Which organism is primarily isolated on Loeffler's medium?

Which organism is primarily isolated on Loeffler's medium?

• A. Corynebacterium diphtheriae
• B. Listeria monocytogenes
• C. Neisseria meningitidis
• D. Bacillus cereus

Answer: (A)

Loeffler's medium is used as a short-term enrichment to promote growth of Corynebacterium diphtheriae and to reveal its characteristic metachromatic (Babes-Ernst) granules when stained. This specific association with metachromatic granules makes it the best medium for isolating this organism. The other bacteria listed do not have this selective relationship with Loeffler's medium and are identified using different media and methods. So the organism primarily isolated on Loeffler's medium is Corynebacterium diphtheriae.

Loeffler's medium is used as a short-term enrichment to promote growth of Corynebacterium diphtheriae and to reveal its characteristic metachromatic (Babes-Ernst) granules when stained. This specific association with metachromatic granules makes it the best medium for isolating this organism. The other bacteria listed do not have this selective relationship with Loeffler's medium and are identified using different media and methods. So the organism primarily isolated on Loeffler's medium is Corynebacterium diphtheriae.