The Raymann Lab
Ecology and evolution of host-associated microbes
Evolution and genomics of opportunistic pathogens
Opportunistic pathogens (OPs) are typically characterized as organisms that can only become pathogenic in susceptible hosts, e.g. hosts with weakened immune systems or altered microbiome composition. However, most of the time they can coexist rather peacefully within their host and can live in several non-host environments. It is possible that the virulence of OPs can evolve by “coincidental” selection because many functional virulence traits are more beneficial for competition outside the host environment. We are interested in understanding which selective forces drive the evolution of virulence in OPs. To address this we study Serratia marcescens, an OP of many animals including honeybees. Our aim is to determine what factors contribute to pathogenicity, how within host evolution impacts virulence, and how the native host microbial community (in our case the honeybee gut microbiota) responds to S. marcescens invasion, i.e. can the microbiome protect its host against infection.
Population dynamics of host-associated microbial communities
Gut microbial communities are important for host health and perturbation of these communities can have detrimental effects, such as increased pathogen infection and other disease states. Not only are honeybees environmentally and agriculturally important, but they are also a great system for studying the evolution and population dynamics of host-associated microbial communities. Honeybees possess a highly conserved relatively simple gut microbiota that consists of only five core species, making it feasible to follow the fine-scale community dynamics of the population over time. We are interested in understanding how the gut microbial community responds to different selective pressures (i.e. antibiotics, chemicals, invasion by pathogens, environmental changes) over time and how and if these changes impact honeybee health.