Seminars – Center for Microbial Dynamics and Infection

Upcoming schedule here. This trainee-run seminar series focused on new research in CMDI. It’s Fridays at 3pm and includes coffee and cookies. Location to be decided for Fall 2025.

Upcoming seminar:

Abstract:

Quorum sensing (QS) is a cell-to-cell communication system involving the production, detection, and response to diffusive signal molecules. QS has often been interpreted as a regulatory mechanism used by bacteria to infer their population density based on signal concentration, and adapt behavioural responses. However, this functional interpretation fails to account for the role of biotic and abiotic factors in modulating QS responses, e.g., by impacting molecular diffusivity and degradation. In particular, the presence of other bacterial species can have a profound effect on a focal species QS regulatory dynamics. One possibility, is that ecological interactions impact signal concentration and associated behaviour via changes in focal species density. A second possibility, is that competitors affect focal species QS and associated behaviour directly, by interfering with signal synthesis, extracellular survival, or response. We systematically explore the impact of direct and indirect modulation of focal species QS through theoretical simulations and experimental observations. We show that microbial communities, besides indirect QS modulation through ecological interactions, can extend a direct influence on focal species QS systems, which can cause delayed quorum-sensing induction.