Dr Conor P O'Byrne

Dr Conor P O'Byrne

Bacterial Stress Response Group

The research focus in my group is on the molecular mechanisms that food-borne bacterial pathogens use to sense and respond to harsh conditions in their environment. Pathogens encounter major physicochemical changes as they transition from food into the host, particularly in relation to pH, osmolarity, oxygen concentration, light and temperature.

Understanding how pathogenic bacteria detect and respond to these changes is critical if we are to devise sensible strategies to prevent their entry into the food chain and to prevent infections from arising in the human population.

In my laboratory we study two important food-borne pathogens, Listeria monocytogenes and Escherichia coli. Current projects on L. monocytogenes are addressing the role of an alternative sigma factor called SigmaB in sensing stress and regulating the appropriate transcriptional response. We are also examining the influence of visible light on L. monocytogenes, including both the mechanism of sensing light and the response generated.

Another project is investigating the response to this pathogen to low pH and in particular the role of glutamate decarboxylation in surviving the transition into the host. Projects on E. coli are addressing the role of the RpoS-mediated stress response in allowing adaptation to non-host environments, in particular soil environments. This is significant because transmission to the food and water chain can be significantly enhanced if strains adapt to long-term survival in non-host environments. Together these projects are seeking to identify novel Achilles heels in these pathogens with a view to mitigating their impact on human health.  

Academic Profile