Babes-Ernst granules are characteristic of which organism?

Babes-Ernst granules are distinctive intracellular inclusions that are characteristic of Corynebacterium diphtheriae, the bacterium responsible for diphtheria. These granules are composed of a polymer of polyphosphate, and their presence is crucial for the identification of this specific organism. Under a microscope, they appear as metachromatic granules, which can be visualized using certain staining techniques, such as Albert's stain.

Corynebacterium diphtheriae exhibits a unique morphology, often described as "Chinese letters," due to its club-shaped cells. Identifying Babes-Ernst granules aids in confirming the diagnosis of infections caused by this pathogen, which is essential because diphtheria can lead to severe respiratory complications and has a significant impact if not treated timely. This characteristic feature differentiates it from the other listed organisms, which do not produce these specific granules.