Purpose: The aim of this study was to attempt to recover structurally intact human NoV, in order to determine the survival of human NoV.
Methods: In this study, a method for the detection of NoV GII.4 in fermented kimchi using a conductive polymer coated magnetic separation combined with Quantitative Reverse Transcription-PCR was developed. Intact viral particles were captured using anionic magnetic beads, which were prepared by the grafting of poly (poly(MVE-MA)) in a dimethyl sulfoxide (DMSO)/phosphate buffer solution. A zeta potential and particle size analyzer was used to measure the zeta potential value of 200 nm magnetic beads coated with anionic polymer.
Results: Our conductive, polymer coated, magnetic beads exhibited zeta potential values between -28.80 and -29.48 mV, demonstrating a negative charge due to coating of the beads with the anionic polymer. Based on conductive polymer coated magnetic beads combined with qRT-PCR results, recovery rates of NoV GII.4 from PBS solution (control) and kimchi samples inoculated with NoV GII.4 were 68.71±3.28% and 41.95±7.38%, respectively. These results verified that GII.4 can be detected in fermented foods by using the conductive polymer coated magnetic beads combined with qRT-PCR method.
Significance: A conductive polymer coated magnetic separation technique removes PCR inhibitors and reduces time-consuming concentration steps for the concentration of virus particles in kimchi samples. Recovery sensitivity achieved using our method was similar to that of other concentration methods such as polyethylene glycol (PEG)-precipitation and ultrafiltration. These results demonstrate that the conductive polymer coated magnetic beads combined with qRT-PCR assay can be used to efficiently and rapidly detect viruses in various food samples.