The objective of the study was determining the prophylactic effect of Lactobacillus casei IMV B-7280, L. acidophilus IMV B-7279, L. delbrueckii subsp. bulgaricus IMV B-7281, Bifidobacterium animalis VKL and B. animalis VKB probiotic strains on experimental vaginitis in BALB/c mice induced by Staphylococcus aureus 8325-4. The infection with S. aureus 8325-4 caused an imbalance of microbiota in the vagina and intestine, as evidenced by an increase in the number of opportunistic microorganisms and a decrease in the amount of lactobacilli and bifidobacteria. L. casei IMV B-7280, B. animalis VKL and B. animalis VKB probiotic strains altered the microbiota spectrum of the vagina and intestine of Staphylococcus-infected mice: the amount of Lactobacillus and bifidobacteria increased with the reduction of the number of opportunistic microorganisms. Also under the influence of these strains, the normalization of the microbiota spectrum typical for vagina and intestine was observed in different periods of observation – in the intestines of mice the number of coliform bacteria increased, the number of microscopic fungi, streptococci and staphylococci decreased; in the vagina, the number of coliform bacteria and microscopic fungi decreased, the number of streptococci normalized. Rapid elimination of S. aureus 8325-4 from the vagina and prevention of the spread of infection to the intestine were observed after use of probiotics. Preventive effect of L. acidophilus IMV B-7279 and L. delbrueckii subsp. bulgaricus IMV B-7281 for bacterial vaginitis in mice was less effective. So, the target probiotic strains L. casei IMV B-7280, B. animalis VKL and B. animalis VKB are promising for the creation of highly effective novel probiotic drugs that can be used for directed prevention of infectious and inflammatory diseases of the genitourinary system caused by pathogenic and opportunistic microorganisms.