Vol 34(2018) N 2 p. 70-79; DOI 10.21519/0234-2758-2018-34-2-70-79
A.A. Kritskii, N.B. Cheldyshova, S.P. Zadnova*, N.A. Plekhanov, and N.I. Smirnova

A Method for Simultaneous Detection of Vibrio cholerae Strains and Drug Resistance Genes in their Genome by Means of Real-Time PCR

The Russian Research Anti-Plague Institute Microbe, 410005, Saratov Russia

Received - 26.12.2017; Accepted - 14.02.2018


A method for simultaneous detection of the occurrence of V. cholerae strains and of the presence of drug resistance genes in their genomes applying PCR with real-time results registration has been developed. The resistance to four antibiotics used for the cholera treatment (tetracycline, trimethoprim, chloramphenicol and ciprofloxacin) was analyzed. The sensitivity of the panel was 1*103 CFU/ml in both pure cultures, imitated clinical material and environmental samples. The efficiency of the PCR was confirmed by the analysis of 60 natural V. cholerae strains isolated in different years from patients and environment. It was established that all the studied V. cholerae O1 biovar El Tor strains isolated before 1993 do not contain the tested drug resistance genes. At the same time, 18 toxigenic clinical strains (90%) imported within 1993-2010 are characterized by a multiple drug resistance; their genomes have the genes of resistance to trimethoprim (dfrA1) and chloramphenicol (floR), whereas 11 strains among them additionally contain the tetR gene providing the tetracycline resistance. Apart from this, non-toxigenic clinical and aqueous V. cholerae strains carrying the qnrVC (qnrVC1) gene responsible for the resistance to ciprofloxacin have been detected during the last few years (Kalmykia, 2011-2013).

drug resistance genes, multiplex real-time PCR, Vibrio cholerae.