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ORIGINAL RESEARCH article

Front. Cell. Infect. Microbiol.

Sec. Antibiotic Resistance and New Antimicrobial drugs

Volume 15 - 2025 | doi: 10.3389/fcimb.2025.1624160

This article is part of the Research TopicAdvancements in Light-Based Technologies for Antimicrobial ControlView all articles

The Combined 410nm and Infrared light Effectively Suppresses Bacterial Survival Under Realistic Conditions

Provisionally accepted
Matthew  StanglMatthew Stangl1Dinesh Kumar  VermaDinesh Kumar Verma2*Areli  MartinezAreli Martinez3Yong-Hwan  KimYong-Hwan Kim2*
  • 1University of Delaware, Newark, United States
  • 2Boise State University, Boise, United States
  • 3Delaware State University, Dover, United States

The final, formatted version of the article will be published soon.

The demand for establishing an effective but inexpensive method to interfere with the spread of infectious diseases has been higher than ever before, since the recent pandemic. As a follow-up study, we tested a few practically applicable lights with a safe 410nm violet light (V) with infrared (IR, 850nm) under realistic conditions to identify an optimal light for suppressing pathogens. Our results indicate that 410nm violet light is as effective as the previously tested 405nm violet light with infrared (850nm).Therefore, we focused on optimizing combined lights (3V-1IR or 2.33V-1IR) with lower power level that is below 24 Watt. Using the Multi Drug Resistant (MDR) Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) from ATCC, we confirmed that the combined 20W light effectively suppressed the survival of both MDR bacterial strains on a smooth surface at the distance of 25cm, 50cm, 1m or 2m, which mimicked the realistic living spaces. As expected, the effectiveness was inversely proportional to the exposed distance. For example, the light exposure suppressed more than 91-97% of E. coli within 1-2 hours and 96-99% of S. aureus within 2-6 hours at short distances (25 or 50cm), whereas it took 6-8 hours to reach 92-95% of E. coli and 91-99% of S. aureus suppression at 1 or 2m. In the mechanistic studies, we confirmed that the bacterial death was mediated by the enhanced level of Reactive Oxygen Species (ROS), in addition to reduced thickness of biofilm from 410nm and 850nm infrared light. Our results strongly support the possible application of using this combined 410nm with infrared light as an inexpensive and practical solution to reduce the potential pathogens, at least from bacterial origins in a variety of living spaces.

Keywords: Living space, 850nm, ROS induction, reduced biofilm, MDR bacteria, E. coli, and S. aureus

Received: 07 May 2025; Accepted: 02 Jul 2025.

Copyright: © 2025 Stangl, Verma, Martinez and Kim. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence:
Dinesh Kumar Verma, Boise State University, Boise, United States
Yong-Hwan Kim, Boise State University, Boise, United States

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