Genetic sequence changes related to the attenuation of avian infectious bronchitis virus strain TW2575/98.

The attenuated avian infectious bronchitis virus (IBV), derived from a wild strain (TW2575/98w) in chicken embryos after 75 passages, is designed as a commercial vaccine strain (TW2575/98vac) to control the disease in Taiwan. The differences in viral infectivity, replication efficiency, and genome sequences between TW2575/98w and TW2575/98vac were determined and compared. TW2575/98vac caused earlier death of chicken embryos and had higher viral replication efficiency.

Optical fiber sensor based on surface plasmon resonance for rapid detection of avian influenza virus subtype H6: Initial studies.

A side-polished fiber optic surface plasmon resonance (SPR) sensor was fabricated to expose the core surface and then deposited with a 40 nm thin gold film for the near surface sensing of effective refractive index changes with surface concentration or thickness of captured avian influenza virus subtype H6. The detection surface of the SPR optical fiber sensor was prepared through the plasma modification method for binding a self-assembled monolayer of isopropanol chemically on the gold surface of the optical fiber. Subsequently, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide/N-hydroxysuccinimide was activated to enable EB2-B3 monoclonal antibodies to capture A/chicken/Taiwan/2838V/00 (H6N1) through a flow injection system.

Detection of infectious bronchitis virus strains similar to Japan in Taiwan.

A total of 1,320 tracheal samples from 66 broiler flocks sent to slaughterhouses and 42 tracheal samples from 42 flocks of local chickens in the field were collected for infectious bronchitis virus (IBV) gene detection by reverse transcription polymerase chain reaction using nucleocapsid-specific primers and spike-specific primers. Prevalence in broiler flocks was 39.4% (26/66) and in local chicken flocks was 11.

Immunochromatographic strip assay development for avian influenza antibody detection.

To detect antibody on pen-side is a rapid way to know the avian influenza (AI) infectious status in a chicken flock. The purpose of this study was to develop an immunochromatographic strip (ICS) assay to detect the antibody against the AI virus (AIV) for field applications. The ICS was constructed by fixing an AIV strain A/chicken/Taiwan/2838V/2000 (H6N1) onto a nitrocellulose membrane as the antigen at the test line and goat anti-rabbit IgG antibody at the control line.

Influenza A(H6N1) Virus in Dogs, Taiwan.

We determined the prevalence of influenza A virus in dogs in Taiwan and isolated A/canine/Taiwan/E01/2014. Molecular analysis indicated that this isolate was closely related to influenza A(H6N1) viruses circulating in Taiwan and harbored the E627K substitution in the polymerase basic 2 protein, which indicated its ability to replicate in mammalian species.

H5 avian influenza virus pathotyping using oligonucleotide microarray.

The H5 avian influenza virus subtype has huge impact on the poultry industry. Rapid diagnosis and accurate identification of the highly pathogenic avian influenza virus and low-pathogenicity avian influenza virus is essential, especially during H5 outbreaks and surveillance. To this end, a novel and rapid strategy for H5 virus molecular pathotyping is presented.

Natural A(H1N1)pdm09 influenza virus infection case in a pet ferret in Taiwan.

Ferrets have demonstrated high susceptibility to the influenza virus. This study discusses a natural 2009 pandemic influenza A (H1N1) (A(H1N1)pdm09) virus infection in a pet ferret (Mustela putorius furo) identified in Taiwan in 2013. The ferret was in close contact with family members who had recently experienced an influenza-like illness (ILI).

Glycosylation at hemagglutinin Asn-167 protects the H6N1 avian influenza virus from tryptic cleavage at Arg-201 and maintains the viral infectivity.

Cleavage of the hemagglutinin (HA) precursor (HA0) by trypsin, which produces the active HA1 and HA2 complex, is a critical step for activating the avian influenza virus (AIV). However, other tryptic cleavage sites on HA might also cause HA degradation and affect the virulence. Otherwise, HA is modified by glycosylation in the host cell.

Avian oncogenic virus differential diagnosis in chickens using oligonucleotide microarray.

Avian oncogenic viruses include the avian leukosis virus (ALV), reticuloendotheliosis virus (REV) and Marek's disease virus (MDV). Multiple oncogenic viral infections are frequently seen, with even Marek's disease vaccines reported to be contaminated with ALV and REV. The gross lesions caused by avian oncogenic viruses often overlap, making differentiation diagnosis based on histopathology difficult.

Gene detection, virus isolation, and sequence analysis of avian leukosis viruses in Taiwan country chickens.

Avian leukosis virus (ALV) infection in Taiwan Country chickens (TCCs) was investigated by using gene detection, virus isolation, and sequence analysis. The blood samples of 61 TCC flocks at market ages from a slaughter house were screened for exogenous ALVs using polymerase chain reaction to investigate the ALV infection status. The buffy coats from three breeder and four commercial chicken flocks were cocultured with DF-1 cells to isolate the virus.

Inhibitory and combinatorial effect of diphyllin, a v-ATPase blocker, on influenza viruses.

An influenza pandemic poses a serious threat to humans and animals. Conventional treatments against influenza include two classes of pathogen-targeting antivirals: M2 ion channel blockers (such as amantadine) and neuraminidase inhibitors (such as oseltamivir). Examination of the mechanism of influenza viral infection has shown that endosomal acidification plays a major role in facilitating the fusion between viral and endosomal membranes.

Detection of anti-reticuloendotheliosis virus antibody by blocking enzyme-linked immunosorbent assay with expression envelope protein.

The current reticuloendotheliosis virus (REV) antibody detection kit that uses enzyme-linked immunosorbent assay (ELISA) needs concentrated virus, which is difficult to obtain due to its poor propagation in cells. In addition, this kit detects only chicken antibody but not other species. To overcome these disadvantages, we cloned and expressed REV env gene to develop monoclonal antibodies (mAbs), which we used for antibody detection in ELISA.

Evolution of infectious bronchitis virus in Taiwan: positively selected sites in the nucleocapsid protein and their effects on RNA-binding activity.

RNA recombination has been shown to underlie the sporadic emergence of new variants of coronavirus, including the infectious bronchitis virus (IBV), a highly contagious avian pathogen. We have demonstrated that RNA recombination can give rise to a new viral population, supported by the finding that most isolated Taiwanese (TW) IBVs, similar to Chinese (CH) IBVs, exhibit a genetic rearrangement with the American (US) IBV at the 5' end of the nucleocapsid (N) gene. Here, we further show that positive selection has occurred at two sites within the putative crossover region of the N-terminal domain (NTD) of the TW IBV N protein.

Preparation of monoclonal antibodies against poor immunogenic avian influenza virus proteins.

This study established a novel method of pre-screening peptides for monoclonal antibody (mAb) production. Whole virus particles were used as antigens to produce mAbs in the first stage. However, most mAbs obtained from this method were aimed toward hemagglutinin.

Nanowire transistor-based ultrasensitive virus detection with reversible surface functionalization.

We have applied a reusable silicon nanowire field-effect transistor (SiNW-FET) as a biosensor to conduct ultrasensitive detection of H5N2 avian influenza virus (AIV) in very dilute solution. The reversible surface functionalization of SiNW-FET was made possible using a disulfide linker. In the surface functionalization, 3-mercaptopropyltrimethoxysilane (MPTMS) was first modified on the SiNW-FET (referred to as MPTMS/SiNW-FET), with subsequent dithiothreitol washing to reduce any possible disulfide bonding between the thiol groups of MPTMS.

Antigen-capture enzyme-linked immunosorbent assays for detection of different H5 avian Influenza A virus.

Avian Influenza A virus (AIV) subtype H5 is divided into American and Eurasian lineages, according to hemagglutinin gene sequences. Although methods for detecting H5 AIVs have been described, no H5 strain-specific detection method has been reported. The purpose of the present study was to develop an antigen-capture enzyme-linked immunosorbent assay (ACE) to detect and differentiate between the American and the Eurasian H5 AIVs.

Development of an antigen-capture enzyme-linked immunosorbent assay using monoclonal antibodies for detecting H6 avian influenza viruses.

The H6 subtype of avian influenza virus (AIV) infection occurs frequently in wild and domestic birds. AIV antigen detection is preferred for controlling AIV as birds are infected before they produce antibodies. The purpose of this study was to develop an early diagnostic method for AIV detection.

Rapid and specific influenza virus detection by functionalized magnetic nanoparticles and mass spectrometry.

Background: The timely and accurate diagnosis of specific influenza virus strains is crucial to effective prophylaxis, vaccine preparation and early antiviral therapy. The detection of influenza A viruses is mainly accomplished using polymerase chain reaction (PCR) techniques or antibody-based assays. In conjugation with the immunoassay utilizing monoclonal antibody, mass spectrometry is an alternative to identify proteins derived from a target influenza virus.

Galectin-1 binds to influenza virus and ameliorates influenza virus pathogenesis.

Innate immune response is important for viral clearance during influenza virus infection. Galectin-1, which belongs to S-type lectins, contains a conserved carbohydrate recognition domain that recognizes galactose-containing oligosaccharides. Since the envelope proteins of influenza virus are highly glycosylated, we studied the role of galectin-1 in influenza virus infection in vitro and in mice.

The infection of chicken tracheal epithelial cells with a H6N1 avian influenza virus.

Sialic acids (SAs) linked to galactose (Gal) in α2,3- and α2,6-configurations are the receptors for avian and human influenza viruses, respectively. We demonstrate that chicken tracheal ciliated cells express α2,3-linked SA, while goblet cells mainly express α2,6-linked SA. In addition, the plant lectin MAL-II, but not MAA/MAL-I, is bound to the surface of goblet cells, suggesting that SA2,3-linked oligosaccharides with Galβ1-3GalNAc subterminal residues are specifically present on the goblet cells.

Immunoadjuvant efficacy of plasmids with multiple copies of a CpG motif coadministrated with avian influenza vaccine in chickens.

Unmethylated CpG motifs are capable of evoking a range of immunostimulatory effects in vertebrates and have tremendous potential to be used as therapeutic agents and adjuvants. This particular type of CpG motif has been demonstrated to be an excellent immune adjuvant mediated by Toll-like receptor 9 (TLR9) in various mammalian vaccines; however, only a few studies confirm its efficacy in avian vaccines. In the present study, immunomodulatory activities of plasmids with various copy numbers of a CpG motif were evaluated in chickens inoculated with an avian influenza vaccine.

Efficacy of avian influenza vaccine in poultry: a meta-analysis.

Vaccination is an effective method for controlling avian influenza (AI), especially in countries with endemic infection. This study conducted a Bayesian meta-analysis to evaluate the efficacy of AI vaccines in chickens. We included both inactivated and recombinant fowlpox virus expressing H5 (rFPV-H5) vaccine studies that used specific-pathogen-free chickens where outcomes against the H5N1 or H5N2 AI viruses were measured.

A low pathogenic H5N2 influenza virus isolated in Taiwan acquired high pathogenicity by consecutive passages in chickens.

H5N2 viruses were isolated from cloacal swab samples of apparently healthy chickens in Taiwan in 2003 and 2008 during surveillance of avian influenza. Each of the viruses was eradicated by stamping out. The official diagnosis report indicated that the Intravenous Pathogenicity Indexes (IVPIs) of the isolates were 0.

A type-specific blocking ELISA for the detection of infectious bronchitis virus antibody.

Infectious bronchitis virus (IBV) infection has been a major threat to the poultry industry worldwide. Current commercially available ELISA kits detect group-specific antibodies; however, to understand the status of field infection, a monoclonal antibody (mAb) blocking ELISA (b-ELISA) against local IBVs was developed. The selected mAb showed specificity to Taiwan IBV strains but had no cross-reactivity with the vaccine strain H120.