title: Evaluation of viral concentration methods from irrigation and processing water.
abstract: Four viral concentration methods were evaluated for their efficiency in recovering murine norovirus-1 (MNV-1) (surrogate for human noroviruses (NoV)) and MS2 bacteriophages from processing water (1L) and four different types of irrigation water (bore hole water, rain water, open well and river water) (2-5L). Three methods were based on the viral adsorption and elution principle, two methods using an electronegative HA-membrane (Katayama et al., 2002), one method using an electropositive Zetapor membrane according to CEN/TC275/WG6/TAG4 and the fourth method was based on size exclusion using a tangential flow filtration system. Detection of MNV-1 was achieved by real-time RT-PCR and detection of MS2 by double-layer plaque assay. For the recovery of MNV-1, the method using an electronegative HA-filter in combination with an elution buffer earlier optimized by Hamza et al. (2009) (Method 1) performed best for all types of water (recovery: 5.8-21.9%). In case of MS2 detection, the best method depended upon the type of water although Method 1 provided the most consistent recovery. To complete this evaluation, the Method 1 was evaluated further for the concentration of human enteric viruses (GI and GII NoV, hepatitis A virus (HAV) and rotaviruses) in the same five types of water. Although detection of rotaviruses (RV) was somewhat less efficient, Method 1 proved reliable for the detection of NoV and HAV in all water types. Mean recovery efficiencies ranging from 4.8% for detection of GI NoV in open well water to 32.1% for detection of HAV in bore hole water, depending on the water type and the viral pathogen analyzed.
authors.affiliation: Department of Food Safety and Food Quality, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium. Ann.dekeuckelaere@UGent.be
authors.forename: Ann
authors.initials: A
authors.lastname: De Keuckelaere
authors.forename: Leen
authors.initials: L
authors.lastname: Baert
authors.forename: Alexandra
authors.initials: A
authors.lastname: Duarte
authors.forename: Ambroos
authors.initials: A
authors.lastname: Stals
authors.forename: Mieke
authors.initials: M
authors.lastname: Uyttendaele
mesh_terms: D000327:Adsorption; D005374:Filtration / Q000379:methods; D030041:Hepatitis A virus / Q000302:isolation & purification; D017909:Levivirus / Q000302:isolation & purification*; D029322:Norovirus / Q000302:isolation & purification*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012401:Rotavirus / Q000302:isolation & purification; D013048:Specimen Handling / Q000379:methods*; D010948:Viral Plaque Assay; D014773:Virology / Q000379:methods*; D014871:Water Microbiology