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As part of our search for less toxic antimicrobial agents from natural resources, the antimicrobial activity of Elfvingin applanata (P_(ers.)) K_(arst). extract was examined alone and in combination with naringenin. EA, the aqueous extract from the carpophores of E. applanata, was lyophilized and a dark brownish powder was obtained. Antimicrobial activity of EA was tested in vitro against nineteen strains of bacteria and eleven strains of fungi by serial broth dilution method, and expressed by minimal inhibitory concentration (MIC). Among nineteen strains of bacteria tested, the antimicrobial activity of EA was the most potent against Proteus vulgaris showing MIC of 1.125 ㎎/㎖. EA also inhibited the growth of the selected fungi at higher concentrations ranging from 7.5 ㎎/㎖ to 15.0 ㎎/㎖. To investigate the effect of antimicrobial combinations of EA with naringenin, the fractional inhibitory concentration index (FICI) was determined by checkerboard assay for each strain. The antimicrobial combinations of EA with naringenin resulted in partial synergism against Staphylococeus aureus only, and showed additive effect in two strains including Klebsiella pneumoniae and Salmonella typhi. Antagonism was not found.
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