PetriKey

Concept

Capsule

Antiphagocytic surface structure

KAP-sool

capsulevirulencepolysaccharidevaccinebacteria

High-yield clue

Capsule often means antiphagocytic virulence vocabulary and vaccine antigen concepts.

Overview

A surface-structure concept used to connect immune evasion, mucoid colony vocabulary, and polysaccharide vaccine framing.

Classification

  • Virulence factor
  • Surface structure

Lab & identification clues

  • Quellung reaction vocabulary
  • Negative stain concept
  • Mucoid colony vocabulary

Associations

  • Streptococcus pneumoniae
  • Klebsiella pneumoniae
  • Neisseria meningitidis

Commonly confused with

  • Endospore
  • Biofilm

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.

OpenStax: Microbiology 2e concept foundationssourceNCBI Bookshelf: Medical Microbiology general conceptssourceCDC: CDC public-health concept pagessource