[Viability and virulence of Francisella tularensis subsp. Holarctica in water ecosystems (experimental study)]

Under conditions of artificial water biocenosis a virulent strain of F. tularensis could be detected in fresh water shrimps and mollusks for about a month, in Conepoda for up to 20 days and in Chydorus sphaericus for up to 7 days from the moment of the aquaria water contamination. In silt F. tularensis could be detected for a longer period (up to 2 months). Daphnia, Oligochaeta and C. sphaericus appeared to be unfavorable environment for this microorganism. The virulence level of F. tularensis microbial cells decreased in paralell with prolongation of their stay in water biocenosis. The presence of water biota favours F. tularensis preservation in water reservoirs for a longer time.