Question

In detail, what are the functional types of bacterial toxins?. give examples of each

Answer 1

There are two types of bacterial toxin:

a) Endotoxin: Present in gram negative bacteria. Lipopolysaccharide, a component of cell wall acts as toxin. Response is non-specific by IL1, IL12, IFN alpha and IFN gama. Responsible for septic shock syndrome: fever and inflammation.

b) Exotoxin: Produced by gram positive bacteria. Response is variable depending upon toxin. E.g.

i. Diphtheria toxin: Cornybacterium diphtheriae is causative agent and acts as ADP-ribosylase of eukaryotic elongation factor 2.

ii. Cholera toxin: Toxin released from Vibrio cholerae ,ADP ribosylate G alpha stimulatory and secrets cAMP in high amount.

iii. Tatenus toxin: Clostridium tetani secreted this toxin acts as Zn dependent endoprotease and cause spasmatic paralysis.

iv. Shiga like toxin: Certain species of E.coli produce this toxin which encode RNA N glysosidase leads to cell death or apoptosis.

v. Anthrax toxin: Bacillus anthracis secrete this and it acts as a calmodulin dependent adenylate cyclase. Induce apoptosis.

vi. Pseudomonous toxin: Secreted by Pseudomonous aeruginosa and acts same as diphtheria toxin.