Location: Produce Safety and Microbiology Research
Title: Broad-range and effective detection of human noroviruses by colloidal gold immunochromatographic assay based on the shell domain of the major capsid proteinAuthor
XU, MENG - Shanghai Jiaotong University | |
LU, FEIFENG - Shanghai Jiaotong University | |
WU, QINGPING - Guangdong Academy Of Agricultural Sciences | |
ZHANG, JUMEI - Guangdong Academy Of Agricultural Sciences | |
Tian, Peng | |
XU, TING - Shanghai Jiaotong University | |
WANG, DAPENG - Shanghai Jiaotong University |
Submitted to: BMC Microbiology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/29/2020 Publication Date: 1/11/2021 Citation: Xu, M., Lu, F., Wu, Q., Zhang, J., Tian, P., Xu, T., Wang, D. 2021. Broad-range and effective detection of human noroviruses by colloidal gold immunochromatographic assay based on the shell domain of the major capsid protein. BMC Microbiology. 21. Article 22. https://doi.org/10.1186/s12866-020-02084-z. DOI: https://doi.org/10.1186/s12866-020-02084-z Interpretive Summary: Human noroviruses (HuNoVs) are a major cause of nonbacterial gastroenteritis in all ages worldwide. The currents detection methods need specialized equipment, reagents, and experienced person to perform. In collaborate with scientists in Shanghai Jiao Tong University, an immunochromatographic assay (ICA) was developed for rapid detection of human noroviruses in clinical samples. An ICA assay is very simple to screen the presence or absence of a target analyte, such as pathogens or biomarkers in the sample tested. The most commonly known type of ICA is the pregnancy test. They are designed to use without any equipment and required minimal training to do. They can be read visually within minutes. The limit of detection (LOD) of ICA we developed was 1.4 ng/ml for viral protein. The LODs for virus in clinical samples were 1.2×10^6 genomic copies (gc) /g and 4.4×10^5 gc/g for GI and GII HuNoV, respectively. A total of 97 clinical samples were tested for HuNoV by real time RT-qPCR method and ICA. Eighty-five samples were tested positive and 12 samples were negative for HuNoV by RT-PCR. Among 85 RT-PCR positive samples, 73 (85.9%) were positive and 12 (14.1%) were negative by ICA assay. None of 12 HuNoV RT-PCR negative samples were detected positive by ICA. The sensitivity, specificity and agreement of the ICA kit were 85.9%, 100% and 87.6%, respectively. The sensitivity and specificity are comparable to the commercial ELISA-based assays with a broader detection range. Both GI and GII HuNoV could be detected by the ICA strip tested. The entire test time was within 15 minutes and the shelf-life was estimated up to two years. Our results demonstrated that the ICA method a promising method for screening HuNoVs. Technical Abstract: Human noroviruses (HuNoVs) are a major cause of nonbacterial gastroenteritis in all ages worldwide. As the replication of HuNoVs in vitro is far from mature to be used routinely, 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 person to perform and extended time to get results. In this study, a colloidal gold based immunochromatographic assay (ICA) was developed for rapid detection of HuNoV in clinical samples. Monoclonal antibodies (McAbs) against the shell domain (S domain) in the major capsid protein VP1 of HuNoV were generated and used as capture and label Abs in ICA strips. The optimal conditions for construction of ICA strip were explored. The limit of detection (LOD) of ICA was 1.4 ng/ml for S protein. The LODs for HuNoV in clinical samples were 1.2×10^6 genomic copies (gc) /g and 4.4×10^5 gc/g for GI and GII HuNoV, respectively. A total of 97 clinical samples were tested for HuNoV by RT-qPCR and ICA. Eighty-five samples were tested positive and 12 samples were negative for HuNoV by RT-qPCR. Among 85 RT-PCR positive samples, 73 (85.9%) were positive and 12 (14.1%) were negative by ICA assay. None of 12 HuNoV RT-qPCR negative samples were detected positive by ICA. The sensitivity, specificity and agreement of the ICA kit were 85.9%, 100% and 87.6%, respectively. The sensitivity and specificity are comparable to the commercial ELISA-based assays with a broader detection range. Both GI and GII HuNoV could be detected by the ICA strip tested. The entire test time was within 15 minutes and the shelf-life was estimated up to two years. Our results demonstrated that the colloidal gold test strips target the S domain protein is a promising method for screening HuNoVs in clinical/environmental samples. |