Inactivation Of Noroviruses And Its Mechanism By Propolis

Objective Establish an effective method for detecting norovirus(NoV GⅡ)in shellfish,then applied in various types of shellifish.Establish infection model of shellfish and research virus inactivation by propolis in water.To evaluate their possible mechanism,the effects of propolis and chlorine dioxide on the NoV(genome and protein)were compared.Methods First,a known amount of NoV GⅡ was spiked onto the shellfish and seven different buffers previously described for eluting NoV GⅡ were evaluated.To optimize a method for concentrating the recovered NoV GⅡ,three concentration methods(PEG precipitation,ultrafiltration and membrane adsorption)were investigated and detection by RT-qPCR.Second,establish infection model of shellfish,determine the target and study on the effect factors on the enrichment and elution of shellfish.Finally,extract the propolis and research its virus inactivation effects on NoV,comparing with chlorine dioxide.And detect the integrity of Genome and protein with RNase A,ELISA and PCR methods.Results The results indicated that,NoV GⅡ was extracted from the shellfish by a direct elution method in the KNT(pH 9.5)buffer,concentrated by PEG and then followed by QIAamp viral RNA mini kit for RNA extraction.The average detection limits for NoV GⅡ were 3.5×105 copies per 10 g of shellfish.The Target detections of shellfish are its stomach and mantle.It’s easy to enrichment virus but difficult to elution for shellfish.As RNase A,ELISA and PCR used,showed that chlorine dioxide worded in nucleic acids while propolis and chlorine dioxide methods all weaken the protective effect of coat protein except propolis.Conclusion The extracted of propolis can play a part on inactivation of NoV and better than chlorine dioxide.It could be developed as an effective and potential candidate to prevent infection on shellfish.