'Glow test' for anthrax could speed up bioterror response
Researchers at the University of Missouri in the US have proved a "glow test" can detect the presence of deadly anthrax bacteria in hours instead of the usual days, promising to significantly cut the time it takes to respond to a potential bioterrorism attack.
Anthrax is not strictly a bacterium but the disease caused by the bacterium Bacillus anthracis, which produces two deadly toxins - lethal toxin and edema toxin.
Recent anthrax research on mice suggests that death is caused primarily by lethal toxin targeting heart cells and muscle cells surrounding blood vessels, and edema toxin targeting liver cells.
Although anthrax is a treatable disease, chances of survival are greatly improved if diagnosis is quick and followed by the right therapy.
Shortly after the 9/11 terror attack in the US in 2001, news outlets and government offices received mailed letters containing anthrax spores that killed 5 people and infected another 17. The ensuing clean up and decontamination cost over $3 million.
Now, first responders have tests to screen for dangerous materials in mailed items. In 2001, no such systems were in place. Yet even today, the test for anthrax agents takes up to 48 hours to return a result.
But the new test being developed at the University of Missouri (MU) together with the private company Guild BioSciences of Charleston, SC, might be about to dramatically change that by identifying the presence of anthrax-causing bacteria within hours.
New test takes only 5 hours to detect anthrax bacteria
George Stewart, professor and medical bacteriologist at MU's Bond Life Sciences Center, explains:
"Normally to identify whether an organism is present, you have to extract the material, culture it, and then pick colonies to examine that might turn out to be anthrax bacteria.
Then you conduct chemical testing which takes some time - a minimum of 24 to 48 hours. Using this newly-identified method, we can reduce that time to about five hours."
The new method uses a bacteriophage - literally "bacteria eater" - a type of virus that invades and kills its bacterial host.
By genetically modifying such phages, scientists can exploit their ability to enter bacteria and do various things, such as send them instructions to trigger cell suicide.
In 2001, no systems for screening dangerous materials in mailed items were in place. Yet even today, the test for anthrax agents takes up to 48 hours to return a result.
David Schofield of Guild BioSciences has engineered a "bioluminescent reporter phage" that glows when it enters live cells of certain bacteria.
The team at MU tested the new phage against a panel of B. anthracis strains and found it not only detected the deadly strains effectively, but also dramatically reduced the test timescale to a few hours. And they found with this method they could also detect even low levels of anthrax bacteria and rule out any false positives.
The phage is highly specific to the deadly anthrax bacteria strains. For example, it failed to detect members of the closely related Bacillus cereus group and other common bacterial pathogens.
Another benefit of using the phage is not only can it show if anthrax bacteria are present, but whether the spores are alive.
Last year, the team reported their work, which is funded by the US Department of Agriculture, in the Journal of Microbiological Methods.
They now plan to seek federal approval so the test can be produced and distributed, says Prof. Stewart, who cautions that while there have not been any further bona fide anthrax attacks since those following 9/11:
"That doesn't mean that it's not going to happen, we just have to be prepared for when it does occur again."
In the meantime, Medical News Today learned how researchers discovered another voracious predator of anthrax bacteria in zebras in Namibia. The predator is also a bacteriophage, in this case an unusually large one called Tsamsa.
Written by Catharine Paddock PhD
Copyright: Medical News Today
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