What disease is caused by the bacterium Clostridium tetani?

The disease caused by the bacterium Clostridium tetani is tetanus. This Gram-positive, anaerobic, spore-forming bacterium can enter the body through a wound and produce tetanospasmin, a powerful neurotoxin responsible for the disease’s characteristic muscle rigidity and spasms.

Tetanospasmin interferes with inhibitory signals in the nervous system, allowing motor neurons to fire excessively. Spasms often begin in the jaw, producing the familiar name “lockjaw,” and may spread to the neck, trunk, and respiratory muscles. Deep puncture wounds are particularly risky because damaged tissue can create the low-oxygen conditions that allow spores to germinate.

Rust itself does not cause tetanus, although rusty outdoor objects may carry contaminated soil and create puncture wounds. Vaccination with tetanus toxoid prevents the toxin from causing disease and remains the main protection. The alternatives describe different bacterial illnesses: diphtheria is caused by Corynebacterium diphtheriae, botulism by Clostridium botulinum, and gas gangrene commonly involves Clostridium perfringens.