Broad-range and Effective Detection of Human Noroviruses by Colloidal Gold Immunochromatographic Assay Based on the Shell Domain of the Major Capsid Protei

Abstract

Background: Human noroviruses (HuNoVs) are a major cause of nonbacterial gastroenteritis in all ages worldwide. As the replication of HuNoVs in vitro is immature, the detection of HuNoVs is depended on molecular assays such as RT-PCR and RT-qPCR. However, these molecular-based techniques require special equipment, unique reagents, experienced operators to perform, and extended time to get results. In addition, the genotypes of HuNoVs are broad. Therefore, a method for rapidly, broad-range, and effective approach for HuNoVs would be more applicable for screening infected people when outbreaks occur.Results: In this study, a colloidal-gold-based immunochromatographic assay (ICA) was developed for highly effective detection of HuNoVs in clinical samples. Monoclonal antibodies (McAbs) against the shell (S) domain in the major capsid protein of HuNoV were used in the ICA. The limitations of detection for HuNoVs in clinical samples were 1.2×106 genomic copies per gram (gc/g) and 4.4×105 gc/g for genogroup I and II (GI and GII) HuNoVs, respectively. A total of 122 samples were tested for HuNoVs by ICA and compared against that by RT-qPCR. The relative sensitivity, specificity and agreement of the ICA was 84.2 % (95% CI: 83.6-84.8 %), 100.0 % (95 % CI: 98.5-100.0 %) and 87.7 % (95% CI: 85.6-89.8 %), respectively. No cross-reaction with other common enteric viruses or bacteria was observed. The ICA could detect a broad range of genotypes, including GI.1, GI.3, GI.4, GI.6, GI.14, GII.2, GII.3, GII.4, GII.6, GII.13, and GII.17 HuNoVs.Conclusions: Our results demonstrated that ICA targeting the S domain protein is a promising candidate for effectively improve identifying different genotypes of HuNoVs in clinical samples with high sensitivity and specificity.