Fingerprinting of human noroviruses co-infections in a possible foodborne outbreak by metagenomics

Authors: LIU, DANLEI - Shanghai Jiaotong University; ZHANG, ZILEI - Shanghai Jiaotong University; LI, SHENWEI - Shanghai International Travel Healthcare Center; WU, QINGPING - Guangdong Institute Of Microbiology; Tian, Peng; ZHANG, ZILONG - Shanghai International Travel Healthcare Center; WANG, DAPENG - Shanghai Jiaotong University

Submitted to: Frontiers in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/9/2020
Publication Date: 11/16/2020
Citation: Liu, D., Zhang, Z., Li, S., Wu, Q., Tian, P., Zhang, Z., Wang, D. 2020. Fingerprinting of human noroviruses co-infections in a possible foodborne outbreak by metagenomics. Frontiers in Microbiology. 333. Article 108787. https://doi.org/10.1016/j.ijfoodmicro.2020.108787.
DOI: https://doi.org/10.1016/j.ijfoodmicro.2020.108787

Interpretive Summary: Human noroviruses (HuNoVs) are the primary non-bacterial pathogen causing acute gastroenteritis worldwide. It is generally believed that co-infection of multiple genotypes of HuNoV happened rarely. The view was challenged in our study by using next generation sequencing to detect different genotypes of HuNoVs from an outbreak in travelers. An investigation was conducted on a cross-border travel group traveled back to China from Thailand for symptoms of diarrhea. Anal swab samples were collected to conduct laboratory inspection. Samples that were test positive for HuNoVs were further analyzed by next-generation sequencing. We demonstrated the outbreak was associated with co-infection of multiple genotypes of HuNoVs. Among the 23 anal swabs, 11 samples were positive for HuNoVs and the viral genome sequences belonged to 9 different genotypes of HuNoVs were obtained from seven patients. Four different genotypes of HuNoV {GI.5(P12), GIXI (GII.P15), GI.7(P7), and GII.8(P8)} were identified in one patient. Two cases each were infected/co-infected by one, two and three genotypes of HuNoVs respectively. Co-infection with both genogroup GI and GII and co-infection by two different P types ([P10] and [P13]) of the same genotype GI were identified in individual patients. Results in this study, for the first time, confirmed the fact that different genogroups and genotypes of HuNoVs can co-infect patients. The study provides evidence of foodborne outbreaks with multiple HuNoVs and raises new concerns for diagnosis and vaccine development.

Technical Abstract: Human noroviruses (HuNoVs) are the primary non-bacterial pathogen causing acute gastroenteritis worldwide. It is generally believed that co-infection of multiple genotypes of HuNoV happened rarely. The view was challenged in our study by using next generation sequencing to detect different genotypes of HuNoVs from an outbreak in travelers. An investigation was conducted on a cross-border travel group traveled back to China from Thailand for symptoms of diarrhea. Anal swab samples were collected to conduct laboratory inspection. Samples that were test positive for HuNoVs were further analyzed by next-generation sequencing. We demonstrated the outbreak was associated with co-infection of multiple genotypes of HuNoVs. Among the 23 anal swabs, 11 samples were positive for HuNoVs and the viral genome sequences belonged to 9 different genotypes of HuNoVs were obtained from seven patients. Four different genotypes of HuNoV {GI.5(P12), GIXI (GII.P15), GI.7(P7), and GII.8(P8)} were identified in one patient. Two cases each were infected/co-infected by one, two and three genotypes of HuNoVs respectively. Co-infection with both genogroup GI and GII and co-infection by two different P types ([P10] and [P13]) of the same genotype GI were identified in individual patients. Results in this study, for the first time, confirmed the fact that different genogroup and genotypes of HuNoVs can co-infect patients. The study provides evidence of foodborne outbreaks with multiple HuNoVs and raises new concerns for diagnosis and vaccine development.