Antimicrobial Drug Discovery from a Unique Host-Microbe Symbiosis

Microbial infections have become a significant cause of morbidity and mortality worldwide. Many existing drugs are beginning to exhibit signs of drug resistance, and thus new medicines to treat these infections are urgently needed. We utilize a unique host-microbe symbiosis as a source of new antimicrobial drug leads, studying the Hawaiian bobtail squid, Eupryma scolopes, to characterize the bacterial consortium in a specialized reproductive gland of female hosts called the accessory nidamental gland (ANG). These bacteria are deposited directly into the jelly coats (JCs) of eggs that are then laid on the seafloor, during which time the developing embryos are exposed and unprotected. Prior observations suggest that these egg clutches are often resistant to predation and/or fouling and our research provides strong evidence that the associated bacteria protect developing eggs from microbial biofilms. Given that these symbioses have naturally evolved to select for bacteria with antimicrobial properties, they provide a source of secondary metabolites that are more likely to have potent antimicrobial activity and thus be poised for future preclinical drug development.