Phenotypic and genotypic assessment of Lactobacillus plantarum influence on Candida albicans fluconazole resistance

Lactobacilli are the most common genera of vaginal microbiota in healthy women, being involved in maintaining the microbial barrier against the development of pathogenic microorganisms in the urogenital tract. Recent studies have shown that the disturbance of microbial environmental balance in the vagina is associated with an increasing risk to develop infections. Over the last years, Candida albicans has continued to be the most frequent species isolated from vaginal yeast infections. The main goal of our studies was to determine the potential influence of lactic acid bacteria strains on the expression of C. albicans CMGBy 13 fluconazole resistance. The present study included 153 lactic acid bacteria strains isolated from fermented food products and human gastrointestinal tracts and one strain of C. albicans CMGBy13 isolated from a patient with vaginal infection. Preliminary analysis included the qualitative screening by disk diffusion assay of lactic acid bacteria strains capacity to increase the fluconazole susceptibility of yeast cells. Two lactic acid bacteria strains, Lactobacillus plantarum CMGB 1 and L. rhamnosus CMGB 38, were selected for further fluorescence microscopy and flow cytometry assays in order to establish their influence on C. albicans efflux pumps activity and, respectively, on the fluconazole resistance genes expression by RT-PCR.