Question

Which of the following statements about M protein is FALSE? Which of the following statements about M protein is FALSE? It is found on fimbriae. It is readily digested by phagocytes. It is found on Streptococcus pyogenes. It is a protein. It is heat- and acid-resistant.

Answer 1

Answer:

It is readily digested by phagocytes.

Explanation:

Virulence factors are protein and sugar molecules found on bacterial and viral surface that help them to gain entry and spread in host's body. They help to evade the immune reaction by the host and help in colonization in host's body.

One such virulence factor is M protein which is found on the surface of many species of Streptococcus, notably Streptococcus pyogenes. It is strongly anti-phagocytic i.e. phagocytes are not able to digest it. It evades phagocytosis by binding to fibrinogen found in host's serum. A structure is formed which inhibits the host's complement system to bind to the peptidoglycan cell wall of bacteria ultimately avoiding phagocytosis. Hence, M protein is readily digested by phagocytes is a false statement.