Synergistic Effect of Zinc Oxide Nanoparticles and Erythromycin on Methicillin Resistant Staphylococcus aureus Isolated from Different Infections

One hundred and Twenty (120) samples were collected from various pathogenic sources (wounds, abscesses, urinary tract infections and blood samples) for the period from September 2019 to December 2019 from Al Salam and Al-KhansaHospitals and the Public Health Laboratory in Mosul city. Samples were cultured on Mannitol Salt Agar medium; 105 samples showed a positive result. 50 isolates fermented mannitol sugar, at a rate of 47.6% depending on the phenotypic characteristics and production of Coagulase, 14 isolates were identified, at a rate of 13.3%, belonging to Staphylococcus aureus the diagnosis were confirmed using VITEK system. The highest isolation rate from wounds was 57%, then abscesses 21%, blood samples 14%, and urinary tract infections 7%. The sensitivity of the isolates was tested for 16 antibiotics, the isolates showed variation in their resistance to antibiotics. Most of the isolates showed high resistance at 92.8% to Oxacillin, with a resistance rate of 85.7% for Erythromycin. The minimum inhibitory concentration (MIC) of Erythromycin was determined and ranged between (1250-5000) mg / cm3. The minimum inhibitory concentration of ZnO nanoparticles was determined at different sizes (30,20, 50-150) nm and ranged between (5000-10000) mg / cm3 for all isolates. The results of the study showed a synergistic effect of Erythromycin with zinc nanoparticles and with good efficacy by inhibiting the bacterial growth of antibiotic-resistant strains as the MIC value of Erythromycin decreased from (1250-5000) mg / cm3 to (19.5-156.25) mg / cm3 when mixed with ZnO nanoparticles are 20 nm. Meanwhile, the MIC value of ZnO nanoparticles decreased from (30,20, 50-150) nm from (5000-10000) mg / cm3 to (78.125-312.5) mg / cm3 when mixed with Erythromycin.