Microbiological surveillance of endoscopes and implications for current reprocessing procedures adopted by an Italian teaching hospital

BACKGROUND: Hospital acquired infections have been associated with the contamination of flexible endoscopes caused by a failure of the reprocessing procedure. Microbiological surveillance of endoscope reprocessing is valuable for assessing contamination by pathogens. The aim of this study is to evaluate microbiological contamination of endoscopes after reprocessing, and the involvement of reprocessing procedures adopted in endoscopy units of an Italian teaching-hospital. METHODS: The study was carried out, on several dates in 2014, in 11 endoscopic operation units equipped with 100 endoscopes (18 bronchoscopes, 41 gastroduodenoscopes, 29 colonoscopes, 12 laryngoscopes) and 9 Automated Endoscope Reprocessors. Presence/absence of common pathogens and indicator micro-organisms (including multi-drug resistant bacteria) and Total Microbiological Count (TMC) were obtained from the biopsy channels of endoscopes after reprocessing, from final rinse water of automated endoscope reprocessors and from tap water applying standard microbiological culture methods. Following the European Guidelines for quality assurance in reprocessing, the post-reprocessing criteria were "absence of indicator micro-organisms and absence of TMC in samples obtained from endoscopes' channels". RESULTS: A total of 180 samples were collected (143 endoscopes, 25 Automated Endoscope Reprocessors and 12 water supply). Compliance to the European Guidelines was achieved for 112 out of the 180 (62.2%) samples analyzed. Presence of indicator micro-organisms (mainly Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and other Gram-negative non-fermenting bacteria) was found in 51 out of 143 endoscopes (35.7%). Multi-drug resistant bacteria were also found. Presence of pathogen micro-organisms was statistically associated with the increase of TMC level, but not with time after reprocessing. CONCLUSION: The study provides information about the microbiological quality of endoscope reprocessing procedures adopted by different endoscopic operation units. The high prevalence of contaminated endoscopes provides evidence of the need to improve the quality of reprocessing.