Chainikova, I.N., Valyshev, A.V., Livshits, N.M., Smolyagin, A.I., Bondarenko, V.M., Bukharin, O.V.

Influence of plasmid pR50 controlling bacterial protease activity on Salmonella experimental infection

Medical Academy, Institute of Cellular and Intracellular Symbiosis, Orenburg; Gamaleya Research Institute of Epidemiology and Microbiology, Moscow, Russia

The comparative analysis of the infectious process and immunological parameters in (CBA ґ C57BL/6)F1 mice infected with S.typhimurium isogenic strains differing by the presence of plasmid pR50 determining protease activity, was carried out. A growth in the expression level of antilactoferrin, anticomplementary and anti-immunoglobulin activity in bacteria isolated from the spleen in the course of the infectious process was detected. In mice infected with S.typhimurium having plasmid pR50, in contrast to nonplasmid recipients, a higher level of contamination of organs, the suppression of spontaneous, stimulated production of interferon-γ and the bactericidal properties of peritoneal macrophages were noted. The data obtained in this investigation suggested that the acquisition of R-plasmid of 50 MD, controlling protease activity and multiple medicinal resistance, contributed to the persistence of intracellular bacteria.
Zh. Mikrobiol. (Moscow), 2006, No. 1, P. 6—9