Abstract: Bacterial ability to survive relies on multiple molecular mechanisms and strategies to thrive in a given ecosystem. To some extent, bacteria, once considered fundamentally solitary organisms, resemble human populations. They engage in multifaceted interactions with other fellows and the environment they live in, deploying a number of tools to gain individual or social advantage. These relationships can be either competitive or cooperative: The battle for food and space can be a fight for survival, yet often a coordinated effort of the entire microbial community and sharing of recourses provides greater benefits.

Equally important to the social skills is the ability to resist external threats, such as those deployed to fight pathogenic strains in human infections, either by immune system or drug-based treatment. This lecture will discuss some of the molecular means of inter-microbial communication/competition and mechanisms enabling evasion of host immunity or antibiotics.