title: The antimicrobial effect of boric acid on Trichomonas vaginalis.
abstract: BACKGROUND
  The treatment options for trichomoniasis are largely limited to nitroimidazole compounds (metronidazole and tinidazole). Few alternatives exist in cases of recalcitrant infections or in cases of nitroimidazole hypersensitivity. Recently, the intravaginal administration of boric acid has been advocated as an alternative treatment of trichomoniasis. However, no in vitro studies are available that directly assess the sensitivity of Trichomonas vaginalis to boric acid.
  
  
  METHODS
  We examined the sensitivity of common laboratory strains and recent clinical isolates of T. vaginalis to boric acid. The effect of increasing concentrations of boric acid on parasite growth and viability was determined, and a minimal lethal concentration was reported. The effect of pH on boric acid toxicity was assessed and compared with that of lactic and acetic acid.
  
  
  RESULTS
  Boric acid is microbicidal to T. vaginalis, and its antitrichomonal activity is independent of environmental acidification. Unlike acetic acid and lactic acid, boric acid exposure results in growth suppression and lethality over a wide range of pH (5-7) and under conditions that are normally permissible for growth in vitro.
  
  
  CONCLUSIONS
  The microbicidal effect of boric acid on T. vaginalis, coupled with its previous clinical use in treating vaginal candidiasis, supports the continued inclusion of boric acid in the therapeutic arsenal for treating trichomoniasis.
authors.affiliation: From the *Departments of Microbiology and Immunology, and †Biochemistry and Nutrition, Des Moines University, Des Moines, IA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Brittingham
authors.forename: Wayne A
authors.initials: WA
authors.lastname: Wilson
mesh_terms: D000282:Administration, Intravaginal; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001888:Boric Acids / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006801:Humans; D016896:Treatment Outcome; D014247:Trichomonas Vaginitis / Q000188:drug therapy*; D014246:Trichomonas vaginalis / Q000254:growth & development* / Q000302:isolation & purification
chemical_list: D000890:Anti-Infective Agents; D001888:Boric Acids; C032688:boric acid