Clostridium perfringens
Morgan Schiermeier

Clostridium perfringens is a Gram-positive bacillus that grows anaerobically. Also, it is a spore-forming bacterium, which allows it to lay dormant within inhospitable environments. It was of particular interest to me due to its ability to cause clinically relevant conditions such as food poisoning and, relatedly, necrotizing enteritis. Further, C. perfringens is not limited to wreaking havoc in humans alone; it is capable of infecting a vast array of animals. This ability to cause enteritis in animals has lead to problems in commercially raised livestock. This deadly bacterium has no proficient treatment in livestock and an infection is a virtual death-sentence.

Human infections lead to ulcer formation, usually on the small intestine. Treatment needs to be as rapid as possible because of the deadly nature of the bacterium and its secreted toxin. Even with treatment, the mortality rate to major infections is around 25%. Untreated, the mortality rate is 100%; again illustrating just how deadly serious an infection can be.

Treatment consists of antibiotics (typically penicillin) and removal of afflicted tissue. Wounds into which C. perfringens has infiltrated may lead to amputation of the afflicted extremity. C. perfringens utilizes an endotoxin to cause its destruction. The endotoxin is made up of proteins. These proteins are able to insert themselves into the membrane of cells – creating a pore. Once a pore is created, the cellular debris is able to pass through and prevent proper functioning and lyses. This destruction of cells is what is observed in necrosing tissue. As the cells lyses, they die. As more and more cells die, a wound is opened – leading to further complications as bodily fluids, materials, and even other bacteria are transferred into other areas where they can cause damage.

Luckily, not all cases are this severe. In fact, many people are resistant to many strains because they posses antibodies capable of recognizing C. perfringens. This is very fortunate as C. perfringens is extremely common. It has been found on every continent inhabited by humans. Most of the time, severe diarrhea, vomiting, and abdominal pain are the only symptoms. The primary way of infection is ingestion (food poisoning), usually from undercooked food as sufficient cooking will kill the bacteria.

Lastly, the microbe can be identified via growth on blood agar. As mentioned earlier, the organism will produce Gram-positive (retain purple) colonies that appear rod-shaped (bacilli). Also, one can check for the through use of a PCR assay to detect the gene creating the toxin. Alternatively, samples can be injected into mice to see if the same effect is elicited.

References:

1. http://ag.arizona.edu/pubs/general/resrpt1998/clostridium.html

2. http://www.idph.state.il.us/Bioterrorism/factsheets/clostridium.htm

3. http://en.wikipedia.org/wiki/Clostridium_perfringen

*Disclaimer - This report was written by a student participaring in a microbiology course at the Missouri University of Science and Technology. The accuracy of the contents of this report is not guaranteed and it is recommended that you seek additional sources of information to verify the contents.

 

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