Gram Positive Cocci
In a school child had abscess on lower leg. Swab taken revealed gram positive beta-hemolytic streptococci, and these were bacitracin sensitive. School physician observed that similar organism was isolated from throats of many other children. Which of the following is true statement with regards to this patient?
|A||Difference in surface protein can differentiate the pathogenic bacteria from the pharyngeal culture bacteria.|
|B||Component C carbohydrate can differentiate the pathogenic bacteria from the throat culture bacteria.|
|C||Mec A gene positive are throat culture streptococci.|
|D||Depending on M protein the cutaneous pathogenic bacteria can be differentiated from the pharyngeal culture bacteria.|
a. Depending on M protein the cutaneous pathogenic bacteria can be differentiated from the pharyngeal culture by
b. M PROTEIN- This substance is a major virulence factor of group A S pyogenes.
c. M protein appears as hair-like projections of the streptococcal cell wall.
d. When M protein is present, the streptococci are virulent, and in the absence of M type-specific antibodies, they are able to resist phagocytosis by polymorphonuclear leukocytes.
e. S pyogenes that lack M protein are not virulent.
f. Immunity to infection with group A streptococci is related to the presence of type-specific protective antibodies to M protein.
g. Because there are many, perhaps 150, types of M protein, a person can have repeated infections with group A S pyogenes of different M types.
h. This typing of S. pyogenes on the basis of M protein is called Griffith typing.
i. Earlier M types cause mainly pharyngeal infections and latter M types mainly cause cutaneous infections.
j. M1 serotypes are most commonly associated with invasive diseases and toxic Streptococcal syndrome.