HELIOS: High-Energy Light Irradiation On Surfaces

Abstract:

A dangerous collision of respiratory agents of disease such as SARS-CoV-2, respiratory syncytial virus (RSV), and influenza type A showcases the urgent need for viral pathogen control. Although there are many ways that can successfully accomplish this task, one of the most effective is through the use of ultraviolet (UV) light. UV light is an efficient and economical antimicrobial method that leaves no chemical residue. UV light could be the key to solving issues such as nosocomial infections, supply shortage issues in personal protective equipment (PPE), which collectively might exacerbate future outbreaks of novel origin. The use of light irradiation to control pathogens is nearly 150 years old when scientists discovered that sunlight had the potential to prevent microbial growth. Since then, multiple studies have concluded that UV light is an effective pathogen control. UV light has been used in classrooms to prevent the spread of measles in schoolchildren years before virologists had identified the viral agent. Likewise, UV irradiation has been employed in hospitals to disinfect the air to control tuberculosis incidence rates. It is evident that UV light has a long and rich history of destroying pathogens, however it has the potential to have an even more exciting future. Here, we demonstrate a low-cost, easily-manufactured, and simple-to-use device that we call HELIOS (High-Energy Light Irradiation On Surfaces). We test HELIOS on a wide cadre of bacterial organisms to assess efficacy against 1) Gram-positive, endospore-producing rods (Bacillus subtilis), 2) photolyase-encoding Gram-negative coccobacilli (Escherichia coli), and 3) Gram-positive tetrads that possess a quadruplicated genome replete with extensive DNA repair systems (Deinococcus radiophilus). HELIOS design contains UV vectors within a protected enclosure and operation is rapid. Our tests were performed on these three species at varying timepoints, ranging from 1-12 minutes in duration and each treatment was assessed for overall antimicrobial killing power.