Background: Multidrug-resistant (MDR) organisms pose an increasingly significant public health challenge, complicating the treatment of numerous healthcare-associated infections with standard topical medications and antibiotics. Among the MDR bacteria, Staphylococcus aureus and Shigella sonnei stand out as virulent agents responsible for severe disease. This study aimed to explore a novel biogenic antibacterial agent as a potential alternative to traditional antibiotics for combating Staphylococcus aureus and Shigella sonnei.
Method: The study involved synthesizing zinc oxide nanomaterial (ZnONM) from the mushroom Ganoderma lucidum and examining its antibacterial potency. To characterize the synthesized nanomaterials, several analytical techniques were performed, including UV-vis spectral analysis, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG-DTA), and dynamic light scattering (DLS). Later, a minimum inhibitory concentration (MIC) test and biofilm inhibition assay (at 4*MIC, 2*MIC, MIC, ½*MIC doses) were conducted to evaluate the antibacterial potency of the synthesized green ZnONM.
Results: The results showed that the synthesized ZnONM samples were monodisperse, moderately stable, and had a mean size distribution of 257.2 nm. The MIC value of ZnONM was 625 μg/ml for both MDR pathogens, with biofilm disruption rates at approximately 60% for S. aureus and 5% for S. sonnei. In addition, ½ MIC of ZnONM showed higher biofilm inhibition of S. aureus than higher doses. Remarkably, in the case of S. aureus, the antibacterial effect of ZnONM was almost 1.6 times more effective than that of azithromycin. Furthermore, a strong positive Pearson correlation between ½*MIC and biofilm disruption for S. aureus highlighted the potential effectiveness of lower-dosage treatments in managing biofilm-related S. aureus infections.
Conclusion: Overall, the present study successfully demonstrated the synthesis of ZnONM, which exhibited promising antibacterial activities at lower concentrations. This highlights its antimicrobial potency as an effective alternative to antibiotics against MDR Staphylococcus aureus and Shigella sonnei.
