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

• Published in: Gastrointestinal endoscopy Vol. 88; no. 2; pp. 292 - 302
• Main Authors: Singh, Harminder, Duerksen, Donald R., Schultz, Gale, Reidy, Carol, DeGagne, Pat, Olson, Nancy, Nugent, Zoann, Bernard, Kathryn A., Alfa, Michelle J.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-08-2018
• Subjects: Adenosine Triphosphate - analysis; Disinfection - methods; Disinfection - standards; Duodenoscopes - microbiology; Enterococcus faecalis - isolation & purification; Equipment Contamination; Escherichia coli - isolation & purification; Quality Control; sRO; SS1E; CDC; CFU; CP cabinet; EGW; MALDI-TOF; IC-LR; RLU; ATP; AER; MIFU
• ISSN: 0016-5107; 1097-6779
• DOI: 10.1016/j.gie.2018.02.018

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.