Investigation into the function and role of a new regulator critical for Type VI secretion system activity and lifestyle switching in Serratia marcescens

Serratia marcescens is a species of bacterium that exists in the environment but also causes opportunistic infections in humans.

To successfully cause infection, S. marcescens must be able to respond to external cues and adapt its lifestyle to either the environment or a clinical setting.

We have identified a key regulator of this lifestyle switch in S. marcescens, which we hypothesise is critical to its ability to adapt to the clinic and cause infection.

Interestingly, this regulator also controls the Type VI secretion system (T6SS), a weapon employed by bacteria to kill microbial competitors. The ability to outcompete rival bacteria is important for success under conditions of limited resources and space.

We aim to develop a molecular understanding of this novel regulatory system and the phenotypes it controls, including T6SS.

A combination of genetic, phenotypic, biochemical and transcriptomic approaches will be used to investigate the signal the system responds to, how the response is orchestrated and the genes that are regulated.

This work will further our understanding of how S. marcescens and related bacteria adapt to the clinical environment, enabling their success as a pathogens, and may contribute to novel therapeutic or diagnostic strategies in the future.