Final answer:
The etiological agent of brucellosis is the Brucella genus of bacteria, which causes zoonotic infections in humans and cattle, often through contaminated milk or direct contact with animals. It can be hard to diagnose and is treated with specific antibiotics.
Step-by-step explanation:
The etiological agent of brucellosis is a group of gram-negative facultative intracellular bacteria within the genus Brucella. These bacteria are known to infect cattle and humans, primarily through the consumption of contaminated milk or close contact with infected animals. Brucella species, including B. abortus, B. canis, B. suis, and B. melitensis, lead to infections known by various names such as undulant fever, Mediterranean fever, or Malta fever. Human brucellosis cases in the US are mostly linked to occupational exposure.
Diagnosing brucellosis can be challenging since Brucella is only reliably found in the blood during the acute fever stage and is difficult to cultivate. It is considered a BSL-3 pathogen, which means it requires higher biosafety levels for laboratory handling. Serological tests like agglutination tests and enzyme-linked immunosorbent assays (ELISAs) are typically used for diagnosis. Treatments for brucellosis include antibiotics such as doxycycline, ciprofloxacin, and rifampin, and the disease can have severe health implications if not treated properly.