Composition of Population of Diphtheria Causative Agent Strains in Russia

Abstract

Aim. Characteristics of clonal composition of Corynebacterium diphtheriae strain populatior in Russia using MLST, as well as evaluation of a possibility of using of this method during execution of monitoring of diphtheria infection causative agent strains. Materials and methods. C. diphtheriae strains, isolated in Russia in 1957 - 2015 and sent to Gabrichevsky MRIEM reference centre for diphtheria and pertussis, were studied. Genotyping of C. diphtheriae using MLST wa: carried out based on sequencing of «housekeeping» gene fragments. ST identification was carriec out according to PubMLST. Results. C. diphtheriae strains of 36 sequence-types (ST) were identified on the territory of Russia - 27 previously known and 9 novel, detected for the first time. 2 sequence types ST25 and ST8 (22% and 18%) dominated. Inter-relation between phenotype properties (toxigenicity and biovar) and membership of C. diphtheriae strains in certain sequence-types was shown - toxigenic and non-toxigenic C. diphtheriae strains of various biovars were characterized by certain sequence-types. Changes of clonal composition of C. diphtheriae population in dynamics of epidemic process of diphtheria infection were shown. Conclusion. Use of MLST allowed to characterized clonal composition of C. diphtheriae strains’ population in Russia and has shown perspectives of use of this method to characterize population of diphtheria causative agent, detect epidemically significant strains and decipher foci of diphtheria infection.