Two enrichment methods for norovirus in urban sewage: a comparative study

Objective To investigate a more suitable enrichment method for norovirus (NoV) monitoring in urban sewage by comparing the recovery rate of NoV in sewage by polyethylene glycol (PEG) precipitation versus electronegative membrane adsorption-ultrasonic oscillation.

Methods NoV was diluted in three gradients and added into urban domestic sewage (100 mL), then concentrated by the two method of PEG precipitation and electronegative membrane adsorption-ultrasonic oscillation. The concentrations of GI and GⅡ virus after enrichment were detected by real-time fluorescent reverse transcription polymerase chain reaction (RT-PCR), and then the recovery rate was calculated.

Results When the concentration of NoV GI was 10^1.4 copies/μL, electronegative membrane adsorption-ultrasonic oscillation had a higher recovery rate than PEG precipitation (P < 0.05). When the concentration of NoV GII was 10^2.6 copies/μL, electronegative membrane adsorption-ultrasonic oscillation had a higher recovery rate than PEG precipitation (P < 0.05).

Conclusion Considering concentration efficiency and other related factors, the method of electronegative membrane adsorption-ultrasonic oscillation is more suitable for the enrichment of NoV in a small volume of sewage.