Which feature is characteristic of Corynebacterium diphtheriae?

Corynebacterium diphtheriae is known for its unique morphology, which includes small, curved rods that can arrange themselves in a characteristic pattern often described as “Chinese letters.” This pattern occurs due to the bacteria's irregular cell division and branching, resulting in the characteristic arrangements seen under a microscope.

The organism is a Gram-positive bacterium, which is crucial in differentiating it from Gram-negative cocci. It does not form spores, which rules out the option related to spore-forming rods. Additionally, filamentous bacteria are not representative of the C. diphtheriae, as this bacterium does not have a filamentous structure but rather appears as short, straight or slightly curved rods. This understanding of the morphological characteristics of C. diphtheriae is essential in clinical microbiology for the identification of this pathogen, especially in cases of diphtheria.