Isolation and identification of vaginal lactobacilli from 223 healthy women of childbearing age

Objective To investigate the major species of vaginal lactobacilli in healthy Chinese women and their capacity to produce hydrogen peroxide(H2O2).Methods Vaginal swab samples were collected from 223 healthy women of childbearing age.The samples were cultured for lactobacilli isolation in Rogosa and MRS medium.Bacterial DNA was extracted and the 16S rRNA was amplified by PCR and analyzed by nucleotide sequencing.The sequences were compared with existing data in GenBank.The identified lactobacilli were inoculated in MRS medium 3,3',5,5'-tetramethylbenzidine(TMB)to observe their capacity to produce H2O2.Results L.crispatus,L.jensenii and L.gasseri were the major species isolated from 223 healthy childbearing women,and account for 53.7%,27.9% and 10.3%,respectively.Other rare types included L.vaginalis(2.2%),L.coleohominis(1.5%),L.johnsonii(1.5%),L.acidophilus(1.5%)and L.fermentum(1.5%).Most of these lactobacilli,particularly L.crispatus and L.jensenii were capable to produce hydrogen peroxide.Conclusion L.crispatus,L.jensenii and L.gasseri are predominant species in the vagina of healthy Chinese women.L.crispatus and L.jensenii are more capable to produce hydrogen peroxide.