[Experimental study of antiviral activity of spore-forming bacterium Bacillus pumilus "Pashkov"].

AIM

To study antiviral activity of metabolites of spore-forming strain "Pashkov" of B. pumilus on the model of enterovirus infection in vitro.

MATERIALS AND METHODS

B. pumilus strain "Pashkov" isolated from environment and identified by common methods. Cell cultures: Vero-6, Vero-ECC, and Vero-E6. Enteroviruses: type 1 poliovirus, Coxsackie B virus (1-6), ECHO-3, and ECHO-6 viruses. Unfectious activity of viruses was evaluated according to their cytopathogenic effect on Vero- E6 cell line by method of serial dilutions. Cultural fluid (CF) for the study was obtained by centrifugation and sterilizing filtration of B. pumilus strain "Pashkov" biomass produced by cultivation during 72 hours on optimized nutrient medium. Cytotoxicity of CF (chronic and acute) and maximal tolerated dose were measured by effect on viability of Vero-E6 cells, which was assessed by trypan blue exclusion test of cell viability. For measurement of antiviral activity (AV-activity), two treatment schedules--therapeutic and prophylactic--were used.

RESULTS

The most sensitive cell lines were Vero-ECC and Vero-E6. Assessment of AV-activity showed that protective effect was observed for all dilutions of CF and lasted for 7 days from time of infection by used doses of virus. CF does not have acute and chronic cytotoxicity. CF studied in vitro with Vero-E6 cells infected with 4 types of enteroviruses provided protection against viruses and had prophylactic effect. Degree of effect of CF depended from type of enterovirus, dose used and CF dilution.

CONCLUSION

For the first time effective antiviral activity of CF, which have low cytotoxicity for Vero-E6 cell culture in vitro and is produced by strain "Pashkov" of B. pumilus, was demonstrated. Obtained data open perspectives for development of medications against enterovirus infections.