Professor Hans-Curt Flemming, from the University of Duisburg-Essen’s Biofilm Centre, (who spoke at a recent Pall Medical-sponsored conference in Liverpool on reducing waterborne infections in healthcare facilities – see pages 31-35), reports that approximately 95% of a water system’s total biomass is attached to its walls – ‘irrespective of the pipe materials used’.
Horne Engineering, the specialist thermostatic mixing valve manufacturer, exhibiting this year, adds: “This means under 5% of the system biomass is available for sample collection for culturing or chemical treatment. If water sampling collects only the planktonic bacteria, then culture results must significantly under-represent the actual contamination level.
“Chemical dosing cannot kill or remove the biofilm either,” the company adds. “An alternative approach must be employed to tackle the 95% biomass that feeds the planktonic population. Periodic high velocity flushing upsets the established flow equilibrium, and shear forces slough off excess biofilm, which is then carried away to drain. Thermal disinfection mitigates retrograde contamination. Horne’s Optitherm and TSV1 surface-mounted shower panels are specifically designed to facilitate flushing and in situ thermal disinfection. Visitors can obtain full details on our stand.”
