CAJ | 학술논문

目的分析湖南省甲型H1N1流行性感冒(流感)大流行后乙型流感的流行情况和病毒基因特征,并探究可能造成其流行的原因.方法对湖南省2010年23家哨点医院门诊流感样病例中采集的咽拭子标本使用犬肾传代细胞进行病毒分离,阳性毒株使用血凝抑制实验进行型别鉴定,对选取的10株乙型流感病毒进行全基因组测序,对序列进行进化树和分子特征分析.结果随着甲型H1N1流感分离毒株的减少,乙型流感病毒在2010年上半年成为优势毒株,以B/Victoria系(BV系)为主,两种型别共存.2010年11起已知型别的聚集性疫情中,7起为乙型流感.在除核蛋白(NP)外的其他聚合酶(PB2、PB1、PA)、血凝素(HA)、神经氨酸酶(NA)、NB蛋白、膜蛋白(M1)、乙型流感病毒M2蛋白(BM2)、非结构蛋白(NS1、NS2)10个蛋白的基因进化树中,10株病毒均按照其系的分类分在BV和B/Florida系(BY系)两个分支中,而NP进化树10株病毒均在BY分支中.与世界卫生组织疫苗株比较,10株病毒11个蛋白的氨基酸同源性均较高,为97.2％～100.0％,但仍发现有一些碱基位点的改变.未发现对NA抑制剂类药物耐药位点的突变.相对于日常监测病毒,2株聚集性疫情毒株编码NA、NB、PB1、PB2和NS2的碱基有一些突变.结论乙型流感病毒有一些基因位点发生插入和重配,显示病毒持续进化,这可能是湖南省甲型H1N1流感大流行后B型流感病毒成为优势毒株的原因.
목적 분석호남성갑형H1N1류행성감모(류감)대류행후을형류감적류행정황화병독기인특정,병탐구가능조성기류행적원인.방법 대호남성2010년23가초점의원문진류감양병례중채집적인식자표본사용견신전대세포진행병독분리,양성독주사용혈응억제실험진행형별감정,대선취적10주을형류감병독진행전기인조측서,대서렬진행진화수화분자특정분석.결과 수착갑형H1N1류감분리독주적감소,을형류감병독재2010년상반년성위우세독주,이B/Victoria계(BV계)위주,량충형별공존.2010년11기이지형별적취집성역정중,7기위을형류감.재제핵단백(NP)외적기타취합매(PB2、PB1、PA)、혈응소(HA)、신경안산매(NA)、NB단백、막단백(M1)、을형류감병독M2단백(BM2)、비결구단백(NS1、NS2)10개단백적기인진화수중,10주병독균안조기계적분류분재BV화B/Florida계(BY계)량개분지중,이NP진화수10주병독균재BY분지중.여세계위생조직역묘주비교,10주병독11개단백적안기산동원성균교고,위97.2％～100.0％,단잉발현유일사감기위점적개변.미발현대NA억제제류약물내약위점적돌변.상대우일상감측병독,2주취집성역정독주편마NA、NB、PB1、PB2화NS2적감기유일사돌변.결론 을형류감병독유일사기인위점발생삽입화중배,현시병독지속진화,저가능시호남성갑형H1N1류감대류행후B형류감병독성위우세독주적원인.
Objective To analyze the prevalence status and the genetic characterizations of influenza B viruses isolated in Hunan Province after pandemic influenza A (H1N1) 2009,and to explore possible reasons for the prevalence.Methods Throat swabs were collected from outpatients with influenza-like illness in 23 sentinel hospitals of Hunan Province in 2010.Influenza viruses were isolated with Madin-Darby canine kidney (MDCK) cells and identified by haemagglutination inhibition test.The genomes of 10 selected influenza B viruses were sequenced and analyzed for phylogenetic and molecular characterization.Results With the reduction of isolation of pandemic influenza A (H1N1)2009 viruses,influenza B virus became the predominant isolated strain in the first half of 2010.Epidemic viruses mainly belonged to the B/Victoria lineage,and both two lineages co-circulated.Seven out of 11 influenza outbreaks caused by type B.Ten strains were filled into 2 branches of BV and BY which were classified by their lineage types in polymerase (PB2,PB1,PA),hemagglutinin (HA),neuraminidase (NA),NB,membrane protein (M1),influenza B virus membrane protein M2 (BM2),and non-structural protein (NS1,NS2) phylogenetic trees except the NP phylogenetic tree in which 10 strains were all in the BY branch.Compared with World Health Organization (WHO) vaccine strains,the amino acid identity of 11 proteins of the 10 strains was high (97.2％-100.0％).However,some amino acid point mutations were found.No mutation was found in drug resistance mutation sites.Some mutations in NA,NB,PB1,PB2 and NS2 molecules were found in 2 strains isolated from outbreaks compared with strains from sentinel surveillance.Conclusions The point mutations,insertions and genetic reassortment indicate viruses sustaining evolution,which is probably the reason for predominant influenza B viruses after pandemic influenza A (H1N1) 2009 in Hunan Province.