What are group C/G streptococci and how are they classified?
Group C and group G streptococci (GCS/GGS) are a group of bacteria, comprising several species, the main human pathogen being Streptococcus dysgalactiae subsp. equisimilis. These streptococci are most commonly identified by the presence of a Lancefield group C or group G antigen on the surface of the bacterium, which is easily detected in the laboratory. The streptococcal grouping scheme was devised in the 1930s by Dr Rebecca Lancefield to characterise beta-haemolytic (red blood cell-destroying) streptococci. Streptococci are also classified into pyogenic (“pus-forming”) streptococci, which include groups A, B, C and G, and non-pyogenic (non “pus-forming”) streptococci which encompasses the mitis, anginosus, bovis, salivarius and mutans sub-groups. Streptococcus pneumoniae, otherwise known as pneumococcus, forms its own distinct group.
