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Using Pathogenomics to Find Out Who Did It
Anthrax Spores. Uncopyrighted picture of Anthrax Spores. Courtesy of Frontier at Kansas State University.
From Bacillus anthracis. Currently seeking permission to use this photo.
There are three main forms of anthrax, which is an infectious disease due to a bacterium called Bacillus anthracis (NIH, 2013). The three forms include infection of the skin, gastrointestinal tract, and lungs (NIH, 2013). Most often, humans become infected with anthrax after coming into contact with an infected animal. Skin infections develop when anthrax spores “touch a cut or scrape on the skin”, gastrointestinal infections occur when a person consumes “anthrax-tainted meat”, and lung infections occur when a person inhales airborne anthrax spores (NIH, 2013). Lung infections only develop when the spores germinate inside the human host. Once they germinate, they “release several toxic substances … [that] cause internal bleeding, swelling, and tissue death” (NIH, 2013).
In 2001, B. anthracis spores were sent through the U.S. postal service to many individuals. Of these individuals, 20 people contracted anthrax and 5 died (ICT, 2011). By sequencing the genomes of the bacteria in the letters, scientists determined that the spores in all of the letters were genetically identical (ICT, 2011). Further, they determined that the spores originated in a flask at the U.S. Army biodefense laboratory in Maryland (ICT, 2011). Through connections to the flask and additional police work, Bruce Ivins, PhD, was determined to be responsible for mailing the spores (ICT, 2011).
Additional information about specific pathogenomics techniques used to identify the flask from which the mailed anthrax spores originated can be found here: http://www.pnas.org/content/108/12/5027.full
Electron Micrograph of Bacillus anthracis spores.Source: CDC Public Health Image Library (ID #2267)
From upmchealthsecurity. Currently seeking permission to use this photo.
In the process of analyzing the B. anthracis strain behind the attacks, researchers identified several genes encoding proteins responsible for allowing the pathogen to enter its host’s cells (NIH, 2003). Their research also showed that B. anthracis, unlike closely related strains, has an “enhanced ability to scavenge iron, which it may use to survive in its host” (NIH, 2003). All of this information suggests that learning more about pathogen genomes and the functions of certain parts of those genomes could “provide targets for drugs designed against the organism” (NIH, 2003)
This is one example of how pathogenomics can be used with regard to bioterrorism. Not only can understanding the genomes of pathogens help in the development of new vaccines and therapeutic treatments and in understanding the evolution and spread of pathogens, it can also be used to find the individuals responsible for bioterrorist attacks as in the case of the anthrax attacks. As pathogenomic methods continue to develop and become more precise, pathogenomics may become more pronounced in criminal investigations.
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