Bacillus anthracis
Zheng (Sarra) Li

In 1877, Robert Koch confirmed that Bacillus anthracis was the cause of the disease Anthrax. 1 B. anthracis was the first organism proven to cause disease, and Louis Pasteur developed a successful vaccine against B. anthracis in 1881.

The most common treatment for the disease caused by B. anthracis, anthrax, is penicillin, since it is very effective against gram-positive bacteria. Other intravenous and oral antibiotics for treating anthrax include fluoroquinolones such as ciprofloxacin (cipro), doxycycline, erythromycin, and vancomycin. 2 Like the name suggests, Bacillus anthracis is a rod-shaped bacteria. It is facultatively anaerobic, and lives in the soil. The B. anthracis endospores can withstand harsh environment and live for decades, even centuries, 2 thus, it is hard to eradicate. Since B. anthracis dwells in soil, it usually causes disease in herbivores that consume grass which is contaminated with the B. anthracis endospores. Carnivores can also be infected with the disease if they ate the sick herbivores; although, most scavengers do not get the disease even if they ate infected animals; also, B. anthracis is ineffective against dogs and cats-only one case of infection in dogs had ever been recorded.

http://upload.wikimedia.org/wikipedia/commons/3/30/B_anthracis_diagram_en.png

There are three types of anthrax: gastrointestinal, cutaneous, and pulmonary. Anthrax is not spread from person to person, but from inhaling the endospores on a person’s clothing or other belongings, or ingesting the endospores in infected meat. B. anthracis’s usual pathway of infection can start from the inhalation of the endospores. The endospores then travel to the alveoli of the lungs, when the macrophages devour them and transport them elsewhere in the bloodstream, they multiply and break open the macrophages which contain them, and contaminate the blood stream which travels through the entire body. 2  Gastrointestinal anthrax is caused by consuming infected meat; the symptoms include “vomiting blood, severe diarrhea, acute inflammation of the intestinal tract, and loss of appetite.”2 The most common form of anthrax is cutaneous anthrax, also known as the skin anthrax. In cutaneous anthrax patients, black skin lesion can be observed on the outer surface of the skin. This observable characteristic gave anthrax its name, which was derived from the Greek word anthracis, meaning coal, referring to these black-centered boil-like tissues. Gastrointestinal and cutaneous anthrax can be treated, but depending on how soon the treatments start, gastrointestinal anthrax has a mortality rate of 20%-60%. 2 On the other hand, cutaneous anthrax is seldom fatal if treated. The most fatal form of anthrax is the pulmonary anthrax, with a mortality rate of almost 100%. 2 This particular strain of B. anthracis is used as a powerful bioweapon.

http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/19057.jpg

  • In Wikipedia [Web]. Retrieved 2/17/09, from http://en.wikipedia.org/wiki/Bacillus_anthracis
  • Anthrax. Retrieved 2/17/09, from http://en.wikipedia.org/wiki/Anthrax

*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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