Effect of asiatic and ursolic acids on growth and virulence factors of uropathogenic Escherichia coli strains

This work was aimed at determining the possible antimicrobial potential of asiatic acid (AA) and ursolic acid (UA) against clinical uropathogenic Escherichia coli strains (UPECs). Phylogenetic affiliations of UPECs and virulence-associated gene carriage have been identified. PCR analysis revealed that the studied E. coli strains belong to phylogenetic group B2. All bacterial isolates were grouped into 4 pathotypes. The following were determined: the minimum inhibitory concentrations (MICs) according to CLSI; P-fimbriae synthesis, based on erythrocyte agglutination; curli fibers, by using YESCA agar with congo red; swimming motility, in motility agar; and alpha-hemolysin, on sheep's-blood agar plates. The differences in antigrowth activities of AA and UA were recorded. Inhibition of P-fimbriae, curli fibers, and alpha-hemolysin production after exposure of UPECs to both AA and UA were observed. Reduction of bacterial motility was also noticed. Our results clearly show the influence of AA and UA on virulence factors of UPEC strains. However, differences between antivirulence activities of AA and UA were not found, although a higher level of antigrowth activity of AA in comparison with UA was shown.