Can Gram-Negative Bacteria Develop Resistance to Antimicrobial Blue Light Treatment?

Abstract

Antimicrobial blue light (aBL) treatment is considered low risk for the development of bacterial resistance and tolerance due to its multitarget mode of action. The aim of the current study was to demonstrate whether tolerance development occurs in Gram-negative bacteria. We evaluated the potential of tolerance/resistance development in Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa and demonstrated that representative Gram-negative bacteria may develop tolerance to aBL. The observed adaption was a stable feature. Assays involving E. coli K-12 tolC-, tolA-, umuD-, and recA-deficient mutants revealed some possible mechanisms for aBL tolerance development.

Combined Antimicrobial Blue Light and Antibiotics as a Tool for Eradication of Multidrug-Resistant Isolates of Pseudomonas aeruginosa and Staphylococcus aureus: In Vitro and In Vivo Studies

“…Overall, this process results in the production of intracellular reactive oxygen species (ROS), which can cause lethal effects in bacterial cells as well as DNA cleavage, lipid and protein oxidation or cell membrane damage [ 7 , 8 ]. The overarching feature of aBL is that this method does not lead to the development of resistance in Gram-positive and Gram-negative bacteria, which has been thoroughly verified by our team [ 9 , 10 ]. aBL as a monotherapy is an effective tool for the eradication of pathogens and inactivation of their virulence factors [ 1 , 11 ].…”

The Parameters Affecting Antimicrobial Efficiency of Antimicrobial Blue Light Therapy: A Review and Prospect

“…It has been suggested that bacteria could develop resistance by changing their cell structure. Multiple sublethal aBL treatments could cause the genetic alterations which lead to the potential of tolerance development in representative Gram-negative bacteria [ 33 ]. More studies are needed to assess the possible resistance development of aBL.…”

Photoinactivation of extensively drug-resistant gram-negative bacteria from healthcare-associated infections in Venezuela

“…5 However, a wide range of microbial cells, including Gram-positive bacteria, Gram-negative bacteria, mycobacteria, yeasts, dermatophytes and moulds in planktonic or biofilm forms, have also proven to be susceptible to blue light. [4][5][6] The aPDI/aBL therapy exploits the photoexcitation of intracellular porphyrins by blue light, leading to energy transfer and the production of highly cytotoxic reactive oxygen species (ROS), such as free radicals, singlet oxygen and peroxides. 6 These ROS cause irreversible intracellular damage by simultaneously affecting numerous cellular targets, including DNA, RNA, proteins, and lipids.…”

“…[4][5][6] The aPDI/aBL therapy exploits the photoexcitation of intracellular porphyrins by blue light, leading to energy transfer and the production of highly cytotoxic reactive oxygen species (ROS), such as free radicals, singlet oxygen and peroxides. 6 These ROS cause irreversible intracellular damage by simultaneously affecting numerous cellular targets, including DNA, RNA, proteins, and lipids. Wavelengths ranging from 400 to 425 nm can be used for bacterial inactivation.…”

“…Unlike antibiotics, full resistance to phototreatment with blue light has not yet been reported. [4][5][6] On the other hand, some factors that favourably influence the microbicidal activity of blue light have been identified, such as the duration of irradiation and the pretreatment of bacterial cells with exogenous photosensitizing substances. 7 These substances are classified according to their origin and chemical structure, where the most commonly used are synthetic dyes, such as methylene blue and toluidine blue.…”