PhD ceremony Ms. J.S. Kovaleva: Microbiological safety in endoscope reprocessing

PhD ceremony: Ms. J.S. Kovaleva, 14.30 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Microbiological safety in endoscope reprocessing

Promotor(s): prof. J.E. Degener, prof. H.C. van der Mei

Faculty: Medical Sciences

The purpose of this thesis is to present an overview of the infections and cross-contaminations related to flexible endoscopy and to illustrate the impact of the presence of biofilm on endoscope reprocessing and development of post-endoscopic infection. The relevance of cleaning, high-level disinfection, drying procedures, and storage in endoscope reprocessing and the role of microbiological surveillance of flexible endoscopes are described. Finally, an overview of the impact of biofilm on endoscope reprocessing and on development of infectious complications related to endoscopy is given.

The effects of per acetic acid disinfectant with and without additional drying on biofilm formation by microorganisms isolated from contaminated flexible endoscopes were investigated. An in vitro biofilm model was applied to mimic the biofilm formation inside the endoscope channels and to imitate the disinfection and drying procedures used for reprocessing of flexible endoscopes in the UMCG. This study illustrates the high efficacy of the drying procedure after the disinfection step against different microorganisms in biofilms. However, disinfection and drying procedures may fail in the endoscope with a manufacturing defect or damaged internal channels when the decontamination process cannot reach all internal parts of the instrument, and biofilm formation will occur within the endoscope channels. Microbiological surveillance of endoscope reprocessing is appropriate to trace contaminations and to prevent contaminations and infections in patients after endoscopic procedures.