Which bacteria is known as group A strep?

Group A streptococcus is referred to as Streptococcus pyogenes. This bacterium is well-known for causing a variety of illnesses, ranging from mild infections like strep throat to more severe conditions such as rheumatic fever and necrotizing fasciitis. The designation "Group A" comes from its classification in the Lancefield classification system, which categorizes streptococci based on the carbohydrate composition of antigens found on their cell wall.

Streptococcus pyogenes is particularly notable for its beta-hemolytic properties, meaning it can break down red blood cells in blood agar, leading to the characteristic clear zone around colonies. This bacterium is also a significant pathogen in both children and adults, making recognition and understanding of its role in disease crucial for healthcare professionals.

In contrast, Streptococcus agalactiae, commonly known as Group B strep, is associated with infections in newborns and pregnant women, while Streptococcus pneumoniae is primarily known for causing pneumonia and meningitis. Streptococcus viridans represents a group of alpha-hemolytic streptococci that are often found in the oral cavity but are not categorized as Group A.