Dynamic in vitro of urogenital E.coli biofilm by estradiol influence
A.E. FARINATI, M. QUINTEROS, M. ARCOS, M.MARQUES, L.SIBERT, N. ROSIERE2; J.GARCIA Universidad del Salvador, Microbiology Department
Bacterial biofilms are associated with a large number of persistent and chronic infections like recurrent urinary tract infections (RUTI) in posmenopausic women. The uropathogenic E.coli (UPEC) adherence to perineal areas and vaginal mucosa is one of the first steps to initiate RUTI. The patients with this pathology were subjected to different prophylactic antibiotic regimens but not always the improvement occurs. Despite significant advances in the understanding of UPEC biology, it is not clear which factors are involved in the recurrence and how to control the RUTI. In previous works we demonstrated the different estrogen activity against vaginal and urogenital biofilms. Aim:to study the in vitro influence of Estradiol Hemisuccinate (EH) on the E.coli BF dynamic as a model for non antibiotic strategy of RUTI control. Methods: 1-Qualitative assay: we study 30 E.coli isolates from urinary tract infections (UTI). The UPEC BF was investigated using a previously described method. Briefly, each UPEC were placed in 6 tubes with Trypticase Soy Broth (TSB). After overnight incubation at 36ºC, one glass coupon (GC) was placed in each tube as an abiotic surface. EH was added to 4 tubes (200 μg/ml) from the beginning (2) and after 12 hours (2). The other 2 were used as controls. All glass coupons were stained with crystal violet and readed at 12 and 24 hours after incubation at 36ºC, by optical microscope. 2- Quantitative assay: We used microtiter assay (MA) to study the early stage of BF formation and the EH concentrations (200 to 25 ug/ml) influence. Following 12 and 24 hours of incubation and the remotion of planktonic bacteria, the crystal violet coloration was employed. For reading a RT-2100C microprocessor (absorbance mode with λ 450nm) was employed. Results: EH improves UPEC BF in the early stage: is more thick and homogeneous than the ones without EH, but at 24 hours fragmentation and dispersion was shown in all isolates tested mainly in presence of exuberant exopolisacharide. The EH activity could not be concentration dependent because the different dilutions have not shown influence on BF quantification. Conclusions: E.coli BF detachment and dispersion are factors to consider as possible strategy to control postmenopausal RUTI. The possibility of local estradiol application on women perineal area is important to restrict the BF development, and the selective pressure due to continuous employ of antibiotics in these patients.