Brucella. spp A

Brucella is the cause of brucellosis, which is a zoonosis. It is transmitted by ingesting contaminated food (such as unpasteurized milk products), direct contact with an infected animal, or inhalation of aerosols. Transmission from human to human, for example through sexual intercourse or from mother to child, is exceedingly rare, but possible. Minimum infectious exposure is between 10 - 100 organisms.

The different species of Brucella are genetically very similar, although each has a slightly different host specificity (see below). Hence, the NCBI taxonomy includes most Brucella species under Brucella melitensis.