The Effect of a Novel Biomedical Technique on the Reprocessing of Duodenoscopes Using Silver Nitrate and Methylene Blue Irradiated with Red Light

Overview

Endoscopy-related infections are becoming increasingly prevalent, particularly in the era of multidrug-resistant bacteria. Duodenoscopes are the most difficult endoscopes to sterilize due to their small and intricate elevator component which is known to harbor bacteria that have the potential to grow biofilms, resulting in nosocomial infections. In addition, multidrug-resistant bacteria are becoming increasingly problematic in the medical field, as bacteria are developing resistance to bactericides at an unprecedented rate. This experiment modeled a duodenoscope contaminated with a biofilm from P. fluorescens (which modeled P. aeruginosa) and tested the bactericidal effect of a solution of silver nitrate and methylene blue when irradiated with red light. Once biofilms were formed on model duodenoscopes, the silver nitrate and methylene blue solution was applied and irradiated with red light. The models were then swabbed and absorbances were tested to compare the amounts of live bacteria. It was concluded that the treatment was a bactericide and effectively eliminated a significant amount of bacteria from the biofilms formed. All three experimental groups demonstrated this bactericide (ANOVA p < 0.0001), allowing for the rejection of the null hypothesis. To increase the validity of these findings, further research involving more real-world hospital conditions is needed.