The identification of vaginal Lactobacillus species and the demographic and microbiologic characteristics of women colonized by these species.

Lactobacillus acidophilus has been reported to be the predominant vaginal species. Vaginal lactobacilli isolated from 215 sexually active women were identified using whole-chromosomal DNA probes to 20 American Type Culture Collection Lactobacillus strains. Most women were colonized by L. crispatus (32%), followed by L. jensenii (23%), a previously undescribed species designated L. 1086V (15%), L. gasseri (5%), L. fermentum (0.3%), L. oris (0.3%), L. reuteri (0.3%), L. ruminis (0.3%), and L. vaginalis (0.3%). H2O2 was produced by 95% of L. crispatus and 94% of L. jensenii isolates, compared with only 9% of L. 1086V. Colonization by L. crispatus or L. jensenii was positively associated with being white (P<.001), age >/=20 years (P=.05), barrier contraceptive usage (P=.008), and lower frequency of bacterial vaginosis (P<.001) and gonorrhea (P=.03). L. crispatus and L. jensenii, not L. acidophilus, are the most common species of vaginal lactobacilli.