Svitlana Ziganshyna1, Anna Guttenberger1, Norman Lippmann2, Sebastian Schulz1, Sven Bercker1, Axel Kahnt3, Tobias Rüffer4, Alexander Voigt4, Khrystyna Gerlach4, Robert Werdehausen5. 1. Department of Anesthesiology and Intensive Care, University of Leipzig, Medical Faculty, Leipzig, Germany. 2. Institute of Medical Microbiology and Epidemiology of Infectious Diseases, University of Leipzig, Medical Faculty, Leipzig, Germany. 3. Leibniz Institute of Surface Engineering (IOM), Leipzig, Germany. 4. Institute of Chemistry, Faculty of Natural Sciences, Technical University of Chemnitz, Chemnitz, Germany. 5. Department of Anesthesiology and Intensive Care, University of Leipzig, Medical Faculty, Leipzig, Germany. Electronic address: werdehausen@medizin.uni-leipzig.de.
Abstract
BACKGROUND: Photodynamic inactivation (PDI) is a promising approach to treat multidrug-resistant infections. However, effectiveness of PDI is limited, particularly in Gram-negative bacteria. The use of photosensitizer (PS) 3,3',3'',3'''-(7,8,17,18-tetrahydro-21H,23H-porphyrine-5,10,15,20-tetrayl)tetrakis[1-methyl-pyridinium]tetratosylate (THPTS) and laser light has led to very promising results. This study focuses on the effects of THPTS in various critical multidrug-resistant bacterial strains and explores the possibility of light-emitting diode (LED)-based activation as a clinically more feasible alternative to laser light. METHODS: THPTS was further chemically characterized and in vitro testing of PDI of different multidrug-resistant bacterial strains was performed under various experimental conditions, including varying drug concentration, incubation time, light source (laser and LED) and light intensity, by determination of viable bacteria after treatment. The effect of hyaluronic acid as an adjuvant for medical applications was also evaluated. RESULTS: Bacterial density of all investigated bacterial strains was reduced by several orders of magnitude, irrespective of multidrug-resistance or hyaluronic acid addition. The effect was less intense in Gram-negative strains (disinfection), and more pronounced in Gram-positive strains (sterilization), even at reduced THPTS concentrations or decreased light treatment intensity. Controls without THPTS or without light treatment did not indicate reduced bacterial density. CONCLUSIONS: PDI with THPTS and laser light was effective in all investigated bacterial strains. Gram-negative strains were less, but sufficiently, susceptible to PDI. Adding hyaluronic acid did not reduce the antibacterial treatment effect. LED-based PDI is equally effective when illumination duration is increased to compensate for reduced light intensity.
BACKGROUND: Photodynamic inactivation (PDI) is a promising approach to treat multidrug-resistant infections. However, effectiveness of PDI is limited, particularly in Gram-negative bacteria. The use of photosensitizer (PS) 3,3',3'',3'''-(7,8,17,18-tetrahydro-21H,23H-porphyrine-5,10,15,20-tetrayl)tetrakis[1-methyl-pyridinium]tetratosylate (THPTS) and laser light has led to very promising results. This study focuses on the effects of THPTS in various critical multidrug-resistant bacterial strains and explores the possibility of light-emitting diode (LED)-based activation as a clinically more feasible alternative to laser light. METHODS:THPTS was further chemically characterized and in vitro testing of PDI of different multidrug-resistant bacterial strains was performed under various experimental conditions, including varying drug concentration, incubation time, light source (laser and LED) and light intensity, by determination of viable bacteria after treatment. The effect of hyaluronic acid as an adjuvant for medical applications was also evaluated. RESULTS: Bacterial density of all investigated bacterial strains was reduced by several orders of magnitude, irrespective of multidrug-resistance or hyaluronic acid addition. The effect was less intense in Gram-negative strains (disinfection), and more pronounced in Gram-positive strains (sterilization), even at reduced THPTS concentrations or decreased light treatment intensity. Controls without THPTS or without light treatment did not indicate reduced bacterial density. CONCLUSIONS: PDI with THPTS and laser light was effective in all investigated bacterial strains. Gram-negative strains were less, but sufficiently, susceptible to PDI. Adding hyaluronic acid did not reduce the antibacterial treatment effect. LED-based PDI is equally effective when illumination duration is increased to compensate for reduced light intensity.
Authors: Sebastian Schulz; Svitlana Ziganshyna; Norman Lippmann; Sarah Glass; Volker Eulenburg; Natalia Habermann; Ulrich T Schwarz; Alexander Voigt; Claudia Heilmann; Tobias Rüffer; Robert Werdehausen Journal: Microorganisms Date: 2022-04-21
Authors: Moritz Lehnig; Sarah Glass; Norman Lippmann; Svitlana Ziganshyna; Volker Eulenburg; Robert Werdehausen Journal: Microorganisms Date: 2022-04-30