Plant-Derived Phytochemicals from Moringa oleifera and Chenopodium album as Inhibitors of Staphylococcus aureus

Staphylococcus aureus is an important bacterial pathogen associated with human, animal, and environmental infections, creating a need to investigate alternative sources of antibacterial compounds. This study evaluated the antibacterial activity of Moringa oleifera and Chenopodium album leaf extracts against S. aureus isolated from poultry-shed soil in Sylhet, Bangladesh. Three bacterial isolates were characterized using microbiological and biochemical methods and further evaluated by PCR amplification of the species-specific nuc gene. Aqueous, ethanolic, and methanolic leaf extracts were prepared and screened using the disc diffusion method. Qualitative phytochemical screening was also performed. Among the tested extracts, the methanolic extract of M. oleifera produced the largest inhibition zone (34.0 ± 0.5 mm), followed by the methanolic extract of C. album (24.0 ± 0.6 mm). The ethanolic extracts produced inhibition zones of 20.0 ± 1.0 mm and 22.0 ± 0.4 mm for M. oleifera and C. album, respectively, whereas no measurable inhibition was observed with the aqueous extracts. The vancomycin reference control produced a 22 mm inhibition zone under the experimental conditions. Qualitative phytochemical screening indicated the presence of several classes of secondary metabolites, including alkaloids, tannins, saponins, flavonoids, coumarins, quinones, phenols, cardiac glycosides, steroids, and triterpenoids. These findings provide preliminary in vitro evidence of antibacterial activity in selected plant extracts and support further investigation using quantitative phytochemical analysis, MIC and MBC determination, identification of active compounds, and broader bacterial isolate panels.