A novel method for the identification of factors involved in host–pathogen interactions in Drosophila melanogaster

• We developed a new method to investigate survival after septic injury in Drosophila.
• We validated the procedure using well characterized immune deficient mutants.
• The method can be used to study the complex immune response after a septic injury.
• The approach is easy to perform, highly reproducible and mimics natural conditions.

A new method was established, standardized and validated for screening factors involved in the response to septic injury in Drosophila melanogaster. The method, based on inducing lesion by removing the tarsal segments of the first pair of legs of Drosophila adults and exposing them to different bacteria, imitates injury that often occurs in the natural habitat. The method is easy to perform, highly reproducible and suitable for large-scale genetic screens with the aim of identifying factors involved in host–pathogen interactions. The technique was validated by using mutant variations of different components of the immune response, blood clotting as well as the involvement of a number of genes known to be instrumental in the humoral and cell-mediated immune responses of Drosophila was confirmed. Moreover, the combination of the present method with antibiotic treatment allows the screening of potential antimicrobial drugs in vivo.