Abstract:
Objective To compare the efficiency of three virus enrichment and concentration methods, i.e. magnetic bead-based extraction, polyethylene glycol (PEG) precipitation, and anion membrane adsorption-elution for enriching norovirus in wastewater and identify the optimal method for norovirus detection in urban sewage.
Methods Sewage samples spiked with norovirus at three different concentrations (serially diluted) were processed using the three enrichment methods mentioned above. The recovery efficiencies of three enrichment methods for norovirus GⅠ and GⅡ were evaluated by using real-time reverse transcription polymerase chain reaction to detect the virus concentrations.
Results For norovirus GⅠ, the recovery rate ranged from (30.50 ± 2.04)% to (34.00 ± 4.49)% by magnetic bead-based extraction, from (6.40 ± 2.72)% to (11.58 ± 2.21)% by PEG precipitation, and from (3.50 ± 1.55)% to ( 9.26 ± 2.82)% by anion membrane adsorption-elution. The magnetic bead-based extraction demonstrated significantly higher recovery rate compared with both PEG precipitation and anion membrane adsorption-elution (F=85.144−109.443, P<0.001). Similarly, for norovirus GⅡ, the recovery rate ranged from (30.37 ± 2.60)% to (34.00 ± 4.52)% by magnetic bead-based extraction, from ( 6.40 ± 2.70)% to (10.59 ± 2.58)% by PEG precipitation, and from (3.50 ± 1.51)% to (7.23 ± 1.99)% by anion membrane adsorption-elution, with magnetic beads again outperforming the other methods (F=71.139−86.526, P<0.001). No significant difference was observed between PEG precipitation and anion membrane adsorption-elution in the recovery rate for either norovirus GⅠ or GⅡ. The processing times for 24 samples were 80 min by magnetic bead-based extraction, 320 min by PEG precipitation and 250 min by anion membrane adsorption-elution, with per-sample costs of 160.00, 16.00, and 18.00 yuan, respectively.
Conclusion Considering recovery efficiency, processing time, and operational simplicity, magnetic bead-based extraction is most effective for norovirus enrichment and concentration in urban sewage.