Uropathogenic Escherichia coli (UPEC) is the most prevalent pathogen causing urinary tract infections (UTIs). UPECs have various virulence factors such as adhesins, biofilm forming and toxin producing etc., to survive in urinary tract. Under certain circumstances probiotics are preferred for prevention and treatment of UTIs. In this study, we aimed to investigate the in-vitro effects of four different Lactobacillus spp. cell-free supernatants on growth and biofilm formation inhibition in clinically isolated UPEC strains. Growths of 50 UPEC strains were determined in 96-well microplate and measured in a spectrophotometer after four hours incubation at 37°C. Biofilm formation was detected by crystal violet staining method on three UPEC strains. Statistical analysis of growth and biofilm formation experiments were performed by Kruskal-Wallis and one-way ANOVA Tukey’s multiple-comparison tests, respectively. All tested cell-free supernatans of lactobacilli inhibited growths (p<0. 0001) and biofilm formation (p<0.05) of UPECs. All results were found to be statistically significant. As a conclusion, our findings supported previous studies which reported the high efficiency of these four Lactobacillus spp. in the prevention of UTIs.
