Antibacterial Activities of Crude Extracts of Tithonia Diversifolia against Common Environmental Pathogenic Bacteria

In-vitro antibacterial activity of methanolic, ethanol and water extract of Tithonia diversifolia was evaluated against Pseudomonas
aeruginosa, Shigella spp, Enterococcus spp, E. coli, and Salmonella spp using Agar well diffusion method. Minimum inhibitory
concentrations (MIC) were performed on bacteria with inhibition zone greater than 14 mm by a modification of standard agar dilution
method. E. coli was found to be more susceptible to the ethanol leaf extract of T. diversifolia at high concentration of 20 mg/mL (24 mm zone of inhibition) follow by Salmonella and Shigella spp both with zone of inhibition 18 mm each when compared to Enterococcus and Pseudomonad spp with zone of inhibition of (16 mm and 11 mm respectively). Enterococcus was found to be more susceptible to crude ethanol extracts of the root with zone of inhibition of 14 mm at high concentration of 20 mg/mL than the methanol and water extracts when compare to others bacteria tested in this study. The values of the MIC ranged between 1.25 mg/mL – 5 mg/mL. However, extracts of T. diversifolia flower did not show any antimicrobial effect in vitro on all the tested bacteria. The activity of the crude extract was found to be concentration dependant on all the organisms tested. Identified chemical compounds from phytochemical results indicated that saponin, alkaloid, flavonoids, phenol and triterpene were the active antibacterial compounds present. The result therefore indicated that T. diversifolia has a broad spectrum antibacterial activity and could serve as a good source of new antimicrobial agent. However, other genera of Gram-positive and Gram-negative bacteria as well as fungi species should be tested in order to ascertain the broad spectrum activity of the crude extract. Further research is underway to evaluate the effect of the crude extract on haematological parameters in-vivo