Comparative Analysis of the Ability to Ferment Carbohydrates in Typical Strains and Genovariants of <I>Vibrio cholerae</I> Biovar El Tor

Carried out is a comparative analysis of the ability to ferment various carbohydrates in the 6 typical strains and 10 genovariants of V. cholerae biovar El Tor, imported to the territory of the Russian Federation. It has been revealed that genovariants, as well as typical El Tor vibrios, ferment mannose, saccharose, and mannite, but are inactive against arabinose and rhamnose. However, it is demonstrated that genovariants, as compared to typical strains of El Tor vibrios, possess lowered capacity to ferment glucose. Both, genovariants and classical vibrios, do not grow on the minimal media with 1 % content of glucose, and are unable to fully ferment glucose up to acetylmethylcarbinol in Voges-Proskauer reaction test. Put forward is a hypothesis that alteration of glucose metabolism in the studied strains of genovariants is probably due to changes in regulating mechanism of some virulence genes

Investigation of Protective Properties of the Constructed Recombinant Biplasmid Strain of <i>Vibrio cholerae</i> O139 Serogroup Producing Cholera Toxin B Subunit and <i>Escherichia coli</i> Colonization Factor CFA/1

The constructed avirulent biplasmid Vibrio cholerae strain KM182 producing cholera toxin B subunit and Escherichia coli colonization factor CFA/1 (providing for antitoxic and anti-colonization immunity formation, correspondently) was demonstrated to protect immunized model laboratory animals from experimental cholera caused by the virulent Vibrio cholerae O139 strain. The optimal doses for immunization and challenging were determined

A Study of Biokinetic Peculiarities and Optimization of the Conditions for Culturing Vibrio cholerae Strains Overproducing Protective Antigens Suitable for Use in the Production

Described in the work are the major biokinetic criteria of the submerged growth process of V. cholerae Ol strains (classical and eltor biovars), O139, non-Ol and non-O139 serogroups, capable of overproducing the main protective antigens (Ol and O139 antigens, type I and II cholera toxin, cholera toxin type II В subunit, toxin-coregulated adhesion pili). The optimal parameters were defined for each strain (nutritional media, pH indices, cultivation time, application of an additional carbohydrate source) facilitating the maximal yield of the protective antigens under the production conditions, thus making it possible to use them as a basis for manufacturing more efficient vaccinal preparations as well as to obtain the main V. cholerae protective antigens as purified drugs for constructing diagnostic preparations