The H9N2 subtype of avian influenza virus(AIV)is widely prevalent in poultry and wild birds globally,and has become the predominant subtype circulating in poultry in China.The H9N2 AIV can directly or indirectly(by se...The H9N2 subtype of avian influenza virus(AIV)is widely prevalent in poultry and wild birds globally,and has become the predominant subtype circulating in poultry in China.The H9N2 AIV can directly or indirectly(by serving as a"donor virus")infect humans,posing a significant threat to public health.Currently,there is a lack of in-depth research on the prevalence of H9N2 viruses in Shanxi Province,central China.In this study,we isolated 14 H9N2 AIVs from October 2020 to April 2022 in Shanxi Province,and genetic analysis revealed that these viruses belonged to 7 different genotypes.Our study on animals revealed that the H9N2 strains we identified displayed high transmission efficiency among chicken populations,and exhibited diverse replication abilities within these birds.These viruses could replicate efficiently in the lungs of mice,with one strain also demonstrating the capacity to reproduce in organs like the brain and kidneys.At the cellular level,the replication ability of different H9N2 strains was evaluated using plaque formation assays and multi-step growth curve assays,revealing significant differences in the replication and proliferation efficiency of the various H9N2 viruses at the cellular level.The antigenicity analysis suggested that these isolates could be classified into 2 separate antigenic clusters.Our research provides crucial data to help understand the prevalence and biological characteristics of H9N2 AIVs in central China.It also highlights the necessity of enhancing the surveillance of H9N2 AIVs.展开更多
One influenza H3N2 virus, A/swine/Shandong/3/2005 (Sw/SD/3/2005), was isolated from pigs with respiratory disease on a farm in eastern China. Genetic analysis revealed that Sw/SD/3/2005 was a triple-reassortant virus ...One influenza H3N2 virus, A/swine/Shandong/3/2005 (Sw/SD/3/2005), was isolated from pigs with respiratory disease on a farm in eastern China. Genetic analysis revealed that Sw/SD/3/2005 was a triple-reassortant virus with a PB2 gene from human-like H1N1, NS from classical swine H1N1, and the remaining genes from human-like H3N2 virus. These findings further support the concept that swine can serve as reservoir or mixing vessels of influenza virus strains and maintain genetic and antigenic stability of viruses. Furthermore, we have successfully established a reverse genetics system based on eight plasmids and rescued Sw/SD/3/2005 through cell transfection. HI tests and RT-PCR confirmed that the rescued virus maintained the biological properties of the wild type Sw/SD/3/2005. The successful establishment of the reverse genetics system of Sw/SD/3/2005 will enable us to conduct extensive studies of the molecular evolution of H3N2 influenza viruses in swine.展开更多
Objective Symptomatic predictors of influenza could assess risks and improve decisions about isolation and outpatient treatment. To develop such predictors, we undertook a prospective analysis of pandemic （HIN1） 200...Objective Symptomatic predictors of influenza could assess risks and improve decisions about isolation and outpatient treatment. To develop such predictors, we undertook a prospective analysis of pandemic （HIN1） 2009 and seasonal influenza （H3N2） in patients attending fever clinics. Methods From 1 May 2009 to 1 January 2010, all adult patients admitted to fever clinics for suspected influenza, confirmed by real time RT-PCR, were enrolled. Predictors of influenza virus infection were selected with logistic regression models. Measures of sensitivity, specificity, positive and negative likelihood ratios （LRs） were calculated to identify the best predictors. Results The clinical features and routine blood test results of influenza （H1N1） 2009 and seasonal influenza were similar. The positive and negative LRs of current US CDC influenza-like illness （ILl） criteria were modest in predicting influenza infection. Our modified clinic predictors improved the ability of the positive and negative LRs to recognize pandemic （HIN1） 2009 and seasonal influenza. The revised criteria are： fever ~ 38 ~C accompanied by at least one of the following--cough, arthralgia or relative iymphopenia. Conclusion Patients with symptoms and signs that meet the new criteria are likely to have influenza and timely antiviral therapy may be appropriate. In addition, physicians should ascertain if influenza is circulating within the community or if there is a contact history of influenza and combine this information with the newly developed criteria to clinically diagnose influenza.展开更多
[Objective] The study aimed to investigate the genetic variation characters of entire sequences between two H9N2 subtype avian influenza virus strains and other reference strains.[Method] The entire sequences of 8 gen...[Objective] The study aimed to investigate the genetic variation characters of entire sequences between two H9N2 subtype avian influenza virus strains and other reference strains.[Method] The entire sequences of 8 genes were obtained by using RT-PCR,and these sequences were analyzed with that of six H9N2 subtype avian influenza isolates in homology comparison and genetic evolution relation.[Result] The results showed that the nucleotide sequence of entire gene of the strain shared 91.1%-95.4% homology with other seven reference strains,and PG08 shared the highest homology 91.3% with C/BJ/1/94;ZD06 shared the highest homology 92.3% with D/HK/Y280/97.HA cleavage sites of two H9N2 subtype avian influenza virus isolated strains were PARSSR/GLF,typical of mildly pathogenic avian influenza virus.[Conclusion] Phylogenetic tree for entire gene of eight strains showed that the genetic relationship was the closest between ZD06 and C/Pak/2/99 strains,which belonged to the Eurasian lineage;PG08 shared the highest homology 91.3% with ZD06,it may be the product of gene rearrangements of other sub-lines.展开更多
[ Objective] The study aimed to understand the genetic characters of H9N2 subtype avian influenza viruses isolated in Belling area. [ Method] HA genes of three H9N2 subtype avian influenza viruses A/Chicken/Beijing/xu...[ Objective] The study aimed to understand the genetic characters of H9N2 subtype avian influenza viruses isolated in Belling area. [ Method] HA genes of three H9N2 subtype avian influenza viruses A/Chicken/Beijing/xu/00, A/Chicken/Beijing/bei/00 and A/Chicken/Beijing/ liu/00 were amplified by RT-PCR and then sequenced. [ Result] The results of phylogenetic analysis showed that A/Chicken/Beijing/xu/00, A/ Chicken/Beijing/bei/00 and A/Chicken/Beijing/liu/00 shared the nucleotide homologies of 84.8% （ Dk/HK/Y439/97 ） -98.0% （ Ck/GX17/00 ）, 85.1% （Dk/HK/Y439/97） - 99.1% （ Ck/GXl 7/00）, 90.7% （ Ck/BJ/3/01 ） - 99.1% （Ck/GX17/00） with the isolates from Hongkong and other are- as of Chinese Mainland respectively. At the same time, the analysis of amino acid indicated that the three isolates belonged to low pathogenic H9N2 isolates of avian origin. The 226^th amino acid of them were L （ Leu）, suggesting their high binding affinity to human cells. There were seven glyco- sylation sites in HA protein, five from HA1 and two from HA2. [ Cenclusien] By analysis at molecular level, it could be concluded that A/Chicken/ Beijing/xu/00, A/Chicken/Beijing/bei/00 and A/Chicken/Beijing/liu/00 were low pathogenic H9N2 isolates of avian origin.展开更多
目的比较RNeasy mini kit(Qiagen)柱子法和Trizol法提取RNA在雪貂肺和肠组织H3N2 SYBRGreen PCR定量中的去干扰作用,从而找到适合该定量体系的RNA提取方法。方法比较Trizol法,RNeasy minikit柱子法,改良RNeasy mini kit柱子法1和改良RNe...目的比较RNeasy mini kit(Qiagen)柱子法和Trizol法提取RNA在雪貂肺和肠组织H3N2 SYBRGreen PCR定量中的去干扰作用,从而找到适合该定量体系的RNA提取方法。方法比较Trizol法,RNeasy minikit柱子法,改良RNeasy mini kit柱子法1和改良RNeasy mini kit柱子法2提取肺肠组织RNA的质量,RNA逆转录成cDNA后,利用SYBR Green PCR方法检测样品中H3N2的载量,比较产物的特异性,综合评价RNA提取方法。结果 4种方法提取的肺和肠组织的RNA质量不相同,紫外分光光度仪测得RNeasy mini kit柱子法提取的RNA的A260/280低于1.8,其余3种方法的A 260/280在1.8～2.1之间,A 260/230只有Trizol法能达到2.0左右,其余3种方法均远低于2.0。电泳可见Trizol法提取的RNA有3条带:28 s、18 s和5 s,而RNeasy mini kit柱子法的RNA除了有28 s、18 s外,还有基因组DNA,改良RNeasy mini kit柱子法1和2提取的RNA只有28 s和18 s带。RNA逆转录后进行荧光定量PCR,从溶解曲线看,不论是鼻甲刮取物还是肺肠组织的样品模板,4种方法获得的样品与标准品均为单一峰溶解曲线峰,并且波峰位置重叠。而鼻甲刮取物定量的产物跑琼脂糖凝胶电泳均为单一的特异性条带,而肺肠组织的产物电泳发现:Trizol法获得的模板定量产物与标准品一致,为单一的特异性条带,而其它3种方法获得的模板则均有非特异性条带。结论鼻甲刮取物的病毒定量选用RNeasy mini kit柱子法提取定量结果与Trizol法一样可靠,说明对于简单样品该体系及引物非常适用,结果可信。对于组织样品肺和肠,Trizol法获得的样品定量结果比其它3种方法可靠。展开更多
[ Objective] To determine the HA gene sequences of four H9N2 Avian influenza virus （AIV） strains and carry out comparative analysis so as to understand the difference and variation pattern of each strain from the an...[ Objective] To determine the HA gene sequences of four H9N2 Avian influenza virus （AIV） strains and carry out comparative analysis so as to understand the difference and variation pattern of each strain from the angle of molecular biology and to know the distribution and epidemic law of H9N2 AIV. [Method] One pair of primers was designed referring to HA gene sequences of H9N2 AIV. The HA genes of A/Chicken/Hebei/WD/98 （H9N2; WD98 for short）, A/Chicken/Hebei/ZD/04 （H9N2; ZD04 for short））, A/Chicken/Beijing/MY/06 （H9N2; MY06 for short） ）, and A/Chicken/Beijing/PG/08 （H9N2; PG08 for short）） were amplified, cloned and sequenced. Then the HA gene sequences of these strains were compared with that of 10 H9N2 AIV stains in GenBank. [Result] The ORF of HA genes of the four strains was 1 683 bp in size, encoding 516 amino acids. The HA gene sequences of the four strains, WD98, MY06, PG08, and ZD04, were 82.6% -95.1%, 83.0% -99.0%, 82.7% -95.5%, and 81.3% -95.7% homologous to that of the 10 H9N2 AIV stains, respectively. And the homology of amino acid was respectively 86.6% -96.3%, 86.6% -97.9%, 87.0% -97.1%, and 86.9% -97.3%. [ Conclusion] The HA gene has greatly high homology among different strains.展开更多
基金Fundamental Research Program of Shanxi Province,China(202103021224156)National Natural Science Foundation of China(32202788)+5 种基金Special Research Fund of Shanxi Agricultural University for High-level Talents,China(2021XG004)Science and Technology Innovation Program of Shanxi Agricultural University,China(2021BQ78)special fund for Science and Technology Innovation Teams of Shanxi Province,China(202304051001041)?Shanxi Province Excellent Doctoral Work Award-Scientific Research Project,China(SXBYKY2021005,SXBYKY2021063,SXBYKY2022014)the Fund for Shanxi“1331 Project”,China(20211331-13)earmarked fund for Modern Agro-industry Technology Research System of Shanxi Province,China.
文摘The H9N2 subtype of avian influenza virus(AIV)is widely prevalent in poultry and wild birds globally,and has become the predominant subtype circulating in poultry in China.The H9N2 AIV can directly or indirectly(by serving as a"donor virus")infect humans,posing a significant threat to public health.Currently,there is a lack of in-depth research on the prevalence of H9N2 viruses in Shanxi Province,central China.In this study,we isolated 14 H9N2 AIVs from October 2020 to April 2022 in Shanxi Province,and genetic analysis revealed that these viruses belonged to 7 different genotypes.Our study on animals revealed that the H9N2 strains we identified displayed high transmission efficiency among chicken populations,and exhibited diverse replication abilities within these birds.These viruses could replicate efficiently in the lungs of mice,with one strain also demonstrating the capacity to reproduce in organs like the brain and kidneys.At the cellular level,the replication ability of different H9N2 strains was evaluated using plaque formation assays and multi-step growth curve assays,revealing significant differences in the replication and proliferation efficiency of the various H9N2 viruses at the cellular level.The antigenicity analysis suggested that these isolates could be classified into 2 separate antigenic clusters.Our research provides crucial data to help understand the prevalence and biological characteristics of H9N2 AIVs in central China.It also highlights the necessity of enhancing the surveillance of H9N2 AIVs.
文摘One influenza H3N2 virus, A/swine/Shandong/3/2005 (Sw/SD/3/2005), was isolated from pigs with respiratory disease on a farm in eastern China. Genetic analysis revealed that Sw/SD/3/2005 was a triple-reassortant virus with a PB2 gene from human-like H1N1, NS from classical swine H1N1, and the remaining genes from human-like H3N2 virus. These findings further support the concept that swine can serve as reservoir or mixing vessels of influenza virus strains and maintain genetic and antigenic stability of viruses. Furthermore, we have successfully established a reverse genetics system based on eight plasmids and rescued Sw/SD/3/2005 through cell transfection. HI tests and RT-PCR confirmed that the rescued virus maintained the biological properties of the wild type Sw/SD/3/2005. The successful establishment of the reverse genetics system of Sw/SD/3/2005 will enable us to conduct extensive studies of the molecular evolution of H3N2 influenza viruses in swine.
基金supported by Chinese National Programs for High Technology Research and Development (863 Program,2008AA02Z416)
文摘Objective Symptomatic predictors of influenza could assess risks and improve decisions about isolation and outpatient treatment. To develop such predictors, we undertook a prospective analysis of pandemic （HIN1） 2009 and seasonal influenza （H3N2） in patients attending fever clinics. Methods From 1 May 2009 to 1 January 2010, all adult patients admitted to fever clinics for suspected influenza, confirmed by real time RT-PCR, were enrolled. Predictors of influenza virus infection were selected with logistic regression models. Measures of sensitivity, specificity, positive and negative likelihood ratios （LRs） were calculated to identify the best predictors. Results The clinical features and routine blood test results of influenza （H1N1） 2009 and seasonal influenza were similar. The positive and negative LRs of current US CDC influenza-like illness （ILl） criteria were modest in predicting influenza infection. Our modified clinic predictors improved the ability of the positive and negative LRs to recognize pandemic （HIN1） 2009 and seasonal influenza. The revised criteria are： fever ~ 38 ~C accompanied by at least one of the following--cough, arthralgia or relative iymphopenia. Conclusion Patients with symptoms and signs that meet the new criteria are likely to have influenza and timely antiviral therapy may be appropriate. In addition, physicians should ascertain if influenza is circulating within the community or if there is a contact history of influenza and combine this information with the newly developed criteria to clinically diagnose influenza.
基金Supported by a Sub-project of 973 Program of China(2005CB523001)~~
文摘[Objective] The study aimed to investigate the genetic variation characters of entire sequences between two H9N2 subtype avian influenza virus strains and other reference strains.[Method] The entire sequences of 8 genes were obtained by using RT-PCR,and these sequences were analyzed with that of six H9N2 subtype avian influenza isolates in homology comparison and genetic evolution relation.[Result] The results showed that the nucleotide sequence of entire gene of the strain shared 91.1%-95.4% homology with other seven reference strains,and PG08 shared the highest homology 91.3% with C/BJ/1/94;ZD06 shared the highest homology 92.3% with D/HK/Y280/97.HA cleavage sites of two H9N2 subtype avian influenza virus isolated strains were PARSSR/GLF,typical of mildly pathogenic avian influenza virus.[Conclusion] Phylogenetic tree for entire gene of eight strains showed that the genetic relationship was the closest between ZD06 and C/Pak/2/99 strains,which belonged to the Eurasian lineage;PG08 shared the highest homology 91.3% with ZD06,it may be the product of gene rearrangements of other sub-lines.
文摘[ Objective] The study aimed to understand the genetic characters of H9N2 subtype avian influenza viruses isolated in Belling area. [ Method] HA genes of three H9N2 subtype avian influenza viruses A/Chicken/Beijing/xu/00, A/Chicken/Beijing/bei/00 and A/Chicken/Beijing/ liu/00 were amplified by RT-PCR and then sequenced. [ Result] The results of phylogenetic analysis showed that A/Chicken/Beijing/xu/00, A/ Chicken/Beijing/bei/00 and A/Chicken/Beijing/liu/00 shared the nucleotide homologies of 84.8% （ Dk/HK/Y439/97 ） -98.0% （ Ck/GX17/00 ）, 85.1% （Dk/HK/Y439/97） - 99.1% （ Ck/GXl 7/00）, 90.7% （ Ck/BJ/3/01 ） - 99.1% （Ck/GX17/00） with the isolates from Hongkong and other are- as of Chinese Mainland respectively. At the same time, the analysis of amino acid indicated that the three isolates belonged to low pathogenic H9N2 isolates of avian origin. The 226^th amino acid of them were L （ Leu）, suggesting their high binding affinity to human cells. There were seven glyco- sylation sites in HA protein, five from HA1 and two from HA2. [ Cenclusien] By analysis at molecular level, it could be concluded that A/Chicken/ Beijing/xu/00, A/Chicken/Beijing/bei/00 and A/Chicken/Beijing/liu/00 were low pathogenic H9N2 isolates of avian origin.
文摘目的比较RNeasy mini kit(Qiagen)柱子法和Trizol法提取RNA在雪貂肺和肠组织H3N2 SYBRGreen PCR定量中的去干扰作用,从而找到适合该定量体系的RNA提取方法。方法比较Trizol法,RNeasy minikit柱子法,改良RNeasy mini kit柱子法1和改良RNeasy mini kit柱子法2提取肺肠组织RNA的质量,RNA逆转录成cDNA后,利用SYBR Green PCR方法检测样品中H3N2的载量,比较产物的特异性,综合评价RNA提取方法。结果 4种方法提取的肺和肠组织的RNA质量不相同,紫外分光光度仪测得RNeasy mini kit柱子法提取的RNA的A260/280低于1.8,其余3种方法的A 260/280在1.8～2.1之间,A 260/230只有Trizol法能达到2.0左右,其余3种方法均远低于2.0。电泳可见Trizol法提取的RNA有3条带:28 s、18 s和5 s,而RNeasy mini kit柱子法的RNA除了有28 s、18 s外,还有基因组DNA,改良RNeasy mini kit柱子法1和2提取的RNA只有28 s和18 s带。RNA逆转录后进行荧光定量PCR,从溶解曲线看,不论是鼻甲刮取物还是肺肠组织的样品模板,4种方法获得的样品与标准品均为单一峰溶解曲线峰,并且波峰位置重叠。而鼻甲刮取物定量的产物跑琼脂糖凝胶电泳均为单一的特异性条带,而肺肠组织的产物电泳发现:Trizol法获得的模板定量产物与标准品一致,为单一的特异性条带,而其它3种方法获得的模板则均有非特异性条带。结论鼻甲刮取物的病毒定量选用RNeasy mini kit柱子法提取定量结果与Trizol法一样可靠,说明对于简单样品该体系及引物非常适用,结果可信。对于组织样品肺和肠,Trizol法获得的样品定量结果比其它3种方法可靠。
基金Supported by subproject of Major State Basic Research Development Program of China (2005CB523001)~~
文摘[ Objective] To determine the HA gene sequences of four H9N2 Avian influenza virus （AIV） strains and carry out comparative analysis so as to understand the difference and variation pattern of each strain from the angle of molecular biology and to know the distribution and epidemic law of H9N2 AIV. [Method] One pair of primers was designed referring to HA gene sequences of H9N2 AIV. The HA genes of A/Chicken/Hebei/WD/98 （H9N2; WD98 for short）, A/Chicken/Hebei/ZD/04 （H9N2; ZD04 for short））, A/Chicken/Beijing/MY/06 （H9N2; MY06 for short） ）, and A/Chicken/Beijing/PG/08 （H9N2; PG08 for short）） were amplified, cloned and sequenced. Then the HA gene sequences of these strains were compared with that of 10 H9N2 AIV stains in GenBank. [Result] The ORF of HA genes of the four strains was 1 683 bp in size, encoding 516 amino acids. The HA gene sequences of the four strains, WD98, MY06, PG08, and ZD04, were 82.6% -95.1%, 83.0% -99.0%, 82.7% -95.5%, and 81.3% -95.7% homologous to that of the 10 H9N2 AIV stains, respectively. And the homology of amino acid was respectively 86.6% -96.3%, 86.6% -97.9%, 87.0% -97.1%, and 86.9% -97.3%. [ Conclusion] The HA gene has greatly high homology among different strains.
