3.17 Brucella Species

Microbiology review for the USMLE Step 1 exam

• Brucella species are gram-negative intracellular coccobacilli that are spread from animals to humans, causing a zoonotic infection called Brucellosis.
• B. melitensis is the most common species that causes infection in humans and is also the most virulent.
• Brucella only requires a very small dose (10-100 bacteria) to cause full-blown disease, often spread through contaminated unpasteurized milk or contact with animal carcasses.
• "Bruce Wayne's goat, Brucella Wayne, helps him SLAUGHTER bad guys"
• Symptoms include cyclical fever and chills, general malaise, headaches, joint pain, and nausea and vomiting.
• Diagnosis can be confirmed through blood cultures and PCR.
• Treatment involves antibiotics, typically doxycycline for a course of 6 weeks.
• People most at risk for infection include those who drink unpasteurized goat milk and those who work with animal carcasses, such as slaughterhouse workers.