Bacterium
Morganella morganii
Urease- and indole-positive nosocomial enteric rod
mor-guh-NELL-uh mor-GAN-ee-eye
High-yield clue
A urease-positive, indole-positive Enterobacterales rod causing catheter-associated/nosocomial UTI is the core study clue.
Overview
A Gram-negative enteric rod in the order Enterobacterales, historically grouped with the Proteae tribe (Morganellaceae). It is an opportunistic pathogen most often linked to healthcare-associated urinary tract and wound infections.
Classification
- Gram-negative
- Rod
- Enterobacterales
- Morganellaceae (Proteae tribe)
- Facultative anaerobe
Lab & identification clues
- Urease positive vocabulary
- Indole positive (contrast Proteus mirabilis, indole negative)
- Inducible AmpC beta-lactamase framing
- Lactose non-fermenter on MacConkey
Associations
- Healthcare-associated UTI study association
- Catheter-associated and postoperative wound infection
- Opportunistic infection in comorbid hosts
- Intrinsic/acquired antimicrobial-resistance framing
Commonly confused with
- Proteus mirabilis
- Providencia species
Frequently asked questions
What is Morganella morganii?
A Gram-negative enteric rod in the order Enterobacterales, historically grouped with the Proteae tribe (Morganellaceae). It is an opportunistic pathogen most often linked to healthcare-associated urinary tract and wound infections.
What is the Gram stain of Morganella morganii?
Morganella morganii is Gram negative.
What are the lab clues for Morganella morganii?
Lab clues for Morganella morganii include Urease positive vocabulary; Indole positive (contrast Proteus mirabilis, indole negative); Inducible AmpC beta-lactamase framing; Lactose non-fermenter on MacConkey.
What is Morganella morganii commonly confused with?
Morganella morganii is commonly confused with Proteus mirabilis and Providencia species.
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.