Abstract
This article presents novel ideas about classification, genomic structure (inverted regions, mobile genetic elements, plasmids, mobilized and conjugated transposons), pathogenicity factors (adhesins, various enzymes, toxins, in particular, data on enterotoxin fragmentinis BFT - B. fragilis toxin), and the role of their metabolites in the manifestation of pathogenicity. Data on the global prevalence of antibiotic resistance in the clinical B. fragilis strains are presented. Mechanisms of development of the drug resistance are considered and the role of cfiA, tet, nim genes in the development of antibiotic resistance is disclosed. Information on the use of the MALDI-TOF MS (matrix-activated laser desorption-ionization time-of-flight mass spectrometry) method for distinguishing B.fragilis strains into two groups based on the ability to carry carbapenem resistant gene (carrying and not carrying cfiA gene) are presented. Basics of modes of emergence of multi-resistance in clinical strains of B. fragilis are considered. In addition, prospects for genome-wide sequencing in predicting antimicrobial resistance are presented. Currently increasing attention of researchers is payed to increase in resistance of B. fragilis to widely used antimicrobials. This is indeed of a great importance when choosing adequate antimicrobial therapy.