title: Limited effectiveness of over-the-counter plant preparations used for the treatment of urinary tract infections as inhibitors of the urease activity from Staphylococcus saprophyticus.
abstract: OBJECTIVE
  Urease is a key virulence factor for the Gram-positive urinary tract pathogen Staphylococcus saprophyticus and a potential target for antimicrobial therapy. The enzyme from S. saprophyticus is unusual in that it does not contain cysteine at the active site. The aims of this study were to test 14 over-the-counter plant preparations as inhibitors of this urease and to determine whether they can prevent the increase in pH that normally occurs in bacterial cultures containing urea.
  
  
  RESULTS
  Urease activity was measured colorimetrically by the formation of ammonium ions. The green tea and Uva-Ursi preparations reduced urease activity in a soluble extract of S. saprophyticus by more than 75%. Two herbal mixtures were weakly inhibitory and reduced activity by about 25%, but the other products had little or no effect. The green tea and Uva-Ursi extracts also inhibited urease activity in whole cells by more than 75%. One of the herbal products (WishGarden UTI) showed some inhibition of urease activity but the other (UTI Clear) did not. The green tea and Uva-Ursi preparations prevented the increase in pH that normally occurs when S. saprophyticus is grown in an artificial urine medium, but this was due primarily to bacterial death. The WishGarden UTI preparation could partially delay the pH increase while allowing some cells to remain viable.
  
  
  CONCLUSIONS
  These results indicate that only a few of the commercially available over-the-counter plant preparations commonly used for the treatment of urinary tract infections (UTIs) can inhibit the urease activity from S. saprophyticus.
  
  
  CONCLUSIONS
  While over-the-counter plant preparations may be considered an alternative to traditional antibiotics for the treatment of UTIs, they should be used with caution and a product should be matched to the properties of the virulence factors of the bacterial pathogen involved.
authors.affiliation: Department of Biology, Creighton University, Omaha, NE, USA.
authors.forename: C E
authors.initials: CE
authors.lastname: Deutch
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D028321:Plant Preparations / Q000737:chemistry / Q000494:pharmacology*; D010944:Plants / Q000737:chemistry*; D013210:Staphylococcus / Q000187:drug effects; D057790:Staphylococcus saprophyticus / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D014510:Urease / Q000037:antagonists & inhibitors* / Q000378:metabolism; D014552:Urinary Tract Infections / Q000188:drug therapy / Q000382:microbiology*; D037521:Virulence Factors / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D028321:Plant Preparations; D037521:Virulence Factors; D014510:Urease
keywords: 
  Staphylococcus saprophyticus
  ; herbal medicines; urease; urease inhibitors; urinary tract infection