Lancefield group

Definition

Lancefield group is a classification system for beta-hemolytic streptococci based on the carbohydrate composition of bacterial antigens found on their cell walls. It categorizes these bacteria into groups A through T.

5 Must Know Facts For Your Next Test

1. The Lancefield classification primarily applies to beta-hemolytic Streptococcus species.
2. Group A Streptococcus (GAS) is known for causing diseases like strep throat and necrotizing fasciitis.
3. Group B Streptococcus (GBS) can be found in the human gut and is a common cause of neonatal infections.
4. The classification relies on serological reactions with specific antibodies to polysaccharides present on the bacterial cell wall.
5. Rebecca Lancefield developed this system in the 1930s, which has since become crucial for identifying pathogenic streptococci.

Review Questions

Related terms

Beta-Hemolytic: Bacteria that completely lyse red blood cells, producing clear zones around colonies on blood agar.

Serotyping: A method used to identify bacteria based on their cell surface antigens.

Streptococcus pyogenes:

A bacterium classified under Group A in the Lancefield system, responsible for various infections including strep throat.