Antibacterial Effect of Zinc Oxide Nanoparticles on MupirocinResistant Staphylococcus aureus Isolated From Nasal Carriers

Introduction: Staphylococcus aureus is one of the main causes of hospital infections. The present study aimed to determine the antimicrobial effect of zinc oxide nanoparticles (ZnONPs) on the growth of mupirocinresistant S. aureus isolates taken from hospital carriers. Methods: The samples were taken from the anterior nasal parts of 150 hospital staff in Gorgan, using a sterile swab. Being cultured on Mannitol salt agar, the suspected colonies were identified through gram staining as well as catalase, coagulase and DNase tests. Resistance of the strains to mupirocin was examined using microdilution broth test. The antibacterial effect of ZnONPs on the mupirocinresistant strains was also investigated using agar well diffusion method. Results: In this study, 48 isolates (32%) were identified as S. aureus, out of which 3 isolates (6.2%) showed high resistance to mupirocin and 14 isolates (29.2%) showed low resistance to this antibiotic. The results of this study revealed that ZnONPs had the highest inhibitory effect on the growth of mupirocinresistant S. aureus in the density of 400 mg/mL. Conclusion: The ZnONPs used in this study had a high dosedependent antimicrobial activity against all drugresistant S. aureus strains.