Antibacterial Activity of African and Asian Zingiberaceae Plant Species against Salmonella typhi

International audience Typhoid fever remains an important public health concern in many low- and middle-income settings, and increasing antimicrobial resistance has encouraged further investigation of plant-derived antibacterial agents. This preliminary in vitro study evaluated the antibacterial activity of ethanolic extracts of two Zingiberaceae species in Uganda, the introduced Zingiber officinale and the indigenous Aframomum angustifolium, against Salmonella typhimurium ATCC/3076, a close relative of Salmonella typhi. Rhizomes were extracted using ethanol. The crude extracts were tested using agar well diffusion, while minimum inhibitory concentration and minimum bactericidal concentration were assessed using serially diluted extracts. Ciprofloxacin was used as the positive control. A. angustifolium produced the highest mean inhibition zone of 33.0 ± 0.5 mm, compared with 30.3 ± 2.08 mm for ciprofloxacin and 17.0 ± 3.8 mm for the combined extract, while no bacterial inhibition was observed with Z. officinale. The lowest inhibitory concentrations observed for A. angustifolium and the combined extract were 0.125 g/ml and 0.250 g/ml, respectively. The minimum bactericidal concentration reported for A. angustifolium was 0.5 g/ml. These findings indicate that the ethanolic rhizome extract of A. angustifolium showed measurable in vitro antibacterial activity against the tested Salmonella strain, whereas Z. officinale did not show activity in this assay. Further studies are required to confirm the active constituents, reproducibility, and relevance against clinically confirmed S. Typhi isolates.