Antimicrobial and Antibiofilm Activity of Biogenic MgO Nanoparticles and Extract from <i>Hibiscus sabdariffa</i> Against Multidrug Resistance

Abstract Diabetic foot ulcers (DFUs) often involve multidrug‐resistant (MDR) infections, complicating treatment. Plant extracts and green‐synthesized nanoparticles are promising alternatives for combating these pathogens. This study aimed to evaluate the antimicrobial and antibiofilm effects of Hibiscus sabdariffa extracts and magnesium oxide nanoparticles (MgO‐GNPs) against MDR bacteria isolated from DFUs, while exploring their mechanisms through in silico analysis. Qualitative phytochemical analysis was performed on Hibiscus extracts. The MgO‐NPs were characterized using Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), ultraviolet–visible spectroscopy (UV–vis), energy dispersive X‐ray analysis (EDX), and scanning electron microscope (SEM). Their antimicrobial effects by MIC against E. coli , P. aeruginosa , and S. aureus . Biofilm inhibition and disruption were assessed in mono‐ and mixed‐species cultures. Molecular docking and molecular dynamics simulations explored interactions between MgO‐GNPs and bacterial enzymes. MgO‐GNPs demonstrated superior antimicrobial activity, with MICs between 22 and 36 µg/mL. They significantly inhibited biofilm formation and disrupted existing biofilms more effectively than Hibiscus extracts. MgO‐GNPs increased ROS levels, damaged bacterial membranes, and suppressed exopolysaccharide and alginate production. In silico studies showed strong binding affinity of MgO‐GNPs to bacterial glycosyltransferases, supporting their mechanism of action. MgO‐GNPs show promising antimicrobial and antibiofilm activity against MDR pathogens. Their ability to target biofilms and bacterial mechanisms suggests they could serve as effective alternatives for managing drug‐resistant DFU infections.