Antibacterial Activity of <i>Allium</i><i> </i><i>Sativum</i>, Z<i>ingiber</i><i> </i><i>Officin

The development of antibiotic resistance has recently increased research attention in exploring novel antimicrobial agents sourced from medicinal plants. In Ethiopia,<i> Allium sativum</i><i> </i>(garlic) and <i>Zingiber officinale</i><i> </i>(ginger) are the most valued medicinal plants. This study investigates the antibacterial properties of extracts obtained from the bulbs and roots of<i> Allium Sativum</i>, Z<i>ingiber Officinale</i> and their synergistic effects against <i>Staphylococcus</i><i> Aureus</i> and <i>Escherichia Coli</i> strains isolated from milk samples. A 50g powdered bulbs of <i>A. sativum </i>and roots of <i>Z. officinale</i> were separately macerated with 500 mL of distilled water and 95% ethanol in sterilized flasks. The antibacterial effects of crude aqueous and hydro-ethanol extracts of the both plants and their synergistic effects with 95% ethanol extracts were assessed using disc diffusion method, with concentrations of 50, 75 and 100 mg/mL for susceptibility testing. The 95% ethanol extracts of both plants had lowest yield percentage as compared to aqueous extracts. ANOVA was used for statistical analysis, with a significance level of <i>P</i> <0.05. Both 95% ethanol as well as distilled water extracts and their synergistic effects with 95% ethanol extracts exhibited antibacterial activity against <i>S.</i><i> Aureus</i> and <i>E. Coli</i> using <i>ciprofloxacin</i> discs as positive and blank discs as a negative control. Among the extracts, the lowest susceptibility was observed for aqueous extracts with inhibition zone of <i>Z. officinale</i> at 50 mg/mL against both bacteria, while <i>E. coli</i> showed a notable susceptibility to <i>Z. officinale</i> at 100 mg/mL. The 95% ethanol extract of <i>A. sativum</i> and its combination showed smaller inhibition zone against both bacteria<i> </i>at 50 mg/mL while, larger inhibition zone was seen with <i>A. sativum</i> against <i>E.</i><i> coli</i> (27.67±0.58 mm) but <i>Z. officinale </i>showed larger inhibitory zone against <i>S. aureus</i> (19.33±1.15 mm) at concentration of 100 mg/mL compared to water extract. In both aqueous and 95% ethanol extracts, there was statistically a significant difference (<i>P</i>≤0.000) in the susceptibility of all tested bacteria. This study indicate that the extracts obtained from of the bulbs of <i>A. sativum</i> and the roots of <i>Z. officinale</i> have promising antibacterial properties, validating their traditional medicinal use for treating infections.