Antimicrobial and Antifungal Potentials of Ocimum gratissimum Leaf Extracts Against Multidrug-Resistant Pathogens

The rise of antimicrobial resistance has created an urgent need for alternative treatment strategies, particularly from natural sources. This study examined the antimicrobial activity of Ocimum gratissimum (African basil) leaf extracts prepared using methanol, ethanol, and water. The extracts were tested against multidrug-resistant bacterial and fungal isolates obtained from wound and systemic infections. Antimicrobial efficacy was assessed using agar well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal/fungicidal concentration (MBC/MFC) assays. Among the three solvents, the methanolic extract showed the strongest activity, with inhibition zones reaching up to 23.0{square}{+/-}{square}0.60 mm. It was most effective against Escherichia coli (MIC: 31.2 mg/ml) and Candida albicans (MIC: 62.5 mg/ml). Statistical analysis revealed significant differences in antimicrobial effects among the different extracts (p < 0.05). The extract demonstrated both growth-inhibitory and microbicidal effects, suggesting a dual mode of action. These findings support the traditional use of O. gratissimum in treating infections and highlight its potential as a plant-based antimicrobial agent, especially in the context of rising drug resistance.