Distribution of the tc -PAIYein Y. enterocolitica strains. Strains investigated are described in Table 3. The lines below the tc-PAIYeare in scale and mark the fragments amplified by PCR. The PCR numbers correspond to those indicated in Additional file 1. Asterisks mark frameshifts in tcaB and tcaC. Dark grey: fragment amplification, light grey: biased results, white: no amplification; nd, not defined, e.g. no PCR was performed. See text for further details.