The bacteria that cause tetanus can survive in a puncture wound that has healed on the outer surface of the skin through what process do these bacteria acquire the energy they need to survive?

Answer 1

Clostridia are saprophytic organisms. The genus contains some of the most dangerous pathogens known to man. (Clostridium perfringens - Gangrene, Food poisoning - Clostridium botulinum - Botulism, Clostridium difficile -Pseudomembranous colitis) C tetani's tetanus toxin (known as tetanospasmin) is an anaerobic rod that is lethal, but it is not as dangerous, as the botulinum toxin produced by C. botulinum.

As with all clostridial wound infections, trauma to the host tissue is the initial event in tetanus, followed by contamination of the wound with C tetani. Without the damage to the tissue, the anaerobic bacteria cannot survive. The damage creates an environment with a potential for reduced oxidation- which is necessary for anaerobic growth. Once growth is initiated, the organism itself stays confined to the necrotic tissue, where the vegetative cells of C tetani elaborate the lethal toxin Tetanospasmin.

The incubation period for C tetani, from contamination to first symptoms depends on the site of the wound and the dose of the bacteria. The further away from the central nervous system, the longer the incubation; a large dose of bacteria in a wound in the upper arm, chest or head may only take a few days, while the infamous rusty nail to the foot - may take several weeks.

The two animal species most susceptible to this toxemia are horses and humans.