Montmorillonite modified with Fe3O4 and tannic acid for inhibition of S. aureus and MRSA biofilm formation

In this study we introduce a novel nano-biocomposite, M-MM-TA, composed of clay montmorillonite (MM) modified with magnetic (M) Fe ₃O ₄ and tannic acid (TA), designed to combat S. aureus , MRSA, and their biofilm. Bacterial attachment and biofilm formation are significant challenges to public health, medicine, and the clinical industry. Staphylococcus aureus ( S. aureus), a gram-positive pathogenic bacterium, is known to be the cause of infectious diseases in both humans and animals. Methicillin-resistant Staphylococcus aureus (MRSA), a major cause of healthcare-associated infections, has emerged due to its resistance to antibiotics. Considering MRSA`s resistance to antibiotics, it is essential to explore and characterize alternative antibacterial agents. Comprehensive characterization through SEM, SEM-EDS, TEM, TEM-EDS, XPS, XRD and VSM analyses confirmed the successful synthesis of M-MM-TA. To confirm the anti-bacterial effects of nanocomposite, we treated M-MM-TA on S. aureus and MRSA. Then we evaluated the anti-biofilm effect of M-MM-TA by using CV staining and live/dead assay. The results showed that M-MM-TA inhibits biofilm formation against S. aureus and MRSA. Additionally, SEM morphological analysis confirmed that M-MM-TA caused dissociation of the bacteria from biofilms. To confirm the mechanism of anti-biofilm effect, gene expression level was analyzed related to biofilm formation. The results showed that icaA, B, C, D genes are downregulated by the M-MM-TA. Overall, these results demonstrated that M-MM-TA has significant potential as an anti-bacterial agent and inhibits biofilm formation against S. aureus and MRSA. These findings suggest that M-MM-TA can be used in various biomedical applications to inhibit gram-positive bacterial infections.