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Photodynamic Activity on Biofilm in Endotracheal Tubes of Patients Admitted to an Intensive Care Unit
Author(s) -
Soares Rosane Bassi,
Costa Denis Honorato,
Miyakawa Walter,
Delgado Maria Goretti Temoteo,
Garcez Aguinaldo Silva,
Yoshimura Tania Mateus,
Ribeiro Martha Simões,
Nunez Silvia Cristina
Publication year - 2020
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/php.13239
Subject(s) - biofilm , ex vivo , methylene blue , microbiology and biotechnology , ventilator associated pneumonia , photodynamic therapy , endotracheal tube , crystal violet , antimicrobial , intensive care unit , human decontamination , in vivo , medicine , antiseptic , intubation , chemistry , in vitro , bacteria , surgery , biology , pathology , intensive care medicine , photocatalysis , biochemistry , genetics , organic chemistry , catalysis
Ventilator‐associated pneumonia (VAP) is an infection that arises after endotracheal intubation affecting patients under intensive care. The presence of the endotracheal tube (ETT) is a risk factor since it is colonized by multispecies biofilm. Antimicrobial photodynamic therapy (aPDT) could be a strategy to decontaminate ETTs. We verify if methylene blue (MB) associated with external illumination of the ETT could be an alternative to destroy biofilm. We performed an in vitro and ex vivo study. In vitro study was performed with P. aeruginosa biofilm grew over ETT for 7 days. After treatment, the surviving cells were cultured for 3 days and the biofilm was analyzed by crystal violet absorbance. Ex vivo study employed ETT obtained from extubated patients. aPDT was performed with MB (100 µ m ) and red LED (λ = 640±20 nm). We quantified the biofilm thickness and used scanning electron microscopy and fluorescence technique to verify morphological and functional changes after aPDT. Our results showed that bacteria remain susceptible to aPDT after sequential treatments. We also attested that aPDT can reduce biofilm thickness, disrupt biofilm attachment from ETT surface and kill microbial cells. These data suggest that aPDT should be investigated to decrease VAP incidence via ETT decontamination.