281 The outbreak of the novel H1N1 influenza A, which began in Mexico, has attracted global attention due to the initial high mortality rate and rapid spread since April 2009. Zoonotic infection from pig to human was initially considered as most of the infected cases in Mexico had a history of close contact with pigs. By genotyping and sequencing the causative virus, it was found that the candi...

We used the neonatal mouse model of rotavirus infection and virus strains SA11-clone 4 (SA11-Cl4) and Rhesus rotavirus (RRV) to examine the mechanism of the extraintestinal spread of viruses following oral inoculation. The spread-competent viruses, RRV and reassortant R7, demonstrated a temporal progression from the intestine, to the terminal ileum, to the mesenteric lymph nodes (MLN), and to t...

From 2014 to 2015, three cases of highly pathogenic avian influenza infection occurred in zoo-housed north-east China tigers (Panthera tigris ssp.altaica) and four tigers died of respiratory distress in succession in Yunnan Province, China. We isolated and characterized three highly pathogenic avian influenza A(H5N1) viruses from these tigers. Phylogenetic analysis indicated that A/tiger /Yunna...

The application of a rapid and direct proteotyping approach with which to identify the gene origin of viral antigens in a reassortant influenza strain is demonstrated. The reassortant strain, constructed for a vaccine against type A 2009 H1N1 pandemic influenza, contains genes derived from a wild-type pandemic strain (A/California/7/2009) and an egg adapted high-growth strain (denoted NYMC X-15...

Two candidate formalin-inactivated vaccines, made from high-growth reassortant viruses with the HA and NA genes from avian viruses in a background of genes derived from A/Puerto Rico/8/34 (PR8), were prepared against H5N1 and H9N2 subtypes (designated as H5N1/PR8 and H9N2/PR8, respectively). These viruses bear the genotypes, antigenicity, and attenuation in mouse models that are desirable in ca...

On 11 June 2009, the World Health Organization declared the first human influenza pandemic since 1968–1969. The responsible virus, pandemic (H1N1) 2009 influenza, is a novel triple-reassortant influenza A virus, incorporating avian, swine and human influenza genes.1 The virus is resistant to the anti-influenza medications, amantadine and rimantadine, but is generally sensitive to the neuraminid...

Given the present extensive co-circulation in pigs of Eurasian avian-like (EA) swine H1N1 and 2009 pandemic (pdm/09) H1N1 viruses, reassortment between them is highly plausible but largely uncharacterized. Here, experimentally co-infected pigs with a representative EA virus and a pdm/09 virus yielded 55 novel reassortant viruses that could be categorized into 17 genotypes from Gt1 to Gt17 based...

Triple-reassortant swine influenza viruses circulating in North American pigs contain the internal genes derived from swine (matrix, non-structural and nucleoprotein), human [polymerase basic 1 (PB1)] and avian (polymerase acidic and PB2) influenza viruses forming a constellation of genes that is well conserved and is called the triple-reassortant internal gene (TRIG) cassette. In contrast, the...

An avian influenza virus strain, A/domestic green-winged teal/Hunan/2036/2007(H3N6) (DGW-T2036), was isolated from healthy domestic green-winged teals (Anas crecca) in Hunan Province, South China. All eight gene segments of the isolate were sequenced. Genomic analysis demonstrated that this H3N6 virus is a novel reassortant avian influenza virus with a gene constellation originating from multip...

A reassortant clade 2.3.4.4 avian influenza A(H5N6) virus was isolated from a fecal sample of a Mandarin duck (Aix galericulata) in South Korea during October 2016. This virus was genetically similar to H5N6 subtype virus isolates from China, Vietnam, Laos, and Hong Kong, including human isolates.