A dynamic flow model mimicking duodenoscope reprocessing after bacterial contamination for translational research

Maarten Heuvelmans; Willem Woudstra; Herman F Wunderink; Jan F Monkelbaan; Henny C van der Mei

doi:10.1017/ash.2022.294

A dynamic flow model mimicking duodenoscope reprocessing after bacterial contamination for translational research

Antimicrob Steward Healthc Epidemiol. 2022 Sep 13;2(1):e153. doi: 10.1017/ash.2022.294. eCollection 2022.

Authors

Maarten Heuvelmans¹, Willem Woudstra², Herman F Wunderink¹, Jan F Monkelbaan³, Henny C van der Mei²

Affiliations

¹ Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
² Department of Biomedical Engineering, University of Groningen, Groningen, The Netherlands.
³ Department of Gastroenterology and Hepatology, University Medical Center Utrecht, Utrecht, The Netherlands.

Abstract

Objective: Duodenoscopy-associated infections and outbreaks are reported globally despite strict adherence to duodenoscope reprocessing protocols. Therefore, new developments in the reprocessing procedure are needed.

Design: We evaluated a novel dynamic flow model for an additional cleaning step between precleaning and manual cleaning in the reprocessing procedure.

Methods: A parallel plate flow chamber with a fluorinated ethylene propylene bottom plate was used to mimic the duodenoscope channels. The flow chamber was inoculated with a suspension containing Klebsiella pneumoniae to simulate bacterial contamination during a duodenoscopic procedure. After inoculation the flow chamber was flushed with a detergent mimicking precleaning. Subsequently the flow chamber was subjected to different interventions: flow with phosphate-buffered saline (PBS), flow with 2 commercial detergents, flow with sodium dodecyl sulfate with 3 different concentrations, and flow with microbubbles. Adhering bacteria were counted using phase-contrast microscopy throughout the experiment, and finally, bacterial viability was assessed.

Results: During precleaning both PBS and 1% (v/v) Neodisher Mediclean Forte were able to desorb bacteria, but neither proved superior. After precleaning only sodium dodecyl sulfate could desorb bacteria.

Conclusions: Flushing during precleaning is an essential step for reducing adhering luminal bacteria, and sodium dodecyl sulfate is a promising detergent for bacterial desorption from duodenoscope channels after precleaning.