“Taxonomic characterisation of Lactobacillus fermentum strains from vaginal samples”, S. Dimitonova, B. Bakalov, S. Danova The complex vaginal ecosystem in healthy women is characterized with a predominance of lactobacilli. But this microflora changes constantly and only 22% of women have a normal Lactobacillus-dominated flora at any given time. The concept that lactobacilli might be useful in displacing and replacing harmful microorganisms on mucosal surfaces accelerate intensive studies on isolation and characterization of vaginal Lactobacilli. In order to detect probiotic lactobacilli in the vagina, a specific methodology must be used to differentiate appropriate isolates, as the vaginal microflora of an individual can harbor five or more different strains of Lactobacillus species. The aim of our study was to characterize by molecular methods 21 newly isolated Lactobacillus strains from Bulgarian women in reproductive ages. Eight of them were identified as L. fermentum by different classical and molecular-taxonomic methods. Molecular typing to the strain level was performed by rybotyping, PCR analysis. By cluster analysis of DNA fingerprints from rep PCR two groups were distinguished. The strains ability to survive at low pH as well to grow fast in the presence of prebiotics (FOS) was proved. Our results could change the opinion for L. fermentum as infrequent species-colonizers of the vagina. The evaluation of bioactivity of these strains is a good way to select probiotic for vaginal use.