The evolution of long-lasting immunity and bacterial antimicrobial resistance
Currently most of my research is focused on understanding the evolution of long-lasting immune function in insects. Thanks to funding by the ERC we are investigating the hypothesis that antimicrobial peptides in insects deal with persistent infections and/or prevent the evolution of resistant bacterial mutants. The main questions are: (a) how to prevent the evolution of bacterial resistance against antimicrobials? (b) Why is it adaptive for insects to exhibit long lasting costly immune responses? We use the beetle Tenebrio molitor to examine the temporal dynamics of an antibacterial response using transcriptomics. Building on this we are manipulating the antimicrobial response in vivoand in vitro. These experiments will investigate the response of the model pathogen Staphyloccocus aureus to the changes in the beetle's 'multidrug' response. S. aureus resistance to these experimental selection scenarios will be studied at the phenotypic and genomic level.
This research takes a novel approach to understand the evolution of drug resistance in pathogens, one of the most important applied evolutionary questions of our times. Elucidating the evolution of integrated immune responses will greatly enhance the understanding of immunity in insects, the most speciose metazoan taxon of great importance to human health (vectors) and nutrition (pollinators).
Priming against insect antimicrobials
A new project investigates if and how insect antimicrobials prime bacteria. Does exposure to one stressor such as antimicrobial peptide determine the response/resistance to a second stressor. To explore these questions we have set up a microfluidic system (‘mother machine’). This research is part of a research consortium on organismic response to stress (http://www.sfb973.de/).
Evolution of sexual dimorphism
I am still following my long standing interest (see 2002 paper in PRSB) on sexual dimorphism in immunity. What are the underlying reasons that in many animals and perhaps plants (Williams et al 2011) females are more immunocompetent than males?
Evolution of metamorphosis
Complete metamorphosis, re-arranging the whole body during the pupal stage, happens in the vast majority of insects. One main problem insects face during metamorphosis is related to their gut flora. If the gut flora would be released into the haemolymph the hosts would die of septic shock. If the host kills of the gut flora completely before metamorphosis, they would have difficulties to acquire the required gut flora from the environment. We have only just started invesitaging how this riddle has been resolved.