Drosophila cecropin as an antifungal agent.

The effects of Drosophila and Hyalophora cecropins were tested against different fungi, both insect pathogens and fungi from the normal environment of Drosophila. The fungi were generally found to be as susceptible to the cecropins as most bacteria, the only exception being the insect pathogen Beauveria bassiana which is completely resistant. This is also the only fungus tested which is virulent to Drosophila, giving 100% lethality within 5 days after injection. Lethal concentrations of cecropins against other fungi tested ranged between 0.4 and 4 microM. Andropin is less fungicidal than the cecropins, and Drosophila cecropin A is somewhat more potent than cecropin B. Even dense cultures of Saccharomyces cerevisiae can be cleared by micromolar concentrations of cecropin, whereas Geotrichum candidum is unaffected by cecropin when tested in a dense culture.