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对2009年长沙麓山国际学校流感暴发疫情进行实验室诊断,并探索新分离的A(H1N1)亚型流感病毒血凝素(HA)的基因特性。对流感暴发疫情的25份鼻/咽拭子标本进行RT-PCR检测和流感病毒分离,然后利用CEQ 8000 Genetic Analysis System对病毒分离株(A/Yuelu/314/2009)进行测序,测序结果提交至GenBank(登录号:FJ912843)并用ClustalX和Mega4.1软件进行序列分析。结果显示,分离出A(H1N1)亚型流感毒株18株,检出21份A(H1N1)亚型流感病毒核酸阳性;A/Yuelu/314/2009(H1N1)HA基因序列与2008~2009年疫苗株(A/Brisbane/59/2007)比较显示:核苷酸和氨基酸同源性均为99%,有6个位点的氨基酸发生了变异(V148A、S158N、G202A、I203D、A206T、W435R),其中一个S158N氨基酸变异位于B抗原表位,HA基因序列上共有潜在糖基化位点9个(27、28、40、71、151、176、303、497、536),与A/Brisbane/59/2007相同且氨基酸序列保守。本实验诊断出此次流感暴发疫情的病原体为A(H1N1)型季节性流感病毒,研究还发现A/Yuelu/314/2009(H1N1)长沙分离株与A/Brisbane/59/2007疫苗株基因序列比较显示并未形成一个新的变种,推测是由于分离株与疫苗株之间基因特性的改变和人群对A(H1N1)亚型流感病毒免疫力降低导致了此次长沙麓山国际学校A(H1N1)亚型流感的暴发。
The laboratory diagnosis of influenza outbreak in Changsha Lushan International School in 2009 was conducted and the genetic characteristics of the newly isolated influenza A (H1N1) influenza virus hemagglutinin (HA) were explored. RT-PCR and influenza virus isolation were performed on 25 nasal / throat swab specimens from the outbreak of influenza and the virus isolates (A / Yuelu / 314/2009) were sequenced using the CEQ 8000 Genetic Analysis System. The sequencing results were submitted to GenBank (Accession No: FJ912843) and sequenced with ClustalX and Mega 4.1 software. The results showed that 18 influenza A (H1N1) strains were isolated and 21 positive samples of influenza A (H1N1) were detected. The sequence of HA / A / Yuelu / 314/2009 (H1N1) The comparison of the vaccine strains (A / Brisbane / 59/2007) showed that the nucleotide and amino acid homology was 99%, and six amino acids were mutated (V148A, S158N, G202A, I203D, A206T and W435R) , One of the S158N amino acid mutations was located on the B antigen epitope, and there were 9 potential glycosylation sites on the HA gene sequence (27,28,40,71,151,176,303,497,536) 59/2007 and the amino acid sequence is conserved. This experiment diagnosed the outbreak of the flu as the pathogen of influenza A (H1N1) type influenza virus, the study also found that the A / Yuelu / 314/2009 (H1N1) Changsha isolate and A / Brisbane / 59/2007 vaccine strain gene sequence The comparison shows that no new variant has been formed, presumably due to the changes in the genetic characteristics of isolates and vaccine strains and the reduced immunity of the population to influenza A (H1N1) influenza virus, leading to the fact that the Changsha Lushan International School A (H1N1) Subtype influenza outbreak.