[The phosphatase activity in representatives of the genus Francisella].

The comparative study of phosphatase activity in the representatives of the genus Francisella--F. tularensis, F. novicida, F. novicida-like, F. philomiragia--revealed that all the bacteria under study synthesized acidic phosphatase. The study also revealed that strains of the Central Asian subspecies possessed the highest enzymatic activity, while holarctic strains either produced no phosphatase at all, or produced less active phosphatase. Bacteria belonging to nonarctic F. tularensis subspecies and other representatives of this genus with the same area of circulation possessed the medium level of activity. Using isogenic F. tularensis variants as a model, we found out that the loss of virulence by bacteria was accompanied by an increase in phosphatase activity. Detergent (0.5% sodium dodecyl sulfate) was found to be capable of selectively inactivate this enzyme in the holarctic strains F. tularensis and F. novicida, F. novicida-like, F. philomiragia. The enzyme immunoassay of Francisella phosphatases made it possible to detect this enzyme in the nonarctic and Central Asian subspecies of F. tularensis and F. novicida, as well as in F. novicida-like, characterized by different electrophoretic mobility. No phosphatase could be visualized in F. tularensis and F. philomiragia holarctic strains.