WHEN a new strain of bacteria causes serious illness, being able to tell quickly whether it arose naturally or is the result of bioterrorism can be vital in devising the public health response. Now a DNA sequencing method that employs electronic sensing has been used to settle the question in a matter of hours rather than months.
In June this year, a 39-year-old man was rushed to the Methodist Hospital in Houston, Texas, with swollen organs and struggling to breathe. Doctors feared the worst. 鈥淭he concern was that it was anthrax,鈥� says , head of pathology at the hospital.
Musser鈥檚 team used technology developed by , based in Guilford, Connecticut, to identify the culprit as Bacillus cereus. Though closely related to B. anthracis, which causes anthrax, B. cereus produces severe infections only if it has gained a cluster of genes from the anthrax bacterium. But did Musser鈥檚 strain do so with the help of bioterrorists?
Advertisement
The Ion Torrent technology converts chemical signals from conventional DNA sequencing into electronic pulses that can be rapidly analysed by a microchip. Within a day, its results showed a lack of 鈥済enetic footprints鈥� that might suggest a natural bacterium had been tampered with, says Musser (Archives of Pathology and Laboratory Medicine, in press).
While the analysis couldn鈥檛 prevent this patient鈥檚 death, the technology was able to quickly rule out a deliberate attack. 鈥淭his represents a new frontier in medicine,鈥� he says.