Question

What is quorum sensing? How is it used? How does it affect virulence and biofilms? What is a biofilm?

Need help with all parts please answer and explain thanks

Answer 1

Quorum sensing is a process where cell to cell communication is carried out among the bacterial population. It leads to regulation of gene expression as a function of cell population density. The extracellular signals that lead to alteration of gene expression among the population are autoinducers. Quorum sensing plays a vital role in controlling gene expression for sporulation, bioluminescence, antibiotic production, biofilm and production of virulence factors.
A Biofilm is an aggregate of microbial cells attached to a surface, it is a complex and dynamic system where the cell population is encased in EPS protecting the cells within the community and facilitates communication among them. Biofilm formation is a protective mode of growth which reduces the effects of environmental hazards on them (Predation, antimicrobials, and resistance to desiccation).
Quorum sensing with help of biofilm formation increases the virulence of a bacterial colony many more times, it helps in selective expression of toxins in a large amount as compared with its planktonic form and them are also able to easily evade the immune system of the host organisms by modifying there surface properties such that the host immune system recognizes it as self-molecules.