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Cell Res. 2017 Oct 24. doi: 10.1038/cr.2017.129. [Epub ahead of print]
H7N9 virulent mutants detected in chickens in China pose an increased threat to humans.
Shi J1, Deng G1, Kong H1, Gu C1, Ma S1, Yin X1, Zeng X1, Cui P1, Chen Y1, Yang H1, Wan X1, Wang X1, Liu L1, Chen P1, Jiang Y1, Liu J1, Guan Y1, Suzuki Y2, Li M1, Qu Z1, Guan L1, Zang J1, Gu W1, Han S1, Song Y1, Hu Y1, Wang Z1, Gu L1, Yang W1, Liang L1, Bao H1, Tian G1, Li Y1, Qiao C1, Jiang L1, Li C1, Bu Z1, Chen H1.
Author information
Abstract
Certain low pathogenic avian influenza viruses can mutate to highly pathogenic viruses when they circulate in domestic poultry, at which point they can cause devastating poultry diseases and severe economic damage. The H7N9 influenza viruses that emerged in 2013 in China had caused severe human infections and deaths. However, these viruses were nonlethal in poultry. It is unknown whether the H7N9 viruses can acquire additional mutations during their circulation in nature and become lethal to poultry and more dangerous for humans. Here, we evaluated the evolution of H7N9 viruses isolated from avian species between 2013 and 2017 in China and found 23 different genotypes, 7 of which were detected only in ducks and were genetically distinct from the other 16 genotypes that evolved from the 2013 H7N9 viruses. Importantly, some H7N9 viruses obtained an insertion of four amino acids in their hemagglutinin (HA) cleavage site and were lethal in chickens. The index strain was not lethal in mice or ferrets, but readily obtained the 627K or 701N mutation in its PB2 segment upon replication in ferrets, causing it to become highly lethal in mice and ferrets and to be transmitted efficiently in ferrets by respiratory droplet. H7N9 viruses bearing the HA insertion and PB2 627K mutation have been detected in humans in China. Our study indicates that the new H7N9 mutants are lethal to chickens and pose an increased threat to human health, and thus highlights the need to control and eradicate the H7N9 viruses to prevent a possible pandemic.Cell Research advance online publication 24 October 2017; doi:10.1038/cr.2017.129.
PMID: 29151586 DOI: 10.1038/cr.2017.129
H7N9 virulent mutants detected in chickens in China pose an increased threat to humans.
Shi J1, Deng G1, Kong H1, Gu C1, Ma S1, Yin X1, Zeng X1, Cui P1, Chen Y1, Yang H1, Wan X1, Wang X1, Liu L1, Chen P1, Jiang Y1, Liu J1, Guan Y1, Suzuki Y2, Li M1, Qu Z1, Guan L1, Zang J1, Gu W1, Han S1, Song Y1, Hu Y1, Wang Z1, Gu L1, Yang W1, Liang L1, Bao H1, Tian G1, Li Y1, Qiao C1, Jiang L1, Li C1, Bu Z1, Chen H1.
Author information
Abstract
Certain low pathogenic avian influenza viruses can mutate to highly pathogenic viruses when they circulate in domestic poultry, at which point they can cause devastating poultry diseases and severe economic damage. The H7N9 influenza viruses that emerged in 2013 in China had caused severe human infections and deaths. However, these viruses were nonlethal in poultry. It is unknown whether the H7N9 viruses can acquire additional mutations during their circulation in nature and become lethal to poultry and more dangerous for humans. Here, we evaluated the evolution of H7N9 viruses isolated from avian species between 2013 and 2017 in China and found 23 different genotypes, 7 of which were detected only in ducks and were genetically distinct from the other 16 genotypes that evolved from the 2013 H7N9 viruses. Importantly, some H7N9 viruses obtained an insertion of four amino acids in their hemagglutinin (HA) cleavage site and were lethal in chickens. The index strain was not lethal in mice or ferrets, but readily obtained the 627K or 701N mutation in its PB2 segment upon replication in ferrets, causing it to become highly lethal in mice and ferrets and to be transmitted efficiently in ferrets by respiratory droplet. H7N9 viruses bearing the HA insertion and PB2 627K mutation have been detected in humans in China. Our study indicates that the new H7N9 mutants are lethal to chickens and pose an increased threat to human health, and thus highlights the need to control and eradicate the H7N9 viruses to prevent a possible pandemic.Cell Research advance online publication 24 October 2017; doi:10.1038/cr.2017.129.
PMID: 29151586 DOI: 10.1038/cr.2017.129