title: Lactobacillus crispatus inhibits growth of Gardnerella vaginalis and Neisseria gonorrhoeae on a porcine vaginal mucosa model.
abstract: BACKGROUND
  The vaginal microbiota can impact the susceptibility of women to bacterial vaginosis (BV) and sexually transmitted infections (STIs). BV is characterized by depletion of Lactobacillus spp., an overgrowth of anaerobes (often dominated by Gardnerella vaginalis) and a pH > 4.5. BV is associated with an increased risk of acquiring STIs such as chlamydia and gonorrhea. While these associations have been identified, the molecular mechanism(s) driving the risk of infections are unknown. An ex vivo porcine vaginal mucosal model (PVM) was developed to explore the mechanistic role of Lactobacillus spp. in affecting colonization by G. vaginalis and Neisseria gonorrhoeae.
  
  
  RESULTS
  The data presented here demonstrate that all organisms tested can colonize and grow on PVM to clinically relevant densities. Additionally, G. vaginalis and N. gonorrhoeae form biofilms on PVM. It was observed that lactic acid, acetic acid, and hydrochloric acid inhibit the growth of G. vaginalis on PVM in a pH-dependent manner. N. gonorrhoeae grows best in the presence of lactic acid at pH 5.5, but did not grow well at this pH in the presence of acetic acid. Finally, a clinical Lactobacillus crispatus isolate (24-9-7) produces lactic acid and inhibits growth of both G. vaginalis and N. gonorrhoeae on PVM.
  
  
  CONCLUSIONS
  These data reveal differences in the effects of pH, various acids and L. crispatus on the growth of G. vaginalis and N. gonorrhoeae on a live vaginal mucosal surface. The PVM is a useful model for studying the interactions of commensal vaginal microbes with pathogens and the mechanisms of biofilm formation on the vaginal mucosa.
authors.affiliation: Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, 4-442 McGuire Translational Research Facility, 2001 6th St. SE, Minneapolis, MN, 55455, USA. bresh006@umn.edu.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Breshears
authors.affiliation: Institute for Genome Sciences, University of Maryland, School of Medicine, Bio Park II, 6th Floor, 801 West Baltimore St., Baltimore, MD, 21201, USA. VEdwards@som.umaryland.edu.
authors.forename: Vonetta L
authors.initials: VL
authors.lastname: Edwards
authors.affiliation: Institute for Genome Sciences, University of Maryland, School of Medicine, Bio Park II, 6th Floor, 801 West Baltimore St., Baltimore, MD, 21201, USA. jravel@som.umaryland.edu.
authors.forename: Jacques
authors.initials: J
authors.lastname: Ravel
authors.affiliation: Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, 4-442 McGuire Translational Research Facility, 2001 6th St. SE, Minneapolis, MN, 55455, USA. peter377@umn.edu.
authors.forename: Marnie L
authors.initials: ML
authors.lastname: Peterson
mesh_terms: D000818:Animals; D000898:Antibiosis; D002264:Carboxylic Acids / Q000378:metabolism; D005260:Female; D006194:Gardnerella vaginalis / Q000254:growth & development*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007778:Lactobacillus / Q000254:growth & development / Q000502:physiology*; D008297:Male; D023421:Models, Animal; D009092:Mucous Membrane / Q000382:microbiology*; D009344:Neisseria gonorrhoeae / Q000254:growth & development*; D009924:Organ Culture Techniques; D013552:Swine; D014621:Vagina / Q000382:microbiology*
chemical_list: D002264:Carboxylic Acids