Evaluation of Secondary Concentration Methods for Poliovirus Detection in Wastewater

Abstract

Effective surveillance of human enteric viruses is critical to estimate disease prevalence within a community and can be a vital supplement to clinical surveillance. This study sought to evaluate simple, effective, and inexpensive secondary concentration methods for use with ViroCap™ filter eluate for environmental surveillance of poliovirus. Wastewater was primary concentrated using cartridge ViroCap filters, seeded with poliovirus type 1 (PV1), and then concentrated using five secondary concentration methods (beef extract-Celite, ViroCap flat disc filter, InnovaPrep® Concentrating Pipette, polyethylene glycol [PEG]/sodium chloride [NaCl] precipitation, and skimmed-milk flocculation). PV1 was enumerated in secondary concentrates by plaque assay on BGMK cells. Of the five tested methods, PEG/NaCl precipitation and skimmed-milk flocculation resulted in the highest PV1 recoveries. Optimization of the skimmed-milk flocculation method resulted in a greater PV1 recovery (106 ± 24.8%) when compared to PEG/NaCl precipitation (59.5 ± 19.4%) ( p = 0.004, t-test). The high PV1 recovery, short processing time, low reagent cost, no required refrigeration, and requirement for only standard laboratory equipment suggest that the skimmed-milk flocculation method would be a good candidate to be field-validated for secondary concentration of environmental ViroCap filter samples containing poliovirus. Electronic supplementary material The online version of this article (10.1007/s12560-018-09364-y) contains supplementary material, which is available to authorized users.

Sewage analysis as a tool for the COVID-19 pandemic response and management: the urgent need for optimised protocols for SARS-CoV-2 detection and quantification

“…Various methods, either individual or combined (i.e. primary and secondary), were reported in the scientific literature for the concentration of viruses from aquatic matrices [ 65 , 66 ], including among others polyethylene glycol (PEG) precipitation [ 67 , 68 ], ferric chloride (FeCl 3 ) precipitation [ 69 ], skimmed milk flocculation (SMF) [ 70 ], glass wool (GW) filtration [ 71 ] or monolithic adsorption filtration (MAF) [ 72 ], ultrafiltration (UF) [ 73 ], and ultracentrifugation [ 74 ].…”

“…The PEG concentration method was also shown to have a remarkably higher proportion of viral reads compared to the SMF and GW methods, and the highest recovery of murine norovirus (MNV) and adenovirus 35 (HAdV) was obtained with PEG followed by MAF, GW, and SMF [ 63 ]. Instead, Falman et al [ 69 ] reported that SMF resulted in a higher recovery of poliovirus type 1 (106 ± 24.8%) when compared to PEG/NaCl precipitation (59.5 ± 19.4%) in wastewater.…”

Viruses in wastewater: occurrence, abundance and detection methods

“…Influents generally have higher concentration of viruses than other environmental samples ( Haramoto et al, 2018 ). Raw wastewater samples have higher turbidity ( Falman et al, 2019 ; Qiu et al, 2016 ; Sidhu et al, 2013 ), higher suspended solids ( Prado et al, 2019 ) and higher organic matter concentrations ( Falman et al, 2019 ) than other environmental water samples. In addition, influent wastewaters have high concentrations of humic acids and heavy metals, that may interfere with the molecular methods of assaying for viruses ( Prado et al, 2019 ).…”

“…VIRADEL method has been widely used for large volumes of sample to be processed, notably river samples ( Hamza et al, 2009 ; Maunula et al, 2012 ), tap water samples ( Hill et al, 2009 ; Polaczyk et al, 2007 ), groundwater samples ( Lee et al, 2011 ), and coastal waters ( Fong et al, 2005 ; Goyal and Gerba, 1983 ; Katayama et al, 2002 ). Wastewater sample volumes ranging from 0.5 to 400 L were used in recent studies that applied VIRADEL as primary concentration method ( Falman et al, 2019 ; Kuo et al, 2010 ; Masclaux et al, 2013 ; Osuolale and Okoh, 2017 ; Prado et al, 2011 ; Soto-Beltran et al, 2013 ). However, the processing of large volumes of samples leads to the concentration of PCR inhibitors.…”

Feasibility of the Bag-Mediated Filtration System for Environmental Surveillance of Poliovirus in Kenya

“…At the time of this study, the secondary concentration method would have required expensive equipment and therefore fewer laboratories would have the capability to implement it. Recent studies have improved the BMFS secondary concentration method to lower the centrifuge speed and eliminate overnight shaking at 4 °C (Falman et al 2019), and field validation has been completed.…”