Buffered charcoal yeast extract medium is used to support the growth of which organism, in addition to its use for Legionella?

• A. MacConkey agar
• B. Buffered charcoal yeast extract
• C. Blood agar with vancomycin
• D. Chocolate agar

Answer: (B)

The main idea here is recognizing the purpose of a specialized culture medium. Buffered charcoal yeast extract medium is specifically designed to support the growth of Legionella species. Its formulation includes charcoal to remove inhibitory substances, a buffered environment to maintain a stable pH, and nutrients from yeast extract along with essential supplements like cysteine and iron that Legionella requires but which aren’t provided by routine media. This combination creates the conditions Legionella needs to grow, which is why it’s the go-to medium for isolating this organism.

Among the options, the one that directly relates to the organism being cultured is the medium itself, since it was developed for Legionella growth. The other media listed are general or selective media not tailored to the strict requirements of Legionella, so they aren’t used for this purpose.