The Designation "Group A," Used to Help Classify Streptococcus Pyogenes

Question

The designation "group A," used to help classify Streptococcus pyogenes, refers to this bacterium's
A) Lancefield antigen.
B) hemolysis pattern.
C) M protein.
D) type of streptokinase produced.
E) disease associations.

Accepted Answer

The designation "group A" refers to the Lancefield antigen, which is a carbohydrate antigen found on the cell wall of Streptococcus pyogenes. This antigen is used to help classify different strains of the bacterium.

Answer: C
 The M protein is a virulence factor found on the surface of Streptococcus pyogenes, and it is a major component of the Lancefield group A antigen. The different forms of the M protein can be used to further classify strains of the bacterium.

Therefore, the best choices are A and C.