title: Lactobacillus proteins are associated with the bactericidal activity against E. coli of female genital tract secretions.
abstract: BACKGROUND
  Female genital tract secretions are bactericidal for Escherichia (E.) coli ex vivo. However, the intersubject variability and molecules that contribute to this activity have not been defined.
  
  
  METHODS
  The bactericidal activity and concentration of immune mediators in cervicovaginal lavage (CVL) collected from 99 healthy women were determined.
  
  
  RESULTS
  CVL reduced the number of E. coli colonies by 68% [-26, 100] (median [range]). CVL were active against laboratory and clinical isolates of E. coli, but were inactive against Lactobacillus species. Bactericidal activity correlated with the concentration of protein recovered (p<0.001), but not with cytokines, chemokines or antimicrobial peptides. Four CVL with>90% inhibitory activity (active) and two with<30% activity were subjected to MS/MS proteomic analysis. 215 proteins were identified and six were found exclusively in active samples. Four of these corresponded to Lactobacillus crispatus or jensenii proteins. Moreover, culture supernatants from Lactobacillus jensenii were bactericidal for E. coli.
  
  
  CONCLUSIONS
  Both host and commensal microbiota proteins contribute to mucosal defense. Identification of these proteins will facilitate the development of strategies to maintain a healthy vaginal microbiome and prevent colonization with pathogenic bacteria such as E. coli that increase the risk for urinary tract infections, preterm labor and perinatal infection.
authors.affiliation: Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, United States of America.
authors.forename: Sabah
authors.initials: S
authors.lastname: Kalyoussef
authors.forename: Edward
authors.initials: E
authors.lastname: Nieves
authors.forename: Ellen
authors.initials: E
authors.lastname: Dinerman
authors.forename: Colleen
authors.initials: C
authors.lastname: Carpenter
authors.forename: Viswanathan
authors.initials: V
authors.lastname: Shankar
authors.forename: Jamie
authors.initials: J
authors.lastname: Oh
authors.forename: Berta
authors.initials: B
authors.lastname: Burd
authors.forename: Ruth H
authors.initials: RH
authors.lastname: Angeletti
authors.forename: Karen W
authors.initials: KW
authors.lastname: Buckheit
authors.forename: David N
authors.initials: DN
authors.lastname: Fredricks
authors.forename: Rebecca P
authors.initials: RP
authors.lastname: Madan
authors.forename: Marla J
authors.initials: MJ
authors.lastname: Keller
authors.forename: Betsy C
authors.initials: BC
authors.lastname: Herold
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry; D002584:Cervix Uteri / Q000382:microbiology* / Q000473:pathology; D019286:Endopeptidase K / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D005260:Female; D005836:Genitalia, Female / Q000382:microbiology; D006801:Humans; D007778:Lactobacillus / Q000378:metabolism; D008875:Middle Aged; D040901:Proteomics / Q000379:methods; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods; D007507:Therapeutic Irrigation / Q000379:methods; D014552:Urinary Tract Infections / Q000382:microbiology; D014621:Vagina / Q000382:microbiology* / Q000473:pathology; D016585:Vaginosis, Bacterial / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D019286:Endopeptidase K