Within the group A, two subgroups were identified namely, A-I and A-II. In subgroup A-I, all wastewater serotype O:6,30-6,31 isolates, human NAG and European O:6,30 isolates were present. Subgroup A-II comprised of all clinical O:6,30-6,31 isolates, most clinical O:6,30 isolates, three pork and pig throat isolates each, and five wastewater isolates belonging to different serotypes. The most common Erastin in vivo RT, RT1 representing 31 isolates
was present in this subgroup. The group B comprised of 15 isolates belonging to RT3 and a single isolate each of RT8 and RT11. Genotypically, this group was quite homogeneous despite belonging to different serotypes, sources and geographic origin. Figure 2 Dendrogram showing relationships of Y. enterocolitica biovar 1A strains based on analysis of restriction types (RTs) generated by MLRT. The dendrogram was Selleck MLN0128 constructed using UPGMA algorithm available in the START software package. NAG: non-agglutinable, ND: not determined,
NK: not known. The analysis of MLRT data by BURST program identified two clonal complexes (Figure 3) corresponding to the clonal groups identified above. The clonal complex A comprising 9 RTs (64 strains) revealed that wastewater serotype O:6,30-6,31 isolates represented by RT2 were present in the innermost circle Selleckchem MM-102 as ancestral strains. The clinical serotype O:6,30-6,31 strains represented by RT1 and RT12 were present in the outer circle as single locus variants (Figure 3a) The double locus variants (RT5 and RT9) and the satellite RTs (RT6 and RT10) were represented by serotypes which are relatively not common. However, not much information could be inferred from clonal complex B (Figure 3b). Figure 3 Clonal complexes identified among 81 strains of Y. enterocolitica biovar 1A by BURST analysis of MLRT data. a) Clonal complex A, b) Clonal
complex B. Each number denotes a restriction type (RT; refer to Figure 2). Radial distribution shows divergent RTs. Ancestral RT is shown in the innermost circle. Single locus variants (SLV) are shown in the second circle and double locus variants (DLV) are represented in the outermost circle. Satellite RTs (RTs present outside the outermost circle) vary by more than two loci Dichloromethane dehalogenase from the ancestral type. Lines indicate whether the RT is SLV (solid line) or DLV (dashed line). Sequencing of amplicons from representative strains confirmed the identity of the genes. Analysis of the sequences also confirmed the restriction patterns observed for each of the six genes. This is the first report on MLRT of Y. enterocolitica. Analysis of linkage disequilibrium and discriminatory indices The frequency of recombination in natural populations can be estimated by calculating index of association (I A) between loci [35]. The results of the analysis of multilocus linkage disequilibrium in Y. enterocolitica are summarized in Table 4. The I A and I S A values for the 81 strains studied by MLEE were 0.613 and 0.128 respectively, which differed significantly (p < 0.