论文部分内容阅读
目的 了解河北省散发腹泻病例诺如病毒的分子特征.方法 收集2015年9月至2016年12月,河北省6市哨点医院散发腹泻病例粪便标本,用实时荧光反转录聚合酶链式反应(real-time reverse transcription polymerase chain reaction,RT-PCR)方法检测标本中的诺如病毒.阳性标本进行基因片段扩增,并测序进行序列比对,确定基因型.对测序所得序列与基因库中诺如病毒参考序列进行同源比对,并做进化树分析.结果 共采集腹泻便样本1 240份,检出诺如病毒阳性样本58份,其中GⅠ型5份,GⅡ型53份.对诺如病毒阳性样品RNA进行测序,得到21条主要衣壳蛋白(VP1)区序列和17条RNA依赖的RNA聚合酶(RNA-dependent RNA-polymerase,RdRP)区序列.经过与GenBank中诺如病毒参考序列比对,得到VP1区5种基因型,GⅡ.4型最多(10/21),其次为GⅡ.17型(4/21),其他还有GⅡ.2型(3/21)、GⅡ.3型(3/21)和GⅡ.6型(1/21).RdRP区有2种基因型,分别为GⅡ.P17型(4/17)和GⅡ.Pe型(13/17).结论 河北省感染诺如病毒散发腹泻病例以GⅡ.4型和GⅡ.17型为主,其他型别也有检出,需要进一步加强监测,及时发现新型毒株.“,”Objective To understand the molecular characteristics of norovirus strains from acute sporadic diarrhea cases in Hebei province.Methods From September 2015 to December 2016,stool specimens of sporadic diarrhea cases were collected from the sentinel hospitals of 6 cities in Hebei province.Norovirus was detected by real-time reverse transcription polymerase chain reaction (RT-PCR).The gene fragments of the virus in positive samples were amplified and sequenced for sequence alignments to determine the genotypes.The sequences obtained by sequencing were used in similarity analysis with the reference sequences in norovirus gene database.The phylogenetic tree was used for the analysis.Results A total of 1 240 stool specimens of diarrhea cases were collected.Fifty-eight samples were positive for noroviruses,including 5 cases of genotype GⅠ and 53 cases of GⅡ.The norovirus RNA fragments in the positive samples were sequenced,and 21 sequences of capsid protein 1 (VP1) region and 17 sequences of RNA-dependent RNA polymerase (RdRp) region were obtained.After comparing with the reference sequences of norovirus in Genbank database,the sequences of VP 1 revealed five genotypes.The predominant type was GⅡ.4 (10/21)followed by GⅡ.17 (4/21) and other genotypes of GⅡ.2 (3/21),GⅡ.3 (3/21) and GⅡ.6 (1/21).Two genoytpes by RdRP sequences were discovered,including GⅡ.P17 (4/17) and GⅡ.Pe (13/17).Conclusions Norovirus GⅡ.4 and GⅡ.17 were predominant among sporadic diarrhea cases in Hebei province,and other types also existed.The surveillance should be enhanced for timely detection of new type of the virus.