Comparative Analysis of Survival Capacity among Typical and Genovariant Strains of <i>Vibrio cholerae</i>, Biovar El Tor <i>in vivo</i> and <i>in vitro</i>

Abstract

Objective of the study was to conduct experiments on survival capacity of toxigenic genovariant strains as compared to typical strains of V. cholerae , biovar El Tor in autoclaved river water and in the organism of laboratory animals. Consequently, it was determined that both, genovariant and typical El Tor vibrios, sustained for a significant period of time (more than 5 months) in the river water, though a number of the bacterial cells in the population of the typical ones gradually decreased, while in the genovariant strains - the growth was observed in between the 7th and 21st day. CFU of the genovariants was 1.5-2.5 and 1.8-3.0 times higher than the amount of typical strain bacteria on the day 7 and day 21, respectively. Selective advantage of genovariants was also confirmed by competitive test in vitro . Furthermore, genovariants dominated over typical strains of V. cholerae , biovar El Tor in the mixed population in vivo (bioassay animals): CFU of the genovariants 1.25-84.0 times exceeded that of the typical strains when seeding out the contents of intestine and gastrointestinal wall homogenate. Put forward was an assumption that one of the factors for genovariant selective advantage might be enhanced adaptation ability affected by changes of cell metabolic activity. Identified capacity of genovariant toxigenic strains - not only to sustain in open water bodies of our country, but also to propagate in there, creates unfavorable epidemiological situation on cholera.

Keywords

• геноварианты v cholerae биовара эль тор
• выживаемость
• речная вода
• лабораторные животные
• genovariants of vibrio cholerae
• biovar el tor
• survival capacity
• river water
• laboratory animals