Occurrence, molecular characterization, and antimicrobial susceptibility of Yersinia enterocolitica isolated from retail food samples in China

Yersinia enterocolitica (Y. enterocolitica) is an important foodborne pathogen that causes gastrointestinal syndromes. The objectives of this study were to examine the incidence of Y. enterocolitica strains in food samples in China and determine their genotypes, in addition to assessing their antimicrobial resistance and pathogenic potential. From June 2015 to June 2016, a total of 1588 food samples were obtained, and 37 (2.33%) were found to be contaminated with Y. enterocolitica. A total of 51 different Y. enterocolitica strains were isolated. All isolates belonged to biotype 1A, and the predominant serotype was O:5. All strains lacked the ail, virF, ystA, and yadA virulence genes, but most strains (>75%) harbored the ymoA, sat, hreP, fepD, and fes genes. Over 85% of the 51 isolated strains were sensitive to tetracycline, trimethoprim/sulfamethoxazole, and chloramphenicol, whereas they were resistant to ampicillin and amoxicillin/clavulanic acid. Furthermore, all the strains were divided into seven clusters according to the results of the enterobacterial repetitive intergenic consensus-polymerase chain reaction. Our research emphasizes, for the first time, that more stringent cold storage methods may increase the risk of Y. enterocolitica contamination.

Automated summary

This study investigated the incidence of Yersinia enterocolitica strains in food samples in China, revealing a low contamination rate, predominance of biotype 1A and serotype O:5, sensitivity to tetracycline, trimethoprim/sulfamethoxazole, and chloramphenicol, and resistance to ampicillin and amoxicillin/clavulanic acid. The strains were divided into seven clusters based on their genetic characteristics. Additionally, the study highlighted the potential risk of Y. enterocolitica contamination associated with stringent cold storage methods.