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 now is largely superfluous due to explosive growth in the number of streptococcal species identified since the 1970s.[2] As of 2016, Lancefield designations are often used to communicate medical microbiological results in the United States. 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
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- ↑ Isenberg, Henry D. 1992. Clinical microbiology procedures handbook. Washington, D.C.: American Society of Microbiology.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Isenberg, H. D., & American Society for Microbiology. (1992). Clinical microbiology procedures handbook. Washington, D.C: American Society of Microbiology.
