Effects of over-the-counter herbal preparations on biofilm formation by the urinary tract pathogen Staphylococcus saprophyticus

Abstract

Staphylococcus saprophyticus is a Gram-positive bacterium that causes urinary tract infections in children, adolescent and adult women, and older adults fitted with catheters. A key virulence factor is its ability to form biofilms on the uroepithelium and implanted devices. Biofilm formation in laboratory cultures of S. saprophyticus was measured after growth in polystyrene plates and staining with crystal violet. Biofilm formation by the type strain ATCC 15305 in enriched P medium or an artificial urine medium was inhibited by commercially-available samples of green tea extract, Uva ursi, turmeric, and cranberry but varied from one supplier to another. It was not inhibited by many other herbal preparations. Although biofilm formation was not reduced by purified gallic acid, catechin, epigallocatechin gallate, or arbutin, it was inhibited by purified curcumin. These results indicate that some caution should be used in selecting herbal preparations to treat urinary tract infections.