Yu Yongxin, Cai Hui, Hu Linghao, Lei Rongwei, Pan Yingjie, Yan Shuling, Wang Yongjie
College of Food Science and Technology, Shanghai Ocean University, Shanghai, China Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation, Ministry of Agriculture, Shanghai, China.
College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.
Appl Environ Microbiol. 2015 Nov;81(21):7615-24. doi: 10.1128/AEM.01729-15. Epub 2015 Aug 28.
Noroviruses (NoVs) are a leading cause of epidemic and sporadic cases of acute gastroenteritis worldwide. Oysters are well recognized as the main vectors of environmentally transmitted NoVs, and disease outbreaks linked to oyster consumption have been commonly observed. Here, to quantify the genetic diversity, temporal distribution, and circulation of oyster-related NoVs on a global scale, 1,077 oyster-related NoV sequences deposited from 1983 to 2014 were downloaded from both NCBI GenBank and the NoroNet outbreak database and were then screened for quality control. A total of 665 sequences with reliable information were obtained and were subsequently subjected to genotyping and phylogenetic analyses. The results indicated that the majority of oyster-related NoV sequences were obtained from coastal countries and regions and that the numbers of sequences in these regions were unevenly distributed. Moreover, >80% of human NoV genotypes were detected in oyster samples or oyster-related outbreaks. A higher proportion of genogroup I (GI) (34%) was observed for oyster-related sequences than for non-oyster-related outbreaks, where GII strains dominated with an overwhelming majority of >90%, indicating that the prevalences of GI and GII are different in humans and oysters. In addition, a related convergence of the circulation trend was found between oyster-related NoV sequences and human pandemic outbreaks. This suggests that oysters not only act as a vector of NoV through environmental transmission but also serve as an important reservoir of human NoVs. These results highlight the importance of oysters in the persistence and transmission of human NoVs in the environment and have important implications for the surveillance of human NoVs in oyster samples.
诺如病毒（NoVs）是全球急性胃肠炎流行和散发病例的主要病因。牡蛎是环境传播的诺如病毒的主要载体，与食用牡蛎相关的疾病暴发屡见不鲜。在此，为了在全球范围内量化与牡蛎相关的诺如病毒的遗传多样性、时间分布和传播情况，从美国国立医学图书馆基因库（NCBI GenBank）和诺如病毒网络暴发数据库下载了1983年至2014年期间存储的1077条与牡蛎相关的诺如病毒序列，然后进行质量控制筛选。共获得665条信息可靠的序列，随后对其进行基因分型和系统发育分析。结果表明，大多数与牡蛎相关的诺如病毒序列来自沿海国家和地区，且这些地区的序列数量分布不均。此外，在牡蛎样本或与牡蛎相关的疫情中检测到80%以上的人类诺如病毒基因型。与非牡蛎相关的疫情相比，牡蛎相关序列中I基因组（GI）的比例更高（34%），在非牡蛎相关的疫情中，II基因组（GII）菌株占绝大多数，超过90%，这表明GI和GII在人类和牡蛎中的流行情况不同。此外，在与牡蛎相关的诺如病毒序列和人类大流行疫情之间发现了相关的传播趋势趋同。这表明牡蛎不仅通过环境传播充当诺如病毒的载体，而且还是人类诺如病毒的重要储存库。这些结果凸显了牡蛎在人类诺如病毒在环境中的持续存在和传播中的重要性，对监测牡蛎样本中的人类诺如病毒具有重要意义。
