ANTIBACTERIAL ACTIVITY OF ETHANOLIC ROOT EXTRACT OF CITRULLUS COLOCYNTHIS AGAINST BACILLUS SUBTILIS AND STAPHYLOCOCCUS AUREUS: A COMPARATIVE MIC AND DISC DIFFUSION STUDY

Abstract

The rising threat of antibiotic resistance has underscored the need to explore alternative antibacterial agents. This study investigates the antibacterial potential of ethanolic root extract of Citrullus colocynthis against two common pathogenic Gram-positive bacteria: Bacillus subtilis and Staphylococcus aureus. The extract was prepared via solvent extraction, and its activity was evaluated using disc diffusion, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and antibiofilm assays. Results revealed significant antibacterial activity, with inhibition zones of 14–17 mm, MIC values of 122 µg/mL for S. aureus and 197 µg/mL for B. subtilis, and MBC values of 112 µg/mL and 192 µg/mL, respectively. The extract also demonstrated biofilm inhibition (70% against S. aureus and 65% against B. subtilis). These findings highlight C. colocynthis as a potential source of plant-derived antimicrobial agents, warranting further phytochemical and in vivo studies.