Turbulent fluid flow is a novel closed-system sample extraction method for flexible endoscope channels of various inner diameters

Overview: Effective sample extraction from endoscope channels is crucial for monitoring manual cleaning adequacy as well as for ensuring optimal sensitivity for culture after disinfection. The objective of this study was to compare the efficacy of Turbulent Fluid Flow (TFF) to Flush (F) or Flush-Brush-Flush (FBF) methods. Materials & methods: Pseudomonas aeruginosa and Enterococcus faecalis in artificial test soil-2015 (ATS2015) were used as bacterial markers while protein and carbohydrate were the organic markers for biofilm formed inside 3.2-mm and 1.37-mm polytetrafluoroethylene (PTFE) channels. TFF was generated using compressed air and sterile water to provide friction for sample extraction. Extraction for biofilm coated PTFE channels as well as for colonoscope channels perfused with ATS2015 containing 10(8) CFU/mL P. aeruginosa, E. faecalis and Candida albicans was determined using TFF compared to FBF and F. Results: The extraction ratio for P. aeruginosa and E. faecalis from biofilm extracted by TFF compared to the positive control was significantly better than F for 1.37-mm channels (>= 0.94 for both bacteria by TFF versus 0.69 to 0.72 by F for P. aeruginosa and E. faecalis, respectively) but not significantly different between TFF and FBF for 3.2-mm channels. F was also ineffective for extraction of protein and carbohydrate from 1.37-mm channels. Extraction efficacy by TFF from inoculated colonoscope channels was > 98% for all test markers. Conclusions: The novel TFF method for extraction of samples from colonoscope channels is a more effective method than the existing FBF and F methods.