Anti‐proliferation effect of blue light‐emitting diodes against antibiotic‐resistant Helicobacter pylori

Abstract

Background and Aim Infection by Helicobacter pylori is implicated in a wide range of upper gastrointestinal diseases. Owing to the rapid emergence of antibiotic‐resistant strains of H. pylori, the development of novel treatment modalities for antibiotic‐resistant H. pylori infection is a key priority. Blue light‐emitting diodes (LED) may represent a unique option owing to their antimicrobial effect. In this study, we aimed to evaluate the anti‐proliferative effect of blue LED against antibiotic‐resistant H. pylori. Methods Ten antibiotic‐resistant strains and one sensitive H. pylori strain were used in this study. After irradiation by blue LED along time course, the viability of H. pylori was evaluated by enumerating colony forming units. Morphological changes in H. pylori were observed using a scanning electron microscope. Reductase activity was measured as an indicator of bacterial cellular activity. Total reactive oxygen species was monitored using fluorescence intensity and fluorescence microscope imaging. Results After irradiation by blue LED, the numbers of H. pylori in all the strains were significantly reduced compared with control group. The H. pylori exhibited a short rod‐shaped morphology after irradiation; no such change was observed in H. pylori not exposed to blue LED. Re‐irradiation of surviving strain after the initial irradiation also exhibited the same anti‐proliferation effect. After blue LED irradiation, bacterial cellular activity was lower, and total reactive oxygen species production was significantly higher in blue LED group, compared with that in control. Conclusions Blue LED could be a new treatment to eradicate infection with antibiotic‐resistant H. pylori.

The in vitro Photoinactivation of Helicobacter pylori by a Novel LED-Based Device

“…As far as the cellular targets are concerned, our scanning electron images show morphological alterations of the bacterial cell wall after administration of a sub-lethal light dose. This could be the main damage of the photodynamic action, leading to bacterial death through leakage of cellular contents or inactivation of membrane transport systems and enzymes (Caminos et al, 2008;Ma et al, 2018).…”

“…Antimicrobial PhotoDynamic Therapy (aPDT) relies on the application of a photosensitizer able to absorb appropriate wavelengths in the visible light range and to react with oxygen molecules inside and around cells, resulting in the production of singlet oxygen or other cytotoxic reactive oxygen species (ROS), which lead to cell death, after inducing photodamage. aPDT can efficiently kill a wide range of bacteria (both antibiotic-susceptible and multi-resistant strains), viruses, fungal, and protozoan parasites (Smijs and Pavel, 2011;Thomas et al, 2015;Wang et al, 2017;Alves et al, 2018;Andrade et al, 2018;Namvar et al, 2019) without causing development of resistance (Al-Mutairi et al, 2018;Ma et al, 2018). This approach is particularly advantageous against bacteria naturally producing and accumulating endogenous photosensitizers such as porphyrins and flavins (Plavskii et al, 2018), physiologically involved in several essential biological functions (e.g., respiration, biological oxidation, photosynthesis, sulfate reduction, metabolism of fats, carbohydrates, and proteins) (Shu et al, 2013;García-Angulo, 2017;Sepúlveda Cisternas et al, 2018).…”

Helicobacter pylori infection: from standard to alternative treatment strategies

“…H. pylori cells exhibited a short rodshaped morphology after irradiation. [8] The decrease in cell activity and significant increase in ROS indicator fluorescence was observed only in samples exposed to blue LED for up to 2 h.…”

A review on the research progress on non-pharmacological therapy of Helicobacter pylori

“…Im et al (2021) proposed an H. pylori-targeted photodynamic therapy system-p3SLP, which yielded significant antibacterial activity and had no adverse side effects on normal tissues and intestinal flora. Ma et al found that a blue light-emitting diode (LED) could inhibit the proliferation of drug-resistant strains of H. pylori in vitro (Ma et al, 2018). Moreover, LED endoscopic capsules combined with active motion systems have been designed based on the combined action of vision and actuation to move precisely to the target area to kill H. pylori (Luzzi and Tortora, 2022).…”