Microbiology
Bacteriological examinations were performed as previously described15 and consisted of direct isolation on selective and non-selective media, Gram staining and plate inoculation after dilution for counting.16 Mycology testing was performed by direct isolation on selective media as previously described.12 Samples were incubated for up to 6 days, and identification was performed by biochemical identification (standard API kits, Biomerieux). In order to rule out extrinsic contamination by the equipment, videoendoscopes were tested for fungal contamination. Sampling of each endoscope was performed twice (two months apart) throughout the study. Briefly, the tip of the disinfected videoendoscopes was placed in an empty, sterile, plastic jar. Two 60-mL syringes pre-filled with sterile saline were infused through the biopsy channel into the sterile jar, with the tip of the scope dipping in the solution. The infused solution was then aspirated through the biopsy channel and placed in a sterile tube for mycological culture.