Antimicrobial properties of protein extracts from wild mushroom fungi and native plant species against hospital pathogens

Michael Hearst^1,2, David Nelson³, Graham McCollum³, Linda M. Ballard⁴, B. Cherie Millar³, Sara Moore^5, Stephen McClean^5, John E. Moore^3,5 and Juluri R. Rao^1,5*

¹Applied Plant Science Division, Agri-Food and Biosciences Institute, Newforge Lane, Belfast,

Northern Ireland, BT9 5PX.

²Grosvenor Grammar School, Cameronian Drive, Belfast, Northern Ireland, BT5 6AX.

³Northern Ireland Public Health Laboratory, Department of Bacteriology, Belfast City Hospital, Lisburn Road, Belfast, Northern Ireland, BT9 7AD.

⁴Ulster Folk and Transport Museum, Cultra, Holywood, Co. Down, Northern Ireland, BT18 0EU.

⁵School of Biomedical Sciences, Centre for Molecular Biosciences, University of Ulster, Cromore Road, Coleraine, Co. Londonderry, Northern Ireland, BT52 1SA.

*Corresponding author. E-mail: jr.rao@afbini.gov.uk, j.rao@ulster.ac.uk.     

Accepted 8 November, 2010

Abstract

Protein extracts of either native or exotic rare mushroom fungi and plants that are normally known for novel therapeutics including immune modulation were investigated for their potential antimicrobial effects. Data obtained using the Kirby-Bauer’s disc-diffusion assay methods showed that a number of locally sourced wild mushroom fungi (e.g. Ganoderma resinaceum, Russula fragilis and Inocybe grammata) had proteins with inherent antimicrobial properties against a number of typical hospital pathogens. The wild type fungus Mycena pura exhibited strong antagonism against Escherichia coli, an organism often commonly associated with nosocomial infections both locally and worldwide. Polyacrylamide gel electrophoresis (PAGE) of protein extracts revealed unique protein banding patterns for the exotic fungal species and possessed significant inhibitory effects against a range of nosocomial pathogens including MRSA, Salmonella, Candida and Aspergillus species. This small-scale study revealed the occurrence of wild fungal peptides of potential therapeutic significance and antimicrobial potential for exploitation in complementary therapies in clinical and veterinary medicine.

Key words:  Exotic fungi and medicinal plants, antibacterial activity.