Presence of ail and ystB genes in Yersinia enterocolitica biotype 1A isolates from game animals in Poland.

The pathogenicity of Yersinia enterocolitica is associated with the presence of plasmid and chromosomal virulence genes. Strains belonging to biotype 1A do not possess pYV plasmids, often harbour the ystB gene and usually lack the ail gene, which is the main virulence marker for Y. enterocolitica. The simultaneous presence of ail and ystB is uncommon. In this study, 21/218 (9.6%) biotype 1A Y. enterocolitica isolates from rectal swabs of wild boar (Sus scrofa; n = 18), red deer (Cervus elaphus; n = 2) and roe deer (Capreolus capreolus; n = 1) in Poland harboured both ail and ystB genes.