Adenovirus, MS2 and PhiX174 interactions with drinking water biofilms developed on PVC, cement and cast iron

摘要

Biofilms colonizing pipe surfaces of drinking water distribution systems could provide habitatnand shelter for pathogenic viruses present in the water phase. This study aims (i) to develop anmethod to detect viral particles present in a drinking water biofilm and (ii) to study viralninteractions with drinking water biofilms. A pilot scale system was used to develop drinking waternbiofilms on 3 materials (7 cm2 discs): PVC, cast iron and cement. Biofilms were inoculated withnviral model including MS2, PhiX174 or adenovirus. Five techniques were tested to recover virusnfrom biofilms. The most efficient uses beef extract and glycine at pH ?9. After sonication andncentrifugation, the pH of the supernatant is neutralized prior to viral analysis. The calculatednrecovery rates varied from 29.3 to 74.6% depending on the virus (MS2 or PhiX174) and thenmaterial. Applying this protocol, the interactions of virus models (MS2 and adenovirus) withndrinking water biofilms were compared. Our results show that adsorption of viruses to biofilmsndepends on their isoelectric points, the disc material and the hydrodynamic conditions. Applyingnhydrodynamic conditions similar to those existing in drinking water networks resulted in a viralnadsorption corresponding to less than 1% of the initial viral load.