Thus, we identified
Y. enterocolitica 1A/O:8 as the most common bioserotype in our
research. Because they lack the 70 kb virulence plasmid (pYV),
biotype 1A strains are considered nonpathogenic. However, more
and more clinical, epidemiological, and experimental evidence
suggests that some biotype 1A strains are virulent and can cause
yersiniosis