Being developed under the DARPA Friend or Foe program, the portable device would be based on biosurveillance technology that detects bacterial pathogens as soon as or before they threaten the military and citizens. Such a device, says the company, could support the future development of medical countermeasures and improved screening tools.
Current biosurveillance strategies are not effective on undiscovered bacterial strains or on bacteria engineered to evade detection. To overcome this problem, Friend or Foe will characterize bacteria quickly by examining its behavior.
"Population growth, global travel, climate change — all of these factors increase the risk of exposure to unfamiliar bacteria," says Aaron Adler, Ph.D. and principal investigator for the Friend or Foe program at Raytheon BBN Technologies. "Most of those bacteria are harmless or even beneficial, but our goal is to develop a system that lets people know quickly when they are not as a cue to take mitigating action."
The screening process begins with collecting and isolating a single bacterium in a tiny cube with a porous membrane. Sensor arrays in the cube make initial measurements on the organism's respiration, consumption of specific nutrients, and metabolite production. Suspect bacteria is then extracted and exposed to synthetic substances that mimic human tissues to test for pathogenicity.
"To get a reliable risk assessment, we need to understand not just the bacteria's genetic makeup, or genotype, but how it functions - its phenotype," says Adler. "We're looking at ways to subject the bacteria to a gauntlet of behavior screenings so we can determine its ability to cause disease."
In effect, says DARPA, the Friend or Foe systems will play the biological equivalent of the game "Twenty Questions," subjecting bacteria to a battery of physical and chemical tests to determine its pathogenicity. Such screening would flag dangerous bacteria for subsequent genetic sequencing to map the newly discovered pathogenic traits to specific genes, the early identification of which could accelerate research into