Characterization of H10-H12 subtypes avian influenza virus isolated from
wild birds in Shanghai, China, 2016 to 2019
Abstract
The H10-H12 subtypes are designated as the “waterfowl-associated”
subtypes and are not frequently detected in nature, but these viruses
can highly reassort with other subtypes of AIVs. It has shown that very
few H10-H12 subtypes were isolated from wild birds in China, it is
essential to conduct the extensive surveillance of these rare subtypes
in wild birds to narrow this knowledge gap in this region. In this
study, 12 AIVs of H10-H12 subtypes were identified with the routine
surveillance in wild birds in Shanghai, China from 2016 to 2019. There
were 2 H10 subtypes, 3 H11 subtypes and 7 H12 subtypes, and the HA-NA
combinations were H10N4, H11N2, H11Nx, H11N9, H12N2, H12N5 and H12N8.
Sequence and phylogenetic analysis showed these gene segments of the 12
strains had high levels of genetic diversity among them, and most of
them were closely related to the Eurasian lineage, and shared high
sequence identity with those isolated from wild birds and domestic ducks
in Japan, Korea, Bangladesh, Vietnam and China located at the East
Asian-Australasian Flyway route. However, part of the gene segments of
the two H12N2 strains (NH112319-H12N2 and NH101807-H12N2) were belonged
to the North American lineage, which indicated that the gene flow and
reassortment had occured between the Eurasian and American lineages in
H12 subtypes. To better understand the ecological and phylodynamic
features of these H10-H12 subtypes in wild birds, it is necessary to
continuously conduct large-scale surveillance of wild birds in future.