Major variants of Tir and intimin are related, to some extent, to the serogroups of the EHEC and EPEC strains, whereas minor variants can exist within a serogroup for the same major variant, although these have not often been defined [25, 26]. EHEC and EPEC MM-102 chemical structure strains belonging to the O26 serogroup classically produce the beta major variant of

Tir and intimin, but their minor variants have not been studied [26, 27]. Only two major variants of TccP have been described that are related to the VX-680 pathotype of the strain [19]. EHEC and EPEC strains of O26 serogroup produce the TccP2 variant with six minor www.selleckchem.com/products/SB-431542.html variants identified [23, 24]. The purposes of this study were (1) to investigate the polymorphism of the tir, eae and tccP2 genes between O26 EPEC and EHEC strains isolated from bovines and from humans; and (2) to determine whether these polymorphisms are specific to bovine or human strains. Results Detection of tir, eae and tccP2 genes All the tested strains of serogroup O26

were found to possess β type eae and tir genes. Moreover, of the 70 tested strains, 10 strains (14% of the strains) presented one or several polymorphisms in these two genes. None of the polymorphic strains possessed polymorphism in both eae and tir genes. Concerning tccP2 detection, 47 of the 70 strains (67% of the strains) were positive for this gene. Most of MRIP the strains possessed tccP2 variants described in strains of serogroup O26. Three strains had tccP2 genes respectively described in strains of serogroup O111, O103 and O55. Polymorphisms in the eae gene For the eae gene, four polymorphisms were detected

in nucleotide positions 255 (G > A), 1859 (C > T), 2415 (A > T) and 2772 (C > T) in eae β gene reference strain 14I3, (accession number FJ609815) and five unique eae β genotypes were defined (Table 1). The “”classical”" genotype (strain 14I3 sequence) was represented by 93% (65+/70) of the strains and the four other genotypes were represented by only one or two strains. Even though there was no statistical significance (p = 0.078), all the strains that presented polymorphism were bovine EPECs. One polymorphism was non-synonymous and gave one genotype different in the amino-acid (AA) sequence: valine was coded in place of alanine in AA position 620. This AA is situated in the D0 Ig-like domain.