Biofilm Destruction on Endotracheal Tubes by Photodynamic Inactivation.

BACKGROUND: Hospital infections are a public health problem that can occur with the use of catheters and endotracheal tubes (ETT). Pathogenic microorganisms may adhere to surfaces of these materials forming a biofilm and produce an extracellular polymer matrix that promotes resistance of microorganisms to factors such as pH, temperature and drugs. The conventional treatment is being made by antibiotics, which has serious adverse effects in immunocompromised patients. Photodynamic therapy (PDT) is an alternative for microbial inactivation noninvasive without the stimulus of microbial resistance. PDT combines light and a photosensitive molecule for produce reactive oxygen species leading to bacterial death.

OBJECTIVE: The objective of this study was to determine the efficacy of a PDT protocol in bacterial inactivation of biofilm ETT.

METHOD: The photosensitizer (PS) used was curcumin and the light source LED at 450nm. A statistical experimental design was used for optimization of antimicrobial PDT.

RESULTS: The highest microbial inactivation was observed with 70% biofilm reduction in conditions 1.25 mg/mL curcumin, 2 h of PS incubation and 50 J/cm2.

CONCLUSION: This study described the photodynamic death of bacteria forming a biofilm on ETT. Parameters optimization was important for clinical application of this system.