Which bacteria appear like curved rods, also known as comma-shaped?

The correct choice is Vibrio, as these bacteria are characterized by their unique curved or comma-like shape. Vibrio species are gram-negative bacteria that are often found in marine environments and can be associated with diseases such as cholera. Their distinctive morphology is a key identifying feature, setting them apart from other bacterial shapes.

Bacillus refers to rod-shaped bacteria, often appearing in straight lines or chains, which does not align with the curved rod description. Spirilium are spiral-shaped bacteria that exhibit a helical form rather than a curved rod structure. Streptococcus consists of spherical-shaped bacteria that typically form chains or pairs and lack the curved morphology seen in Vibrio. Understanding these characteristics is crucial in microbiology for accurately identifying and differentiating between various bacterial species.