A goat-and-sheep bacterium that reaches people through unpasteurised dairy and causes a long, relapsing fever. Explore its illustrative 3D model, human context, and sources.
PHAC describes Brucella as Gram-negative cocci or small rods, aerobic, non-motile and urease positive, with transmission by ingestion, direct contact via skin abrasions and mucous membranes, and inhalation; the host range covers humans, cattle, swine, goats, sheep, deer, caribou, elk, dogs and coyotes. The LPSN etymology records that the species epithet melitensis refers to the Island of Malta, where the organism was first isolated by Bruce in 1893. PHAC describes a systemic illness with intermittent fever, headache, weakness, profuse sweating, chills and joint pain, a case-fatality rate of less than 2% for untreated cases and a potentially long recovery, and an incubation period that is highly variable at 5 to 60 days and occasionally several months.
PHAC gives a case-fatality rate of less than 2% for untreated brucellosis but notes it may have a long recovery period, and CDC lists ongoing effects including recurring fevers, arthritis, heart infection and neuropsychiatric symptoms. Risk follows exposure to infected animals and their products, especially unpasteurised dairy, rather than contact with other people. Because reporting is patchy, published global case figures should be treated cautiously.
Brucella melitensis · A very short coccobacillus, almost coccal in outline. No measured size is implied. This is a species-informed teaching diagram; colours, proportions, envelope spacing and internal detail are illustrative. The model uses muted illustrative colours; stains, colony pigments and microscopy colourization are not natural cell colours. Anatomy is enlarged for phone viewing. Morphology reference: Brucella (B. abortus, B. canis, B. melitensis, B. suis) · pathogen safety data sheet.
Source check: 2026-09-20. Educational content; independent scientific review remains pending.