[Phylogenetic analysis of genomes of Vibrio cholerae strains isolated on the territory of Rostov region].

AIM: Determination of origin of 2 Vibrio cholerae strains isolated on the territory of Rostov region by using full genome sequencing data. MATERIALS AND METHODS: Toxigenic strain 2011 EL- 301 V. cholerae 01 El Tor Inaba No. 301 (ctxAB+, tcpA+) and nontoxigenic strain V. cholerae O1 Ogawa P- 18785 (ctxAB-, tcpA+) were studied. Sequencing was carried out on the MiSeq platform. Phylogenetic analysis of the genomes obtained was carried out based on comparison of conservative part of the studied and 54 previously sequenced genomes. RESULTS: 2011EL-301 strain genome was presented by 164 contigs with an average coverage of 100, N50 parameter was 132 kb, for strain P- 18785 - 159 contigs with a coverage of69, N50 - 83 kb. The contigs obtained for strain 2011 EL-301 were deposited in DDBJ/EMBL/GenBank databases with access code AJFN02000000, for strain P-18785 - ANHS00000000. 716 protein-coding orthologous genes were detected. Based on phylogenetic analysis strain P- 18785 belongs to PG-1 subgroup (a group of predecessor strains of the 7th pandemic). Strain 2011EL-301 belongs to groups of strains of the 7th pandemic and is included into the cluster with later isolates that are associated with cases of cholera in South Africa and cases of import of cholera to the USA from Pakistan. CONCLUSION: The data obtained allows to establish phylogenetic connections with V cholerae strains isolated earlier.

[Comparative assessment of dot-immunoassay and immunochromatography methods for detection of 01 serogroup of vibrio cholerae].

AIM: Comparative study of sensitivity and specificity of immunochromatographic (IC) assay kit and dot-immunoanalysis for assessment of feasibility of their use for laboratory diagnostics of cholera. MATERIALS AND METHODS: Experimental lots of IC assay kit and dot-immunoassay (DIA) for detection of Vibrio cholerae serogroup 01 serovars Ogava and Inaba were constructed on the basis of species-specific monoclonal antibodies (MCA) conjugated with colloid gold (IC) and peroxidase (DIA). Hybridoma-producer of MCAwas obtained and stored in liquid nitrogen in Rostov-on-Don Research Institute for Plague Control. It was deposited in specialized collection of cell cultures of vertebrates in Institute of Cytology (Saint Petersburg). RESULTS: Strong specificity of IC assay kit and DIA relative to cholera vibrios 01 and absence of crossreactivity with closely related and heterologous microorganisms were shown. Minimal quantity of vibrios, which could be detected using IC assay kit and DIA, was 107 and 105-106 microbial cells respectively. CONCLUSION: Performance of IC assay takes 5-15 min, DIA--1.5 hour, they allow to visually assess the reaction, do not require instrumentation and in perspective both methods could be used on defined stages of scheme for laboratory analysis of cholera.