Abstract
Background To mitigate duodenoscope contamination, recent design enhancements have primarily
focused on the distal tip. However, the working channels remain unchanged, which may
be linked to biofilm formation. We assessed the persistence of microorganisms, indicative
of biofilm formation, in reprocessed duodenoscopes in a non-clinical endoscopic retrograde
cholangiopancreatography (ERCP) simulation setting.
Methods Three new duodenoscopes were over-soiled in non-clinical ERCP simulations followed
by reprocessing. After 40 tests, the Pseudomonas aeruginosa strain in the soil (Pa-type 1) was switched to a different P. aeruginosa strain (Pa-type 2) for 20 subsequent tests. Cultures of the tip and working channel
were acquired after high level disinfection and overnight storage.
Results One duodenoscope showed persistent growth of P. aeruginosa from the fifth test until the end of the study. Pa-type 1 remained present until
the end of the study in the cultures of this duodenoscope, even after discontinuation
of exposure to that specific strain. The other two duodenoscopes only showed incidental
contamination.
Conclusion Persistent contamination by Pa-type 1 was seen in one out of three duodenoscopes
after exposure to supraphysiological levels of gut microorganisms. No clear explanation
was found for this persistent contamination as exposure and handling were identical
and no abnormalities of this particular duodenoscope were identified by borescope
inspection.
