Browsing by Author "Freney, J."

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A new procedure allowing the complete removal and prevention of hemodialysis biofilms
(2005-08) Marion-Ferey, Karine; Pasmore, M.; Freney, J.; Delawari, E.; Renaud, F.; Costerton, J. William; Traeger, J.
Most currently used disinfectants for dialysis machines have a good bactericidal efficacy on biofilms but leave dead cells on the surface. This contributes to the regrowth of biofilm and the release of pyrogens. A new anti-biofilm procedure consisting of sequential treatment combining enzymes and detergents is able to detach adherent cells. The efficacy of this procedure was assessed both in vitro and in reality. For in vitro studies, a biofilm model was set up. Studies were also performed in reality in a clinically used dialysis machine. Biofilm removal was first monitored by image analysis. Then the biomass was detached by scraping and quantified by plate counts and endotoxin level measurement. Treated samples were compared to untreated control samples. The procedure led to the complete detachment of the biomass, both in vitro and in the reality situation. The aim of this procedure is to replace or complete the usual disinfection methods for medical devices.
Using an efficient biofilm detaching agent: An essential step for the improvement of endoscope reprocessing protocols
(2006-10) Marion-Ferey, Karine; Freney, J.; James, Garth A.; Bergeron, E.; Renaud, R. N. R.; Costerton, J. William
Biofilms develop inside endoscope channels even when valid endoscope reprocessing protocols are applied. The use of an efficient biocide is not sufficient if the channels are not cleaned thoroughly prior to disinfection. This study compared new anti-biofilm combinations of detachment promoting agents with a cleaning product in current use. Tests were performed using Teflon tubing and a contamination device that reproduces conditions that are prevalent during endoscopy. Products were subjected to static + brushing or dynamic treatments, and their ability to remove a preformed biofilm was assessed. The residual biofilm after treatment was assessed and compared with untreated controls. The percentage of surface covered by biofilm was measured after staining with crystal violet. Culturable bacteria levels were determined by plating the bacteria scraped from the tubing surface and counting the colony-forming units (CFU). Further tests were performed on actual endoscopes that had been contaminated artificially. Biofilm removal was confirmed by scanning electron microscopy. This study showed that the new anti-biofilm products prevented the build-up of biofilm and removed a mature biofilm (approximately 108 CFU/cm2), whereas protocols based on detergent-disinfectants containing quaternary ammonium compounds showed low efficacy as these protocols and products fixed the biofilm on the endoscope surfaces. The new procedure and agents represent a new approach to biofilm control that may improve the efficacy of endoscope reprocessing, and reduce the risk of transmitting infections.