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Toluidine blue O photodynamic inactivation on multidrug‐resistant pseudomonas aeruginosa
Author(s) -
Tseng S.P.,
Teng L.J.,
Chen C.T.,
Lo T.H.,
Hung W.C.,
Chen H.J.,
Hsueh P.R.,
Tsai J.C.
Publication year - 2009
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.20765
Subject(s) - pseudomonas aeruginosa , efflux , microbiology and biotechnology , photodynamic therapy , photosensitizer , multiple drug resistance , bacteria , chemistry , antibacterial activity , antibiotics , biology , biochemistry , photochemistry , genetics , organic chemistry
Background and Objectives Multidrug‐resistant (MDR) Pseudomonas aeruginosa infection is becoming a critical problem worldwide. Currently, only limited therapeutic options are available for the treatment of infections caused by MDR P. aeruginosa , therefore, the development of new alternative treatments is needed. Toluidine blue O (TBO) is an effective antibacterial photosensitizing agent against various bacteria. However, reports on antibacterial photosensitization of MDR bacteria are limited. This study aims to determine the in vitro photobactericidal activity of TBO against MDR P. aeruginosa . Study Design/Materials and Methods The efficacy of antibacterial photodynamic inactivation, DNA fragmentation and protein carbonylation of three MDR P. aeruginosa strains and one susceptible strain was compared using TBO as the photosensitizer followed by red light irradiation (630 nm, 90 J/cm 2 ) from a light‐emitting diode light source. Subsequently, the efficacy of TBO photodynamic inactivation (TBO‐PDI) on 60 MDR strains, including 11 with the efflux pump phenotype and 49 with no pump activity, was tested using the minimum lethal drug concentration (MLC) assay. Results TBO‐PDI caused similar bactericidal effect (6–7 logs of killing effect), DNA fragmentation and protein carbonylation in three MDR and one susceptible P. aeruginosa strains. Although the TBO accumulation assay indicated that TBO is a substrate for the efflux pump, TBO‐PDI produce similar photobactericidal activity against 60 MDR P. aeruginosa strains, either with or without efflux‐pump phenotype, and 19 susceptible strains. Conclusion MDR did not affect the susceptibility of P. aeruginosa strains to TBO‐PDI. The efflux pump played an insignificant role in TBO‐PDI of MDR P. aeruginosa . Lasers Surg. Med. 41:391–397, 2009. © 2009 Wiley‐Liss, Inc.