Burkholderia cepacia
Justin Steenhoek

Burkholderia cepacia is a gram-negative rod that is 1.6-3.2 m m in length. It was discovered in 1949 by Walter Burkholder at Cornell University in rotting onions. B. cepacia is a strict aerobe and a chemoorganotroph with an optimum temperature of 30 to 35 degrees Celsius. It is found in soil, water and on plants and can survive longer in wet environments then in dry ones. It is unique in the way that is can be versatile in its uses, plant pathogen, human pathogen, bioremediation agent, and a biocontrol agent.

It can be used as a biocontrol agent because it produces multiple antibiotics against pathogenic fungi in plants. It is not a toxic fungicide, so it does not pollute the water or soil. Burkholderia cepacia has the ability to metabolize almost anything available to it, even chlorinated hydrocarbons. These hydrocarbons are commonly found in commercial pesticides and herbicides. It is possible to add this bacterium to sites that are contaminated by these toxins and clean up the environment. Weed-B-Gone, a common household herbicide, is popular because it does its job and is easily degradable by organisms in the soil. B. cepacia is one of the most effective bacteria at degrading the chemicals.

Unfortunately, the bacterium has problems that need to be handled before widespread usage. One is that is can resist multiple antibiotics and has been found able to grow on penicillin medium. It can mutate quickly and adapt due to its unusually large genome to defend against antibiotics. In the early seventies, it was found to be a human pathogen and causes mild respiratory disease and urinary tract infections, in addition to being the causative agent of "foot rot" in swamps. B. cepacia was usually found in hospitals as an opportunistic pathogen. In the eighties, it was found to cause life threatening pulmonary infections in cystic fibrosis patients. The complications caused by Burkholdheria cepacia had a mortality rate of 80%. This bacteria and Pseudomonas aeruginosa enhance each other in their effects in cystic fibrosis patients causing major problems. Due to the problems that Burkholderia cepacia can cause, currently the CDC and the EPA has a moratorium against Bc pesticides and herbicides.

Reference:

Bergey's Manual of Systematic Bacteriology", Vol. 2, Williams and Wilkins, 1989.

The Prokaryotes", Volume III, Second Edition, Springer-Verlog, 1992.

APSnet, http://www.scisoc.org/feature/BurkholderiaCepacia/Top.html

Emerging Infectious Diseases, Vol. 4, No. 2, April - June 1998,

http://www.cdc.gov/ncidod/EID/vol4no2/holmes.htm

 

 

*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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