Avian metapneumovirus (aMPV) and Newcastle disease virus (NDV) are threatening avian pathogens that can cause serious respiratory diseases in poultry worldwide. Vaccination, combined with strict biosecurity practices,...Avian metapneumovirus (aMPV) and Newcastle disease virus (NDV) are threatening avian pathogens that can cause serious respiratory diseases in poultry worldwide. Vaccination, combined with strict biosecurity practices, has been the recommendation for controlling these diseases in the field. In the present study, we generated NDV LaSota vaccine strain-based recombinant viruses expressing the glycoprotein (G) of aMPV, subtype A or B, using reverse genetics technology. These recombinant viruses, rLS/aMPV-A G and rLS/aMPV-B G, were characterized in cell cultures and evaluated in turkeys as bivalent, next-generation vaccines. The results showed that these recombinant vaccine candi-dates were slightly attenuated in vivo, yet maintained similar growth dynamics, cytopathic effects, and virus titers in vitro when compared to the parental LaSota virus. The expression of the aMPV G protein in recombinant virus-infected cells was detected by immunofluorescence. Vaccination of turkeys with rLS/aMPV-A G or rLS/aMPV-B G conferred complete protection against velogenic NDV, CA02 strain challenge and partial protection against homologous patho-genic aMPV challenge. These results suggest that the LaSota recombinant virus is a safe and effective vaccine vector and expression of the G protein alone is not sufficient to provide full protection against aMPV-A or -B infections. Ex-pression of other aMPV-A or -B virus immunogenic protein(s) individually or in conjunction with the G protein may be necessary to induce stronger and more protective immunity against aMPV diseases.展开更多
用测定新城疫病毒(NDV)毒力的经典方法,即鸡胚平均死亡时间(MDT)和脑内接种致病指数(ICPI),对源于鸡、鸽、鹅、珍珠鸡、孔雀、鹌鹑和画眉鸟等7种禽(鸟)源的共14个禽Ⅰ型副粘病毒(APMV 1)广西分离株,分别测定了毒力。同时对分离株F基因...用测定新城疫病毒(NDV)毒力的经典方法,即鸡胚平均死亡时间(MDT)和脑内接种致病指数(ICPI),对源于鸡、鸽、鹅、珍珠鸡、孔雀、鹌鹑和画眉鸟等7种禽(鸟)源的共14个禽Ⅰ型副粘病毒(APMV 1)广西分离株,分别测定了毒力。同时对分离株F基因的N 端前段和HN基因的C 末端片段进行扩增、测序和分析,并绘制系谱树。结果发现,分离株的MDT在36h～75h之间,除1株鸽源毒株gxp22的ICPI值为0外,其余分离株在1 09～1 95之间;除孔雀源的分离株gxpc52在F基因裂解位点附近的氨基酸序列为112R R Q R R F117之外,其它13株均为112R R Q K R F117,都符合强毒株的特征。所有分离株与国内参考强毒株F48E8和国外参考强毒株HER/33在HN基因C 末端终止密码子的位置相同,也符合强毒株的特征。根据F基因核苷酸序列绘制的系谱树发现,近几年来在广西流行的APMV 1毒株的基因型为Ⅶd亚型;根据HN基因核苷酸序列绘制的系谱树表明,广西各种禽源AP MV 1分离株可分为2个群。研究的结果表明,根据F基因裂解位点附近的氨基酸序列和HN蛋白翻译的终止密码子的位置判定APMV 1毒力的结果,都与毒株在临床上的致病情况相符。因此,根据F基因和HN基因序列和结构的特征,均可以判定APMV 1临床分离株的体内致病性。展开更多
利用Primer Explorer V4在线软件设计针对B亚型禽偏肺病毒(aMPV)F基因的特异性引物,并从反应时间、温度、各组分浓度等方面优化了反应体系和反应条件,建立了B亚型aMPV逆转录环介导等温核酸扩增(RT-LAMP)快速检测方法。该方法能够在63℃...利用Primer Explorer V4在线软件设计针对B亚型禽偏肺病毒(aMPV)F基因的特异性引物,并从反应时间、温度、各组分浓度等方面优化了反应体系和反应条件,建立了B亚型aMPV逆转录环介导等温核酸扩增(RT-LAMP)快速检测方法。该方法能够在63℃条件下1h内实现B亚型aMPV F基因片段的特异性扩增,与其他病毒,如H9N2亚型禽流感病毒(AIV)、新城疫病毒(NDV)、传染性支气管炎病毒(IBV)、传染性法氏囊病病毒(IBDV)等的核酸无交叉反应。反应结果可直接用肉眼判断。对质粒DNA的最小检测量为1×102拷贝/μL。利用建立的检测方法对20份疑似aMPV样品进行检测,其阳性检出率为10%。结果表明,建立的B亚型aMPV RT-LAMP检测方法具有快速、准确、特异性强、灵敏度高的特点,可应用于相关疾病的临床诊断。展开更多
文摘Avian metapneumovirus (aMPV) and Newcastle disease virus (NDV) are threatening avian pathogens that can cause serious respiratory diseases in poultry worldwide. Vaccination, combined with strict biosecurity practices, has been the recommendation for controlling these diseases in the field. In the present study, we generated NDV LaSota vaccine strain-based recombinant viruses expressing the glycoprotein (G) of aMPV, subtype A or B, using reverse genetics technology. These recombinant viruses, rLS/aMPV-A G and rLS/aMPV-B G, were characterized in cell cultures and evaluated in turkeys as bivalent, next-generation vaccines. The results showed that these recombinant vaccine candi-dates were slightly attenuated in vivo, yet maintained similar growth dynamics, cytopathic effects, and virus titers in vitro when compared to the parental LaSota virus. The expression of the aMPV G protein in recombinant virus-infected cells was detected by immunofluorescence. Vaccination of turkeys with rLS/aMPV-A G or rLS/aMPV-B G conferred complete protection against velogenic NDV, CA02 strain challenge and partial protection against homologous patho-genic aMPV challenge. These results suggest that the LaSota recombinant virus is a safe and effective vaccine vector and expression of the G protein alone is not sufficient to provide full protection against aMPV-A or -B infections. Ex-pression of other aMPV-A or -B virus immunogenic protein(s) individually or in conjunction with the G protein may be necessary to induce stronger and more protective immunity against aMPV diseases.
文摘用测定新城疫病毒(NDV)毒力的经典方法,即鸡胚平均死亡时间(MDT)和脑内接种致病指数(ICPI),对源于鸡、鸽、鹅、珍珠鸡、孔雀、鹌鹑和画眉鸟等7种禽(鸟)源的共14个禽Ⅰ型副粘病毒(APMV 1)广西分离株,分别测定了毒力。同时对分离株F基因的N 端前段和HN基因的C 末端片段进行扩增、测序和分析,并绘制系谱树。结果发现,分离株的MDT在36h～75h之间,除1株鸽源毒株gxp22的ICPI值为0外,其余分离株在1 09～1 95之间;除孔雀源的分离株gxpc52在F基因裂解位点附近的氨基酸序列为112R R Q R R F117之外,其它13株均为112R R Q K R F117,都符合强毒株的特征。所有分离株与国内参考强毒株F48E8和国外参考强毒株HER/33在HN基因C 末端终止密码子的位置相同,也符合强毒株的特征。根据F基因核苷酸序列绘制的系谱树发现,近几年来在广西流行的APMV 1毒株的基因型为Ⅶd亚型;根据HN基因核苷酸序列绘制的系谱树表明,广西各种禽源AP MV 1分离株可分为2个群。研究的结果表明,根据F基因裂解位点附近的氨基酸序列和HN蛋白翻译的终止密码子的位置判定APMV 1毒力的结果,都与毒株在临床上的致病情况相符。因此,根据F基因和HN基因序列和结构的特征,均可以判定APMV 1临床分离株的体内致病性。
文摘利用Primer Explorer V4在线软件设计针对B亚型禽偏肺病毒(aMPV)F基因的特异性引物,并从反应时间、温度、各组分浓度等方面优化了反应体系和反应条件,建立了B亚型aMPV逆转录环介导等温核酸扩增(RT-LAMP)快速检测方法。该方法能够在63℃条件下1h内实现B亚型aMPV F基因片段的特异性扩增,与其他病毒,如H9N2亚型禽流感病毒(AIV)、新城疫病毒(NDV)、传染性支气管炎病毒(IBV)、传染性法氏囊病病毒(IBDV)等的核酸无交叉反应。反应结果可直接用肉眼判断。对质粒DNA的最小检测量为1×102拷贝/μL。利用建立的检测方法对20份疑似aMPV样品进行检测,其阳性检出率为10%。结果表明,建立的B亚型aMPV RT-LAMP检测方法具有快速、准确、特异性强、灵敏度高的特点,可应用于相关疾病的临床诊断。
