Antibacterial activity of Zingiber officinale extract on clinical isolates; Salmonella typhi, Staphylococcus aureus and Escherichia coli

This study investigated the antibacterial activity of Zingiber officinale (ginger) extracts against selected pathogenic bacteria. Fresh rhizomes of Z. officinale were collected from Wadata market in Makurdi, Benue State, air-dried, and pulverized into powder. Aqueous and ethanolic extracts were prepared at varying concentrations (500, 250, 125, 62.5, and 31.25 mg/mL). Phytochemical screening revealed the presence of bioactive compounds including phenols, quinones, terpenoids, tannins, alkaloids, saponins, and steroids. Test organisms used were Escherichia coli, Staphylococcus aureus, and Salmonella sp., which were obtained and confirmed through cultural, morphological, and biochemical methods in the Microbiology Laboratory of Joseph Sarwuan Tarka University, Makurdi. Ciprofloxacin (500 mg/mL) served as the control drug. Antibacterial susceptibility testing was carried out, and zones of inhibition were measured in millimetres. At 500 mg/mL, ethanolic extract showed the highest activity, with S. aureus exhibiting the largest inhibition zone (16.33±3.19 mm), followed by E. coli (12.33±6.17 mm), while Salmonella sp. showed the lowest inhibition (3.33±3.33 mm). Interestingly, both aqueous and ethanolic extracts inhibited S. aureus and E. coli, whereas Salmonella sp. responded only to aqueous extract. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined in triplicates, and results were analysed using Analysis of Variance (ANOVA) in SPSS version 21. The findings demonstrate that Z. officinale extracts possess significant antibacterial activity against S. aureus, E. coli, and Salmonella sp., suggesting their potential as effective, affordable alternatives to conventional antibiotics for managing bacterial infections