EJMS

Abstract

Antimicrobial activity of different crude extracts from venom sac of the wasp, Vespa orientalis were tested against selected bacterial and fungal pathogens. The bacterial strains tested were Staphylococcus aureus, S. epidermidis, Streptococcus pyogenes and Bacillus subtilis (Gram-positive); Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia and Enterobacter cloacae (Gram-negative). While, the fungal species tested were Aspergillus niger, A. flavus, A fumigatus (filamentous fungi), Candida albicans, C. tropicalis, Geotrichum candidum (yeasts). The different crude venom extracts showed a good antimicrobial activity against both Gram-postive and Gram-negative bacteria. Ethyl acetate extract of venom sac caused the highest antibacterial activity against the Gram-positive bacteria, Bacillus subtilis. Also, the same extract caused the highest antibacterial activity against the Gram-negative bacteria, Klebsiella pneumonia. The highest antifungal activity of crude venom extract was caused by ethyl acetate extract against Geotrichum candidum, Candida tropicalis and Aspergillus fumigatus. Generally, the bacterial strains tested were more sensitive to the different extracts of venom sac than the fungal strains tested. Protein electrophoresis of different crude venom extracts of V. orientalis recorded one major protein band of 42.78, 54.18 and 21.50 kDa in ethyl acetate, methanolic and petroleum ether extract, respectively. However, the present study seems to be complemented by parallel ongoing research on peptides/proteins isolation and characterization to know the peptides or proteins responsible for the antimicrobial activity.