Edited sentence: Beta-hemolytic streptococci are further characterised via the Lancefield serotyping – based on specific carbohydrates in the bacterial cell wall.In the medical setting, the most important groups are the alpha-hemolytic streptococci, S.These are named Lancefield groups A to T, although some species, such as S.pneumoniae and Streptococcus Viridans-group, and the beta-hemolytic streptococci of Lancefield groups A and B (also known as “Group A Strep” and “Group B Strep”).pneumoniae, do not express Lancefield antigens