Dual light wavelengths effective against antibiotic-resistant bacterium.

Scientists have combined two light wavelengths to deactivate a bacterium that is invulnerable to some of the world's most widely used antibiotics, giving hope that the regime could be adapted as a potential disinfectant treatment.

Under the guidance of project leader Dr. Gale Brightwell, scientists at New Zealand’s AgResearch demonstrated the novel antimicrobial efficiency of a combination of two light wavelengths against a ‘superbug’ known as antibiotic-resistant extended-spectrum beta-lactamase E. coli.

A combination of far UVC (222 nm) and blue Led (405 nm) light have been shown to be effective in the inactivation of a wide range of microorganisms while being much safer to use and handle as compared to traditional UVC at 254 nm, she said.

“The E. coli we chose for this investigation were extended-spectrum beta- lactamases producing E. coli (ESBL-Ec) as these bacteria produce enzymes that break down and destroy commonly used antibiotics, including penicillins and cephalosporins, making these drugs ineffective for treating infections,” she said.

The team found that a combination of dual far-UVC and Blue Led Light could be used to disinfect both antibiotic resistant and antibiotic sensitive E. coli, offering a non-thermal technology that may not drive further antibiotic resistance.

Reference: Dual wavelengths of light effective against antibiotic-resistant bacterium, Journal of Applied Microbiology, DOI 10.1093/jambio/lxad124