Clinical Microbiology and Antimicrobial Chemotherapy. 2013; 15(1):72-79
To determine lactobacilli species diversity in different states of vaginal microbiota in pregnant women using culture, mass-spectrometry, and DNAbased assays.
A total of 163 pregnant women (18 to 40 years of age) were examined in the 2nd or 3rd trimester. A comprehensive microbiological examination of vaginal swabs, including Gram staining, methylene blue staining, and culture was performed. All isolated microorganisms were identified to species level using mass-spectrometry. Quantification of Lactobacillus spp. and genotyping of 6 lactobacilli species (L. crispatus, L. iners, L. jensenii, L. gasseri, L. johnsonii, L. vaginalis) were performed by real-time PCR.
Using mass-spectrometry, a total of 15 lactobacilli species were identified and cultured on standard selective media. Of these, 3 species (L. crispatus, L. jensenii and . gasseri) were found more often than others. Based on the both assays, L. crispatus appeared to be the most frequent species in pregnant women with normocenosis (>60%). PCR assay showed significant place of L. iners among vaginal lactobacilli species. Using mass-spectrometry, 8 lactobacilli species were identified in pregnant women with normocenosis, and 15 species in bacterial vaginosis. Conception about leading role of L. acidophilus among lactobacilli from vaginal microbiota was contradicted.
MALDI-TOF mass-spectrometry could identify 15 species of vaginal lactobacilli and, therefore, may be recommended for identification of cultured lactobacilli. L. iners is unable to be cultured on standard selective media. Based on the PCR data, L. iners was found in 84.6% of pregnant women with bacterial vaginosis. Analysis of vaginal lactobacilli species isolated from pregnant women with absolute normocenosis suggests that predominance of L. crispatus may be considered as a measure of normal vaginal microbiota.