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?

Ans. is 'd' i.e., Depending on M protein the cutaneous pathogenic bacteria can be differentiated from the pharyngeal culture bacteria (Ref: Sherris Medical Microbiology, p. 716)* Bacitracin sensitive gram positive beta hemolytic cocci is streptococcus pyogenes.* Two most common sites of infection with streptococci are the upper respiratory tract (pharyngitis, tonsillitis) and the skin (impetigo).* S. pyogenes causing skin infection (impetigo) tend to belong to different 'M' serotypes than those associated with respiratory infection (pharyngitis)."The M protein types of a S. pyogenes most commonly associated with skin infection (impetigo) are different from those causing respiratory infection (pharyngitis).