Introduction and objective:
The increasing emergence of antibiotic-resistant bacteria, particularly in poultry farming environments, poses a serious threat to both animal and human health. The aim of the study is to evaluate the antimicrobial potential of the aqueous and ethanol plant extracts of Ginger (Zingiber officinale) , Garlic (Allium sativium) and Scent leaf (Ocimum gratissimum), respectively, at different concentrations against E. coli isolated from poultry drinking troughs on three farms in Enugu, Nigeria.

Material and methods:
E. coli was isolated using standard microbiological techniques. Antimicrobial susceptibility of the bacteria to ethanol and aqueous plant extracts as well as conventional antibiotics was assessed using the agar well diffusion method. The plasmid profiles of the bacterial isolates were determined via agarose gel electrophoresis.

Results:
The bacterial counts from the drinking troughs ranged from 2.0 × 10⁴ – 7.9 × 10⁴ CFU/cm² . While some differences were observed between farms and sample points, there was a varying degree of antibacterial activity of Zingiber officinale, Allium sativium and Ocimum gratissimum against Escherichia coli. The ethanolic extract of all plants showed higher zones of inhibition than the aqueous extracts. The ethanolic extracts of Zingiber officinale (garlic) at higher concentrations of 250 µl exhibited zones of inhibition of 41 mm for EA1 and 37 mm for EA2, surpassing that of the control, Ofloxacin antibiotics (10 μg) (39–41 mm) which was one of the most potent of all the conventional antibiotics used against E. coli isolates. All E. coli isolates revealed the presence of single plasmids of 10 kbp indicating potential for antibiotic resistance.

Conclusions:
Plant extracts, particularly ethanol extracts of Zingiber officinale and Allium sativium, has promising antimicrobial activity against resistant strains of E. coli. Further studies are needed to explore the mechanism of action and optimize plant extract formulations for broader application.