Organism diversity between women with and without bacterial vaginosis as determined by polymerase chain reaction denaturing gradient gel electrophoresis and 16S rRNA gene sequence

Abstract

The aim of this study was to characterize the different structures of microbial communities between 20 healthy women and 17 bacterial vaginosis (BV)-positive women of reproductive age using denaturing gradient gel electrophoresis (DGGE). Vaginal samples from 17 BV-positive and 20 BV-negative women were subjected to DNA extraction, and amplified with eubacterial 16S rRNA gene-specific primers via polymerase chain reaction. The polymerase chain reaction products were separated using DGGE. Bands were excised, re-amplified, purified and sequenced. DNA sequences were compared with GenBank database. Phylip software packages were used to calculate sequencing data and form a phylogenetic tree to identify the genetic relations for microbiota inhabited in vaginal ecosystems of BV-positive women. In total, 28 kinds of organisms were detected that comprised BV(+) vagina microbial community, varying from three to nine kinds with an average of 5.71 kinds per woman. Only seven species were detected in BV(-) women, ranging between one and five species with an average of 2.40 species per woman, which was significantly lower than that detected in BV(+) women (t = 7.39, P < 0.001). A strain of Uncultured Lactobacillus sp. clone EHFS1_S05c (29/37; 78.38%) was most commonly presented in both BV-negative and BV-positive women, but the mean proportion of this Lactobacillus sp. strain to the whole microbial population colonized in the vaginal tract of BV(-) women was sharply higher than that calculated from BV(+) women (t = 2.92, P < 0.01). The findings indicate further diversity in the category of vaginal microorganisms associated with BV. The presence of Gardnerella vaginalis is not necessary as a sign for gynecologists to determine whether or not a woman is affected by BV.