Abstract

Bacteria use a wide variety of simple signaling molecules to communicate both within their own species and with other species around them. Infection progression, community behaviour, virulence, spore formation and bioluminescence (light production) are often controlled by simple chemical signals released by different bacterial species into the environment. It is easiest to consider these signals as early pheromones. The bacteria sense the number of signaling molecules in their environment and when they sense that their population number has reached a certain ‘quorum’ they act accordingly, either by forming spores, producing light or in the case of Erwinia, attacking a plant. Our lab uses basic microbiological tools to study this process known as ‘quorum sensing’ in the plant pathogen Erwinia carotovora and in the animal pathogen Serratia marscesans. I aim to focus on the broad themes in ‘quorum sensing’ and how bacteria are using chemical signals to ensure successful infections despite our efforts to stop them.