Brucella abortus
Meghan Ray

Brucella abortus is a rod shaped coccus that is a facultative aerobe. This microorganism is also a mesophile that grows optimally at 37 degrees Celsius and depends greatly on its host for nutrients. In fact, it is incapable of reproducing outside of a host. It is a gram negative microorganism that causes late term abortions in cattle and can cross species and infects humans with undulant fever. According to the ATCC website, this microorganism is shipped freeze dried and has a bio safety level of 1. The ATCC website also priced B. abortus at $240.00.

The organism can be transmitted from cattle to cattle by coming in contact with infected placenta and or infected semen.  In humans, undulant fever is usually contracted by eating cheese or unpasteurized milk. It is called undulant fever because the fever usually “undulates” up and down each day. It is also a problem for slaughter house workers and large animal veterinarians. Symptoms include: fever, chills, weakness, weight loss, fatigue, abdominal pain, back pain, loss of appetite, and joint pain. Undulant fever is usually not deadly and can be treated by a combination of antibiotics of doxycycline and rifampin.

B. abortus was first discovered by Dr. David Bruce on the island of Malta. Though it is mostly eradicated in the United States due to an almost $3.5 billion dollar vaccination plan, it is still a problem in many developing countries. According to the CDC, there are usually between 100 and 200 cases in the US each year.

Because of how easily B. abortus is spread from one organism to another, it makes for a potential bioterrorist hazard. It would make an ideal bioterrorist weapon because it affects both livestock and humans with fairly long term effects; however most cattle in the US have been vaccinated. An organism closely related to B. abortus called Brucella suis was examined by the US as a potential weapon in the late 60’s. It has recently resurfaced in research due to the increased fear of bioterrorism. The United States is currently looking into methods to detect B. abortus in a host. B. abortus is also being researched because of its ability to elude the immune system. This microorganism enters the cells and attaches itself to the endoplasmic reticulum. From there, B. abortus regulates apoptosis by telling the cell not to die and is able to resist the immune system.


*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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