Characterizing the Antimicrobial Properties of 405 nm Light and the Corning® Light‐Diffusing Fiber Delivery System

Abstract

Background and ObjectivesHospital‐acquired infections (HAIs) and multidrug resistant bacteria pose a significant threat to the U.S. healthcare system. With a dearth of new antibiotic approvals, novel antimicrobial strategies are required to help solve this problem. Violet‐blue visible light (400–470 nm) has been shown to elicit strong antimicrobial effects toward many pathogens, including representatives of the ESKAPE bacterial pathogens, which have a high propensity to cause HAIs. However, phototherapeutic solutions to prevention or treating infections are currently limited by efficient and nonobtrusive light‐delivery mechanisms.Study Design/Materials and MethodsHere, we investigate the in vitro antimicrobial properties of flexible Corning® light‐diffusing fiber (LDF) toward members of the ESKAPE pathogens in a variety of growth states and in the context of biological materials. Bacteria were grown on agar surfaces, in liquid culture and on abiotic surfaces. We also explored the effects of 405 nm light within the presence of lung surfactant, human serum, and on eukaryotic cells. Pathogens tested include Enterococcus spp, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp., Staphylococcus epidermidis, Streptococcus pyogenes, Candida albicans, and Escherichia coli.ResultsOverall, the LDF delivery of 405 nm violet‐blue light exerted a significant degree of microbicidal activity against a wide range of pathogens under diverse experimental conditions.ConclusionsThe results exemplify the fiber's promise as a non‐traditional approach for the prevention and/or therapeutic intervention of HAIs. Lasers Surg. Med. © 2019 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

Candida spp./Bacteria Mixed Biofilms

“…The in vitro antimicrobial features of flexible Corning®light-diffusing fiber (LDF) on ESKAPE and other relevant pathogens (S. epidermidis, Streptococcus pyogenes, C. albicans, and E. coli) were measured. The authors found that the LDF delivery of 405 nm violet-blue light had a significant antimicrobial activity towards a wide range of pathogens under diverse experimental conditions [140]. Regarding in vivo assays, the drug had efficacy in invasive candidiasis, aspergillosis, and pneumocystis.…”

Inactivation Effect of Violet and Blue Light on ESKAPE Pathogens and Closely Related Non-pathogenic Bacterial Species – A Promising Tool Against Antibiotic-Sensitive and Antibiotic-Resistant Microorganisms

“…Endoscopically delivered light reduced gastric Helicobacter pylori infection ( Ganz et al, 2005 ), urinary tract infection could successfully be treated in a rat model ( Huang et al, 2018 ) and biofilm growth on catheter material was demonstrated to be reduced by the influence of irradiation ( Vollmerhausen et al, 2017 ). The development of a light diffusing fiber delivery system ( Shehatou et al, 2019 ), a minimally invasive ingestible capsule ( Romano et al, 2016 ), the investigation of a continuous surface disinfection of hospital rooms during the patient’s presence ( Maclean et al, 2013 ) and a whole range of different patents ( Ahmed et al, 2018 ), demonstrate simultaneously the emerging significance of light-based technologies and their applicability.…”

Microbial Photoinactivation by Visible Light Results in Limited Loss of Membrane Integrity

“…Bacterial photoinactivation with visible light represents a promising microbial inactivation strategy, with many advantages and various potential applications [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. Violet light with a wavelength of around 405 nm seems to be especially effective [ 8 , 9 ], but also blue light around 450 nm exhibits antimicrobial properties [ 10 , 11 ].…”