Abstract

The combined antibacterial effect of the leaf extracts of Dissotis theifolia with some disc antibiotics was investigated. Extraction of the dried pulverized leaves of the plant was carried out using maceration method and some portion of the extract further fractionated in a chromatographic column. The antibiogram of the test microorganisms was determined using the agar-diffusion method while the in vitro activity of the combination of sub-bacteriostatic concentrations of the extract and column fraction F2 with some disc antibiotics was evaluated using the overlay inoculum susceptibility disc method. Fractionation of the extract yielded three column fractions (F1-F3) with only F2 showing remarkable antibacterial activity. Results of the antibiograms clearly demonstrated the resistance and susceptibility pattern of the test isolates against the disc antibiotics. Combinations of most of the disc antibiotics with the extract and column fraction F2 of D. theifolia produced antagonistic (P≤0.05) and indifferent effects (P≤0.05), respectively.