Antimicrobial activity of some local mushrooms on pathogenic isolates

The antimicrobial properties of ethanol, hot and cold extracts of some mushroom species (Russula vesca, Auricularia auricular, Pleurotus squarrosulus, Volvariaella vulvae) on some Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Salmonella typhi), Gram positive bacteria (Bacillus cereus, Staphylococcus aureus, Streptococcus pneumoniae) and yeast (Candida albicans) were investigated. The Minimum Inhibitory Concentrations (MIC) was evaluated for each of extracts of the mushrooms. Antimicrobial activity was performed by agar disc diffusion. The hot water extracts of R. vesca inhibited growth of E. coli, S. typhi, P. mirabilis and C. albicans. Ethanolic extract of A. auricular showed wide spectrum of antimicrobial effect against test organisms with the exception of S. typhi and P. aeruginosa. P. squarrosulus showed antimicrobial activity against K. pneumoniae (6.14mm), S. pneumoniae (5.12mm), and C. albicans (4.10). P. aeruginosa was resistant to almost all extracts of the four species of mushroom except the hot water extract of P. squarrosulus which showed zone of inhibition (3.41mm). V. vulvae showed antimicrobial activity against S. typhi (4.60mm). Ethanol and hot water extracts of most of the mushroom species contained more bioactive substance than cold water extract. The significance of antimicrobial activity of mushroom extracts was compared with the standard antibiotics (gentamicin, 5µg/disc) using chi – square. There were significant difference between the mean zone of inhibition of the ethanol extract of P. squarrosulus and the standard antibiotic against test organisms at 5% level. The results obtained in this study suggest that P. squarrosulus possessed broad-spectrum of activity against microbial isolates used.