CAJ | 학술논문

目的了解2009年上海地区人群流行性感冒(流感)的流行特征和流行期间甲型H1N1分离株基因和抗原的变异.方法采集2009年上海地区哨点医院和学校聚集性流感样患者咽拭子标本,接种犬肾细胞(MDCK细胞)分离流感病毒,直接荧光免疫法鉴定流感病毒型,RT-PCR法鉴定亚型,对部分甲型H1N1流感病毒进行血凝素(HA)、神经氨酸酶(NA)等片段全基因测序,分析甲型H1N1流感病毒HA、NA等基因变异.结果 2009年上海地区冬春季人群流感中,季节性H1N1和H3N2流感同时存在,进入第32周时,甲型H1N1和季节性H3N2流感同时流行,第40周后主要是甲型H1N1流行.甲型H1N1流行株HA进化分析显示,不同区域、不同月份分离株互有穿插,上海地区分离株聚集成簇形成一个分枝,与西班牙、俄罗斯、丹麦等国的流行株接近.HA演绎推导氨基酸位点虽有变异,但都不位于抗原决定区域;NA基因演绎推导氨基酸位点未观察到274位点及与耐奥司他韦药物相关其他位点的变异;PB2蛋白氨基酸序列分析显示,第627位和第701位氨基酸分别是谷氨酸和天冬氨酸,为禽源流感病毒PB2蛋白氨基酸位点.结论 2009年上海地区冬春季人群流感,季节性H1N1和H3N2同时流行,夏秋季开始甲型H1N1、季节性H3N2在人群中同时流行,之后以甲型H1N1为主.甲型H1N1与早期分离株比较有一定变异,但尚未出现流行病学意义的抗原漂移株,仍表现为对人的高亲和力和低致病性特征.
목적 료해2009년상해지구인군류행성감모(류감)적류행특정화류행기간갑형H1N1분리주기인화항원적변이.방법 채집2009년상해지구초점의원화학교취집성류감양환자인식자표본,접충견신세포(MDCK세포)분리류감병독,직접형광면역법감정류감병독형,RT-PCR법감정아형,대부분갑형H1N1류감병독진행혈응소(HA)、신경안산매(NA)등편단전기인측서,분석갑형H1N1류감병독HA、NA등기인변이.결과 2009년상해지구동춘계인군류감중,계절성H1N1화H3N2류감동시존재,진입제32주시,갑형H1N1화계절성H3N2류감동시류행,제40주후주요시갑형H1N1류행.갑형H1N1류행주HA진화분석현시,불동구역、불동월빈분리주호유천삽,상해지구분리주취집성족형성일개분지,여서반아、아라사、단맥등국적류행주접근.HA연역추도안기산위점수유변이,단도불위우항원결정구역;NA기인연역추도안기산위점미관찰도274위점급여내오사타위약물상관기타위점적변이;PB2단백안기산서렬분석현시,제627위화제701위안기산분별시곡안산화천동안산,위금원류감병독PB2단백안기산위점.결론 2009년상해지구동춘계인군류감,계절성H1N1화H3N2동시류행,하추계개시갑형H1N1、계절성H3N2재인군중동시류행,지후이갑형H1N1위주.갑형H1N1여조기분리주비교유일정변이,단상미출현류행병학의의적항원표이주,잉표현위대인적고친화력화저치병성특정.
Objective To understand epidemic characteristics of human influenza A and the genetic and antigenic variations of H1N1 influenza A isolates in Shanghai area in 2009. Methods Throat swabs were collected from patients with influenza-like illness in the sentinel surveillance clinic in Shanghai area in 2009, then inoculated in Madin-Darby canine kidney (MDCK) cell lines. The types of influenza were identified by direct immunofluorescence assay (DIF) and the subtypes were determined by reverse transcriptase-polymerase chain reaction (RT-PCR). Segments of hemagglutinin (HA) and neuraminidase (NA) genes of some 2009 H1N1 influenza A isolates were amplified and sequenced. HA and NA gene mutations of 2009 H1N1 influenza A isolates were analyzed. Results Seasonal H1N1 and H3N2 influenza A viruses co-circulated during the spring of 2009 in Shanghai area. Seasonal H3N2 began to co-circulate with 2009 H1N1 in August (the 32nd week) and finally2009 H1N1 became dominate since the 40th week. The phylogenetic tree of 2009 H1N1 HA segment revealed that the isolates from different regions and months were interspersed with each other, but all were clustered into one branch which closed to strains in Spain, Russia, Denmark and other European countries. Mutations were found in some HA amino acid sites, but none of them was in the antigenic determinant region. No change was observed in the 274 NA amino acid residues which were related to the drug resistance to oseltamivir. PB2 protein analysis showed that the 627 and 701 amino acid residues were glutamic acid and aspartic acid respectively, which were the same encoded amino acid with avian flu PB2 protein. Conclusions Seasonal H1N1 and H3N2 co-circulated in the spring of 2009, then both 2009 H1N1 and seasonal H3N2 were prevalent in Summer and Autumn, and 2009 H1N1 finally became dominate in Autumn. Compared to early 2009 H1N1 strains, variations are detected in H1N1 influenza A viruses, but none of them has epidemiological influence, and viruses still show high affinity with human and low-pathogenic characteristics.