Which organism forms small ground-glass colonies on buffered charcoal yeast extract agar after about a week of incubation?

Prepare for the CAMLPR Microbiology Test. Utilize flashcards and engaging multiple-choice questions, each equipped with descriptions and explanations. Ready yourself for an excellent performance!

Legionella are fastidious organisms that need a specialized medium and longer incubation to grow. Buffered charcoal yeast extract agar provides the nutrients and environment (including charcoal to detoxify substances and added cysteine and iron) that Legionella require, so colonies form only after several days and appear as small, ground-glass gray colonies. This slow, distinctive growth on BCYE helps distinguish it from other bacteria. For example, Pseudomonas aeruginosa grows quickly on routine media and shows typical features like pigments and odor rather than tiny ground-glass colonies on BCYE; Haemophilus influenzae needs X and V factors and grows best on chocolate agar with tiny colonies; Klebsiella pneumoniae forms larger, mucoid lactose-fermenting colonies on standard media.