Clostridium tetani animated Clostridium tetani infections

Clostridium tetani morphology

  • Gram-positive, anaerobic bacteria
  • often stain Gram-negative or Gram-variable
  • motile (flagella), slim rods
  • the organism produces terminal spores (a drumsticks appearance)

Infections caused by Clostridium tetani bacteria

Clostridium tetani is the causative agent of tetanus. Tetanus bacteria are everywhere in the environment, including soil, dust and manure. The bacteria can get into the body through broken skin, usually through injuries from contaminated objects. Tetanus is often associated with rust, especially rusty nails. It does not spread from person to person.

Tetanus is an infection characterized by muscle spasms. In the most common type the spasms begin in the jaw and then progress to the rest of the body. These spasms usually last a few minutes each time and occur frequently for three to four weeks. Spasms may be so severe that bone fractures may occur. Other symptoms may include: fever, headache, trouble swallowing, high blood pressure, and a fast heart rate. Onset of symptoms is typically three to twenty one days following infection. Mortality rates reported vary from 40% to 78% (Wikipedia).

C. tetani produces two toxins, tetanospasmin and tetanolysin. Tetanospasmin is a neurotoxin that causes the clinical manifestations of tetanus. Tetanus toxin is generated in living bacteria, and is released when the bacteria lyse. The genes for toxin production are encoded on a plasmid which is present in all toxigenic strains (Wikipedia). Tetanus bacilli multiply locally and neither damage nor invade adjacent tissues.

In fatal cases, death usually results from exhaustion and respiratory failure.

Infections caused by Clostridium tetani bacteria

  • tetanus

Deaths caused by Clostridium tetani (2004)

  • Worldwide incidence:
  • Worldwide deaths:

Clostridium tetani treatment

Tetanus toxoid and immunoglobulin
  • Tetanus toxoid can be given in case of a suspected exposure to tetanus. In such cases, it can be given with or without tetanus immunoglobulin (tetanus antitoxin).

Curarelike drugs
  • In severe cases, curarelike drugs are used to block nerve impulses at the neuromuscular junctions.

Antibiotic treatment
  • penicillin G
  • metronidazole

Clostridium tetani vaccination




Textbook of bacteriology

Colony appearance

clostridium tetani morphology clostridium tetani cell morphology clostridium tetani