Vaginal Lactobacillus microbiota of healthy women in the late first trimester of pregnancy.

OBJECTIVE This study was undertaken to characterise the dominant species of Lactobacillus colonising the vagina of healthy pregnant women, to examine some of their phenotypic and genotypic properties, and to gain a better understanding of the potential role of species, which might be associated with infection-free status. DESIGN A prospective descriptive cohort study. SETTING Department of Obstetrics and Gynaecology, Medical University of Vienna and Medical School, Vienna, Austria. SAMPLE A total of 200 women in the late first trimester of pregnancy without clinical signs of vaginal infection were included in the study. Of these, 126 women were found to have a normal vaginal flora based on Gram stain. METHODS Culture probes from those 126 women were further processed for identification of Lactobacillus species. Overall, 168 colonies from 84 women were identified as belonging to the Lactobacillus genus. Based on the combined results of microbiological methods and genus-specific, multiplex, and species-specific polymerase chain reaction, lactobacilli were recovered from 72 women. MAIN OUTCOME MEASURES Identification of Lactobacillus species of the vaginal flora of healthy pregnant women. RESULTS The most frequently occurring species were Lactobacillus crispatus and Lactobacillus gasseri, followed by Lactobacillus jensenii and Lactobacillus rhamnosus. CONCLUSIONS Our results may have implications on the composition and on the use of Lactobacillus preparations for the prevention of recurrent vaginal infection.