Group A Streptococcus (Streptococcus pyogenes): the Most Interesting Pathogen in the World

Group A Streptococcus, or Streptococcus pyogenes, is a facultatively anaerobic Gram-positive coccus and one of the most common causes of bacterial infection in humans. The introduction of antibiotics has greatly reduced the morbidity and mortality associated with this organism, but despite uniform susceptibility to treatments of choice, it remains a significant human pathogen. It is particularly problematic in underdeveloped and lower socioeconomic status countries, where hygiene may be suboptimal. This review covers a wide range of topics related to the organism, including diagnosis, treatment, and clinical manifestations. Where possible, the review addresses less conventional and often controversial topics that have not been extensively reviewed elsewhere, such as the activity of trimethoprim sulfamethoxazole against the species, penicillin tolerance, and the use of protein synthesis inhibitors to reduce toxin production and improve outcomes.