Group A Streptococcus

Various haemolytic groups, GAS is beta haemolytic.  Other groups of beta haemolytic identified by Rebecca Lancefield.

  • Beta haemolytic Group B is seen in the genitourinary tract of women and is an important pathogen in neonates.
  • Groups C and G both cause invasive disease, both have M proteins, more common throat carriage in developing countries. Maybe also responsible for acute rheumatic fever.
  • Alpha-haemolytic (strep viridans) are associated with line infections and endocarditis.
  • Gamma-haemolytic include enterococci, of which faecium is usually resistant to amoxicillin but faecalis is usually sensitive. Of note, some enterococci are now resistant to vancomycin (VRE).