Assessment of the capacity of Lactobacillus to inhibit the growth of uropathogens and block their adhesion to vaginal epithelial cells

To gain insight into the mechanisms by which Lactobacillus blocks the adher ence of uropathogens to vaginal epithelial cells and inhibits their growth, 15 Lactobacillus strains and 22 uropathogens were studied. Lactobacilli fr om hemagglutination group III, identified as Lactobacillus crispatus, showe d greater capacity to block uropathogen adherence than those from hemagglut ination groups II and I (61.9%, 49.5%, and 52.6% of blockage, respectively) . Pseudomonas aeruginosa PA5 and Klebsiella pneumoniae KP7 were the uropath ogens most susceptible to blockage, and Staphylococcus aureus SA11 and Prot eus mirabilis PM1 were the most resistant. Lactobacillus inhibited uropatho gen growth better in liquid assays; the 3 Lactobacillus groups showed simil ar inhibitory power (72.3%, 71.9%, and 74.2% of light transmittance). P. ae ruginosa PA5 was the most inhibited, and Enterococcus species E15 was the l east inhibited. There is considerable variation among Lactobacillus strains regarding their adherence to uroepithelium, blockage of uropathogen attach ment, and inhibition of uropathogen growth. Although these properties are i ndependent, they may coincide and therefore allow for these strains to bala nce the vaginal ecosystem and to make them useful as probiotics.