Final answer:
Group A strep, also known as Streptococcus pyogenes, is a gram-positive bacterium that causes various human diseases. It is ß-hemolytic and produces virulence factors that contribute to its pathogenicity.The correct option is B.
Step-by-step explanation:
Group A strep, also known as Streptococcus pyogenes, is a gram-positive, spherical bacteria that is categorized in the Lancefield group A. It is a ß-hemolytic streptococci, which means it causes complete hemolysis on blood agar plates.
In 1933, Rebecca Lancefield developed a method to serotype ß-hemolytic strains of Streptococcus species, using an agglutination assay. She discovered that certain strains of S. pyogenes, which belong to Group A strep, were associated with various human diseases.
S. pyogenes is considered a pyogenic pathogen and is responsible for causing strep throat, impetigo, and more severe infections like necrotizing fasciitis. It produces virulence factors such as M proteins and streptolysins that contribute to its pathogenicity.The correct option is B.