Characterization of Yersinia spp. strains isolated from pigs in Abidjan, Cte dIvoire, West Africa

The aim of this study was to evaluate the prevalence and determine the molecular virulence of the pathogenic Yersinia spp. strains recovered from raw pig samples from a slaughterhouse in Abidjan, Côte d’Ivoire. A total of 460 raw pig samples including 200 tongues, 150 tonsils, 110 feces, were characterized phenotypically and genotypically for virulence genes. The strains were also tested for the presence of virulence gene using polymerase chain reaction (PCR). Nine (2%) Yersinia strains were isolated from the 460 samples. The isolates belonged to various bio-serogroup such as Yersinia enterocolitica 4/O:3/VIII (33.3%), Yersinia intermedia 4/autoagglutinable (44.4%) and Y. intermedia 5/O:7,8-8-8,19 (22.2%). Tonsils were the most contaminated organ from pig with 66.7% of isolated Yersinia strains. The Yersinia strains exhibited phenotypic virulence characteristics and virulence genes such as ail (3/9), ystA (8/9) and yadA (2/9). Two Y. enterocolitica 4/O:3 strains carried simultaneously all three virulence genes. Among these bacteria, virulent strains of Y. enterocolitica were found, with biotype and serogroup related to human diseases, representing a risk for the consumers of pork. This study is the first that documented the occurrence of pathogenic Yersinia and related species in pigs in Côte d’Ivoire. The occurrence of virulence strains of Y. enterocolitica shows that pork is a potential source of human infection by this species and the circulation of Yersinia spp. in pigs in Côte d’Ivoire. Key words: Yersinia, pigs, virulence, polymerase chain reaction (PCR).