The role of extracellular vesicles and genotypic characterization in antibiotic resistance formation of clinical Staphylococcus aureus isolates in causative flora of patients with diabetic foot syndrome

Abstract

It has been suggested that defense against macroorganism immune factors is carried out by forming membrane vesicles with lytic action on Gram-positive bacteria, which in turn may cause antibiotic resistance in microorganisms. Staphylococcus aureus (S. aureus) is a common pathogen causing diabetic foot syndrome (DFS). We described antibiotic resistance and the role of lytic vesicles as antibiotic resistance factors in cultures of S. aureus isolates and S. aureus reference strains. Moreover, we used Bacillus subtilis (B. subtilis) to determine the lytic effect of vesicles in 36 patients of different ages with ischaemic and mixed forms of DFS. As a result of this study, we found that membrane vesicles have a lytic effect, with lysis zones forming both around vesicles of reference strains of S. aureus and their clinical isolates and around vesicles of reference strains of B. subtilis. Among genes encoding resistance to various antibiotics, blaCTX-M-2 were detected in 16.7% of clinical strains, Erm and Tet genes in 11.1%, Mec-1 in 5.5%, VanA and VanB genes in 5.5%. Plasmid-mediated quinoloneresistance genes qnrB were also detected in 5.5% of strains. Meanwhile, multiple resistance was detected in 11.1% of clinical strains of S. aureus. Further studies should analyze the contribution of the described genes to adhesion and membrane vesicle formation and their significance in the pathogenesis of wound healing in patients with DFS and wounds and infections of other origins.