Microbe Interactions -Human

Question 1

Diptheria

Answer 1

A-B Toxin
Produced by Corynebacterium diptheriae
Fragment B promotes specific binding of the toxin to a host cell receptor
After binging, proteolytic cleavage between fragment A and B allows fragment A into the host cytoplasm

Question 2

Diptheria cont.

Answer 2

Fragment A then disrupts protein synthesis by blocking transfer of an amino acid from a transfer of an amino acid from a tRNA to the growing polypeptide chain

Question 3

Diptheria cont.

Answer 3

The toxin inactuvates elongation factor 2 by catalysing the attachment of ADP ribose from NAD+
Following ADP ribosylation, the activity of the modified elongation factor 2 decreases dramatically and protein synthesis stops

Question 4

Endotoxins

Answer 4

Liposaccharides derived from outer membrane of gram -ve bacteria
Released upon lysis of the bacteria, they cause fever in host
Pyrogens-affect temperature controlling centre of the brain

Question 5

Sweat glands

Answer 5

eccrine
apocrine
sebaceous

Question 6

3 categories of exotoxins

Answer 6

cytolytic toxins
superantigen toxins
A-B toxins