Incidence and antibiotic susceptibilities of Yersinia enterocolitica and other Yersinia species recovered from meat and chicken in Tehran, Iran

The objective of this study is to investigate the prevalence and determine the antimicrobial susceptibility pattern of Yersinia species in beef meat and chicken meat samples in different seasons. In this study 379 pieces of beef and chicken meats were examined for the presence of Yersinia species between April 2007 and March 2008. 25 g of homogenized food samples was pre-enriched in PBS then it was cultured on cefsulodin-irgasan-novobiocin (CIN) agar. Susceptibility testing of bacterial strains was performed at 28˚C by the agar diffusion method. Yersinia spp. was isolated from 60 of 379 (15.8%) beef meat and chicken meat samples. Y. entrocolitica was found in 48 of 60 (80%) positive samples. The rate of other 3 Yersinia spp, Y. ferederiksenii, Y. intermedia, Y. kristensenii, were 7(11%), 4(6%) and1 (0.01%) out of 60 isolates, respectively. 98% of isolates were susceptible to choloramphenicol and gentamicin. The most antibiotic resistance belongs to cephalothine (98%). Our results showed that isolation ratio of Y. enterocolitica and the other species is higher in cold climates. The majority of isolates were resistant to cephalothine. The most active pharmacologic agents were chloramphenicol, gentamicin and trimetoprim.   Key words: Yersinia enterocolitica, antimicrobial susceptibility, beef meat, chicken.