The enzymes studied were:

malate dehydrogenase (MDH; EC 1.1.1.37), malic enzyme (ME; EC 1.1.1.40), glucose-6-phosphate dehydrogenase (G6P; EC 1.1.1.49), isocitrate dehydrogenase (IDH; EC 1.1.1.42), alpha esterase (EST-A; EC 3.1.1.1) and glutamate dehydrogenase (GD2; EC 1.4.1.4). The enzymes MDH, ME, G6P and IDH were electrophoresed in Tris citrate buffer (pH 8.0). For EST-A, potassium phosphate buffer (gel buffer, pH 7.0; Pitavastatin chemical structure electrode buffer, pH 6.7) was used and GD2 was electrophoresed in a lithium hydroxide buffer (gel buffer, pH 8.3; electrode buffer, pH 8.1). Replicate samples from reference strain were run on each gel, which facilitated comparison of the gels. The mobilities of the enzymes from different samples on the same gel were compared. For each enzyme, the distinct mobility variants were designated Ruboxistaurin purchase as electromorphs and numbered in order of decreasing rate of anodal migration. The electromorphs of an enzyme were equated with alleles at the corresponding structural gene locus. Each strain was characterized on the basis of combination

of its electromorphs obtained for the six enzymes. Distinct profiles of electromorphs corresponding to multilocus genotypes were designated as electrophoretic types (ETs). Statistical analyses Computer find more programs written by Prof T. S. Whittam were used to analyze the ET data and calculation of genetic diversity [20]. Genetic diversity (h) at an enzyme locus (i.e., the probability that two isolates differ at the j locus) was calculated from the allele frequencies as h j = n (1 – Σx i 2)/n – 1), where x i is the frequency of the ith allele at the j locus and n is the number of isolates [33]. Mean genetic diversity per locus (H) was calculated

as the arithmetic average of h values for all loci. The genetic distances between pairs of ETs were calculated as the proportions of loci at which dissimilar electromorphs occurred. Clustering of data was performed from a matrix of pairwise genetic distances by the average-linkage method (unweighted pair group method using arithmetic averages or UPGMA). Multilocus restriction typing (MLRT) Genomic DNA was extracted using DNeasy tissue kit (Qiagen) as per the manufacturer’s instructions. The six genes encoding housekeeping Exoribonuclease enzymes: malate dehydrogenase (mdh), adenylate cyclase (cya), glutamine synthetase (glnA), glucose-6-phosphate dehydrogenase (zwf), isocitrate dehydrogenase (icdA) and glutamate dehydrogenase (gdhA) were selected. For amplification of these genes, Yersinia consensus primers were designed using nucleotide sequences from Y. enterocolitica 8081 (biovar 1B, AM286415), Y. pestis (AE009952) and Y. pseudotuberculosis (BX936398) available at EMBL and GenBank databases, after pairwise alignment of the sequences using ClustalW http://​www.​ebi.​ac.​uk/​clustalW.