title: Lactobacillus crispatus dominant vaginal microbiome is associated with inhibitory activity of female genital tract secretions against Escherichia coli.
abstract: OBJECTIVE
  Female genital tract secretions inhibit E. coli ex vivo and the activity may prevent colonization and provide a biomarker of a healthy microbiome. We hypothesized that high E. coli inhibitory activity would be associated with a Lactobacillus crispatus and/or jensenii dominant microbiome and differ from that of women with low inhibitory activity.
  
  
  METHODS
  Vaginal swab cell pellets from 20 samples previously obtained in a cross-sectional study of near-term pregnant and non-pregnant healthy women were selected based on having high (>90% inhibition) or low (<20% inhibition) anti-E. coli activity. The V6 region of the 16S ribosomal RNA gene was amplified and sequenced using the Illumina HiSeq 2000 platform. Filtered culture supernatants from Lactobacillus crispatus, Lactobacillus iners, and Gardnerella vaginalis were also assayed for E. coli inhibitory activity.
  
  
  RESULTS
  Sixteen samples (10 with high and 6 with low activity) yielded evaluable microbiome data. There was no difference in the predominant microbiome species in pregnant compared to non-pregnant women (n = 8 each). However, there were significant differences between women with high compared to low E. coli inhibitory activity. High activity was associated with a predominance of L. crispatus (p<0.007) and culture supernatants from L. crispatus exhibited greater E. coli inhibitory activity compared to supernatants obtained from L. iners or G. vaginalis. Notably, the E. coli inhibitory activity varied among different strains of L. crispatus.
  
  
  CONCLUSIONS
  Microbiome communities with abundant L. crispatus likely contribute to the E. coli inhibitory activity of vaginal secretions and efforts to promote this environment may prevent E. coli colonization and related sequelae including preterm birth.
authors.affiliation: Department of Obstetrics & Gynecology and Women's Health, Albert Einstein College of Medicine, Bronx, New York, United States of America.
authors.forename: Jeny P
authors.initials: JP
authors.lastname: Ghartey
authors.affiliation: Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, United States of America.
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Smith
authors.affiliation: Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, United States of America.
authors.forename: Zigui
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, United States of America.
authors.forename: Niall
authors.initials: N
authors.lastname: Buckley
authors.affiliation: Departments of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York, United States of America.
authors.forename: Yungtai
authors.initials: Y
authors.lastname: Lo
authors.affiliation: Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York, United States of America.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Ratner
authors.affiliation: Department of Obstetrics & Gynecology and Women's Health, Albert Einstein College of Medicine, Bronx, New York, United States of America; Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, United States of America; Department of Microbiology-Immunology, Albert Einstein College of Medicine, Bronx, New York, United States of America.
authors.forename: Betsy C
authors.initials: BC
authors.lastname: Herold
authors.affiliation: Department of Obstetrics & Gynecology and Women's Health, Albert Einstein College of Medicine, Bronx, New York, United States of America; Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, United States of America; Departments of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York, United States of America; Department of Microbiology-Immunology, Albert Einstein College of Medicine, Bronx, New York, United States of America.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Burk
mesh_terms: D000328:Adult; D004926:Escherichia coli / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D007778:Lactobacillus / Q000302:isolation & purification*; D064307:Microbiota; D011247:Pregnancy; D014621:Vagina / Q000382:microbiology*; D055815:Young Adult