Advances Developed To Detect Bioterrorist Agents Could Find Use In Protecting Food Supplies

May 20, 2002

Advances Developed To Detect Bioterrorist Agents Could Find Use In Protecting Food Supplies

SALT LAKE CITY – Technologies developed by Lawrence Livermore National Laboratory researchers and other scientists to fight bioterrorism could find another use — detecting naturally occurring pathogens in food.

Livermore biomedical scientist Paula McCready will deliver that message today during a session of the American Society for Microbiology at the Salt Palace Convention Center.

"The tools we use to develop DNA signatures for the detection of bioterrorist agents could also be used to search out food-borne pathogens," McCready said. (DNA signatures are areas or regions of DNA unique to specific organisms).

"We believe people are going to look at the problem of food-borne pathogens differently because of the new tools that are becoming available."

Finding the DNA signatures for bacteria that cause food poisoning would allow laboratories to more rapidly identify their presence in food and in the environment.

Among the bacteria that could be identified, according to McCready, are Camphylobacter, a bacterium present in undercooked chicken, or different types of Salmonella, a bacterium that can be found in eggs, juice, fruit or vegetables.

Previously, diagnostic tests to identify and type these bacteria normally required many hours to days to complete because of the need to culture and prepare samples, as well as conduct analysis.

However, with the rapidly growing development of DNA signatures and new polymerase chain reaction (PCR)-based DNA analysis systems, the tests can now be conducted in less than one hour.

"We can also tailor our tests to distinguish harmful forms of different organisms from the benign forms," McCready said.

Livermore researchers and other biomedical scientists have developed highly accurate DNA signatures for the bacteria that cause plague and anthrax, as well as for other organisms.

This work has been done in collaboration with Los Alamos National Laboratory researchers and the Bioterrorism Rapid Response and Advanced Technology Laboratory of the Centers for Disease Control in Atlanta.

During the past year, the Livermore DNA assays have been used to test more than 10,000 complex environmental samples. Individual DNA markers in these assays have been accurate 99.99 percent of the time and the composite pathogen test has been 100 percent accurate, McCready said.

Before breakthroughs in DNA sequencing and other advances, it often required years to find unique DNA signatures to help identify some harmful organisms, McCready said. DNA signatures can now be found in weeks to months.

"The reason this is important is because if a new bug is identified, we can quickly develop DNA signatures for new strains of pathogens," she said.

The use of DNA signatures to detect food-borne diseases would represent another application for the emerging technology. Last year, Livermore’s DNA signatures were used for the first time to detect a public health disease in the environment when collaborators at Northern Arizona University (NAU) used them to detect plague.

In the past, tests to confirm whether plague is present in an environment have usually required seven to 10 days.

Last spring’s finding of plague, in a small rural community northwest of Flagstaff, Ariz., was confirmed within four hours by a team of researchers led by NAU microbiology professor and plague expert Paul Keim.

The Livermore DNA signatures were also used in February as part of a detection system deployed by Los Alamos and Livermore national laboratories at the Salt Lake City Olympic Games.

Designed to detect the criminal use of biological agents, the system is called the Biological Aerosol Sentry and Information System, or BASIS.

Founded in 1952, Lawrence Livermore National Laboratory is a national security laboratory, with a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by the University of California for the U.S. Department of Energy’s National Nuclear Security Administration.

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