Antibacterial activity of Chaga mushroom (Inonotus obliquus) extract against Staphylococcus aureus and Salmonella typhimurium: An In Vitro Study

Abstract

Inonotus obliquus (Chaga mushroom) is a herbal and edible mushroom widely distributed in different regions, especially temperate regions. Chaga parasites on the trunk of angiosperms and grows, forming an irregular black mass. The medical importance of Chaga has been reported from ancient cultures to data due to its activity against a wide range of diseases. In the present study, the ethyl acetate extract of the Chaga mushroom has been tested against two bacterial pathogens, Staphylococcus aureus ATCC25923 and Salmonella typhimurium ATCC14028. The antimicrobial activity of the extract showed high activity with inhibition zone diameters of 25 mm for S.aureus and 28 mm for S.typhimurium and minimum inhibitory concentration (MICs) of 3.125 µg/ml for both bacterial pathogens. GC-MS analysis of the extract revealed several compounds with seven major compounds; they are 3-pentanone, propyl butyrate, Ethyl propionate, Trimethylsilymethanol, Neopentyl glycol, n-butyl acetate, and 1-butanol-3-methyl acetate. The antibacterial mode of action of Chaga extract was also elucidated by studying the effect of the extract on cell membrane permeability and recoded high effect on bacterial cell membrane permeability, which was confirmed by transmission electron microscope (TEM) images that revealed leakage of bacterial cell content outside the cells and death.