Incidence and pathogenicity of Yersinia spp. isolates from poultry in Spain Original Research Article

Forty eviscerated and refrigerated chicken carcasses were collected from retail outlets in León (Spain) and investigated for the presence of Yersinia spp. Following a two-step enrichment procedure (phosphate buffer saline was used as primary enrichment and bile oxalate sorbose as secondary enrichment), yersiniae were isolated on cefsulodin-irgasan-novobiocin (CIN) and MacConkey agar. Yersinia spp., Y. enterocolitica and Y. frederiksenii were detected in 26 (65%), 22 (55%) and six (15%) samples, respectively. The incidence ofYersinia and Y. enterocolitica was greater than that obtained in poultry meat by the majority of the consulted authors. Of the 68 Yersinia isolates, 52 were identified as Y. enterocolitica and 16 as Y. frederiksenii. Biotyping of Y. enterocolitica revealed that 45 (86·5%) strains corresponded to biotype 1A, and three (5·8%) to biotype 3. Four (7·7%) strains could not be classified. Two biotype 3 strains were found to be presumptively virulent according to the dye (Congo red and crystal violet) binding, low-calcium response, and pyrazinamidase activity techniques. It is suggested from results that the presence of Yersinia in poultry could represent a health risk for consumers in Spain. The education of people involved in production, processing and final preparation of poultry products are required in order to assure adequate cooking and to avoid cross-contamination.