Biofilm Formation In Duodenoscope Working Channels In A Simulated Ercp Setting

Aims Despite adjustments of the distal tip, with completely disposable caps and elevators, contamination of duodenoscopes still prevails. This might be due to biofilm formation inside the channels. In this study, biofilm formation inside working channels of duodenoscopes was researched in a simulated ERCP setting.

Methods Three new duodenoscopes (DEC ED34-i10T2, Pentax) were used in a simulated ERCP setting where they were soiled with artificial test soil (ATS2015, Healthmark) containing an excessive amount of 10^8 CFU/mL of Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli and Enterococcus faecium. Soiling was followed by manual cleaning, high level disinfection (HLD) and overnight storage in drying cabinets. After forty tests, only the P. aeruginosa strain (Pa-Type 1) was switched to a different P. aeruginosa strain (Pa-Type 2) for twenty subsequent tests. Cultures of the tip and working channel were acquired after HLD and overnight storage. Maldi-Tof MS was used to differentiate between the presence of the two different P. aeruginosa strains.

Results One of the three duodenoscopes showed persistent growth of P. aeruginosa from the fifth test until the end of the study. Pa-Type 1 remained present in the cultures of this duodenoscope, despite the fact that soiling with that specific strain was discontinued, until the end of the study with just a few negative tests in between. Quickly after introduction, Pa-Type 2 became also present in conjunction to Pa-Type 1. Borescope inspections of all three duodenoscopes revealed no abnormalities. The other two duodenoscopes only showed incidental contamination.

Conclusions The persistent contamination by Pa-Type1, even after replacing with Pa-Type2 and 55 times HLD, of one duodenoscope, suggests presence of a biofilm. No clear explanation was found for the formation of this biofilm, as no abnormalities of this duodenoscope were identified and the other two exact same duodenoscopes did not develop persistent positive cultures.

Citation Kwakman J, Bruno M, Vos M. eP514 BIOFILM FORMATION IN DUODENOSCOPE WORKING CHANNELS IN A SIMULATED ERCP SETTING. Endoscopy 2021; 53: S269.

Publication History

Article published online:
19 March 2021