WARNING: This is not sci-fi, but a story based on scientific theories of bacterial and immune behavior.
We all fear tetanus, the disease that we can “catch” from rusty nails and that we receive booster shots to prevent. The causative agent Clostridium tetani is a bad boy that does more than just play dirty—it kills dirty. Found in rich soil fertilized by animals carrying the bacteria in their gastrointestinal tracts, this species of bacteria lies dormant in a protective spore. It kills by releasing two different toxins in the victim’s partially healed wound. C. tetani is one of three muchachos in the genus Clostridium that cause serious human disease. C. botulinum is the infamous cause of botulism and C. perfringens causes gas gangrene and food poisoning. These bacteria are referred to as anaerobes because of their distaste for oxygen, or as microbiologists like to say for the bugs’ particularly strong distaste, “obligate anaerobes.” Their long persistence in the environment is credited their spore-producing capabilities which allows them to survive long periods of time in unfavorable conditions.
So, what’s the story on this tiny culprit?
Chapter 1: Innocence
Little Miss Muffin sat down for some chow, and along came a jumping spider and jumped down beside her, and frightened Miss Muffin away. As Miss Muffin ran, she stumbled and fell onto soft pasture soil. The palm of her right hand landed on a thin, long, rusty nail. Her hand suffered a puncture that only bled slightly with moderate pain, so she thought little of it. Miss Muffin brushed herself off and skipped to a nearby pond in search of bullfrogs.
Chapter 2: The Invader
Residing once inside a Jersey cow, but now no longer, A Clostridium tetani bacterium landed on the ground with a thud. “Oh dear, there is oxygen. I can’t survive in oxygen, thus I must form a protective capsule layer around myself.” It then encased itself in a spore, thus protecting the rod-shaped bacterium from oxygen and adverse environmental conditions. This “endospore” had the appearance of an elongated drumstick. C. tetani also produced tetanospasmin.
Two years later, a lack of oxygen dissolved the capsule, and C. tetani was liberated. “Freedom baby!” The tetanospasmin was released from C. tetani as the bacterium lysed open from its spore. C. tetani grew flagella and swam in the body with its new motility. It replicated its circular chromosome of DNA, the bacterium divided in half, and formed two C. tetani. Again, and again, the bacteria divided and the infection grew in Miss Muffin’s hand. The production of the destructive tetanolysin thus also increased and was dispersed by the bloodstream.
Chapter 3: Miss Muffin Fights Back.
What will happen to Miss Muffin? Will the tetanospasmin debilitate her nerves and the tetanolysin damage her tissue? How will she fight back? Come back for more exciting microbiological adventures with Miss Muffin.
References:
Murray Patrick, Ken Rosenthal, George Kobayashi, and Michael Pfaller. Medical Microbiology, 4th Ed. St. Louis, Mosby, Inc, 2002.
About the author:
Theresa Adams graduated from Washington State University, Pullman, with a BS in Microbiology. She is married to a handsome guy named Ethan and has two little boys who are not aware of the of term “germs” and instead are occasionally reminded of “icky microbes.” She agrees with King David, that we are “fearfully and wonderfully made,” Ps. 139:14.
