contains 10 primer pairs that amplify products with different sizes, and validation studies using reference and wild strains showed that the results were reliable enough. The one-shot PCR method reported here might be a promising tool for the identification and subtyping of EHEC strains for outbreak investigations as well as for the surveillance.