Tetanus in animals

Abstract

Tetanus is a neurologic disease of humans and animals characterized by spastic paralysis. Tetanus is caused by tetanus toxin (TeNT) produced by Clostridium tetani, an environmental soilborne, gram-positive, sporulating bacterium. The disease most often results from wound contamination by soil containing C. tetani spores. Horses, sheep, and humans are highly sensitive to TeNT, whereas cattle, dogs, and cats are more resistant. The diagnosis of tetanus is mainly based on the characteristic clinical signs. Identification of C. tetani at the wound site is often difficult.

Keywords: Clostridium tetani; animals; diagnosis; tetanus; tetanus toxin.

Figure 1.

Structure of tetanus toxin (TeNT) and schematic representation of its mode of action. H_C = receptor binding domain; H_N = translocation domain; LC = light chain or enzymatic domain containing the enzymatic site. TeNT is transported from contaminated wound to the central nervous system by retrograde axonal transport through motor neurons and possibly sensory neurons. In the spinal cord and brain, TeNT targets inhibitory interneurons blocking the release of glycine and GABA. This results in muscular hyperactivity subsequent to stimuli (e.g., touch, light, noise, temperature) as a result of the absence of inhibitory control.