The Lactobacillus rhamnosus and Lactobacillus fermentum strains from human biotopes characterized with MLST and toxin-antitoxin gene polymorphism

The diversity of Lb. rhamnosus and Lb. fermentum strains isolated from feces, saliva, and the vaginal cavity of 18–22-year-old healthy women residing in central regions of the Russian Federation has been characterized. The results obtained using multilocus sequence typing were identical to those obtained with the analysis of genetic and genomic polymorphism in TA systems. Different as well as identical Lb. rhamnosus and Lb. fermentum sequence types (ST) were isolated from various parts of the body of the same person. Identical ST were also isolated from different women, suggesting that such strains belong to a common pool of strains circulating among the population members. Our results demonstrate that TAs are suitable for characterizing intra-specific diversity of Lb. rhamnosus and Lb. fermentum strains. The advantage of using polymorphisms in TA systems for genotyping is based on the weak number of genes used, and consequently, less time is required for the analysis. © 2017, Springer-Verlag Berlin Heidelberg.