duck infections

The emergence of duck tembusu virus (DTMUV), a new member of the Flavivirus genus, has caused great economical loss in the poultry industry in China. Since the outbreak and spread of DTMUV is hard to control in a clinical setting, an efficient and low-cost oral delivery DNA vaccine SL7207 (pVAX1-C) based on the capsid protein of DTMUV was developed and evaluated in this study. The antigen capsid protein was expressed from the DNA vaccine SL7207 (pVAX1-C), both in vitro and in vivo. The humoral and cellular immune responses in vivo were observed after oral immunization with the SL7207 (pVAX1-C) DNA vaccine...

BACKGROUND: The American Gastroenterological Association (AGA) and European Association for the Study of the Liver (EASL) recommend that hepatitis B surface antigen (HBsAg)-negative and hepatitis B core antibody (anti-HBc)-positive patients who receive immunosuppression should be monitored for hepatitis B virus (HBV) infection regardless of hepatitis B surface antibody (anti-HBs) status. However, anti-HBs may provide protection against infection. To investigate whether the presence of anti-HBs in addition to anti-HBc confers protection, we classified HBsAg(-) kidney transplantation (KT) patients into 4 groups according to anti-HBc and anti-HBs status, and compared the HBV infection rate between the anti-HBc(+)anti-HBs(+) group and the other 3 groups...

During an outbreak of Wellfleet Bay virus (WFBV) in common eiders ( Somateria mollissima) from the Cape Cod region of Massachusetts, several birds were diagnosed with trichomonosis consisting of multiple trichomonad species. Six birds were examined, with trichomonads found in ceca in four birds and associated typhlitis in three of these four birds. PCR and DNA sequencing utilizing trichomonad-specific primers targeting the ITS1 region of the ribosomal DNA (rDNA) revealed the presence of Tetratrichomonas gallinarum in the gastrointestinal tracts of five birds and Trichomonas spp...

BACKGROUND: Marek's disease virus (MDV) resides in the genus Mardivirus in the family Herpesviridae. MDV is a highly contagious virus that can cause neurological lesions, lymphocytic proliferation, immune suppression, and death in avian species, including Galliformes (chickens, quails, partridges, and pheasants), Strigiformes (owls), Anseriformes (ducks, geese, and swans), and Falconiformes (kestrels). CASE PRESENTATION: In 2015, two red-crowned cranes died in Nanjing (Jiangsu, China)...

Wild ducks are known to be able to carry avian influenza viruses over long distances and infect domestic ducks, which in their turn infect domestic chickens. Therefore, prevention of virus transmission between ducks and chickens is important to control the spread of avian influenza. Here we used a low pathogenic wild aquatic bird virus A/duck/Moscow/4182/2010 (H5N3) for prevention of highly pathogenic avian influenza virus (HPAIV) transmission between ducks and chickens. We first confirmed that the ducks orally infected with H5N1 HPAIV A/chicken/Kurgan/3/2005 excreted the virus in feces...

H5N6 avian influenza viruses (AIVs) can cause severe pneumonia and death in humans. However, the molecular determinants of H5N6 influenza virus mammalian adaption are still unclear. Three amino acid substitutions (HA A150V, PA A343T, PB2 E627K) are observed in H5N6 virus A/duck/Zhejiang/6D2/2013 (6D2) in lung-to-lung passage in mice. These substitutions are crucial to the pathogenicity of mouse-adapted virus. In this study, we investigated the contribution of each amino acid substitution in the virus by reverse genetics...

Programmed death-1 (PD-1), upon engagement by its ligands, programmed death ligand-1 (PD-L1) and programmed death ligand-2 (PD-L2), provides signals that attenuate adaptive immune responses. Here we describe the identification of the Pekin duck PD-L2 (duPD-L2) and its gene structure. The duPD-L2 cDNA encodes a 321 amino acid protein that has an amino acid identity of 76% and 35% with chicken and human PD-L2, respectively. Mapping of the duPD-L2 cDNA with duck genomic sequences revealed an exonic structure similar to that of the human P dcd1lg2 gene...

Highly pathogenic avian influenza (HPAI) A(H5N6) and A(H5N8) virus infections resulted in the culling of more than 37 million poultry in the Republic of Korea during the 2016/17 winter season. Here we characterize two representative viruses, A/Environment/Korea/W541/2016 [Em/W541(H5N6)] and A/Common Teal/Korea/W555/2017 [CT/W555(H5N8)], and evaluate their zoonotic potential in various animal models. Both Em/W541(H5N6) and CT /W555(H5N8) are novel reassortants derived from various gene pools of wild bird viruses present in migratory waterfowl arising from eastern China...

H6 subtype avian influenza viruses (AIV), established in terrestrial poultry, have jumped species barriers and caused human infection indicating pandemic potential of the virus. Here, we report isolation, and antigenic and genetic characterization of two H6N2 viruses isolated from apparently healthy domestic ducks in Kerala and Assam, India during 2014 and 2015, respectively. Hemagglutination inhibition assay revealed antigenic divergence between the two isolates. This result was corroborated by amino acid differences at 55 positions (15...

Duck Tembusu virus (DTMUV), a newly emerging virus in ducks, was first reported in China in 2010. However, an unknown severe contagious disease associated with severe neurological signs and egg production losses in ducks, resembling to DTMUV infection, was observed in Thailand since 2007. To determine the presence of DTMUV in 2007, the clinical samples from affected ducks collected in 2007 were tested for DTMUV using pathological and virological analyses. Gross and histopathological lesions of affected ducks were mostly restricted to the ovary, brain and spinal cord, and correlated with the presence of flavivirus antigen in the brain and spinal cord samples...

To probe the epidemiology of duck circovirus (DuCV) in migrating wild ducks in China, 189 samples collected from 11 species of wild ducks from 2013 to 2016 were analyzed by PCR. Four positive samples were obtained from Mallard (2), Green-winged Teal (1), and Falcated Duck (1), and the positive rate was 2.12%. The homologous alignment of the complete genome shows that the homology of the wild duck strains is 81.6 to 95.1% to each other and 81.4 to 100% to the 32 strains from other origins. Amino acids alignment revealed that the mutable ORF2 gene has six major variable regions and many random mutation points...

To analyse the function of the duck plague virus (DPV) glycoprotein J homologue (gJ), two different mutated viruses, a gJ deleted mutant ΔgJ and a gJR rescue mutant gJR with US5 restored were generated. All recombinant viruses were constructed by using two-step of RED recombination system implemented on the duck plague virus Chinese virulent strain (DPV CHv) genome cloned into a bacterial artificial chromosome. DPV-mutants were characterized on non-complementing DEF cells compared with parental virus. Viral replication kinetics of intracellular and extracellular viruses revealed that the ΔgJ virus produce a 10-fold reduction of viral titers than the gJR and parental virus, which especially the production of extracellular infectivity was affected...

In this study, we report the establishment and characterization of a new epithelial cell line, goose embryonated epithelial cell line (GEE), derived from embryonic goose tissue. The purified GEE cell line can efficiently grow over 65 passages in the M199 medium supplemented with 10% fetal bovine serum at 37°C. Immunofluorescence assay was used to identify purified GEE cells as epithelial cell line by detecting expression of the Keratin-18 and -19. Further characterizations demonstrated that the GEE cell line can be continuously subcultured with (i) a high capacity to replicate for over 65 passages, (ii) a spontaneous epithelial-like morphology, (iii) constant chromosomal features and (iv) without an evidence of converting to tumorigenic cells either in vitro or in vivo study...

In southwestern France, during the winter of 2016-2017, the rapid spread of highly pathogenic avian influenza H5N8 outbreaks despite the implementation of routine control measures, raised the question about the potential role of airborne transmission in viral spread. As a first step to investigate the plausibility of that transmission, air samples were collected inside, outside and downwind from infected duck and chicken facilities. H5 avian influenza virus RNA was detected in all samples collected inside poultry houses, at external exhaust fans and at 5 m distance from poultry houses...

Novel duck reovirus (NDRV), the prototype strain of the species Avian orthoreovirus (ARV), is currently an infectious agent for ducks. Studies on NDRV replication and pathogenesis have been hampered by the lack of an available reverse-genetics system. In this study, a plasmid-based reverse-genetics system that is free of helper viruses has been developed. In this system, 10 full-length gene segments of wild-type NDRV TH11 strain are transfected into BSR-T7/5 cells that express bacteriophage T7 RNA polymerase...

Wild dabbling ducks are the main reservoir for avian influenza (AI) viruses and pose an ongoing threat to commercial poultry flocks. Combining the (i) size of that population, (ii) their flight distances and (iii) their AI prevalence, the density of AI-infected dabbling ducks (DID) was calculated as a risk factor for the introduction of AI viruses into poultry holdings of Emilia-Romagna region, Northern Italy. Data on 747 poultry holdings and on 39 AI primary outbreaks notified in Emilia-Romagna between 2000 and 2017 were used to validate that risk factor...

OBJECTIVE: To understand the current status of the sanitation of freshwater aquaculture environments, and Clonorchis sinensis infection of freshwater fish in the aquaculture and market in a city of Pearl River Delta region, so as to provide the evidence for formulating the prevention and control strategy of clonorchiasis sinensis. METHODS: In 2016, based on the distribution of freshwater aquaculture, 36 freshwater fish ponds among 14 towns were selected for sampling and investigation, and 10-20 pieces were collected from each pond...

Ducks, the reservoir host, are generally permissive to influenza A virus infection without disease symptoms. This natural ecology was upset by the emergence of H5N1 strains, which can kill ducks. To better understand host-virus interactions in the reservoir host, and influenza strain-specific molecular contributions to virulence, we infected White Pekin ducks with three similar H5N1 viruses, with known differences in pathogenicity and replication rate. We quantified viral replication and innate immune gene activation by qPCR, in lung and spleen tissues, isolated on each of the first 3 days of infection...

Viral membrane proteins are prime targets in the combat against infection. Still, their structure determination remains a challenge, both with respect to sample preparation, and the need for structural methods allowing analysis in a native-like lipid environment. Cell-free protein synthesis and solid-state NMR are promising approaches in this context, one with respect to its high potential of native expression of complex proteins, and the other for its ability to analyze membrane proteins in lipids. We here show that milligram amounts of the small envelope protein of the duck hepatitis B virus (DHBV) can be produced using cell-free expression, and that the protein self-assembles into subviral particles...

Hydropericardium syndrome and inclusion body hepatitis, together called hydropericardium-hepatitis syndrome, are acute infectious diseases found in chickens. These diseases are caused primarily by fowl adenovirus serotype 4 (FAdV-4) strains. In this study, we isolated a FAdV-4 strain (SD0828) from clinically diseased chickens and phylogenetically analyzed the L1 loops of the hexon protein sequences in 3-week-old specific pathogen-free chickens and ducks infected intramuscularly and orally, determining differences in the pathogenicity by observing clinical signs and gross and histological lesions...