Bacteriotherapy by using lactobacilli in the prevention of urinary tract infections in a mice model

CLARA SILVA DE RUIZ; MARIA ELENA FÁTIMA NADER

Badajoz, España

Conferencia; BioMicroWorld Conference. I International Conference on Envirommental, Industrial and Applied Microbiology; 2005

Biomicroworld 2005. Formatex

BACTERIOTHERAPY BY USING LACTOBACILLI IN THE PREVENTION OF URINARY TRACT INFECTIONS IN A MICE MODEL   C.SILVA, M.e.Nader-Macias UNIVERSIDAD NACIONAL DE TUCUMAN. Ayacucho 491. S.M. de Tucumán. Argentina M.E. NADER-MACIAS CERELA (Centro de Referencia para Lactobacilos) CONICET, Chacabuco 145, Tucumán, Argentina. The Urinary Tract Infections are one of the main causes of infections, mainly in prepubers and postmenopausal women, and also their recurrence. These infections produce high costs of health, morbidity, mortality and productivity losses. The preventive and therapeutic measures include subtherapeutic doses of wide spectra antibiotics for long periods of time, estrogens local therapy, local hygiene with disinfectants, etc. Another approach is the use of live microorganisms named probiotic to prevent the onset of pathogenic microorganisms. Lactobacillus are being frequently used to produce physiological effects on the host, in the gastrointestinal or urinary tract [1]. The isolation of lactobacilli from the urogenital tract of mice was performed [2] and an experimental model in mice set up to evaluate the colonization ability of selected probiotic strains [3]. The objectives of the present work was to study the preventive effect of probiotic lactobacilli against the challenge of different uropathogenic microorganisms in different conditions. L. fermentum CRL 1058, highly H202 producer, autoagglutinating strains, able to adhere to epithelial cells, was intraurethrally administered to Balb/c mice at four doses of 1x109 CFU included in microscopic agarose beads. Later, they were intraurethrally challenged with uropahogenic Escherichia coli and Klebsiella pneumonia at a dose of 1 x 109 CFU. The experiments were done by using both preventive and therapeutics experimental procedure. Mice were sacrificed by cervical dislocation at different post-challenge days. Microbiological, cytological, histological and electronic microscopy studies were performed at the urinary tract organs (urethra, ureter, bladder and kidney). The levels of sera antibodies was also studied. The effect of antibiotics (ampicilin) and estradiol were also studied on the kinetics of colonization of lactobacilli and pathogens. The results showed that L. fermentum CRL 1058 is able to colonize the urinary tract of mice up to 7th days  post-administration, without producing adverse effects or ultrastructural modifications in all the organs of the urinary tracts. Eventhough the therapeutic treatment with lactobacilli showed a decrease in the number of E. coli in the tract, the prevention with lactobacilli was effective by clearing all the pathogen from the tract. The preventive treatment with Ampicilin and estradiol showed an increase in the number of lactobacilli being more effective in the pathogen clearence. As there is a probiotic effect not only with viable lactobacilli, but also with dead and sonicated microorganisms, the mechanisms involved in the probiotic effect were steric hindrance, competitive exclusion, stimulation of the immune system and production of inhibitory substances Acknowledgements This work was supported by CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina) grants  References [1].Reid G, Howard J, Gan BS. Trends in Microbiol. (2001) 9: 424-428 [3].Nader M.E, M.E. López, C. Silva , A. Ruiz Holgado. Microbiologie, Aliments, Nutrition. (1992).10:43-47. [4].C. Silva, M.E. Nader, M.E. López, A.. Ruiz Holgado. Microbiologie. Aliments. Nutrition. (1993) Vol. 11:391-397. Topic: Microbial Biotechnology