Question

What is a virulence in bacteria giving 3 structural and 3 enzymatic examples and what is their role in causing pathogenicity?..

Answer 1

Virulence is the ability of the organism to infect or invade the host and cause the disease.

Virulence factors are the molecules or physical property of bacteria to affect the host

Virulence factors helps the bacteria in three ways causing the pathogenicity-

1.invade the host

2. Cause disease.

3. Evade the host immunity and defense .

Following are the type of virulence factors -

Physical-

1. Adherence - the bacteria colonize mucosal sites in host bod by using pili (fimbriae) to adhere to cells.

2. Capsule - many bactery are covers by capsule that help them to protect from opsonization.

3.invasion factors- surface molecules that help the bacteria to invade the host cells.

Chemical -

1. Endotoxin- endotoxin are the lipopolysaccharides that are present in the wall of bacteria can cause inflammatory reaction into the host body . Present in gram negative bacteria.

2 Exotoxins- several type of enzymes and protein secreted by bacteria.example is botulinum toxin secreted by clostridium botulinum .

3 siderophores- these are the iron binding factors that compete with the host to bind with iron which is bount to transferrin heamoglobin etc.