L5. Quorum Sensing

Question 1

Describe the role of adaptation and conservation of resources in bacterial virulence

Answer 1

Host Adaptation: Pathogenic bacteria have evolved various mechanisms to adapt to and exploit host environments. This adaptation includes the ability to adhere to host tissues, evade host immune responses, acquire nutrients, and form biofilms. By adapting to specific host niches, pathogens can establish infections and persist within the host for extended periods.

Nutrient Acquisition: Bacterial pathogens must acquire essential nutrients from their host environment to support their growth and survival. However, host environments often present limited nutrient availability and competition from the host microbiota. Pathogens employ various strategies to scavenge and acquire nutrients, such as utilizing host-derived molecules, secreting enzymes to degrade host tissues, and competing with commensal bacteria for resources.

Energy Conservation: Bacterial virulence often requires the expression of energy-intensive processes, such as the production of toxins, secretion systems, and adhesion molecules. Pathogens must efficiently allocate and conserve energy to support these virulence-associated functions while adapting to nutrient-limiting conditions within host environments.

Metabolic Adaptations: Pathogenic bacteria exhibit metabolic flexibility and adaptability to survive and proliferate in diverse host environments. They can switch between different metabolic pathways to utilize available carbon sources, withstand oxidative stress, and adapt to varying oxygen levels encountered during infection. Metabolic adaptations contribute to bacterial persistence and virulence within the host.

Quorum Sensing: coordinate gene expression in response to changes in population density. – regulate expression of virulence factors, biofilm formation, and other cooperative behaviors.
synchronizing = optimize virulence and enhance their ability to cause disease

Question 2

Describe is cell-to-cell communication in bacterial populations, and how it contributes to coordination of behaviour

Question 3

Explain quorum sensing and its significance in regulating gene expression.

Question 4

What is the Lux operon, and what is its role in bioluminescence?

Answer 4

genetic locus in bioluminescent bacteria (e.g Vibrio fisheri)
synthesis of luciferase - catalyst
synthesis of autoinducers for quarum sensing

Question 5

what is the difference between autoinducers in gram pos and negs