Original article Clinical endoscopy| Volume 88, ISSUE 2, P292-302, August 2018

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Impact of cleaning monitoring combined with channel purge storage on elimination of Escherichia coli and environmental bacteria from duodenoscopes

Published:February 21, 2018DOI:

      Background and Aims

      We aimed to determine whether monitoring of duodenoscope cleaning by rapid adenosine triphosphate (ATP) combined with channel-purge storage could eliminate high-concern microorganisms.


      In a simulated-use study, suction channels, as well as lever recesses, from 2 duodenoscopes models and the unsealed elevator guidewire (EGW) channel from 1 of these 2 duodenoscopes (the other model has a sealed EGW) were perfused with ATS2015 containing approximately 8 Log10 colony-forming units (CFU)/mL of both Enterococcus faecalis and Escherichia coli. Pump-assisted cleaning was monitored by rapid ATP testing. Duodenoscopes exceeding 200 relative light units (RLUs) were recleaned. Clean duodenoscopes were processed through an automated endoscope reprocessor and then stored in a channel-purge storage cabinet for 1 to 3 days. Cultures of EGW channel and instrument channel combined with the lever recess (IC-LR) were taken after storage. The impacts of extended cleaning and alcohol flush were evaluated.


      E coli was reliably eliminated in IC-LR and EGW channels of 119 duodenoscope tests (59 with sealed EGW and 60 with nonsealed EGW). However, actionable levels of E faecalis and environmental bacteria persisted. Neither alcohol flush nor extended cleaning resulted in a reduction of actionable levels for these organisms. Identification of isolates indicated that residual organisms in duodenoscope channels were hardy Gram-positive bacteria (often spore formers) that likely originated from environmental sources.


      These data indicate that high-concern Gram-negative bacteria but not E faecalis or environmental bacteria can be reliably eliminated by use of the manufacturer’s instructions for reprocessing with ATP monitoring of cleaning and channel-purge storage conditions.


      AER (automated endoscope reprocessor), ATP (adenosine triphosphate), CDC (Centers for Disease Control), CFU (colony-forming unit), CP cabinet (channel-purge storage cabinet), EGW (elevator guidewire), IC-LR (instrument channel–lever recess), MALDI-TOF (matrix-assisted laser desorption/ionization-time of flight), MIFU (manufacturer’s instructions for use), RLU (relative light unit), sRO (sterile reverse osmosis), SS1E (Steris System 1E)
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      Linked Article

      • Antimicrobial decontamination of endoscopes: Are we there yet?
        Gastrointestinal EndoscopyVol. 88Issue 2
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          The growth of GI endoscopy provision globally has mirrored developments in the management of GI disease. Endoscopic procedures have become increasingly complex and are often performed in critically ill patients. All endoscopes have the potential to harbor and transmit pathogens, which could cause lethal healthcare-associated infections (HAIs). Data from the Centers for Disease Control and Prevention (CDC) suggest that the prevalence of HAIs has been on the decline.1 Endoscopy is generally safe, and HAIs associated with endoscopy have been uncommon despite the volume of procedures performed annually.
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