Streptococcus species are divided into several groups, the most significant of which include Group A (GAS), Group B (GBS), and the Viridans group. Group A streptococci, such as Streptococcus pyogenes, are known for causing diseases like strep throat, scarlet fever, and rheumatic fever. Group B streptococci, such as Streptococcus agalactiae, are primarily associated with neonatal infections. The Viridans group, which includes species like Streptococcus mutans and Streptococcus sanguinis, are important in dental caries and endocarditis.
