Detection of microbial contamination in dialysis water and gastrointestinal endoscopes by the Uro4 HB&L™ system

Abstract

Patients undergoing haemodialysis are exposed to a great volume of dialysis water and therefore its microbial analysis is important for patient safety. Furthermore, microbial surveillance is reported in several guidelines as a necessary means to identify contamination of gastrointestinal endoscopes in order to reduce the potential of infection risk. Here we evaluated the Uro4 HB&L™ automated system to detect microbial contamination in dialysis water and gastrointestinal endoscopes. A total of 222 samples were collected during a six month period. Dialysis water and gastrointestinal endoscopes were evaluated both with the reference culture methods and the Uro4 HB&L^TM system. Bacterial identification was performed using a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The results show that the Uro4 HB&L^TM system has high specificity but a lesser sensitivity than traditional culture method, even if it might allow the identification of more exigent bacteria in terms of nutrition. The Uro4 HB&L^TM system gives positive results in less time than culture method but the possibility to generate false negative results imposes that it should be associated with a traditional 48h agar culture.

Keywords: Culture; Dialysis; MALDI-TOF; rRNA gene.