In Vitro Investigation of the Potential of Ficus exasperata Extracts Against Bacterial Pathogens Isolated from Chickens

Campylobacter species and Escherichia coli are leading causes of bacterial diarrhea in humans and livestock globally, often transmitted through food and water with poultry, pigs, and cattle, as reservoirs, are increasingly resistant to antibiotics, necessitating alternative therapeutic strategies. Building on previous reports of the antibacterial, cytotoxic, phytochemical, and antioxidant properties of Ficus exasperata leaf extracts as phytogenic feed additives for chickens, this study expands the scope by evaluating additional clinical E. coli isolates with their selectivity index, genotoxicity assays and profiling the methanol extract using standard bioassays and GC-MS. The methanol extract demonstrated broad and best efficacy across all tested bacteria, though the aqueous had the highest total antibacterial activity (2 308 mL/g). The reference strains (ATCC) were more resistant than clinical isolates. The methanol extract showed the lowest cytotoxicity (LC₅₀: 0.99 mg/mL on Vero cells and 2.69 mg/mL on Caco-2 cells) and the highest selectivity indices (Vero: 6.33; Caco-2: 14.17). It was non-mutagenic to Salmonella typhimurium TA98 compared to acetone extract. The GC-MS analysis of methanol extract revealed 9-Octadecen-1-ol (24.52%) as the most abundant compound. The methanol extract showed promising potential for further in vivo testing as phytogenic feed additives and alternatives for managing campylobacteriosis and colibacillosis in chickens.