Spiral-shaped bacteria are called

• A. Spirochetes
• B. Coccobacilli
• C. Bacilli
• D. Vibrios

Answer: (A)

Spiral-shaped bacteria are called spirochetes. In microbiology, bacteria come in shapes like spherical (cocci), rod-shaped (bacilli), and spiral forms. Among the spiral forms, there are two groups: spirilla, which are rigid spirals with external flagella, and spirochetes, which are long, flexible spirals that move by axial filaments located between their inner and outer membranes. That means they have a distinctive corkscrew motion, helping them navigate through viscous environments. Examples include Treponema pallidum (syphilis) and Borrelia burgdorferi (Lyme disease). This flexible spiral form is the characteristic feature that makes spirochetes the term used for spiral-shaped bacteria.