Occurrence of pathogenicYersinia enterocoliticaandYersinia pseudotuberculosisin small wild rodents

Abstract

SUMMARYRodents are a potential source of pathogenicYersinia enterocoliticaandY. pseudotuberculosis. In order to study this, 190 rodents were captured and sampled on seven pig farms (n=110), five chicken farms (n=55) and six other locations (n=25) in Sweden. Pigs from three of the pig farms were also sampled (n=60). PathogenicY. enterocoliticawas detected by TaqMan PCR in about 5% of rodent samples and 18% of pig samples. Only rodents caught on pig farms tested positive for the pathogen.Y. enterocoliticabioserotype 4/O:3 strains isolated from the rodent and pig samples were compared by pulsed-field gel electrophoresis and revealed a high degree of similarity, which was confirmed by random amplified polymorphic DNA.Y. pseudotuberculosiswas only detected in one rodent sample. Thus, rodents may be vectors for the transmission of pathogenicY. enterocoliticato pigs, acting as carriers rather than a reservoir, and should therefore remain an important issue in hygiene control measures on farms.