Question

what are virulence factors? List and describe the different types of virulence factors that can exist?

Answer 1

Virulence factors are the molecules produced by microorganisms that help them to infect a host cell, colonize a habitat, suppress the immune system of the host cell or move across a cell.

Following are different types of virulence factors:

1. Invasion factors: THese factors are used by bacteria to infect the host cells by degrading its cell wall, plasma membrane or the immune cells.

2. Exotoxins: Exotoxins are chemicals or molecules released by bacteria in the outside environment that are harmful to the organisms or cells living in the surrounding habitat. Exotoxins are used by the microbes to colonize a habitat.

3. Endotoxins: These are toxic biomolecules that are stored inside the bacteria and released when the they die or lyse, thus giving an advantage for the spores and the other bacteria to grow.

4. Capsule - Capsule is a covering of complex polysaccharides present outside the cell wall that prevents bacteria from other microbes or the immune system of its host.

5. Adhering factors - Certain structures such as pili or mucus help bacteria to attach themselves to the surface of other organisms and obtain nutrition from them

6. Siderophores - These are factors or biomolecules produced by bacteria to compete for iron present in the hemoglobin of the host cells.