深圳地区环境水体和人群中诺如病毒监测与分析

Surveillance and analysis of noroviruses in water environment and human population in Shenzhen

摘要:

【目的】检测深圳地区环境水体和人群的诺如病毒(NoVs)，探讨其是否在两者之间循环传播。【方法】2014年3月至2015年2月检测24份深圳茅洲河河水标本和287份腹泻患者粪便标本。河水标本经过混合纤维素酯膜和PEG法二次浓缩后提取核酸，粪便标本无需浓缩，稀释离心后直接提取核酸。应用实时荧光逆转录PCR初步分型，RT-PCR扩增ORF2保守区域衣壳蛋白(VP1)基因后测序确定亚型、分析不同来源病毒的同源性；同时建立基因进化树，进一步分析不同来源NoVs的亲缘关系。【结果】在河水标本和腹泻患者粪便标本中，NoVs阳性率分别为23.1%和17.4%，其中上下游河水标本阳性率分别为8.3%和41.7%，河水中NoVGI型和NoVGII型的阳性率为16.7%和8.3%。扩增阳性样本发现茅洲河水中检出NoV主要是GI.6型，其次是GII.4 Sydney_2012型，而从腹泻胃肠炎患者粪便标本中检出NoVs主要是NoVGII.4 Sydney_2012型和少量的GII.3型。同时期水体和人群粪便标本来源的NoVGII.4 Sydney_2012型VP1基因相似性98.2%–100.0%。【结论】NoVGII.4 Sydney_2012型是深圳地区主要的流行株。NoVs在环境水体和人群中于某种程度上存在循环传播。

Abstract:

[Objective] This study aimed to monitor noroviruses (NoVs) in the water environment and human population in Shenzhen city, and to explore the relationship for NoVs circulation between the two media. [Methods] Twenty-four water samples from Maozhou River and 287 clinical specimens were collected in Shenzhen city from March 2014 to February 2015. Water samples were firstly concentrated by mixed cellulose ester microporous membrane and PEG, and clinical specimens were directly diluted for RNA extraction. NoVs were firstly detected through real time RT-PCR, and the ORF2 capsid protein gene (VP1) of NoVs were got by RT-PCR and sequenced for genotype analysis. Homology and phylogenetic analyses were performed to investigate the relationship between the NoVs from environment water and those from human population. [Results] The positive rate for the water samples was 23.1%, including 8.3% and 41.7% positive rates for the upstream and downstream samples, respectively; while the positive rate for clinical specimens was 17.4%. The positive rate of genotype NoVGI and GII was 16.7% and 8.3% in the water samples, respectively. The VP1 partial gene sequence analysis showed that GI.6 was predominant in the water samples, in which GII.4 Sydney_2012 was also detected. Meanwhile, compared with GGII.3, GII.4 Sydney_2012 was more prevalent in human population. The nucleotide homology of partial VP1 gene of GII.4 Sydney_2012 from different samples showed 98.2%–100.0%. [Conclusion] NoVGII.4 Sydney_2012 was the predominant genotype in human population of Shenzhen city. To some extent, NoVs were probably circulating between water environment and human population.