Characterization ofYersinia enterocoliticaBiotype 1A Strains Isolated from Swine Slaughterhouses and Markets

Abstract

Yersinia enterocoliticais an important foodborne pathogen that causes illness in humans and animals.Y. enterocoliticais also the most heterogeneous species of the genus and is divided into distinct serotypes and over six biotypes.Y. enterocoliticabiotype 1A strains are classically considered as nonpathogenic; however, some biotype 1A isolates have been considered as causative of gastrointestinal disease, yielding symptoms indistinguishable from those produced by pathogenic biotypes. Even after decades of isolation of clinical strains, the pathogenic mechanisms of these isolates are still not fully understood. In the present study, 122Yersinia enterocoliticabiotype 1A strains isolated from swine slaughterhouses and meat markets in Sao Paulo, Brazil, were characterized according to the presence of the virulence genesail,virF, andystA. A total of 94 strains were positive to at least one virulence gene (77.05%), and 67 were positive to all of them (54.92%). Twenty-two strains were submitted to PFGE genotyping resulting in 22 distinct pulsotypes, varying from 50% to 84% of genetic similarity. Any clustering tendency among pulsotypes related to origin, isolation site, or even virulence profile was not observed. The present study reports an important contamination of the environment in swine slaughterhouses, meat markets, and pork, by potentially virulentY. enterocoliticabiotype 1A.