Lancefield grouping

Lancefield grouping is a method of grouping catalase-negative, coagulase-negative bacteria based on the carbohydrate composition of bacterial antigens found on their cell walls.^[1] The system, created by Rebecca Lancefield, was historically used to organize the various members of the family Streptococcaceae, which includes the genera Lactococcus and Streptococcus, but has since been largely abandoned due to explosive growth in the number of streptococcal species identified since the 1970s.^[2] Enterococcus, formerly known as Group D Streptococcus, was believed to be a member of the genus Streptococcus until 1984, after the Lancefield criteria were devised, and so were included in the original Lancefield grouping.^[3] Many - but not all - species of streptococcus are beta-hemolytic. Notably, Enterococcus and Streptococcus bovis (Lancefield Group D) are not beta-hemolytic.^[4] Though there are many groups of streptococcus, only five are known to commonly cause disease in immune-competent human beings: Group A, Group B, both members of Group D, and two groups that lack the Lancefield carbohydrate antigen: streptococcus pneumoniae and Viridans streptococci.^[5]

Classification

Group A - Streptococcus pyogenes
Group B - Streptococcus agalactiae
Group C - Streptococcus equisimilis, Streptococcus equi, Streptococcus zooepidemicus, Streptococcus dysgalactiae
Group D - Enterococci, Streptococcus bovis
Group E - Streptococcus milleri and mutans
Group F - Streptococcus anginosus
Group G - Streptococcus canis and Streptococcus dysgalactiae
Group H - Streptococcus sanguinis
Group L - Streptococcus dysgalactiae
Group M - Streptococcus fryi sp. nov
Group N - Lactococcus lactis
Group R&S - Streptococcus suis
other Streptococcus species are classified as 'non-Lancefield Streptococci'

References

↑ Todar, Kenneth. "Neisseria gonorrhoeae, the Gonococcus, and Gonorrhea.". Lectures in Microbiology. 2009.
↑ Isenberg, Henry D. 1992. Clinical microbiology procedures handbook. Washington, D.C.: American Society of Microbiology.
↑ Lancefield RC (1933). "A serological differentiation of human and other groups of hemolytic streptococci.". J Exp Med 57 (4): 571–95. doi:10.1084/jem.57.4.571. PMC 2132252. PMID 19870148.
↑ Priloska, G. "Virulence factors and antibiotic resistance in Enterococcus faecalis isolated from urine samples.".
↑ Isenberg, H. D., & American Society for Microbiology. (1992). Clinical microbiology procedures handbook. Washington, D.C: American Society of Microbiology.

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