Trueperella pyogenes is a Gram-positive bacterium causing purulent infections in many animal species, including the European bison. However, the data about the virulence and genetic relationships of T. pyogenes strains isolated from these wild ruminants are strongly limited. The aim of this study was to investigate the prevalence of T. pyogenes infections in the European bison, and to evaluate the genetic diversity of isolates from these animals. In the time span of 10 years, 328 European bison from 16 different locations were examined. The standard bacteriological methods were used for T. pyogenes isolation and identification from clinical specimens obtained from urogenital tract infections and abscesses of different locations. The presence of genes encoding known virulence factors was investigated by PCR, and the genetic diversity of T. pyogenes strains was examined with the RAPD-PCR method. The prevalence of T. pyogenes infections was 14.6%, and the pathogen was isolated from both female (47.9% of isolates) and male (52.1% of isolates) European bison. It should be highlighted that a considerable number of strains were isolated from the prepuce and penis infections. Therefore, the role of T. pyogenes in the pathogenesis of balanoposthitis should be seriously perceived. A total of 39 T. pyogenes strains were subjected to genetic characterization. All studied strains carried the plo gene, while the nanH (25.6%), nanP (23.1%), cbpA (7.7%), fimA (97.4%), fimC (69.2%), fimE (92.3%) and fimG (15.4%) genes were present with a variable frequency among the tested strains. The virulence genotype plo/fimA/fimC/fimE was dominant. RAPD-PCR typing showed a high level of genetic diversity among European bison T. pyogenes strains, and a total of 31 different RAPD profiles were distinguished. In a few cases, the same RAPD profile was found in strains obtained from animals living in the same area. This study provided the first data about the prevalence and genetic relationships of T. pyogenes in the Polish population of European bison. However, further epidemiological investigations are needed to understand the routes of transmission and dissemination of the pathogen in these wild animals.
Keywords: European bison; RAPD-PCR typing; Trueperella pyogenes; epidemiology; genetic diversity; virulence factors.