A Study of antibacterial activity of plant extract and essential oil of Myrtus communis against resistant strains of Staphyloccocus aureus bacteria to selective antibiotics

Infectious diseases caused by gram- positive bacteria، drug resistant Staphyloccocus aureus strains which often originate from hospitals environment، are increasing in many countries of، worldwide. Because of that، lots of efforts have been done to find new compounds as suitable superseded instead of antibiotics. In this research، antibacterial effect of plant ethylic essential oil and extract of Myrtus communis against several clinical antibiotic resistant strains of S. aureous were investigated. Plant extraction and essential oil extraction from M. comminus species were performed using Rotary and Clevenger apparatus، respectively. Sampling was carried out from nose and throat area of patients. Seventeen strains of S. aureous were isolated and after that purified. Minimum Inhibitory Concentration (MIC) and Minimum Bacterial Concentration (MBC) of plant extract as well as essential oil from M. comminus on bacteria were determined using micro dilution broth method at six different concentrations. Sensitivity of strains against some antibiotics was investigated using standard disc''s diffusion Corbei-baer method. The results indicated that plant''s essential oil and plant''s extract have a significant effect on concentration of 5 mg/ml whereas 10 mg/Kg was belonging to high Minimum Bacterial Concentration (MBC) for both treatments. The Assessment of antibacterial effects of some antibiotics showed that the majority of strains have similar sensitivities. But Penicillin and Cefexime showed the least antibiotic effect. All strains showed resistant reaction to Vancomycin. Plant''s extract and essential oil from Myrtus communi have antibacterial effects on S. aureus strains at high concentration; such compounds can be used in medical treatments.