Antibiotic-producing Symbionts in Temperate Formicidae

Environmental sources for novel antibiotic-producing bacteria in our project have been expanded beyond non-living reservoirs to include arthropods from three orders: Diptera, Hemiptera and Hymenoptera. Whole-body homogenate of the insects was plated on agar media for growth of bacteria. The bacterial isolates were tested for ability to inhibit Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The Hymenoptera yielded a number of bacterial isolates which had antibiotic activity, whereas the Diptera and Hemiptera yielded no isolates with activity. This may be either a taxonomic pattern or an environmental pattern, as the Diptera and Hemiptera specimens were collected in different environments than were the Hymenoptera.