Comparative analysis of adaptation properties in typical and genetically altered Vibrio cholerae El Tor strains

Abstract

Aim. Study of biological properties in natural strains of genovariants of V. cholerae biovar El Tor, affecting their adaptation capacities under nutrient deficiency while comparing them with typical strains. Materials and methods. Competitive sampling was carried out through plating a mixture of cells of the two strains under investigation into autoclaved river water. Growth rate was evaluated through the optic density values. Gene expression was studied applying RT-PCR with designed primers and probes. Results. It is established that during combined cultivation of V. cholerae El Tor typical strains and genovariants under the shortage of nutrient substances (autoclaved river water), at room temperature, the level of survivability in genetically altered strains is higher than in typical strains, which points to their expressed adaptation advantages over the typical ones under the stated conditions. It is demonstrated that selective benefits of genovariant strains are provided by higher cell growth rate and increased rpoS gene expression. Conclusion. Obtained have been new data on the ability of bacterial strains of V. cholerae El Tor genovariants to rapidly grow and better express global regulator of stress response, rpoS gene, which, probably, contributes to their enhanced adaptation not only under nutrient deficiency, but under the influence of other stress factors too.