Module 2

Rods (bacilli) are elongated cylinders.

•  Cocci are perfect spheres.

•  Spirilla are rigid helices with external flagella.

•  Vibrios look like commas or slightly bent rods.

•  Spirochetes are thinner, more flexible corkscrews (often shown with axial filaments).

•  Strepto- = chains, Diplo- = pairs, Staphylo- = irregular clusters.