Transcriptomic Analysis of the Serratia marcescens Response to Batrachochytrium dendrobatidis

Global amphibian declines and extinction events are currently occurring at an unprecedented rate. While various factors are influencing these declines, one factor that is readily identifiable is disease. Specifically, the fungal pathogen Batrachochytrium dendrobatidis is thought to play a major role in amphibian declines in tropical and neotropical regions of the globe. While the effects of this chytrid fungus have been shown to be devastating, certain individuals and relict populations have shown resistance. This resistance has been attributed in part to the cutaneous microbiome. Many identified bacterial species that make up the microbiome have shown anti-B. dendrobatidis activity in vitro. One bacteria that is commonly associated as being a member of the amphibian microbiome across amphibian species and shows such anti-B. dendrobatidis activity is Serratia marcescens. Here, we look at transcriptomic shifts in gene expression of S. marcescens (high homology to strain WW4) in response to both live and heat-killed B. dendrobatidis. Overall design: Six samples were analyzed in this study. Three different treatments were utilized with two biological replicates of each. The three treatments included growth of Serratia marcescens with B. dendrobatidis, with heat-killed B. dednrobatidis, and without any B. dendrobatidis (control).