The antibacterial activity of the crude leaf extract of Stachytarpheta jamaicensis against Streptococcus pneumoniae
Abstract
A susceptibility study was conducted to assess the antibacterial effect of ethanolic Stachytarpheta jamaicensis leaf extract against Streptococcus pneumoniae, the bacteria that infects the human upper respiratory tract. The study was carried out at the Department of Plant sciences, Microbiology and Biotechnology, Makerere University Uganda. The plant’s antibacterial activity was compared to that of the positive control (oxacillin) and the negative control (Dimethyl sulfoxide) using the agar-well diffusion method. Different concentration levels i.e., 100%, 50% and 25%, of both the plant extract and the positive control were used.
The plant extract exhibited antibacterial activity against S. pneumoniae (p < 0.05). The best antibacterial activity of the extract was recorded at 100% concentration, hence this activity is concentration-dependent. The antibacterial activities of oxacillin and S. jamaicensis were not statistically significantly different (p > 0.05). The minimum inhibitory concentration of S. jamaicensis determined was at 31.25µg/mL, lower than that of the positive control of 3.90µg/mL.
Thus, the ethanolic crude leaf extract of S. jamaicensis has antibacterial activity against S. pneumoniae. However, this crude extract cannot be used as an antibiotic as its therapeutic success is not established in this study