Antibiotic Susceptibility of Acalypha Wilkesiana Leaf Extracts Against Selected Bacteria Isolates.

The increasing prevalence of antibiotic-resistant pathogens necessitates the search for alternative antimicrobial agents, including plant-based therapeutics. This study investigated the antibiotic susceptibility of Acalypha wilkesiana leaf extracts against selected microbial isolates, including Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Ethanolic leaf extracts at a concentration of 250 mg/mL were evaluated using the agar well diffusion method, with ciprofloxacin (10 μg/g) serving as the positive control. Zones of inhibition were measured to determine antibacterial efficacy. The results showed that ciprofloxacin exhibited significant zones of inhibition against E. coli (23.0–23.5 mm), S. aureus (38–41 mm), and P. aeruginosa (45–53 mm). In comparison, the leaf extract demonstrated moderate activity with inhibition zones of 11.5–12.6 mm, 10.0–13.7 mm, and 10.0–11.4 mm respectively against the same organisms. The extract showed higher efficacy against S. aureus than the Gram-negative isolates, suggesting that cell wall structure influences susceptibility. The antibacterial activity of the extract is attributed to bioactive compounds, such as flavonoids, tannins, saponins, and alkaloids, known to disrupt bacterial membranes and inhibit metabolic processes. While the extract's efficacy was lower than ciprofloxacin, the findings highlight its potential as a supplementary antimicrobial agent, particularly against Gram-positive bacteria. Further studies are recommended to isolate and identify the active compounds, optimize extraction methods, evaluate synergistic effects with standard antibiotics, and assess the extract's safety for therapeutic applications. These findings support the potential use of Acalypha wilkesiana in combating antibiotic-resistant infections.