Which statement about C. burnetii is accurate?

• A. Facultative intracellular coccobacillus
• B. Obligate extracellular cocci
• C. Obligate intracellular rod
• D. Facultative extracellular bacillus

Answer: (A)

Understanding Coxiella burnetii's intracellular lifestyle and shape is being tested. This organism is a small Gram-negative bacterium that replicates inside host cells, especially within acidified phagolysosomes of macrophages, so it is an intracellular pathogen. Its morphology is best described as a coccobacillus—short, oval-rod shaped rather than purely cocci or a long bacillus. Describing it as a facultative intracellular coccobacillus communicates both its intracellular growth tendency and its characteristic shape. The other descriptions conflict with its intracellular nature or its coccobacillary form, so they don’t fit as well.