Bacterium
Streptococcus pyogenes
Group A beta-hemolytic streptococcus
STREP-toh-KOK-us py-AH-jeh-neez
High-yield clue
Chains + beta-hemolysis + Group A is the core recognition pattern.
Overview
A Gram-positive coccus used to connect chains, Group A classification, beta-hemolysis, and classic toxin/immune complication vocabulary.
Classification
- Gram-positive
- Cocci
- Chains
- Group A Streptococcus
Lab & identification clues
- Catalase negative
- Beta-hemolysis
- Bacitracin sensitivity is a classic teaching clue
Associations
- Pharyngitis concept
- Skin infection concepts
- Scarlet fever clue
- Post-streptococcal immune vocabulary
Commonly confused with
- Streptococcus agalactiae
- Staphylococcus aureus
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.