Streptococcus pyogenes Group ____ strep?

Streptococcus pyogenes Group ____ strep?

• A. Group B
• B. Group C
• C. Group D
• D. Group A

Answer: (D)

Streptococcus pyogenes is classified as Group A streptococcus because Lancefield grouping uses a specific carbohydrate in the cell wall to categorize beta-hemolytic streptococci. This grouping identifies S. pyogenes with Group A, setting it apart from other groups. In the lab, Group A strep often shows beta-hemolysis on blood agar and is typically bacitracin sensitive and PYR positive, which helps confirm its identity. Group B includes Streptococcus agalactiae (neonatal infections), while Groups C and D refer to other streptococcal species, not S. pyogenes. So the blank is Group A.

Streptococcus pyogenes is classified as Group A streptococcus because Lancefield grouping uses a specific carbohydrate in the cell wall to categorize beta-hemolytic streptococci. This grouping identifies S. pyogenes with Group A, setting it apart from other groups. In the lab, Group A strep often shows beta-hemolysis on blood agar and is typically bacitracin sensitive and PYR positive, which helps confirm its identity. Group B includes Streptococcus agalactiae (neonatal infections), while Groups C and D refer to other streptococcal species, not S. pyogenes. So the blank is Group A.