Concept
Serotype and serotyping
Antigen-based strain classification
SEER-oh-type
High-yield clue
Serotypes are defined by surface antigens (like capsular polysaccharide or O/H antigens), letting one species split into many antigenic variants.
Overview
A serotype is a subgroup within a species distinguished by its surface antigens, and serotyping is the antigen-based method used to tell these subgroups apart. It is central to epidemiology and vaccine design.
Classification
- Immunology/epidemiology concept
- Antigen-based strain subgrouping
- Uses antibody-antigen reactions
Lab & identification clues
- Salmonella typed by O (somatic) and H (flagellar) antigens
- Pneumococcus and Haemophilus typed by capsular polysaccharide
- Antisera agglutination distinguishes serotypes (vocabulary)
Associations
- Vaccine coverage is often serotype-specific
- Serotype tracking supports outbreak surveillance
- Explains many capsular types within one species
Commonly confused with
- Serotype vs species
- Serotype vs genotype
Your notes
Original microbiology concept summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC/WHO topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment selection, infection-control instructions, or specimen-handling guidance.