Final answer:
Streptococcus pyogenes causes beta hemolysis on blood agar, which is characterized by a clear area around the bacterial colonies due to the complete lysis of red blood cells.
Step-by-step explanation:
On blood agar, Streptococcus pyogenes causes beta hemolysis. This type of hemolysis is indicated by a clear halo of hemolysis surrounding the colonies of the bacteria on blood agar, demonstrating that the red blood cells in the medium have been completely lysed. S. pyogenes is known as a Group A, β-hemolytic Streptococcus and is a common cause of bacterial infections such as pharyngitis and skin infections. It is important to accurately diagnose this bacterium as it is associated with serious illnesses and can be easily spread. Laboratory tests identify S. pyogenes by its β-hemolytic activity on blood agar and its susceptibility to 0.04 units of bacitracin.