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目的了解广西壮族自治区一起感染性腹泻疫情中GⅡ.4型诺如病毒(Norovirus)的基因特征。方法采用荧光定量逆转录-聚合酶链反应,对采集于这起疫情的34份粪便标本进行诺如病毒核糖核酸(RNA)的检测,并对随机选取的1份阳性样本进行N/S区核苷酸序列测定和分析,并构建系统进化树。结果34份粪便标本中,有29份检测诺如病毒RNA阳性,阳性率为85.3%。随机选取的1株诺如病毒株(LC17株)的N/S区核苷酸序列与GⅡ型所有亚型参考株相比,其与第4亚型(GⅡ.4型)的参考株——Lordsdale/1993/UK株的核苷酸序列同源性为93.3%,在遗传进化树图中,与GⅡ.4型株病毒在一簇。与早年流行的GⅡ.4型流行株同源性为94.7%~96.5%,与国内外2006年流行株同源性为98.2%~98.6%,但与1株广州株相比,同源性仅为94.7%。结论此次感染性腹泻疫情是由诺如病毒GⅡ.4型感染所致,其病毒基因型在广西壮族自治区是首次发现和报导。GⅡ.4型毒株在不断的进化,并在核苷酸序列特征和毒株地域分布上表现出多样性,需加强对诺如病毒的分子流行病学研究,了解基因型的分布,鉴别其来源和传播途径,对控制诺如病毒感染有重要意义。
Objective To understand the genetic characteristics of GⅡ.4 Norovirus in an epidemic of infectious diarrhea in Guangxi Zhuang Autonomous Region. Methods 34 cases of stool samples collected from this outbreak were tested for norovirus RNA by fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR). One positive sample was randomly selected for N / S nuclear Nucleotide sequence determination and analysis, and construction of phylogenetic tree. Results Of the 34 stool samples, 29 were positive for Norovirus RNA, with a positive rate of 85.3%. The nucleotide sequence of the N / S region of one randomly selected Norovirus strain (LC17 strain) was compared with the reference strains of the fourth subtype (GⅡ.4) The nucleotide sequence homology of Lordsdale / 1993 / UK strain was 93.3%. In the phylogenetic tree, it was clustered with GⅡ.4 strain. The homology with early epidemic type GⅡ.4 strains was 94.7% ~ 96.5%, which was 98.2% ~ 98.6% homologous with that of the domestic and international epidemic strains in 2006. However, compared with one strain of Guangzhou, homology was only 94.7%. Conclusion The epidemic of infectious diarrhea is caused by Norovirus GⅡ.4 infection. The genotype of the virus is first reported and reported in Guangxi Zhuang Autonomous Region. The genotype GII.4 is evolving continuously, showing diversity in nucleotide sequence characteristics and geographical distribution of the strains. It is necessary to strengthen the molecular epidemiological study of norovirus and to understand the distribution of genotypes and to identify their Source and route of transmission are important for controlling norovirus infection.