Testing the Effect of Internal Genes Derived from a Wild-Bird-Origin H9N2 Influenza A Virus on the Pathogenicity of an A/H7N9 Virus.
Since 2013, avian influenza A(H7N9) viruses have diversified into multiple lineages by dynamically reassorting with other viruses, especially H9N2, in Chinese poultry. Despite concerns about the pandemic threat posed by H7N9 viruses, little is known about the biological properties of H7N9 viruses that may recruit internal genes from genetically distinct H9N2 viruses circulating among wild birds. Here, we generated 63 H7N9 reassortants derived from an avian H7N9 and a wild-bird-origin H9N2 virus. Compared with the wild-type parent, 25/63 reassortants had increased pathogenicity in mice. A reassortant containing PB1 of the H9N2 virus was highly lethal to mice and chickens but was not transmissible to guinea pigs by airborne routes; however, three substitutions associated with adaptation to mammals conferred airborne transmission to the virus. The emergence of the H7N9-pandemic reassortant virus highlights that continuous monitoring of H7N9 viruses is needed, especially at the domestic poultry/wild bird interface.
National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Beijing 100101, China.
Wen
W
Su
National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Chengmin
C
Wang
National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Jing
J
Luo
National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Yuliang
Y
Zhao
Department of Infectious Diseases, Hangzhou Center for Disease Control and Prevention, Hangzhou, Zhejiang 310021, China.
Yan
Y
Wu
National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Beijing 100101, China.
Lin
L
Chen
National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Beijing 100101, China.
Na
N
Zhao
National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Beijing 100101, China.
Meng
M
Li
National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Chao
C
Xing
National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Huimin
H
Liu
National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Hong
H
Zhang
Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University Ithaca, NY 14853-5786, USA.
Yung-fu
YF
Chang
State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071, China.
Tianxian
T
Li
Department of Infectious Diseases, Hangzhou Center for Disease Control and Prevention, Hangzhou, Zhejiang 310021, China.
Hua
H
Ding
Department of Basic Sciences, College of Veterinary Medicine, and Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA.
Xiufeng
X
Wan
National Research Center for Wildlife Born Diseases, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: hehx@ioz.ac.cn.
Hongxuan
H
He
D000818:Animals; D002645:Chickens; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D064766:Influenza A Virus, H7N9 Subtype / Q000235:genetics* / Q000472:pathogenicity*; D053127:Influenza A Virus, H9N2 Subtype / Q000235:genetics* / Q000472:pathogenicity; D005585:Influenza in Birds / Q000821:virology; D007251:Influenza, Human / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009976:Orthomyxoviridae Infections / Q000821:virology; D010802:Phylogeny