Tampa, FL (May 22, 2002) — The University of South Florida Center for Biological for Defense has developed a new method to more safely and rapidly detect anthrax in powders and on surfaces.
The technique makes anthrax spores harmless to handle without destroying the spore-protected DNA needed to identify the deadly bacterium — which means more laboratories could test samples and rule out negative results if another anthrax outbreak occurs.
The method will be reported today at the annual meeting of the American Society of Microbiology in Salt Lake City, UT.
"We found a way to speed up the turnaround of test results," said pathobiologist Vicki Ann Luna, PhD, a research associate at the USF Center for Biological Defense. "It would help alleviate the backlog of specimens and the long wait for results that can produce fear and anxiety."
The new sample preparation method reduces the time needed to detect even traces of anthrax from three or four days to six to eight hours, Luna said.
Last year, after inhalation anthrax killed a South Florida man and anthrax spores were found in letters, public health laboratories were inundated with "suspicious" powders and environmental swabs. In Florida, the job of testing hundreds of samples daily was limited to three of the state's public health laboratories — facilities with the protective equipment and clothing needed to work with potentially deadly samples.
It quickly became obvious that a faster method was needed to safely test for the presence of anthrax spores.
Ideally, work in a Bio-Safety Level 3 facility should be limited to the initial sample preparation, and subsequent evaluation, which requires more labor and space, could be performed in a Bio-Safety Level 2 lab, said Andrew Cannons, PhD, scientific director for the USF Center for Biological Defense. This would speed up sample processing and prevent bottlenecks in workload during outbreaks, Cannons said.
The technique devised by the USF group would render the anthrax spores safe enough for any laboratory (Bio-Safety Levels 2 and 1) to test, Luna said.
The technique combines three simple processes — germination, sonication and autoclaving — to prepare a sample for molecular identification and confirmation of Bacillus anthracis. Germination causes the dormant anthrax spores to sprout, exposing the germ contained within the protective shell. Sonication breaks up the bacterial spores with high frequency sound waves. Finally, autoclaving destroys with heat the spores' ability to cause disease, but leaves the germ's genetic material intact so that it can be identified by PCR.
"This method detects less than 10 anthrax spores per sample and may even detect as few as 1 or 2 spores," Luna said. "There may be a few false positives, but you'd rather have a false positive result for anthrax than a false negative. You definitely don't want to miss anything."
Luna and her colleagues Debra King, Mike Robeson and others at the Center for Biological Defense developed the new method with the guidance of Jacqueline Cattani, PhD, center director; Philip Amuso, PhD, laboratory director for the Florida Department of Health; and Cannons.
The Center for Biological Defense is a joint project of the University of South Florida College of Public Health and the Florida Department of Health. Funded by the U.S. Department of Defense since October 2000, the center conducts biodefense research and provides education and training aimed at protecting the nation from the threat of bioterrorism.
Materials provided by University Of South Florida Health Sciences Center. Note: Content may be edited for style and length.
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