Surface antigens of Streptococci pnuemomiae

Question 1

What are the surface antigens of streptococcus pnuemonia?

Answer 1

Capsular polysaccharisde
each serotype is chemically distinct
Can be isolated due to there immunological activity

Question 2

What is the most important virulence factor of pnuemococcus?

Answer 2

the capsule- protects against phagocytosis

rough is non virulent

Question 3

What C substance?

Answer 3

teichoic acid, which contains choline phosphate, is a major constituent of cell wall.

Question 4

What is the M protein antigen?

Answer 4

used for antigenic typing of pneumococcal isolates

not antiphagocytic - not an important virulence factor

Question 5

What are extracellular products of pnuemococci?

Answer 5

Pneumolysin 
purpura-producing principle 
Neuraamidase 
IgA protease 
Amidase

Question 6

What is pneumolysin?

Answer 6

Pneumococci produce a hemolysin

Question 7

What is purpra-producing principle?

Answer 7

causes purpura and dermal hemorrhage

derived from petidoglycan

Question 8

What is neursminidase?

Answer 8

active against glycosyl groups on cell surface glycoproteins, and may play a role in the spread of pneumococci through infected tissues.

Question 9

What is IgA protease?

Answer 9

produced by pneumococci and other bacteria that infect mucosal surfaces. It cleaves secretory immunoglobulin IgA at the hinge region, preparing it for further degradation by other proteases.

Question 10

What is amidase?

Answer 10

an autolysin produced by S. pneumoniae

induces inflammation