Brucella Species

Jaffar A. Al-Tawfiq, M.D. , Paul G. Auwaerter, M.D.


  • Aerobic, intracellular Gram-negative coccobacilli [Fig 1] causing brucellosis.
  • Grows on various media, usually within 24-48h of inoculation.
  • Zoonotic disease, the most important species for human infections:
    • B. abortus (cattle, buffalo)
    • B. melitensis (goat, sheep, camel)
    • B. suis (swine, wild animals)
    • B. canis (dog)
    • Less common:
      • B. ovis (sheep)
      • B. neotomae (desert and wood rats)
      • Three marine species also described as afflicting marine mammals (B. delphini, B. pinnipediae, B. cetaceae) have been described causing human disease.
  • Most human infections are due to B. arbortus and B. melitensis.
    • There is a correlation between seroprevalence in animals and human cases.
    • Recently, several taxonomists merged the free-living, environmental Ochrobactrum species with members of the genus Brucella. However, this may cause clinical misunderstanding if these are not reported distinctively.
      • Laboratories reporting Brucella species causing human disease should make a distinction between these from non-pathogenic organisms, namely Ochrobactrum species.

There's more to see -- the rest of this topic is available only to subscribers.

Last updated: July 8, 2023