Animals ; Birds ; China ; epidemiology ; Humans ; Influenza A Virus, H5N1 Subtype ; physiology ; Influenza A Virus, H7N7 Subtype ; physiology ; Influenza A Virus, H9N2 Subtype ; physiology ; Influenza A virus ; physiology ; Influenza, Human ; epidemiology ; prevention & control

The expression of the hemagglutinins of Avian influenza virus H5 H7and H9 subtypes was studied in this article by Pichia pastoris, one of the eukaryotis expression systems. Three reconstructed expression plasmids and engineering strains, named pPIC9K-H5HA, pPIC9K-H7HA, pPIC9K-H9HA and GS115/pPIC9K-H5HA, GS115/pPIC9K-H7HA, GS115/pPIC9K-H9HA repectively, were obtained. The reconstructed yeast engineering strains were identified by MD and MM plate selecting and PCR. The induced interests proteins were examined by SDS-PAGE and Western-bloting,the results showed that the interest genes were expressed exactly. And this will be helpful in the future study of antigen detection and antibody detection kit, as well in the subunit vaccines developing.
Animals ; Hemagglutinin Glycoproteins, Influenza Virus ; biosynthesis ; genetics ; Influenza A Virus, H5N1 Subtype ; genetics ; Influenza A Virus, H7N7 Subtype ; genetics ; Influenza A Virus, H9N2 Subtype ; genetics ; Pichia ; genetics ; metabolism

In 2013, two episodes of influenza emerged in China and caused worldwide concern. A new H7N9 avian influenza virus (AIV) first appeared in China on February 19, 2013. By August 31, 2013, the virus had spread to ten provinces and two metropolitan cities. Of 134 patients with H7N9 influenza, 45 died. From then on, epidemics emerged sporadically in China and resulted in several victims. On November 30, 2013, a 73-year-old woman presented with an influenza-like illness. She developed multiple organ failure and died 9 d after the onset of disease. A novel reassortant AIV, H10N8, was isolated from a tracheal aspirate specimen that was obtained from the patient 7 d after onset. This case was the first human case of influenza A subtype H10N8. On 4 February, 2014, another death due to H10N8 avian influenza was reported in Jiangxi Province, China.
Aged ; China ; epidemiology ; Female ; Humans ; Influenza A Virus, H10N8 Subtype ; classification ; Influenza A Virus, H7N9 Subtype ; classification ; Influenza A Virus, H9N2 Subtype ; classification ; Influenza, Human ; epidemiology ; virology ; Phylogeny ; Reassortant Viruses ; classification

Worldwide, avian influenza H9N2 viruses of different lineages are the most widespread viruses in poultry. However, to date, cases in Russia have not been documented. In this study, we report the first detection of a G1-like H9N2 virus from poultry sampled at live-bird markets in Russia (Far East region) during the winter of 2018 (isolate A/chicken/Amur_Russia/17/2018). We assume there has been further circulation of the A/chicken/Amur_Russia/17/2018 H9N2 virus in the Russian Far East with possible distribution to other regions or countries in 2018–2019.
Animals ; Far East ; Genotype ; Influenza A Virus, H9N2 Subtype ; Influenza in Birds ; Poultry ; Russia

To evaluate the optimal administration frequency for interferon-α (IFN-α) and the effect of its combined use with inactive virus on chicken flocks, the prokaryotic expression plasmid pET-22b-ChIFN-α was constructed and transferred into Escherichia coli BL21(DE3) host bacteria to induce the expression of chicken IFN-α and to harvest recombinant proteins inclusion bodies. The expression of recombinant chicken IFN-α was confirmed by SDS-PAGE, and the results demonstrated that the chicken IFN-α (20 kDa) was highly expressed using the prokaryotic expression vector with a concentration of 0.2 mg/mL in the medium. Chicken IFN-α was diluted to 2.5×10⁴ U/fowls and administered to immunized specific-pathogen-free chickens orally in combination with inactivated H9N2 subtype influenza virus. Chicken that received chicken IFN-α were safe after three repeated immunizations (96 h). In addition, chicken IFN-α could induce higher levels of antiviral-related inducible genes in peripheral blood, spleen, and thymus of chicken flocks. The results of a challenge assay revealed that the lowest detoxification rates of chicken IFN-α ranged from three to five days, suggesting a higher capacity to resist H9N2 subtype avian influenza virus. The present study obtained the optimal immune frequency and immunization period for chicken IFN-α to provide theoretical support for the optimal clinical application of IFN-α.
Administration, Oral ; Animals ; Chickens ; Humans ; Influenza A Virus, H9N2 Subtype ; Interferon-alpha ; Virus Replication

BACKGROUNDTo understand the characterization of genome of a strain of avian influenza A H9N2 virus repeatedly isolated from a child with influenza illness. Thereafter to reveal the origin of this H9N2 virus.

METHODSViruses were passed in embryonated hen eggs and virion RNA was extracted from allantoic fluid and reverse transcribed to synthesize cDNA. cDNA was amplified by PCR and the PCR product was purified with a purification kit. Afterwards RNA sequence analysis was performed by dideoxynucleotide chain termination and a cloning method. Finally, phylogenetic analysis of the sequencing data was performed with MegAlign (Version 1.03) and Editseg (Version 3.69) softwares.

RESULTSGenome of A/Guangzhou/333/99 (H9N2) virus was closely related to avian influenza A H9N2 virus, but obvious difference from that of A/Duck/Hong Kong/Y439/97(H9N2) virus, as well as its genome did not include any RNA segment derived from human influenza A virus. However, the genes encoding the HA,NA,NP and NS proteins of A/Guangzhou/333/99 virus were derived from those of G9 lineage virus, the rest genes encoding the M and three polymerase (PB2,PB1 and PA) proteins were derived from G1 lineage strain.

CONCLUSIONSA/Guangzhou/333/99 virus was a reassortant derived from reassortment betweenG9 and G1 lineages of avian influenzaA(H9N2) viruses. Therefore, the most possibility is that it is derived from avian influenza A virus directly. The results do not only demonstrate that avian influenza A (H9N2) virus could infect men, but also firstly prove that the genetic reassortment could be occurred between different genetic lineages of avian influenza A (H9N2) viruses in the nature.

Animals ; Base Sequence ; Chick Embryo ; Child ; Genome, Viral ; Humans ; Influenza A Virus, H9N2 Subtype ; Influenza A virus ; genetics ; Influenza, Human ; virology ; Phylogeny

Specific primers and TaqMan MGB probes were designed with Primer Express 2.0 software according to the conserved region of the H5, H9, H7 subtype AIV hemagglutinin gene to make research of real-time fluorescent one-step PCR in the differential detection of H5, H9, H7 subtype avian influenza inactivated vaccines. The result showed that the method was specific and reproducible. No cross-reaction was discovered with other avian disease vaccines. Real-time fluorescent PCR provided a specific, sensitive, rapid and convenient method for the subtype identification of avian influenza inactivated vaccines.
Animals ; Hemagglutinin Glycoproteins, Influenza Virus ; immunology ; Humans ; Influenza A Virus, H5N1 Subtype ; immunology ; Influenza A Virus, H7N7 Subtype ; immunology ; Influenza A Virus, H9N2 Subtype ; immunology ; Influenza A virus ; classification ; immunology ; Influenza Vaccines ; analysis ; classification ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Vaccines, Inactivated ; analysis

LG1 strain of avian influenza virus H9N2 was passaged continuously for 40 generations in chicken embryos with anti-LG1 maternal antibodies in 4 parallel experiments, of which 3 experiments had a stable mutation of "G" to "A" at #99 of the neuraminidase gene(NA)from the 20th passage resulting in a change of Met to Ile and 2 had a stable mutation of "A" to "G" at #473 of the NA gene from the 30th passage resulting in a change of Asn to Ser which occurred in the 50th passage of another experiment. Eighty continuous passages in chicken embryos without antibody did not have the same mutation, indicating that the mutations of the 2 positions were associated with selective pressure of antibodies. Analysis of the ratios of nonsynonium (NS) vs synonium (S) mutations of nucleic acids demonstrated that NS/S of 4 parallel experiments with antibodies was 4.6 (32/7) compared with 2.0 (16/8) of the 2 experiments without antibodies and this significant difference implied the selective pressure of antibodies.
Animals ; Antibodies, Viral ; immunology ; Chick Embryo ; Influenza A Virus, H9N2 Subtype ; genetics ; immunology ; Mutation ; Neuraminidase ; genetics

Samples of chicken, duck, quail, and pigeon were collected from Jiangsu, Anhui, and Hebei in 2009-2011, and sixteen H9N2 subtype isolates of avian influenza virus (AIV) were identified. The eight full-length genes of 16 AIV isolates were amplified by RT-PCR and sequenced. Genome sequence analysis showed that the amino acid motif of cleavage sites in the HA gene was P-S-R/K-S-S-R, which was consistent with the characterization of the LPAIV, and the Leucine (L) at the amino acid position 226 in the HA genes of all isolates indicated the potential of binding with SAalpha, 2-6 receptor. All isolates had a S to N substitution at residue 31 in the M2 gene, which is related to the resistance phenotype of adamantanes. The key molecular features of 16 AIV isolates from different hosts were same. Genome phylogenetic analysis revealed that all 16 H9N2 subtype AIVs originated from F98-like virus as backbone and formed two new genotypes through reassortment with HA gene of Y280-like virus and PB2 and M genes of G1-like virus. Our findings suggest that more attention should be paid to the surveillance of H9N2 influenza virus and its direction of reassortment.
Genome, Viral ; Hemagglutinin Glycoproteins, Influenza Virus ; genetics ; Influenza A Virus, H9N2 Subtype ; classification ; genetics ; Neuraminidase ; genetics ; Phylogeny ; Sequence Analysis, DNA

To investigate the susceptibility of Chukars to duck avian influenza virus H9N2 and explore their role in interspecies transmission of influenza viruses. Chukars were inoculated with duck avian influenza viruses H9N2. The present study demonstrated that inflammatory lesions and virus antigen were present in the trachea, bronchus, and parabronchus, and the viruses could be isolated from throat swabs and lung tissue homogenate supernatants. At 14 d post virus inoculation, anti-H9 influenza virus antibody in the serum was detected. The results indicated that Chukars are susceptible to duck avian influenza virus and serve as an intermediate host, thereby facilitating viral gene evolution and supporting the need for continued surveillance of epidemiology and evolution of the influenza virus in Chukars.
Animals ; Galliformes ; Influenza A Virus, H9N2 Subtype ; pathogenicity ; physiology ; Influenza in Birds ; virology ; Respiratory System ; pathology ; virology ; Virus Replication ; physiology