[Multilocus sequencing of Corynebacterium diphtheriae strains isolated in Russia in 2002 - 2012]

Characterization of contemporary C. diphtheriae strains isolated in Russia by using multilocus DNA sequencing (MLST).

28 toxigenic C. diphtheriae strains isolated in Russia in 2002-2012 and sent to diphtheria and pertussis reference center of Gabrichevsky Research Institute of Epidemiology and Microbiology were studied. C. diphtheriae strain genotyping was performed by using MLST based on atpA, dnaE, dnaK, fusA, leuA, odhA and rpoB gene fragments. Identification of alleles and ST was carried out according to EMBL/GenBank and PubMLST, eBurst approach was used for cluster analysis.

By using MLST contemporary toxigenic C. diphtheriae strains isolated in Russia in 2002 - 2012 were characterized. 8 genotypes (ST41, ST5, ST8, ST28, ST25, ST44, ST-new1 and ST-new2) were identified, 3 among them were dominating--ST8, ST28 and ST-new1. Most of the toxigenic strains belong to biovar gravis and ST8. Among biovar mitis strains a higher heterogeneity by ST membership was noted, but with prevalence of ST28 strains.

Use of MLST allowed to characterize contemporary circulating population of toxigenic C. diphtheriae strains isolated in Russia and showed perspective of application of this method for characterization of diphtheria causative agent population and detection of epidemically significant strains, as well as juxtaposing of them with genetic structure of foreign strains.