Which type of bacteria is characterized as rod-shaped?

The classification of bacteria into different shapes is fundamental in microbiology, and the term that refers specifically to rod-shaped bacteria is "bacilli." Bacilli bacteria can vary in length and can exist as single cells, pairs, or even in chains, but their defining characteristic is their elongated, cylindrical shape, resembling rods.

In contrast, the other types mentioned - cocci are spherical, sprilla are spiral-shaped, and vibrio are comma-shaped. Understanding these bacterial shapes is essential for identification and can be crucial in clinical settings when diagnosing infections and choosing appropriate treatments. Thus, recognizing that bacilli is the term used for rod-shaped bacteria solidifies the understanding of bacterial morphology.