What is the difference between spirillum and spirochetes?

Answer 1

Spirochetes have a spiral shape, a flexible cell wall, and motility mechanisms based on structures called axial filaments. Each axial filament is composed of fibrils extending toward each other between two layers of the cell wall.

Spirochetes are very slender and difficult to see under the light microscope. They are cultivated with great difficulty (some cannot be cultivated), and their classification is based on their morphology and pathogenicity. Certain species inhabit water environments, while others are parasites of arthropods (such as ticks and lice) as well as warmblooded animals. Spirochetes include Borrelia burgdorferi, the agent of Lyme disease, Treponema pallidum, the cause of syphilis, and Leptospira interrogans, the agent of leptospirosis.

Spirilla have a spiral shape, a rigid cell wall, and motility mechanisms based on polar flagella. The genera Spirillum, Aquaspirillum, and Azospirillum are widely dispersed among and readily isolated from numerous environments. These organisms are aerobic bacteria wound like helices.

Answer 2

Spirilla are rigid, helical-shaped bacteria with flagella that move in a corkscrew motion, while spirochetes are flexible, helical-shaped bacteria that move by axial filaments called endoflagella encased within the periplasmic space. Spirilla are typically larger and have a more pronounced spiral shape compared to spirochetes.