Multilocus Sequencing ofCorynebacterium pseudotuberculosisBiotype Ovis Strains

Abstract

ThirteenCorynebacterium pseudotuberculosisbiotype ovis strains isolated from clinical cases of caseous lymphadenitis in Hungary were characterised using multilocus sequencing and their phylogenetic comparison was carried out on the basis of four housekeeping genes (groEL1,infB,dnaK, andleuA). The in silico analysis of the 16 frequently studied housekeeping genes showed thatC. pseudotuberculosisstrains could be readily distinguished fromC. diphtheriaeandC. ulceransstrains; however, sequences of the same genes in the two biotypes of theC. pseudotuberculosiswere highly similar; the heterogeneity values were low. GenesdnaK,infB,groEL1, andleuA showed marked genetic variation withinC. pseudotuberculosis, and strains of the two biotypes of C. pseudotuberculosiscould be differentiated. Analysis of the individual genes showed a fairly conservative nature ofC. pseudotuberculosisbiotype ovis strains. The greatest genetic differentiation was seen in thednaKandinfBgenes and concatenations of these two genes were very useful in the genetic separation of the studied strains.