Blood cultures are the recommended method for recovering which organism?

• A. Acinetobacter baumannii
• B. Brucella canis
• C. Chlamydia trachomatis
• D. Yersinia enterocolitica

Answer: (B)

Blood cultures are particularly effective for recovering organisms that cause systemic bacteremia, where the pathogen circulates in the blood during infection. Brucella species, including Brucella canis, tend to cause persistent bacteremia and are slow-growing, so isolating them from blood after several days of incubation is the most reliable way to confirm infection. This makes blood culture the preferred method for diagnosing brucellosis, since other sample types may not reliably yield the organism.

In contrast, Chlamydia trachomatis does not grow on routine bacterial culture and requires cell culture or nucleic acid amplification tests; Yersinia enterocolitica is typically detected in stool samples and clinical presentations outside of bloodstream infection, though it can be recovered from blood in rare septic cases; Acinetobacter baumannii can be recovered from blood during bacteremia but is not uniquely associated with blood culture as its primary diagnostic method.