title: Bactericidal effects of 405 nm light exposure demonstrated by inactivation of Escherichia, Salmonella, Shigella, Listeria, and Mycobacterium species in liquid suspensions and on exposed surfaces.
abstract: The bactericidal effect of 405 nm light was investigated on taxonomically diverse bacterial pathogens from the genera Salmonella, Shigella, Escherichia, Listeria, and Mycobacterium. High-intensity 405 nm light, generated from an array of 405-nm light-emitting diodes (LEDs), was used to inactivate bacteria in liquid suspension and on exposed surfaces. L. monocytogenes was most readily inactivated in suspension, whereas S. enterica was most resistant. In surface exposure tests, L. monocytogenes was more susceptible than Gram-negative enteric bacteria to 405 nm light when exposed on an agar surface but interestingly less susceptible than S. enterica after drying onto PVC and acrylic surfaces. The study findings, that 405 nm light inactivates diverse types of bacteria in liquids and on surfaces, in addition to the safety advantages of this visible (non-UV wavelength) light, indicate the potential of this technology for a range of decontamination applications.
authors.affiliation: The Robertson Trust Laboratory for Electronic Sterilisation Technologies, Department of Electronic and Electrical Engineering, University of Strathclyde-Glasgow, Glasgow G1 1XW, UK. lynne.murdoch@strath.ac.uk
authors.forename: Lynne E
authors.initials: LE
authors.lastname: Murdoch
authors.forename: Michelle
authors.initials: M
authors.lastname: Maclean
authors.forename: Endarko
authors.initials: E
authors.lastname: Endarko
authors.forename: Scott J
authors.initials: SJ
authors.lastname: MacGregor
authors.forename: John G
authors.initials: JG
authors.lastname: Anderson
mesh_terms: D000362:Agar / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D058491:Bacterial Load / Q000528:radiation effects; D004202:Disinfectants / Q000494:pharmacology; D004203:Disinfection / Q000379:methods; D004926:Escherichia coli / Q000254:growth & development / Q000528:radiation effects*; D008027:Light; D008089:Listeria monocytogenes / Q000254:growth & development / Q000528:radiation effects*; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability; D009169:Mycobacterium tuberculosis / Q000254:growth & development / Q000528:radiation effects*; D011143:Polyvinyl Chloride / Q000737:chemistry; D019779:Salmonella enterica / Q000254:growth & development / Q000528:radiation effects*; D012764:Shigella sonnei / Q000254:growth & development / Q000528:radiation effects*
chemical_list: D000900:Anti-Bacterial Agents; D004202:Disinfectants; D000362:Agar; D011143:Polyvinyl Chloride