To assess the clinical utility of the crude ethanolic extract of the leaves of Varthemia iphionoides (Compositae), minimal inhibitory concentrations (MICs) were determined using agar dilution technique. Accordingly, The MICs of of this plant extract ranged from 0.0313-1 mg/ml for three clinical taphylacaccus
aureus strains and ATCC strains of Bacillus subtilis and Staphylococcus epidermidis, whereas Escherichia coli studied in this report was found to exhibit higher MIC value (4 mg/ml). The effect of combinations of ethanolic extract of Varthemia iphionoides and cefotaxime was investigated by means of fractional inhibitory concentration (FIC) indices. Using the FIC indices, synergistic interactions were observed against B. subtilis (ATCC 6633) and S. ureus strains (FIC indices of 0.75-0.875); while combinations against E. coli and S. epidermidis (ATCC 25923) exhibited antagonistic interactions (FIC indices of 2.5 to 16.4). Synergy was confirmed at cefotaxime concentrations corresponding to 1/2 MIC and an ethanol extract concentrations
corresponding to 1/4 MIC and lower.