tetano
Editor, Senior Moderator
Infect Genet Evol. 2019 Nov 21:104117. doi: 10.1016/j.meegid.2019.104117. [Epub ahead of print] [h=1]Genetic and antigenic characterization of the first H7N7 low pathogenic avian influenza viruses isolated in Vietnam.[/h]
Le KT[SUP]1[/SUP], Okamatsu M[SUP]1[/SUP], Nguyen LT[SUP]2[/SUP], Matsuno K[SUP]3[/SUP], Chu DH[SUP]4[/SUP], Tien TN[SUP]5[/SUP], Le TT[SUP]6[/SUP], Kida H[SUP]7[/SUP], Sakoda Y[SUP]8[/SUP].
[h=3]Author information[/h] 1 Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kitaku, Sapporo, Hokkaido 060-0818, Japan. 2 Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kitaku, Sapporo, Hokkaido 060-0818, Japan; Department of Veterinary Medicine, College of Agriculture, Can Tho University, Can Tho 900000, Viet Nam. 3 Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kitaku, Sapporo, Hokkaido 060-0818, Japan; Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido 001-0020, Japan. 4 Department of Animal Health, Ministry of Agriculture and Rural Development, Ha Noi 115-19, Viet Nam. 5 Regional Animal Health Office VII, Department of Animal Health, Ministry of Agriculture and Rural Development, Can Tho 900000, Viet Nam. 6 Sub-Departments of Animal Health, Ministry of Agriculture and Rural Development, Vinh Long 890000, Viet Nam. 7 Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido 001-0020, Japan; Research Center for Zoonosis Control, Hokkaido University, Kita-20 Nishi-10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan. 8 Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kitaku, Sapporo, Hokkaido 060-0818, Japan; Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido 001-0020, Japan. Electronic address: sakoda@vetmed.hokudai.ac.jp.
[h=3]Abstract[/h] During the annual surveillance of avian influenza viruses (AIVs) in Vietnam in 2018, three H7N7 AIV isolates were identified in domestic ducks in a single flock in Vinh Long province. The present study is the first documented report of H7N7 virus isolates in Vietnam and aimed to characterize these viruses, both genetically and antigenically. Deduced amino acid sequences for the hemagglutinins (HAs) indicated a low pathogenicity of these viruses in chickens. Phylogenetic analysis revealed that the H7 HA genes of these isolates were closely related to each other and belonged to the European-Asian sublineage, together with those of H7N3 viruses isolated from ducks in Cambodia during 2017. They were not genetically related to those of Chinese H7N9 or H7N1 viruses that were previously detected in Vietnam during 2012. Interestingly, the M genes of the two H7N7 virus isolates were phylogenetically classified into distinct groups, suggesting an ongoing reassortment event in domestic ducks because they were isolated from the same flock. These H7N7 viruses exhibited somewhat different antigenic characteristics compared with other representative H7 low pathogenic AIVs. Surprisingly, the antigenicity of Vietnamese H7N7 viruses is similar to Chinese H7N9 highly pathogenic AIV. The findings of this study suggest that H7N7 viruses may be undergoing reassortment and antigenic diversification in poultry flocks in Vietnam. The silent spread of Vietnamese H7N7 viruses in chickens may lead to acquire high pathogenicity in chickens although the zoonotic potential of the viruses seems to be low since these viruses retain typical avian-specific motifs in the receptor-binding site in the HA and there is no mutation related to mammalian adaptation in PB2 gene. Thus, these results highlight the need for continuous and intensive surveillance of avian influenza in Vietnam, targeting not only highly pathogenic AIVs but also low pathogenic viruses.
Copyright ? 2018. Published by Elsevier B.V.
[h=4]KEYWORDS:[/h] Antigenicity; Genetics; H7 avian influenza virus; Vietnam
PMID: 31760087 DOI: 10.1016/j.meegid.2019.104117
Le KT[SUP]1[/SUP], Okamatsu M[SUP]1[/SUP], Nguyen LT[SUP]2[/SUP], Matsuno K[SUP]3[/SUP], Chu DH[SUP]4[/SUP], Tien TN[SUP]5[/SUP], Le TT[SUP]6[/SUP], Kida H[SUP]7[/SUP], Sakoda Y[SUP]8[/SUP].
[h=3]Author information[/h] 1 Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kitaku, Sapporo, Hokkaido 060-0818, Japan. 2 Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kitaku, Sapporo, Hokkaido 060-0818, Japan; Department of Veterinary Medicine, College of Agriculture, Can Tho University, Can Tho 900000, Viet Nam. 3 Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kitaku, Sapporo, Hokkaido 060-0818, Japan; Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido 001-0020, Japan. 4 Department of Animal Health, Ministry of Agriculture and Rural Development, Ha Noi 115-19, Viet Nam. 5 Regional Animal Health Office VII, Department of Animal Health, Ministry of Agriculture and Rural Development, Can Tho 900000, Viet Nam. 6 Sub-Departments of Animal Health, Ministry of Agriculture and Rural Development, Vinh Long 890000, Viet Nam. 7 Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido 001-0020, Japan; Research Center for Zoonosis Control, Hokkaido University, Kita-20 Nishi-10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan. 8 Laboratory of Microbiology, Faculty of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kitaku, Sapporo, Hokkaido 060-0818, Japan; Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido 001-0020, Japan. Electronic address: sakoda@vetmed.hokudai.ac.jp.
[h=3]Abstract[/h] During the annual surveillance of avian influenza viruses (AIVs) in Vietnam in 2018, three H7N7 AIV isolates were identified in domestic ducks in a single flock in Vinh Long province. The present study is the first documented report of H7N7 virus isolates in Vietnam and aimed to characterize these viruses, both genetically and antigenically. Deduced amino acid sequences for the hemagglutinins (HAs) indicated a low pathogenicity of these viruses in chickens. Phylogenetic analysis revealed that the H7 HA genes of these isolates were closely related to each other and belonged to the European-Asian sublineage, together with those of H7N3 viruses isolated from ducks in Cambodia during 2017. They were not genetically related to those of Chinese H7N9 or H7N1 viruses that were previously detected in Vietnam during 2012. Interestingly, the M genes of the two H7N7 virus isolates were phylogenetically classified into distinct groups, suggesting an ongoing reassortment event in domestic ducks because they were isolated from the same flock. These H7N7 viruses exhibited somewhat different antigenic characteristics compared with other representative H7 low pathogenic AIVs. Surprisingly, the antigenicity of Vietnamese H7N7 viruses is similar to Chinese H7N9 highly pathogenic AIV. The findings of this study suggest that H7N7 viruses may be undergoing reassortment and antigenic diversification in poultry flocks in Vietnam. The silent spread of Vietnamese H7N7 viruses in chickens may lead to acquire high pathogenicity in chickens although the zoonotic potential of the viruses seems to be low since these viruses retain typical avian-specific motifs in the receptor-binding site in the HA and there is no mutation related to mammalian adaptation in PB2 gene. Thus, these results highlight the need for continuous and intensive surveillance of avian influenza in Vietnam, targeting not only highly pathogenic AIVs but also low pathogenic viruses.
Copyright ? 2018. Published by Elsevier B.V.
[h=4]KEYWORDS:[/h] Antigenicity; Genetics; H7 avian influenza virus; Vietnam
PMID: 31760087 DOI: 10.1016/j.meegid.2019.104117