Biofilm accumulation in new flexible gastroscope channels in clinical use

Abstract

Objective: Assess the accumulation of protein and biofilm on the inner surfaces of new flexible gastroscope (FG) channels after 30 and 60 days of patient use and full reprocessing. Design: Clinical use study of biofilm accumulation in FG channels. Setting: Endoscopy service of a public hospital. Methods: First, we tested an FG in clinical use before the implementation of a revised reprocessing protocol (phase 1 baseline; n = 1). After replacement of the channels by new ones and the implementation of the protocol, 3 FGs were tested after 30 days of clinical use (phase 2; n = 3) and 3 FGs were tested after 60 days of clinical use (phase 3; n = 3), and the same FGs were tested in phase 2 and 3. Their biopsy, air, water, and air/water junction channels were removed and subjected to protein testing (n = 21), bacteriological culture (n = 21), and scanning electron microscopy (SEM) (n = 28). Air–water junction channels fragments were subjected to SEM only. Results: For the FGs, the average number of uses and reprocessing cycles was 60 times. Extensive biofilm was detected in air, water, and air–water junction channels (n = 18 of 28). All channels (28 of 28) showed residual matter, and structural damage was identified in most of them (20 of 28). Residual protein was detected in the air and water channels of all FG evaluated (phases 1–3), except for 1 air channel from phase 2. Bacteria were recovered from 8 of 21 channels, most air or water channels. Conclusions: The short time before damage and biofilm accumulation in the channels was evident and suggests that improving the endoscope design is necessary. Better reprocessing methods and channel maintenance are needed.

Significant increased bacterial contamination with endoscope overnight and weekend storage times

“…Even if all the reprocessing steps are strictly adhered to, if moisture remains inside endoscope channels, microbial proliferation will occur. 12,18 Thus, the use of FAD cabinets for endoscopes is recommended, 2,8,9,11,19 as it reduces residual moisture within endoscope channels. 5 Moisture can be still detected on endoscope channels after 24 h of storage in the conventional cabinets (nonforced-air), although channels are completely dry after only 1 h in FAD.…”

“…We have previously found that it only takes between 30 and 60 days, of clinical use, for new endoscope channels to become extensively contaminated with biofilms. 12 Biofilms are very difficult to completely remove by reprocessing, as evidenced in several studies. 4,12,[20][21][22] Although the storage cabinets tested in this study did not have FAD, they had germicidal UV-emitting lamps and air filters; therefore, it is unlikely that the FG became contaminated from eternal sources during storage.…”

“…12 Biofilms are very difficult to completely remove by reprocessing, as evidenced in several studies. 4,12,[20][21][22] Although the storage cabinets tested in this study did not have FAD, they had germicidal UV-emitting lamps and air filters; therefore, it is unlikely that the FG became contaminated from eternal sources during storage. 20 Isolation of Gram-negative rods predominated, including clinically relevant species such as E. coli, P. aeruginosa, and S. marcescens.…”

“…The average number of times a gastroscope was used, and reprocessed was estimated to be three times/day or 60 times/month. 12 The gastroscopes were evaluated as per the investigated service clinical use and reprocessing routine. The reprocessing of gastroscopes in the service includes: precleaning, leak test, manual cleaning, automated cleaning and disinfection (ENDOCLEAR-A ALX1012/DL, Brazil) in 2% glutaraldehyde, alcohol rinsing, drying, and storage as per national standards and professional organization's recommendations.…”

Endoscope reprocessing: How to perform an adequate air drying?

“…Significant biofilm formation has been reported on dismantled endoscope channels during endoscope reprocessing [21]. Biofilm formation depends on various factors.…”