O1 Serogroup Cholera Vibrios Isolated from the Rostov-on-Don Water Bodies in the Course of Surveillance in 2008–2012

Identified are the peculiarities of biological properties and origin of cholera vibrio O1 serogroup strains isolated from the Rostov-on-Don water bodies in the course of surveillance in 2008–2012. 41 atoxigenic V. cholerae O1 strains have been isolated from 767 water samples and investigated. Stable tendency of isolation of increased numbers of atoxigenic V. cholerae O1 strains over time has been demonstrated. In addition, in the strains under study detected have been the genes of additional pathogenicity factors, by PCR genotyping using specific primers for 45 nucleotide sequences associated with V. cholerae pathogenicity. The strains have also been classified according to 19 VNTR-genotypes grouped into 6 clusters based on VNTR-typing using exclusive copyright locus-specific primers. Discovered have been the strains with similar genotypes though isolated at different points both throughout the year and over the period of several years. These ones have probably been imported. They are characterized by a capacity to persist in ambient water bodies for a certain period of time

Cholera Vibrios non-O1/non-O139 Isolated in the Process of Epidemiological Monitoring over Rostov-on-Don Water Basins and Drain Sewage System within the Period of 2009–2011

Studied have been biological properties of cholera vibrios non-O1/non-O139 circulating in the Rostov-on-Don surface waters and drain sewage system within the period of 2009–2011. Overwhelming majority of the isolates have been classified as typical ones in terms of their phenotype. However 90 strains (21 %) out of total 280 have been identified as atypical ones against agglu­tina­bility in the slide-agglutination and full-scale agglutination reaction to diagnostic cholera sera. Put forward are recommendations on performance of the differentiation between V. cholerae non-O1/non-O139 and V. cholerae O1/O139. Specified are predominant sero­groups of the strains which turned to be unchanged within the stated period (O16, O53, O76, and O67). Revealed is the strain genotype variability and low probability of virulence manifestations. Demonstrated is the futility of the blind gene- and serological typing of aquatic strains

Stabilized Phase Variants of <I>Vibrio cholerae</I> El Tor P-18895

Produced have been stabilized phase variants of V. cholerae El Tor P-18895 (O- and rugose colonies). Frequency of reversion to initial ST-phenotype does not exceed 10 %. Identity of the origin is verified in VNTR. Evaluated has also been their activity by means of the following diagnostic tests: agglutination assay, sensitivity to diagnostic bacteriophages test, and studies of growth behavior in solid nutrient media. Stabilized variants of V. cholerae El Tor P-18895 can be deployed for further investigations of peculiarities of biofilm formation on various surfaces, bacterial resistance to environmental factors, and for the enhancement of methods for isolation of cholera vibrio variants from ambient environment