Question

You are studying a bacterial pathogen that can evade the host's immune system with ease. Which of the following virulence factors would it most likely possess?

A. Hemolysin

B. Adhesins

C. Coagulase

D. Endotoxin

Answer 1

Endotoxins, which are the integral part of Gram negative cell wall (lipid A component of Gram negative bacteria) is released by lysis of bacteria and cause various biological changes

1)Macrophage activation leading to Cytokine release

2)Complement activation leading to hypotension shock, fever

3)Coagulation pathway activation leading to thrombosis and DIC

4)Platelet activation leading to thrombosis

5)Endothelial activation leading to increased capillary permeability

6)Mast cell activation leading to release of histamine causing muscle contraction and increased vascular permeability

Gram negative septicemia caused by endotoxin is extremely fatal. Because of the various biological effects on host cell caused by endotoxin, it can easily invade host defence mechanism.