The M protein of Streptococcus pyogenes
A)is the basis for the organism belonging to Lancefield Group A.
B)gives rise to a zone of beta hemolysis on blood agar.
C)protects against phagocytosis and enhances adherence.
D)is also called streptokinase.
E)protects against lysozyme damage.

Question

Quizplus · Accepted Answer

The M protein of Streptococcus pyogenes protects against phagocytosis by immune cells and enhances adherence to host cells, allowing for colonization and infection to occur.

Answer: A
 The M protein is also the basis for the organism belonging to Lancefield Group A, a classification system based on the serotyping of bacterial cell wall antigens.

Answer: B
 The zone of beta hemolysis on blood agar is caused by the streptolysin O enzyme produced by some strains of Streptococcus pyogenes, not by the M protein.

Answer: D
 Streptokinase is a different protein produced by Streptococcus pyogenes that is involved in the breakdown of blood clots.

Answer: E
 The M protein does not protect against lysozyme damage, which is a bacterial defense mechanism that targets the cell walls of bacteria.

The M Protein of Streptococcus Pyogenes