“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.