Which statement is true of Brucella?

• A. They are strictly human pathogens.
• B. They are nonfastidious and grow on most nonselective laboratory media.
• C. The risk of accidental laboratory infection is no greater than with any other organism.
• D. Slide agglutination in antisera is a commonly used screening test for identification.

Answer: (D)

Brucella identification commonly relies on serologic methods because these bacteria are slow-growing and fastidious, making rapid, culture-based confirmation challenging. Using antisera in a slide agglutination test provides a quick screening means to detect Brucella antigens present in a sample or isolate. When the specific Brucella antisera encounters the corresponding antigens, visible clumping occurs, indicating Brucella presence and guiding further confirmatory testing. This approach is favored in many labs for its speed, simplicity, and cost-effectiveness as an initial screen.

It’s worth noting that Brucella are zoonotic and require careful biosafety handling, with higher infection risks in laboratory settings than many other organisms. They are not strictly human pathogens, and they are fastidious, not nonfastidious, which is why the other statements don’t fit.