[Source: PLoS ONE, full page: (LINK). Abstract, edited.]
Open Access / Peer-Reviewed
Research Article
Origin and Characteristics of Internal Genes Affect Infectivity of the Novel Avian-Origin Influenza A (H7N9) Virus
Yan Feng, Haiyan Mao, Changping Xu, Jianmin Jiang, Yin Chen, Juying Yan, Jian Gao, Zhen Li, Shichang Xia, Yiyu Lu
Published: Nov 22, 2013 / DOI: 10.1371/journal.pone.0081136
Abstract
Background
Human infection with a novel avian-origin influenza A (H7N9) virus occurred continuously in China during the first half of 2013, with high infectivity and pathogenicity to humans. In this study, we investigated the origin of internal genes of the novel H7N9 virus and analyzed the relationship between internal genes and infectivity of the virus.
Methodology and Principal findings
We tested the environmental specimens using real-time RT-PCR assays and isolated five H9N2 viruses from specimens that were positive for both H7 and H9. Results of recombination and phylogeny analysis, performed based on the entire sequences of 221 influenza viruses, showed that one of the Zhejiang avian H9N2 isolates, A/environment/Zhejiang/16/2013, shared the highest identities on the internal genes with the novel H7N9 virus A/Anhui/1/2013, ranging from 98.98% to 100%. Zhejiang avian H9N2 isolates were all reassortant viruses, by acquiring NS gene from A/chicken/Dawang/1/2011-like viruses and other five internal genes from A/brambling/Beijing/16/2012-like viruses. Compared to A/Anhui/1/2013 (H7N9), the homology on the NS gene was 99.16% with A/chicken/Dawang/1/2011, whereas only 94.27-97.61% with A/bramnling/Beijing/16/2012-like viruses. Analysis on the relationship between internal genes and the infectivity of novel H7N9 viruses were performed by comparing amino acid sequences with the HPAI H5N1 viruses, the H9N2 and the earlier H7N9 avian influenza viruses. There were nine amino acids on the internal genes found to be possibly associated with the infectivity of the novel H7N9 viruses.
Conclusions
These findings indicate that the internal genes, sharing the highest similarities with A/environment/Zhejiang/16/2013-like (H9N2) viruses, may affect the infectivity of the novel H7N9 viruses.
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Citation: Feng Y, Mao H, Xu C, Jiang J, Chen Y, et al. (2013) Origin and Characteristics of Internal Genes Affect Infectivity of the Novel Avian-Origin Influenza A (H7N9) Virus. PLoS ONE 8(11): e81136. doi:10.1371/journal.pone.0081136
Editor: Matthias Johannes Schnell, Thomas Jefferson University, United States of America
Received: July 2, 2013; Accepted: October 18, 2013; Published: November 22, 2013
Copyright: ? 2013 Feng et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work was supported by the Key Medical Subjects Construction Project of Zhejiang Province (XKQ-009-003). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
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Open Access / Peer-Reviewed
Research Article
Origin and Characteristics of Internal Genes Affect Infectivity of the Novel Avian-Origin Influenza A (H7N9) Virus
Yan Feng, Haiyan Mao, Changping Xu, Jianmin Jiang, Yin Chen, Juying Yan, Jian Gao, Zhen Li, Shichang Xia, Yiyu Lu
Published: Nov 22, 2013 / DOI: 10.1371/journal.pone.0081136
Abstract
Background
Human infection with a novel avian-origin influenza A (H7N9) virus occurred continuously in China during the first half of 2013, with high infectivity and pathogenicity to humans. In this study, we investigated the origin of internal genes of the novel H7N9 virus and analyzed the relationship between internal genes and infectivity of the virus.
Methodology and Principal findings
We tested the environmental specimens using real-time RT-PCR assays and isolated five H9N2 viruses from specimens that were positive for both H7 and H9. Results of recombination and phylogeny analysis, performed based on the entire sequences of 221 influenza viruses, showed that one of the Zhejiang avian H9N2 isolates, A/environment/Zhejiang/16/2013, shared the highest identities on the internal genes with the novel H7N9 virus A/Anhui/1/2013, ranging from 98.98% to 100%. Zhejiang avian H9N2 isolates were all reassortant viruses, by acquiring NS gene from A/chicken/Dawang/1/2011-like viruses and other five internal genes from A/brambling/Beijing/16/2012-like viruses. Compared to A/Anhui/1/2013 (H7N9), the homology on the NS gene was 99.16% with A/chicken/Dawang/1/2011, whereas only 94.27-97.61% with A/bramnling/Beijing/16/2012-like viruses. Analysis on the relationship between internal genes and the infectivity of novel H7N9 viruses were performed by comparing amino acid sequences with the HPAI H5N1 viruses, the H9N2 and the earlier H7N9 avian influenza viruses. There were nine amino acids on the internal genes found to be possibly associated with the infectivity of the novel H7N9 viruses.
Conclusions
These findings indicate that the internal genes, sharing the highest similarities with A/environment/Zhejiang/16/2013-like (H9N2) viruses, may affect the infectivity of the novel H7N9 viruses.
_____
Citation: Feng Y, Mao H, Xu C, Jiang J, Chen Y, et al. (2013) Origin and Characteristics of Internal Genes Affect Infectivity of the Novel Avian-Origin Influenza A (H7N9) Virus. PLoS ONE 8(11): e81136. doi:10.1371/journal.pone.0081136
Editor: Matthias Johannes Schnell, Thomas Jefferson University, United States of America
Received: July 2, 2013; Accepted: October 18, 2013; Published: November 22, 2013
Copyright: ? 2013 Feng et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work was supported by the Key Medical Subjects Construction Project of Zhejiang Province (XKQ-009-003). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
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