Colonies described as resembling droplets of mercury are characteristic of which organism?

Colonies described as resembling droplets of mercury are characteristic of which organism?

• A. Bordetella pertussis
• B. Burkholderia cepacia
• C. Campylobacter jejuni
• D. Yersinia pestis

Answer: (A)

Mercury-drop–like colonies are a classic clue for Bordetella pertussis. This organism is fastidious and grows best on Bordet-Gengou or Regan-Lowe media, where it forms tiny, shiny, convex colonies that are described as resembling droplets of mercury. That distinctive, gleaming, drop-like appearance helps differentiate it from other organisms such as Burkholderia cepacia, Campylobacter jejuni, or Yersinia pestis, which do not produce these mercury-like colonies on their usual culture media. Remember, colony morphology provides a useful initial hint, but confirmatory tests are needed for definite identification.

Mercury-drop–like colonies are a classic clue for Bordetella pertussis. This organism is fastidious and grows best on Bordet-Gengou or Regan-Lowe media, where it forms tiny, shiny, convex colonies that are described as resembling droplets of mercury. That distinctive, gleaming, drop-like appearance helps differentiate it from other organisms such as Burkholderia cepacia, Campylobacter jejuni, or Yersinia pestis, which do not produce these mercury-like colonies on their usual culture media. Remember, colony morphology provides a useful initial hint, but confirmatory tests are needed for definite identification.