Experimental investigations on the immunomodulating activity of polybacterial preparation for peroral immunotherapy and immunoprophylaxis of uroinfections.

The immunomodulating effect of a polybacterial immunostimulator Urostim in experimental animal models was investigated. The preparation was created for immunotherapy and immunoprophylaxis of uroinfections. It consists of killed bacterial cells and their lysates of four microbial species: Escherichia coli expressing type 1 pili, Rc mutant of E. coli, Klebsiella pneumoniae, Proteus mirabilis and Enterococcus faecalis, BALB/c mice and guinea-pigs were treated orally with Urostim for 5 or 10 days, respectively. A stimulatory effect of Urostim on phagocytosis (increased phagocytic index and phagocytic number) of mice peritoneal exudate cells was observed. An increased number of plaque-forming cells and elevated titres of haemagglutinating antibodies in mice demonstrated activation of humoral immunity. Lymphoproliferative studies showed a significant response to phytohaemagglutinin (PHA) and Urostim, especially after the second application of the preparation. At the same time no changes in the absolute number of peripheral blood lymphocytes were found. An active protection of mice against a systemic infection and of guinea-pigs against uroinfection caused by Gram-negative bacteria was obtained. In conclusion, the results obtained characterize Urostim as an effective immunostimulator. Its peroral application leads to the activation of innate resistance, cell-mediated, humoral and local immunity.