Genetic and antigenic characterization of the first H7N7 low pathogenic avian influenza viruses isolated in Vietnam

被引：6

作者：

Le, Kien Trung ^{[1
]}

Okamatsu, Masatoshi ^{[1
]}

Lam Thanh Nguyen ^{[1
,2
]}

Matsuno, Keita ^{[1
,3
]}

Duc-Huy Chu ^{[4
]}

Tien Ngoc Tien ^{[5
]}

Tung Thanh Le ^{[6
]}

Kida, Hiroshi ^{[3
,7
]}

Sakoda, Yoshihiro ^{[1
,3
]}

机构：

[1] Hokkaido Univ, Fac Vet Med, Lab Microbiol, Kita Ku, Kita 18 Nishi 9, Sapporo, Hokkaido 0600818, Japan

[2] Can Tho Univ, Coll Agr, Dept Vet Med, Can Tho 900000, Vietnam

[3] Hokkaido Univ, Global Inst Collaborat Res & Educ GI CoRE, Sapporo, Hokkaido 0010020, Japan

[4] Minist Agr & Rural Dev, Dept Anim Hlth, Hanoi 11519, Vietnam

[5] Minist Agr & Rural Dev, Dept Anim Hlth, Reg Anim Hlth Off 7, Can Tho 900000, Vietnam

[6] Minist Agr & Rural Dev, Subdept Anim Hlth, Vinh Long 890000, Vietnam

[7] Hokkaido Univ, Res Ctr Zoonosis Control, Kita Ku, Kita 20 Nishi 10, Sapporo, Hokkaido 0010020, Japan

来源：

INFECTION GENETICS AND EVOLUTION | 2020年 / 78卷

基金：

日本学术振兴会;

关键词：

H7 avian influenza virus; Vietnam; Genetics; Antigenicity; A VIRUS; DOMESTIC DUCKS; A(H7N9) VIRUS; HEMAGGLUTININ; DETERMINANTS; OUTBREAKS; HOKKAIDO; CAMBODIA; JAPAN; H5;

D O I：

10.1016/j.meegid.2019.104117

中图分类号：

R51 [传染病];

学科分类号：

100401 ;

摘要：

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.

引用

页数：8