Bacterium
Brucella species
Undulant fever, unpasteurized dairy zoonosis
broo-SEL-uh
High-yield clue
Undulant (relapsing) fever from unpasteurized dairy or livestock exposure is the classic brucellosis study clue.
Overview
Small Gram-negative coccobacilli that are facultative intracellular pathogens causing brucellosis (undulant fever), classically from unpasteurized dairy and occupational animal contact.
Classification
- Gram-negative
- Coccobacillus
- Brucellaceae
- Aerobe
- Facultative intracellular
Lab & identification clues
- Slow-growing, fastidious vocabulary
- Facultative intracellular survival concept
- Serology-based identification vocabulary
- Select-agent handling framing (concept-level)
Associations
- Unpasteurized dairy and animal-product transmission vocabulary
- Farmers, veterinarians, abattoir occupational risk
- Undulant fever and osteoarticular presentation vocabulary
Commonly confused with
- Francisella tularensis
- Coxiella burnetii
Frequently asked questions
What is Brucella species?
Small Gram-negative coccobacilli that are facultative intracellular pathogens causing brucellosis (undulant fever), classically from unpasteurized dairy and occupational animal contact.
What is the Gram stain of Brucella species?
Brucella species is Gram negative.
What are the lab clues for Brucella species?
Lab clues for Brucella species include Slow-growing, fastidious vocabulary; Facultative intracellular survival concept; Serology-based identification vocabulary; Select-agent handling framing (concept-level).
What is Brucella species commonly confused with?
Brucella species is commonly confused with Francisella tularensis and Coxiella burnetii.
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.