Social Wasp Venom: a Treasure of Antimicrobial Peptides

Background Antimicrobial peptides (AMPs) are versatile molecules that are vital for combating pathogenic microorganisms, including bacteria, fungi, and viruses. Insects thrive well in microbe-rich environments and rely on their cellular and humoral immune systems for defense. The humoral system, among other constituents, chiefly comprises antimicrobial peptides. Interestingly, the venom of hymenopteran insects has been identified as a rich repository of these peptides. Results This study aimed to explore the potential of social wasp venom as a source of antimicrobial peptides, focusing on two species viz. Ropalidia marginata and Vespa tropica. Venom gland extracts from both species were tested against Staphylococcus aureus (MTCC 3160) and Escherichia coli (MTCC 2692), which are gram-positive and gram-negative bacteria respectively. Vespa tropica venom showed antimicrobial activity against both bacteria, while Ropalidia marginata venom was effective only against Staphylococcus aureus . Reverse phase- High performance liquid chromatography (RP-HPLC) was carried out with a peptide-specific protocol to separate fractions of peptides from the venom. Seven fractions were obtained from each species. Two fractions from Vespa tropica exhibited antimicrobial activity against both Staphylococcus aureus and Escherichia coli , while two fractions from Ropalidia marginata were effective only against Staphylococcus aureus . Additionally, two fractions from each species showed antibacterial activity against the plant pathogen Xanthomonas oryzae pv. oryzae, while no antifungal activity was observed against Sclerotium rolfsii . Further analysis of the active fractions using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) revealed the presence of six peptides in each species with m/z 932.280 to m/z 1729.650 for Ropalidia marginata and m/z 1386.182 to m/z 1695.805 for Vespa tropica . Conclusion This study elucidates the antimicrobial potential of social wasp venom against a range of bacterial pathogens, suggesting its potential in both therapeutic and agricultural contexts.