Synergism Effects of Vancomycin and Zinc Oxide Nanoparticles on Methicillin Resistance Staphylococcus aureus (MRSA) and Lung Cancer

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen and a historically emerging zoonotic pathogen of public health and veterinary importance. It can cause severe chronic infections. The morbidity of MRSA infections has increased worldwide and is of great concern. Nevertheless, a change in treatment strategies, including the use of new antibiotics or combination therapy, is necessary for the treatment of this infection. The research investigated the synergistic effects of vancomycin and zinc oxide on MRSA and the viability of the lung cancer cell line A549 and the normal cell line BEAS.  Materials and Methods: In this study, the minimum inhibitory concentration (MIC) of zinc oxide nanoparticles (ZnO-NPs) and vancomycin was determined using the microdilution method. The fractional inhibitory concentration index (FICI) was calculated using the checkerboard method to evaluate the synergistic effect of ZnO-NPs and vancomycin. The effect of the combination of ZnO-NPs and vancomycin on the viability of lung cancer cell line A549 was also tested by MTT assay. Results: The MIC values showed that all isolates were sensitive to vancomycin with the exception ofexcept for one isolate with an MIC of ≤2 µg/mL. The synergistic effect of the combination of ZnO NPs and vancomycin was observed in two MRSA isolates and one MSSA strain using the checkerboard methodUsing the checkerboard method, the synergistic effect of the combination of ZnO-NPs and vancomycin was observed in two MRSA isolates and one MSSA strain. The combination of vancomycin and ZnO NPs caused less viability in the A549 lung cancer cell line (25.7%) than in BEAS (90%). Conclusion: Combining vancomycin and ZnO-NPs at appropriate dosage intervals may be beneficial in treating MRSA. The combination of vancomycin and ZnO-NPs may also play a dual role in lung cancer patients with evidence of resistance to MRSA by reducing cancer cell survival.