SPECIES IDENTIFICATION OF VAGINAL LACTOBACILLI ISOLATED IN REPRODUCTIVE-AGE WOMEN

Objective. To determine the species composition of microaerophilic lactobacilli in reproductive-age women in normocenosis, mesocenosis, and bacterial vaginosis. Subjects and methods. Three hundred and eighty-sixty lactobacilli isolated from the vagina of 30 nonpregnant women of reproductive age, among whom 10 had normocenosis, 10 had mesocenosis, and 10 had bacterial vaginosis. Lactobacilli were identified from the protein spectrum by mass spectrometry. The authors studied the ability of all the isolates to synthesize hydrogen peroxide, as well as strain heterogeneity by repetitive element sequence-based polymerase chain reaction (REP-PCR) typing. Results. Isolated 379 (98.2%) lactobacilli species were identified. Six species of the Lactobacillus genus with a great predominance of 3 species: L. crispatus, L. jensenii, and L. gasseri (94.7%) were isolated. In most women of each group, Lactobacillus isolates were represented as any one species: L. crispatus (59.4%) in normocenosis, L. jensenii (53.6%) in mesocenosis, and all three leading species (30% each) in bacterial vaginosis. In women with normocenosis, 96.7% of the Lactobacillus isolates produced hydrogen peroxide, in mesocenosis, 30% of the isolates lost this capacity, and in bacterial vaginosis, the latter was absent in almost 50% of the isolates. The isolates that were from one woman and belonged to one species did not differ in PCR-derived genomic fingerprints, which suggests that they belong to one strain, but at this time the isolates show varying capacities to produce hydrogen peroxide. Conclusion. The resident vaginal microflora in reproductive-age women shows a predominance of 3 Lactobacillus species (L. crispatus, L. jensenii, L. gasseri) regardless the vaginal microbiota (normocenosis, mesocenosis, or bacterial vaginosis). Individual Lactobacillus populations are homogeneous in terms of species composition in the majority of women; the isolates genetically belong to one strain, but may differ in their ability to produce hydrogen peroxide, which counts in favor of the opinion as to the epigenomic inheritance of this sign.

vaginal Lactobacillus species, mass spectrometry, the state of vaginal microbiota, reproductive age