Distribution And Character Of The Human Noroviruses Receptor-like In Leaf Of Romaine Lettuce

Human norovirus (HuNoVs) is the main cause of human non-bacterial gastroenteritis.Fruits and vegetables (such as lettuce, strawberry) surface could adsorpt HuNoVs, is one of the important carrier of HuNoVs transmission. However, the information of virus receptor and virus transmission related to pollution and transmission mechanisms were rarely seen.Therefore, explore the distribution of HuNoVs in fruits and vegetables and analysis of HuNoVs receptor and its character in fruits and vegetables, is the breakthrough to reveal HuNoVs spread mechanism in the fruits and vegetables.Based on the preliminary work, in this study, we used an surface display system to present the protruding domain of GI.1/GII.4 HuNoV capsid protein on E.coli surface as the HuNoV surrogate. The binding and distribution of HuNoVs receptors on the lettuce surface were analyzed by laser confocal fluorescence microscopy.The HuNoV receptors types and properties in lettuce leave extract were analyzed by ELISA. The results are as follows:(1) The binding of INP-P(GI.1/GII.4)BL21 on lettuce was studied by laser confocal fluorescence microscopy. The results showed that HuNoVs were easily binding on leaf, veins and stomata of lettuce leaves. Correspondingly, the binding ability of HuNoV with new leaf was poor.(2) ELISA was used to detect the HuNoV receptor in the lettuce leaves extract. The results showed that saliva and PGM treatment could inhibit the binding of INP-P(G?.1/G?.4)BL21 to lettuce leave extract; NaIO4 significantly inhibited the binding of INP-P(G?.1/G?.4)BL21 to lettuce leave extract. After boiling, the binding of INP-P(G?.4)BL21 to lettuce leave extract could be partially inhibited. Therefore, lettuce could be combined HuNoV with like-HBGAs glycoprotein, and the combination of the main components was polysaccharide group. G?.4 HuNoV could specifically bind to the protein in the lettuce extract, but G?.1 HuNoV did not have this phenomenon.(3) pH had little effect on the binding of HuNoVs with lettuce. The electrostatic force and hydrophobic interaction play an important role in binding HuNoVs with lettuce.