Isolation and characterization of six gamma-irradiated bacteriophages specific for MRSA and VRSA isolated from skin infections

Although skin infections are usually uncomplicated, it may indicate systemic disease or lead to life-threatening systemic infections. Staphylococcus aureus is the most common cause of skin infections. Treatment is complicated by continuous emergence of resistant S. aureus especially methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant S. aureus (VRSA). Therefore, searching for new alternatives is essential to combat this escalating antibiotic resistance. Bacteriophage therapy is a promising solution in the post antibiotic area. Bacteriophage therapy confers safety and higher rate of success. In the present study, 10 bacteriophages (belonging to the family Siphoviridae and Myoviridae) were isolated with lytic activity against MRSA &VRSA isolated from skin infections. The strongest six of ten phages were characterized morphologically by a JOEL_JEM_1010 electron microscope, physically through evaluating their lytic activity against wide ranges of temperature (35–95° C), PH (3–10) and radiation doses (0.5–2.5kGy) and biologically by evaluating their host ranges and phage longevity (1–120 day) in vitro. Finally, the anti-Staphylococcal effect of the isolated bacteriophages was tested and revealed that they have alone activity (10, 12) and synergistic activity with vancomycin and erythromycin by increasing their inhibition zone diameters (16, 22) mm, respectively.