Bioactivity of Four Nigerian Wild Mushrooms against Some Typed Clinical Isolates

Abstract

This study aimed at investigating the antimicrobial activity of some wild Nigerian mushrooms against selected typed clinical isolates. We collected wild mushrooms from an integrated organic farm in Ilesa, Southwest Nigeria. Crude methanolic extracts of Lentinus squarrosulus Mont., Termitomyces robustus (Beeli) R. Heim, Trametes ochracea (Pers.) Gilb. & Ryvarden and Xylaria hypoxylon (L.) Grev. were screened singly and in different combinations for bioactivity against the selected bacterial and yeast isolates. The minimum inhibitory concentration (MIC) and chemical constituents of the extracts were studied following standard procedures. Overall, we obtained a total of 16 mushrooms belonging to 14 genera. The extracts showed varied clearance zones against at least one of the eight bacteria, and one yeast when applied singly with the antimicrobial inhibitory zone ranging from 7.2 mm to 20.0 mm in Staphylococcus aureus (T. ochracea extract) and Pseudomonas aeruginosa (L. squarrosulus extract) respectively. Furthermore, the MIC ranged from 2.09 to 16.75 mg/mL. When combined, the blends were active against some Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa and Proteus mirabilis) but inactive against the Gram-positive bacteria and yeast. Except for X. hypoxylon, other extracts contained saponins, tannins and terpenoids. Our findings revealed that the wild mushrooms are potential antimicrobial agents against the tested isolates.