Barcoded spores technology could improve emergency response to biological attack

ABERDEEN PROVING GROUND, Md. – It looks like anthrax. It resembles most of the physical properties of the Bacillus anthracis bacteria. It even has a genetic make-up similar to that of the deadly pathogen, and most importantly, it makes hardy, durable spores like its virulent cousin. But it is not anthrax. It is an imposter that is being used as a simulant in a groundbreaking effort at the U.S. Army Edgewood Chemical Biological Center (ECBC) to improve emergency preparedness in the event of a biological attack.

The simulant, Bacillus thuringiensis subspecies kurstaki (Btk), is safe, found in nature and is available to the public at garden supply stores as a gypsy moth caterpillar control agent in organic farming. For Henry S. Gibbons, Ph.D., research microbiologist at ECBC, it is the cornerstone of his group’s work with a barcoded spore technology that uses small genetic signatures to track and identify the simulant spores during large-scale outdoor testing. Monitoring the transportation patterns of simulant strains that mimic the behavior of actual anthrax spores increases the quality of data gathered by researchers, which could eventually be used to help mitigate the costs of clean-up and the extent of social disruption in the event of a real world biological attack.

“The barcoded spore technology helps us prepare for the eventuality of an attack. If we get hit again with something, we will have a better sense of where to clean it up, where it is likely to go, where to focus our emergency response efforts and determine what areas are at greatest risk,” explained Gibbons.

Each genetic signature, or barcode, contains common and specific tags that are integrated into neutral regions of the DNA of the simulant Btk for tracking. ECBC researchers are able to detect and discriminate the barcoded strains from wild-type strains as well as from each other, which enables large-scale testing that could sample more than a dozen pieces of information and dramatically optimize data gathering.

Previous data gathering methods used by ECBC at the Edgewood Area of the Aberdeen Proving Ground, Md. were expensive, labor intensive and involved more than 50 people to set up the outdoor detectors, which collected a limited amount of information in a single test. According to Gibbons, the barcoded spore technology simplifies collection efforts, reduces testing costs and improves the control of previous uncontrollable variables that affect how bacterial spores behave when discharged in an open environment. Large-scale testing could now give researchers the opportunity to trace the simulant in more populous locations such as city subways or residential suburbs.

The simulant Btk strains used in the barcoded spore testing were selected by ECBC because of the Center’s commitment to safely conducting projects in an environmentally sound manner. The simulant is an ingredient registered with the federal Environmental Protection Agency (EPA) and found in common commercial products such as Dipel or Thuricide pest control, which is sold online and across the country at garden supply stores. The kind of large-scale testing in various conditions that Gibbons is striving for is a direct result of the heightened safety measures his team uses on a daily basis, with the EPA-registered Btk strain living at the core of the work.

“Better testing methods under multiple conditions can help improve our predictive models for different potential biothreat scenarios,” said Gibbons. “We’re hoping that we have a technology in these barcoded spores that can actually allow some testing on either mock structures or various test beds where people can do some of these modeling studies with an organism that is relatively representative of what they would find in actual virulent Bacillus anthracis.”

This new technology could be a tremendous asset to clean-up efforts in the wake of a future biological attack, he said, recalling how swabbing representative areas of various locations during the 2001 anthrax attack was the only effective way to track the pathogen during its outbreak through the U.S. Postal Service more than a decade ago. It marked the country’s first case of bioterrorism when contaminated letters were mailed to congressional leaders and members of the news media. Gibbons called the Amerithrax events, as it was classified by the FBI, “one of the major catalysts for the expansion of the biodefense industry as we know it today.”

“One of the problems that came out of the aftermath of the anthrax attacks was we didn’t have a good sense of where to look for these spores and how to track them. We still don’t have a very good sense for how long they’ll last in a given environment,” said Gibbons. “Anthrax has stunningly long term viability and that’s one of the problems of the anthrax clean-up. The current standards for clean is there are no spores in a given location, but how do you certify that? Do you swab every centimeter of every surface?”

The work being done by Gibbons and his team furthers emergency response efforts with a barcoded spore technology that expands testing opportunities across research communities. The vast amount of information collected and data gathered could have a monumental impact on how first responders, medical personnel and decontamination teams operate during a potential crisis and future attack.

As a premier Center that specializes in solutions to counter chemical biological threats to U.S. forces and the nation, ECBC’s best offense is a good defense. In order to prepare for the worst-case scenario, the Center is continuing extensive research and engineering innovative technologies that unite and inform the national defense community.

Henry S. Gibbons, Ph.D., along with more than 30 ECBC employees, are the authors of two articles on the methodology and process of the genetic barcoded spore technology that will be published in the December issue of Applied and Environmental Microbiology. The academic journal is peer-reviewed and published by the American Society for Microbiology located in Washington, D.C.

For more information about ECBC, visit http://www.ecbc.army.mil/.