Protective Effect of Vaginal Lactobacillus paracasei CRL 1289 against Urogenital Infection Produced by Staphylococcus aureus in a Mouse Animal Model

摘要

Urogenital infections of bacterial origin have a high incidenceamong the world female population at reproductive age.Lactobacilli, the predominant microorganisms of the healthyvaginal microbiota, have shown a protective effect against thecolonization and overgrowth of urogenital pathogens that increasedthe interest for including them into probiotics products assignedto restore the urogenital balance. In the present work, wedetermined in a mouse animal model the capability of Lactobacillus paracasei CRL 1289, a human vaginal strain with probiotic properties, to prevent the vaginal colonization of a uropathogenic strain of Staphylococcus aureus.Six-week-old female BALB/c mice, synchronized in their estralcycle, were intravaginally inoculated with two doses of 109 lactobacilli before challenging them with a single dose of 105 or 107 CFU of S. aureus. The vaginal colonization of both microorganisms and the effect on the vaginal structure were determined at 2, 5, and 7 days after pathogeninoculation. Control mice and those challenged only with thepathogen showed an insignificant lactobacilli population, whereas 105 lactobacilli/mL of vaginal homogenate were recovered at 2days after challenge from the L. paracasei CRL 1289 andthe probiotic + pathogen groups, decreasing this number on thefollowing days. The treatment with L. paracasei CRL 1289decreased significantly the number of staphylococci recovered at 2and 5 days when mice were challenged only with 105 CFU ofpathogen. The inoculation of S. aureus produced aremarkable inflammatory response and structural alterations in thevaginal mucosa that decreases in a significant manner when themice were protected with L. paracasei CRL 1289. Theresults obtained suggest that this particular Lactobacillus strain could prevent the onset of urogenital infections by interfering with the epithelialcolonization by uropathogenic S. aureus.