Publications & Reports

Vaginal concentrations of lactic acid potently inactivate HIV.

Aldunate M, Tyssen D, Johnson A, Zakir T, Sonza S, Moench T, Cone R, Tachedjian G
Centre for Virology, Burnet Institute, Melbourne, Victoria 3004, Australia.


OBJECTIVES: When Lactobacillus spp. dominate the vaginal microbiota of women of reproductive age they acidify the vagina to pH <4.0 by producing approximately 1% lactic acid in a nearly racemic mixture of d- and l-isomers. We determined the HIV virucidal activity of racemic lactic acid, and its d- and l-isomers, compared with acetic acid and acidity alone (by the addition of HCl). METHODS: HIV-1 and HIV-2 were transiently treated with acids in the absence or presence of human genital secretions at 37 degrees C for different time intervals, then immediately neutralized and residual infectivity determined in the TZM-bl reporter cell line. RESULTS: l-lactic acid at 0.3% (w/w) was 17-fold more potent than d-lactic acid in inactivating HIVBa-L. Complete inactivation of different HIV-1 subtypes and HIV-2 was achieved with >/=0.4% (w/w) l-lactic acid. At a typical vaginal pH of 3.8, l-lactic acid at 1% (w/w) more potently and rapidly inactivated HIVBa-L and HIV-1 transmitter/founder strains compared with 1% (w/w) acetic acid and with acidity alone, all adjusted to pH 3.8. A final concentration of 1% (w/w) l-lactic acid maximally inactivated HIVBa-L in the presence of cervicovaginal secretions and seminal plasma. The anti-HIV activity of l-lactic acid was pH dependent, being abrogated at neutral pH, indicating that its virucidal activity is mediated by protonated lactic acid and not the lactate anion. CONCLUSIONS: l-lactic acid at physiological concentrations demonstrates potent HIV virucidal activity distinct from acidity alone and greater than acetic acid, suggesting a protective role in the sexual transmission of HIV.



  • Journal: The Journal of Antimicrobial Chemotherapy
  • Published: 08/05/2013
  • Volume: 68
  • Issue: 9
  • Pagination: 2015-25


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