Antibacterial Efficacy of Plant Aqueous Extracts Against Escherichia coli O157:H7 Bacteria in Grenada, West Indies

Shekinah Morris, DVM, Harry Hariharan, DVM, PhD, TM Reddy, MD, Kamashi Kumar, MVSc, PhD


Issue: Volume 75 Summer 2025

Online Publication Date: 13 June 2024


Antimicrobial resistance has developed as a major health problem worldwide, endangering the efficacy of antibiotics and imposing a severe burden of resistant infections. The progressive increase in the prevalence of multiple resistant bacterial strains paves the way for the selection of natural plants with antibacterial properties as an alternative substitution for the treatment of bacterial infections. Hence, this study was conducted to determine the antibacterial efficacy of neem (Azadirachta indica), moringa (Moringa oleifera), and curry leaf (Murraya koenigii) against Escherichia coli (E coli) O157:H7 isolated from a fecal sample of a goat from Grenada. This is the first medicinal plant-based research study in Grenada on this important zoonotic pathogen. Aqueous extracts of medicinal plants were evaluated for antibacterial efficacy in vitro, using the agar well diffusion method, and subsequently compared with the antibacterial drug gentamicin. The resulting data demonstrated that aqueous plant extracts of neem leaves, moringa leaves, and curry leaves exhibited in vitro antibacterial efficacy comparable to that of gentamicin against E coli O157:H7 goat isolate. Hence, these plants could be used as an effective substitute for antibacterial agents in prophylactic or therapeutic control of bacterial infections in Grenada.