Molecular detection of mecA gene from methicillin-resistant Staphylococcus aureus isolated from clinical and environmental samples and its potential inhibition by phytochemicals using in vitro and in silico approach

The increasing prevalence of Methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) has posed significant challenges in clinical and environmental settings. MRSA's resistance is attributed to the <i>mecA</i> gene, which encodes the penicillin-binding protein 2a (PBP2a), conferring resistance to β-lactam antibiotics. This study aimed to molecularly detect the <i>mecA</i> gene in MRSA isolates from clinical and environmental samples and identify potential inhibitors of PBP2a using in vitro and in silico approaches. A total of 180 samples were collected, isolating 64 <i>Staphylococcus aureus</i> strains, of which 10 (37%) were confirmed as MRSA. Molecular detection confirmed the presence of the <i>mecA</i> gene in these isolates. Phytochemical analysis of <i>Acacia nilotica</i> and <i>Mangifera indica</i> extracts revealed bioactive compounds with antimicrobial properties. In vitro antimicrobial testing showed the plant extracts demonstrated significant inhibitory effects against MRSA, with minimum inhibitory concentrations (MIC) ranging from 0 to 6.20 mg/mL. Molecular docking and molecular dynamics simulation analyses identified three compounds (CID_628694, CID_546930, and CID_620007) with strong binding affinities and stable interactions with PBP2a, suggesting their potential as novel inhibitors. These findings highlight the therapeutic potential of phytochemicals in combating MRSA and provide a basis for future experimental validations.