Studies on evaluation of antibacterial activities of some cultivated mushrooms against human pathogenic bacteria

Abstract

Mushrooms have been used as source of nutritive food and medicine since ancient time. The indiscriminate utilization of modern antibiotic drugs has caused the development of multiple drug resistance in pathogenic microbes. The antimicrobial properties of herbs and mushrooms have proved to be fruitful in getting rid of from the problem of multiple drug resistance. In this study, the antibacterial activity of acetone, aqueous and methanol extracts of Agaricus bisporus, Calocybe indica, Flammulina velutipes, Pleurotus florida, and Volvariella volvacea were investigated against human pathogenic bacteria. The antimicrobial activity  of these mushrooms were evaluated following the agar well diffusion method against Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes and gram negative bacteria Shigella dysenteriae, Salmonella typhi and Escherichia coli. All the studied mushrooms displayed considerable antibacterial activity against all the pathogenic bacteria under study and it was found to be extraction solvent dependent. The zones of growth inhibition of 12.26-14.80 mm in Agaricus bisporus, 12.84-15.31mm in Calocybe indica, 13.82-16.17 mm Flammulina velutipes, 12.2-14.80 mm in Pleurotus florida, and 12.34-15.84 mm in Volvariella volvacea were recorded in acetone extract. The zones of growth inhibition of 10.73-11.23 mm in Agaricus bisporus, 10.63-12.62 mm in Calocybe indica, 12.50-13.84 mm Flammulina velutipes, 11.14-11.97 mm in Pleurotus florida, and 11.51-12.31 mm in Volvariella volvacea were observed in aqueous extract. The zone of inhibition observed in methanol extract were 13.06-14.93 mm in Agaricus bisporus, 11.96-14.01 mm in Calocybe indica, 12.01-13.41 mm Flammulina velutipes, 13.02-13.74 mm in Pleurotus florida, and 13.32-15.21 mm in Volvariella volvacea. The minimum inhibitory concentration (MIC) of acetone extract ranged from 0.3125 µg/100µl-0.625 µg/100µl, aqueous extract 0.625 µg/100µl-2.5 µg/100µl and methanol extract 0.3125 µg/100µl-1.25 µg/100µl. The results emphasize that there is a need for further studies to isolate and characterize the bioactive compounds present in these cultivated mushrooms so that their antibacterial potential can be used to develop effective drugs against these human pathogenic bacterial strains.Keywords: Mushrooms, antibacterial, minimum inhibitory concentration, zone of inhibition.