Targeted laser pulses can destroy harmful viruses and bacteria, showing promise in treating infections in people, scientists say.

Researchers at Arizona State University designed a technique of zapping microorganisms with laser pulses without damaging healthy human cells. They say the approach, called impulsive stimulated Raman scattering (ISRS), could eventually be used to kill viruses like HIV and bacteria that plague many hospital wards.

Lasers could eventually be used to kill viruses like HIV, say scientists.
(Photo courtesy U.S. Environmental Technology Laboratory)

The study was published Thursday by the Journal of Physics: Condensed Matter.

"Although it is not clear at the moment why there is a large difference in laser intensity for inactivation between human cells and microorganisms such as bacteria and viruses, the research so far suggests that ISRS will be ready for use in disinfection and could provide treatments against some of the worst, often drug-resistant, bacterial and viral pathogens," Prof. Kong-Thon Tsen from Arizona State University said in a release.

Scientists showed in lab studies with E. coli bacteria that by controlling the wavelengths and pulse widths of the lasers, the bacteria could be zeroed in on and killed.

They also applied laser pulses to mammalian cells to determine their survival. This gave them a sense of intensity thresholds for bacteria, viruses and mammalian cells.

They discovered that viruses had a much lower damage threshold than the mammalian cells, giving them a clear picture of the intensity of laser pulses that can be applied without damaging healthy cells.

Current approaches to zapping viruses and bacteria involve the use of UV rays, which lead to cellular damage.