Two novel ail-positive biotype 1A strains of Yersinia enterocolitica isolated in China with unequal adhesion and invasion properties

•Two biotype 1A Yersinia enterocolitica carrying the ail gene.•Strain SDWL-003 shared ail sequences identical to A1 pattern.•The ail sequences of strain 2006RAT formed an entirely new pathogenic pattern.•Some strains of 1A biotype gain potential pathogenicity.