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Avian orthoavulavirus 13 (AOAV-13), also named avian paramyxovirus 13 (APMV-13), has been found sporadically in wild birds around the world ever since the discovery of AOAV-13 (AOAV-13/wild goose/Shimane/67/2000) in a wild goose from Japan in 2000. However, there are no reports of AOAV-13 in China. In the present study, a novel AOAV-13 virus (AOAV-13/wild goose/China/Hubei/V93-1/2015), isolated from a wild migratory waterfowl in a wetland of Hubei province of China, during active surveillance from 2013 to 2018, was biologically and genetically characterized. Phylogenetic analyses demonstrated a very close genetic relationship among all AOAV-13 strains, as revealed by very few genetic variations. Moreover, pathogenicity tests indicated that the V93-1 strain is a low virulent virus for chickens. However, the genome of the V93-1 virus was found to be 16,158 nucleotides (nt) in length, which is 12 nt or 162 nt longer than the other AOAV-13 strains that have been reported to date. The length difference of 12 nt in strain V93-1 is due to the existence of three repeats of the conserved sequence, "AAAAAT", in the 5′-end trailer of the genome. Moreover, the HN gene of the V93-1 virus is 2070 nt in size, encoding 610 aa, which is the same size as the AOAV-13 strain from Japan, whereas that of two strains from Ukraine and Kazakhstan are 2080 nt in length, encoding 579 aa. We describe a novel AOAV-13 in migratory waterfowl in China, which suggests that diversified trailer region sequences and HN gene lengths exist within serotype AOAV-13, and highlight the need for its constant surveillance in poultry from live animal markets, and especially migratory birds. [ABSTRACT FROM AUTHOR]

[Display omitted] Migratory birds are considered natural reservoirs of avian influenza A viruses (AIVs). To further our viral ecology knowledge and understand the subsequent risk posed by wild birds, we conducted a 4-year surveillance study of AIVs in the bird wintering wetlands of the Yangtze River, China. We collected over 8000 samples and isolated 122 AIV strains. Analyses were then carried out with 108 novel sequenced genomes and data were deposited in GISAID and other public databases. The results showed that the Yangtze River wintering wetlands functioned as a mixing ground, where various subtypes of AIVs were detected harboring a high diversity of nucleotide sequences; moreover, a portion of AIV gene segments were persistent inter-seasonally. Phylogenetic incongruence presented complex reassortment events and distinct patterns among various subtypes. In addition, we observed that viral gene segments in wintering wetlands were closely related to known North American isolates, indicating that intercontinental gene flow occurred. Notably, highly pathogenic H5 and low pathogenic H9 viruses, which usually circulate in poultry, were found to have crossed the poultry/wild bird interface, with the viruses introduced to wintering birds. Overall, this study represented the largest AIV surveillance effort of wild birds within the Yangtze River wintering wetlands. Surveillance data highlighted the important role of wintering wild birds in the ecology of AIVs and may enable future early warnings of novel AIV emergence. [ABSTRACT FROM AUTHOR]

Abstract: Historical geological events and climatic changes are believed to have played important roles in shaping the current distribution of species. However, sympatric species may have responded in different ways to such climatic fluctuations. Here we compared genetic structures of two corvid species, the Azure-winged Magpie Cyanopica cyanus and the Eurasian Magpie Pica pica, both widespread but with different habitat dependence and some aspects of breeding behavior. Three mitochondrial genes and two nuclear introns were used to examine their co-distributed populations in East China and the Iberian Peninsula. Both species showed deep divergences between these two regions that were dated to the late Pliocene/early Pleistocene. In the East Chinese clade of C. cyanus, populations were subdivided between Northeast China and Central China, probably since the early to mid-Pleistocene, and the Central subclade showed a significant pattern of isolation by distance. In contrast, no genetic structure was found in the East China populations of P. pica. We suggest that the different patterns in the two species are at least partly explained by ecological differences between them, especially in habitat preference and perhaps also breeding behavior. These dissimilarities in life history traits might have affected the dispersal and survival abilities of these two species differently during environmental fluctuations. [Copyright &y& Elsevier]

To discover sources for novel anti-influenza drugs, we evaluated the antiviral potential of nine extracts from eight medicinal plants and one mushroom ( Avena sativa L., Hordeum vulgare Linn. var. nudum Hook. f., Hippophae rhamnoides Linn., Lycium ruthenicum Murr., Nitraria tangutorum Bobr., Nitraria tangutorum Bobr. by-products, Potentilla anserina L., Cladina rangiferina (L.) Nyl., and Armillaria luteo-virens ) from the Qinghai-Tibetan plateau against the influenza A/H3N2 virus. Concentrations lower than 125 μg/mL of all extracts demonstrated no significant toxicity in MDCK cells. During screening, seven extracts ( A. sativa , H. vulgare , H. rhamnoides , L. ruthenicum , N. tangutorum , C. rangiferina , and A. luteo-virens ) exhibited antiviral activity, especially the water-soluble polysaccharide from the fruit body of the mushroom A. luteo-virens . These extracts significantly reduced the infectivity of the human influenza A/H3N2 virus in vitro when used at concentrations of 15.6-125 μg/mL. Two extracts ( N. tangutorum by-products and P. anserina ) had no A/H3N2 virus inhibitory activity. Notably, the extract obtained from the fruits of N. tangutorum and N. tangutorum by-products exhibited different anti-influenza effects. The results suggest that extracts of A. sativa , H. vulgare , H. rhamnoides , L. ruthenicum , N. tangutorum , C. rangiferina , and A. luteo-virens contain substances with antiviral activity, and may be promising sources of new antiviral drugs.

We have surveyed avian influenza virus (AIV) genomes from live poultry markets within China since 2014. Here we present a total of 16,091 samples that were collected from May 2016 to February 2019 in 23 provinces and municipalities in China. We identify 2048 AIV-positive samples and perform next generation sequencing. AIV-positive rates (12.73%) from samples had decreased substantially since 2016, compared to that during 2014-2016 (26.90%). Additionally, H9N2 has replaced H5N6 and H7N9 as the dominant AIV subtype in both chickens and ducks. Notably, novel reassortants and variants continually emerged and disseminated in avian populations, including H7N3, H9N9, H9N6 and H5N6 variants. Importantly, almost all of the H9 AIVs and many H7N9 and H6N2 strains prefer human-type receptors, posing an increased risk for human infections. In summary, our nation-wide surveillance highlights substantial changes in the circulation of AIVs since 2016, which greatly impacts the prevention and control of AIVs in China and worldwide.