Bacterium
Serratia marcescens
Red-pigmented healthcare-associated rod
seh-RAY-shuh mar-SESS-enz
High-yield clue
Red prodigiosin pigment plus DNase positivity is the classic recognition clue for this healthcare-associated rod.
Overview
A Gram-negative enteric rod famous in coursework for producing the red pigment prodigiosin at room temperature and for causing opportunistic healthcare-associated infections.
Classification
- Gram-negative
- Rod
- Enterobacterales
- Facultative anaerobe
- Motile
Lab & identification clues
- Red prodigiosin pigment vocabulary
- DNase positive concept
- Slow or late lactose fermentation
- Inducible AmpC beta-lactamase vocabulary
Associations
- Catheter and device-associated infection vocabulary
- Respiratory and urinary study association
- Multidrug-resistance framing
Commonly confused with
- Enterobacter cloacae
- Klebsiella pneumoniae
Frequently asked questions
What is Serratia marcescens?
A Gram-negative enteric rod famous in coursework for producing the red pigment prodigiosin at room temperature and for causing opportunistic healthcare-associated infections.
What is the Gram stain of Serratia marcescens?
Serratia marcescens is Gram negative.
What are the lab clues for Serratia marcescens?
Lab clues for Serratia marcescens include Red prodigiosin pigment vocabulary, DNase positive concept, Slow or late lactose fermentation, and Inducible AmpC beta-lactamase vocabulary.
What is Serratia marcescens commonly confused with?
Serratia marcescens is commonly confused with Enterobacter cloacae and Klebsiella pneumoniae.
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.