PetriKey

Bacterium

Staphylococcus aureus

Gram-positive cocci in clusters

STAFF-ih-lo-KOK-us AW-ree-us

Gram positivegram-positivecoccicatalasecoagulaseskintoxin

High-yield clue

Clusters + catalase positive + coagulase positive is the classic study clue.

Overview

A high-yield Gram-positive coccus commonly used to connect catalase, coagulase, toxin concepts, abscess patterns, and antimicrobial resistance vocabulary.

Classification

  • Gram-positive
  • Cocci
  • Clusters
  • Facultative anaerobe

Lab & identification clues

  • Catalase positive
  • Coagulase positive
  • Golden colonies in many teaching examples
  • Beta-hemolysis is often emphasized in class

Associations

  • Skin and soft-tissue infection concepts
  • Food poisoning toxin concept
  • Toxic shock toxin concept
  • MRSA as resistance vocabulary

Commonly confused with

  • Staphylococcus epidermidis
  • Streptococcus pyogenes

Your notes

Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.

OpenStax: Microbiology 2e organism classification foundationssourceNCBI Bookshelf: Medical Microbiology organism chapterssourceCDC: CDC disease and public-health topic pagessource