Combined effects of bacteriophage vB_SauM-515A1 and antibiotics on the Staphylococcus aureus clinical isolates

Abstract

Currently, the search for new therapy options for infectious diseases caused by multidrug-resistant Staphylococcus aureus is a priority. Combining antibiotics with virulent (lytic) bacteriophages may be considered a viable alternative to conventional antibiotic therapy. The study was aimed to assess the combined effects of the lytic bacteriophage vB_SauM-515A1 of Herelleviridae family and antibiotics of various classes on the Staphylococcus aureus clinical strains. Strains (n = 4) belong to the clinically significant sequence types ST1, ST8, ST121 and are characterized by multidrug resistance. Efficiency of the combination use of two antibacterial agents was assessed by comparison of optical densities of the test samples and controls after 24 hrs. of incubation. Mutually enhancing activities of bacteriophage used in combination with oxacillin, tetracycline and linezolid were revealed, in contrast to the separate use of each agent. Efficiency generally increased with the selected optimum multiplicity of infection values. No antagonism was revealed when combining the phage with antibiotics. Thus, virulent bacteriophage vB_SauM515A1 can be considered as a possible auxiliary therapeutic agent for antimicrobial-resistant strains of Staphylococcus aureus.