Since 30 March 2013,the Chinese Center for Disease Control and Prevention(China CDC)has reported the first laboratory-confirmed cases of influenza A H7N9 virus human infection.This new pathogen caused 144 human infect...Since 30 March 2013,the Chinese Center for Disease Control and Prevention(China CDC)has reported the first laboratory-confirmed cases of influenza A H7N9 virus human infection.This new pathogen caused 144 human infections with 47 fatal cases in year 2013,and continued to bring another wave in 2014,caused another 273 infections with 108deaths as of 27th April.The H7N9 influenza virus has again raised the global concerns of the potential pandemics.Studies of the origin and evolution of this virus revealed that the novel H7N9 influenza virus was reassorted from H7,N9and H9N2 subtypes of influenza viruses from domestic ducks,wild waterfowls and poultry,respectively;and the processes of genetic reassortments were sequential and dynamic[1?3].展开更多
Although worldwide concern has been raised since the large-scale outbreak of highly pathogenic avian influenza in wild birds at Qinghai Lake,China in 2005,the factors responsible for the ability to kill waterfowl rema...Although worldwide concern has been raised since the large-scale outbreak of highly pathogenic avian influenza in wild birds at Qinghai Lake,China in 2005,the factors responsible for the ability to kill waterfowl remain unclear. The why and how questions of the H5N1 virus species-jump into its reservoir host need to be answered. In this report we test the pathogenicity and adaptation of Qinghai Lake (Clade 2.2) isolate to Muscovy ducks for further understanding of this virus. The isolate was highly pathogenic in ducks and retained its high pathogenicity even after 20 generations of passage in ducks. During the process of serial passages,only the NS gene developed non-synonymous substitutions,which caused two mutations in NS1 protein (Val23Ala and Leu207Pro) and one in NS2 (Phe55Leu). These mutations persisted immutably through all subsequent passages and the pathogenicity remained high,implying that highly pathogenic H5N1 virus remains stable in aquatic birds through oral transmission. Although the exact functions of these mutations are not known,our results provide an important foundation for further understanding the characteristics of the Qinghai Lake isolates.展开更多
文摘Since 30 March 2013,the Chinese Center for Disease Control and Prevention(China CDC)has reported the first laboratory-confirmed cases of influenza A H7N9 virus human infection.This new pathogen caused 144 human infections with 47 fatal cases in year 2013,and continued to bring another wave in 2014,caused another 273 infections with 108deaths as of 27th April.The H7N9 influenza virus has again raised the global concerns of the potential pandemics.Studies of the origin and evolution of this virus revealed that the novel H7N9 influenza virus was reassorted from H7,N9and H9N2 subtypes of influenza viruses from domestic ducks,wild waterfowls and poultry,respectively;and the processes of genetic reassortments were sequential and dynamic[1?3].
基金Supported by the National Natural Science Foundation of China (Grant No. 30599434)the National Basic Research Program of China (Grant No. 2005CB523001)+1 种基金a grant from NIH (Grant No. 3U19AI051915-05S1)GFG is a distinguished young investigator of the NSFC (Grant No. 30525010)
文摘Although worldwide concern has been raised since the large-scale outbreak of highly pathogenic avian influenza in wild birds at Qinghai Lake,China in 2005,the factors responsible for the ability to kill waterfowl remain unclear. The why and how questions of the H5N1 virus species-jump into its reservoir host need to be answered. In this report we test the pathogenicity and adaptation of Qinghai Lake (Clade 2.2) isolate to Muscovy ducks for further understanding of this virus. The isolate was highly pathogenic in ducks and retained its high pathogenicity even after 20 generations of passage in ducks. During the process of serial passages,only the NS gene developed non-synonymous substitutions,which caused two mutations in NS1 protein (Val23Ala and Leu207Pro) and one in NS2 (Phe55Leu). These mutations persisted immutably through all subsequent passages and the pathogenicity remained high,implying that highly pathogenic H5N1 virus remains stable in aquatic birds through oral transmission. Although the exact functions of these mutations are not known,our results provide an important foundation for further understanding the characteristics of the Qinghai Lake isolates.
