EVALUATION OF THE INTRAVAGINAL ADMINISTRATION OF HUMAN VAGINAL LACTOBACILLI IN A MURINE EXPERIMENTAL MODEL

DE GREGORIO PR ; JUÁREZ TOMÁS MS; SANTOS V; NADER-MACÍAS MEF

Congreso; VII CONGRESO ARGENTINO DE MICROBIOLOGÍA. SAMIGE DEL BICENTENARIO; 2011

The female urogenital tract diseases (DTUG) are the result of an imbalance of the ecosystem urogenital, produced by endogenous factors (own host) or exogenous. The above factors affect the vaginal microbiota indigenous resulting in a decrease in lactic acid bacteria protective, mainly lactobacilli which are the predominant organisms of the ecosystem in balance. One of the alternatives proposed for the prevention and/or treatment of DTUG is the use of probiotic products containing acid lactic bateria. The objectives of the present work were to evaluate if vaginal lactobacilli selected by their potentially probiotic properties are recuperated in the vaginal tract of mice once inoculated intra vaginally and if they produce some type of adverse effect. Five different strains of human vaginal lactobacilli (Lactobacillus gasseri CRL (Centro de Referencia para Lactobacillos Strains Collection) 1263, L. gasseri CRL 1509, L. reuteri CRL 1324, L. salivarius CRL 1328 and L. rhamnosus CRL 1332 were studied. They were administered intravaginally in order to 107 and 108 CFU/ml to different groups of mice cycled to the same point of the estrous cycle with an intramuscular single dose of 0.5 mg of estradiol hemisuccinate 48 hours before the beginning of the experiments. The inoculations to mice were performed two times every day (10 hours in between) during two days. Mice were sacrificed at 2 and 4 days post-inoculation to determine the number of lactobacilli in vaginal washings. Standard cytology and histological techniques were applied to study the production of adverse effect.  The recuperation of L. gasseri CRL 1263 and L. salivarius CRL 1328 inoculated in different doses intaravaginally in mice was evaluated in vaginal washings and homogenate. Mice were inoculated two times every day (10 hours in between) during two days (dose 1) or four days (dose 2). The sacrificed were realised at 2, 5 and 7 days post-inoculations. The five strains were able to persist in the vaginal tract to day 4, being the results similar on all strain assayed. On day 2 post-inoculation all the strain were present in vaginal washing in the order of 103 to 104 CFU/ 50 µl. On day 4 were observed in all the strain a decrease of 1-2 logarithmic units compared to day 2. The inoculation of lactobacilli no produced modification to structural level in the vaginal tract of mice, the patterns of the different layers of the epithelial and connective tissues were similar both in control mice and lactobacilli-treated mice in all the days studied.  With dose 1 was observed that the viable counts both L. gasseri CRL 1263 and L. salivarius CRL 1328 were in the order the 103 CFU/50µl and 103 CFU/70mg in vaginal washing and homogenates respectively. Only L. salivarius CRL 1328 persist in the vaginal tract to day 5 post-inoculation being its viable counts higher in vaginal washing (102 CFU/ 50µl) than in homogenates (10 CFU/ 70 mg). With dose 2 there was no significant difference with respect to the results obtained with dose 1. The results presented in this work support the use of vaginal lactobacilli as probiotics to restore the ecological balance of the tract, because they do not produce adverse effect.