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Transposable elements (TEs), such as endogenous retroviruses (ERVs), are common in the genomes of vertebrates. ERVs result from retroviral infections of germ-line cells, and once integrated into host DNA they become part of the host's heritable genetic material. ERVs have been ascribed positive effects on host physiology such as the generation of novel, adaptive genetic variation and resistance to infection, as well as negative effects as agents of tumorigenesis and disease. The avian leukosis virus subgroup E family (ALVE) of endogenous viruses of chickens has been used as a model system for studying the effects of ERVs on host physiology, and approximately 30 distinct ALVE proviruses have been described in the Gallus gallus genome. In this report we describe the development of a software tool, which we call Vermillion, and the use of this tool in combination with targeted next-generation sequencing (NGS) to increase the number of known proviruses belonging to the ALVE family of ERVs in the chicken genome by 4-fold, including expanding the number of known ALVE elements on chromosome 1 (Gga1) from the current 9 to a total of 40. Although we focused on the discovery of ALVE elements in chickens, with appropriate selection of target sequences Vermillion can be used to develop profiles of other families of ERVs and TEs in chickens as well as in species other than the chicken. [ABSTRACT FROM AUTHOR]

Following the introduction of highly pathogenic avian influenza (HPAI) virus subtype H5N1, the Egyptian government implemented a massive poultry vaccination campaign as the cornerstone of its policies to control the virus. The efficacy of vaccination has been evaluated primarily by measuring titers of antibodies inhibiting the hemagglutinating activity of the viral hemagglutinin (HA). However, other aspects of the host response remain poorly understood. In the present study, in addition to hemagglutination inhibition (HI) titers, cytokine profiles were examined and IFNγ concentrations were measured in vivo after immunization with a whole inactivated virus (WIV) prepared from a classical strain of clade 2.2.1.2 (C121) and an antigenic drift variant of clade 2.2.1.1 (V1063). The results revealed an earlier response and higher HI titers and IFNγ levels in sera from chickens immunized with C121, accompanied by significantly higher expression of IL8, IL10, and IL18 in the spleen and IL6 and IL10 in the bursa, compared to those immunized with V1063. Furthermore, stimulation of the HD11 cell line with C121 induced gradual upregulation of pro-inflammatory cytokines, which was observed at 24 hours post-inoculation (hpi), and became more pronounced at 48 and 72 hpi, accompanied by upregulation of IFNα. Conversely, V1063 induced very early transient higher expression of pro-inflammatory cytokines at 3 and 6 hpi accompanied by upregulation of IL10, which then decreased at 24, 48 and 72 hpi. In summary, our results provide evidence of a correlation between adaptive immune responses induced by WIVs and higher expression of IL10 and IL18 in addition to early induction of IFNα. These findings could be used to improve immune responses induced by WIVs. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Razi Institute is the property of Institut Razi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archives of Razi Institute is the property of Institut Razi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Avian influenza virus subtypes H5, H7, and H9 related epidemics are accountable for huge losses to the poultry and avian industry in Pakistan. Well-timed and accurate diagnosis of subtype(s) concomitant with a specific epidemic allows a margin of prophylaxis to farmers through requisite vaccination. The current study was designed to develop and validate a rapid, accurate, and efficient diagnostic technique based on a modified strategy in reverse transcription PCR (RT-PCR) for simultaneous detection of avian influenza virus subtypes H5, H7, and H9. Instead of 3 pairs of primers, a single common forward sense primer and 3 negative sense primers specific for 3 subtypes were used. Genotyping on 2% agarose gel sorted out specific products of desired sizes for individual and mixture samples of three subtypes. [ABSTRACT FROM AUTHOR]

Infectious bronchitis virus ( Gammacoronavirus , Coronaviridae ) is a genetically variable RNA virus (27.6 kb) that causes one of the most persistent respiratory disease in poultry. The virus is classified in genotypes with different epidemiological relevance and clinical implications. The present study reports the development and validation of specific RT-qPCR assays for the detection of two major IBV genotypes: South America I (SAI) and Asia/South America II (A/SAII). The SAI genotype is an exclusive and widespread South American lineage while the A/SAII genotype is distributed in Asia, Europe and South America. Both identification assays employ TaqMan probes that hybridize with unique sequences in the spike glycoprotein gene. The assays successfully detected all the assessed strains belonging to both genotypes, showing high specificity and absence of cross-reactivity. Using serial dilutions of in vitro-transcribed RNA we obtained acceptable determination coefficients, PCR efficiencies and relatively small intra- and inter-assay variability. The assays demonstrated a wide dynamic range between 10 1 –10 7 and 10 2 –10 7 RNA copies/reaction for SAI and A/SAII strains, respectively. The possibility to characterize a large number of samples in a rapid, sensitive and reproducible way makes these techniques suitable tools for routine testing, IBV control, and epidemiological research in poultry. [ABSTRACT FROM AUTHOR]

Copyright of Avian Diseases is the property of American Association of Avian Pathologists, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Vlaams Diergeneeskundig Tijdschrift is the property of Ghent University, Faculty of Veterinary Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Avian pathogenic Escherichia coli (APEC) causes avian colibacillosis, which results in economic and welfare costs in the poultry industry worldwide. The pathogenesis of avian pathogenic E. coli strains is not well defined. Here, the function of an outer membrane protein encoded by the ireA gene of avian pathogenic E. coli strain DE205B was investigated. Results: The ireA gene was distributed in 32.9 % (46/140) of tested E. coli strains, with high percentages in the phylogenetic ECOR groups B2 (58.8 %, 10/17) and D (55.9 %, 19/34). The gene expression level of ireA of APEC strain DE205B in high Fe M9 media was 1.8 times higher (P < 0.05) than that in low Fe M9 media. An ireA deletion mutant and complementary strain were constructed. Compared with the wild-type strain DE205B, the expression of most ferric uptake genes in the ireA deletion mutant were significantly upregulated (P < 0.05). The adhesion ability of the ireA deletion mutant to DF-1 cells was significantly decreased. The survival rate of ireA deletion mutant was reduced 21.17 % (P < 0.01), 25.42 (P < 0.05) and 70.0 % (P < 0.01) under alkali, high osmolarity, and low temperature (4 °C) conditions, respectively, compared with the wild-type strain. Conclusions: The results suggested that the protein encoded by the iron-regulated gene ireA has roles in adhesion and stress resistance in avian pathogenic E. coli. [ABSTRACT FROM AUTHOR]

Background: Knowing the genome characteristics of circulating Newcastle disease viruses [avian paramyxoviruses (APMV-1) and pigeon paramyxoviruses (PPMV-1)] is important to devise appropriate diagnostics and control strategies. APMVs originating from chicken and wildlife in Pakistan are well-elucidated; nevertheless, molecular characterization for the circulating PPMV-1 is largely unknown. Findings: Here, we have performed fusion (F) and hemagglutinin (HN) gene based characterization of PPMV-1 isolated from an outbreak in a pigeon flock. With F proteolytic cleavage site (RRQKR↓F), characteristic of velogenic/mesogenic serotype, the complete F and HN gene based sequence analysis of the isolate revealed evolutionary relationship to genotype VI. Further analysis of hyper-variable region of F-gene demonstrated clustering of the study isolate with genotype VIb. The deduced residue analysis for both F and HN protein showed a number of substitution mutations in the functional domains distinct from representative strains of each genotype including the vaccine strains; some of them were found exclusive to the study isolate. Conclusions: Though limited and preliminary data, the findings enhance our knowledge towards circulating strains of PPMVs in Pakistan. Further studies are needed to ascertain its potential for transmission in the wild birds, commercial and backyard poultry and its subsequent shedding into the environment. [ABSTRACT FROM AUTHOR]

Constant monitoring is performed to elucidate the role of natural hosts in the ecology of Newcastle disease virus (NDV). In this study, an NDV strain isolated from an asymptomatic pigeon was sequenced and analysed. Results showed that the full-length genomes of this isolate were 15,198 nucleotides with the gene order of 3'-NP-P-M-F-HN-L-5'. This NDV isolate was lentogenic, with an intracerebral pathogenicity index of 0.00 and a mean time of death more than 148 h. The isolate possessed a motif of -112E-R-Q-E-R-L117- at the F protein cleavage site. In addition, 7 and 13 amino acid substitutions were identified in the functional domains of fusion protein (F) and haemagglutinin-neuraminidase protein (HN) proteins, respectively. Analysis of the amino acids of neutralizing epitopes of F and HN proteins showed 3 and 10 amino acid substitutions, respectively, in the isolate. Phylogenetic analysis classified the isolate into genotype Ib in Class I. This isolate shared high homologies with the NDV strains isolated from wild birds and waterfowl in southern and eastern parts of China from 2005 to 2013. To our knowledge, this study is the first to report a NDV strain isolated from pigeon that belongs to genotype Ib in Class I, rather than to the traditional genotype VI or other sub-genotypes in Class II. This study provides information to elucidate the distribution and evolution of Class I viruses for further NDV prevention. [ABSTRACT FROM AUTHOR]

A peptide enzyme linked immunosorbent assay (ELISA) based on an epitope in the haemagglutinin (HA) of avian influenza virus H5N1, amino acid positions 274-288 (HA274-288) was evaluated for detection of H5N1-specific antibodies. An optimized ELISA based on the tetrameric form of the HA274-288 epitope designated MP15 gave low background with non- immune chicken sera and detected vaccinated and infected birds. The HA274-288 epitope was highly conserved in Indonesian H5N1 strains and antibody responses were detected in the majority of the vaccinated chickens regardless of the H5N1 strain used for vaccination. The HA274-288 epitope was also conserved in the majority of H5N1 strains from the neighbouring Asian region, and other H5 subtypes potentially allowing for a wider use of the MP15 ELISA in H5N1 vaccinated and infected flocks. The MP15 ELISA results correlated significantly with haemagglutination inhibition (HI) test results and test sensitivity and specificity were 87% and 92%, respectively. The MP15 ELISA titres were significantly higher than the HI titres in all immune sera allowing for sera to be tested at a single dilution of 1:400 which is of advantage in routine surveillance. The study indicated that the MP15 ELISA is potentially useful for serological detection of H5N1 vaccinated or infected poultry and to have some advantages over the standard HI test for routine monitoring of flocks' immunity after vaccination. [ABSTRACT FROM AUTHOR]

This study involved a human infection with avian influenza H7N9(A) virus in Zhejiang province, the first one after implementing the closure measures of living poultry markets in China. The clinical symptoms, epidemiological and virological characteristics of the case were described briefly, and as the emphasis, H7N9 virus was detected quantitatively and continuously from the collected samples in 10 different periods of the patient’s treatment in order to reveal changes of viral load in patient’s body during the treatment. This study first used reverse-transcription droplet digital PCR (RT-ddPCR) assays to monitor viral load dynamically for human H7N9 infection, synchronously performing real-time RT-PCR as a reference technology to obtain more comprehensive data for comparison. Our results indicated that RT-ddPCR compared to real-time RT-PCR is more sensitive and accurate for quantifying H7N9 viral load without the use of standard curves. Furthermore it can provide reference data for clinical policies including infectivity judgement, ward transferring and therapy adjustment for the patient during treatment. [ABSTRACT FROM AUTHOR]

The main objective of this study was to determine the possible effects of thymoquinone (TQ) and curcumin (Cur) on immune-response and pathogenesis of H9N2 avian influenza virus (AIV) in turkeys. The experiment was performed on 75 non-vaccinated mixed-sex turkey poults, divided into 5 experimental groups (A, B, C, D, and E) of 15 birds each. Group A was kept as non-infected and a non-treated negative control (ctrl group) while group B was kept as infected and non-treated positive control (H9N2 group). Turkeys in groups A and B received normal commercial feed while turkeys in groups C and D received TQ, and Cur respectively, and group E concurrently received TQ and Cur from d one through the entire experiment period. All groups were challenged intra-nasally with H9N2 AIV (A/chicken/Pakistan/10RS3039-284-48/2010) at the fourth wk of age except group A. Infected turkeys showed clinical signs of different severity, showing the most prominent disease signs in turkeys in group B. All infected turkeys showed positive results for virus shedding; however, the pattern of virus shedding was different, and with turkeys in group B showing more pronounced virus secretion than the turkeys in the other groups receiving different levels of TQ and Cur. Moreover, significantly higher antibody titer against H9N2 AIV in turkeys shows the immunomodulatory nature of TQ and Cur. Similarly, increased cytokine gene expression suggests antiviral behavior of TQ and Cur especially in combination, leading to suppressed pathogenesis of H9N2 viruses. However, reduced virus shedding and enhanced immune responses were more pronounced in those turkeys receiving TQ and Cur concurrently. This study showed that supplements of TQ and Cur in combination would significantly enhance immune responsiveness and suppress pathogenicity of influenza viruses in turkeys. [ABSTRACT FROM AUTHOR]

Poultry colibacillosis due to Avian Pathogenic Escherichia coli (APEC) is responsible for several extra-intestinal pathological conditions, leading to serious economic damage in poultry production. The most commonly associated pathologies are airsacculitis, colisepticemia, and cellulitis in broiler chickens, and salpingitis and peritonitis in broiler breeders. In this work a total of 66 strains isolated from dead broiler breeders affected with colibacillosis and 61 strains from healthy broilers were studied. Strains from broiler breeders were typified with serogroups O2, O18, and O78, which are mainly associated with disease. The serogroup O78 was the most prevalent (58%). All the strains were checked for the presence of 11 virulence genes: 1) arginine succinyltransferase A (astA); ii) E.coli hemeutilization protein A (chuA); iii) colicin V A/B (cvaA/B); iv) fimbriae mannosebinding type 1 (fimC); v) ferric yersiniabactin uptake A (fyuA); vi) iron-repressible high-molecular-weight proteins 2 (irp2); vii) increased serum survival (iss); viii) iron-uptake systems of E.coli D (iucD); ix) pielonefritis associated to pili C (papC); x) temperature sensitive haemaglutinin (tsh), and xi) vacuolating autotransporter toxin (vat), by Multiplex-PCR. The results showed that all genes are present in both commensal and pathogenic E. coli strains. The iron uptake-related genes and the serum survival gene were more prevalent among APEC. The adhesin genes, except tsh, and the toxin genes, except astA, were also more prevalent among APEC isolates. Except for astA and tsh, APEC strains harbored the majority of the virulenceassociated genes studied and fimC was the most prevalent gene, detected in 96.97 and 88.52% of APEC and AFEC strains, respectively. Possession of more than one iron transport system seems to play an important role on APEC survival. [ABSTRACT FROM AUTHOR]

In 2015, a major outbreak of highly pathogenic avian influenza virus (HPAIV) infection devastated poultry facilities in Minnesota, USA. To understand the potential role of wild birds, we tested 3,139 waterfowl fecal samples and 104 sick and dead birds during March 9-June 4, 2015. HPAIV was isolated from a Cooper's hawk but not from waterfowl fecal samples. [ABSTRACT FROM AUTHOR]

In the past few years, Newcastle disease virus (NDV) strains with epizootic characteristics belonging to subgenotypes VIIi and XIIIb emerged in the Middle East and Asia. In this study, 2 NDV strains—1 representative of subgenotype VIIi isolated in Israel (Kvuzat/13) and 1 representative of subgenotype XIIIb isolated in Pakistan (Karachi/07)—were characterized by intracerebral pathogenicity index and detailed clinicopathologic assessment. The intracerebral pathogenicity index values for Kvuzat/13 and Karachi/07 were 1.89 and 1.85, respectively, classifying these strains as virulent by international standards. In 4-week-old White Leghorn chickens, both strains caused 100% mortality within 4 (Kvuzat/13) and 5 (Karachi/07) days postinfection. Histopathology and immunohistochemistry for NDV nucleoprotein showed that both strains had wide systemic distribution, especially targeting lymphoid organs and mucosa-associated lymphoid tissues in the respiratory and intestinal tracts. Results of the animal experiment confirm that both Kvuzat/13 and Karachi/07 are highly virulent and behaved as velogenic viscerotropic NDV strains. [ABSTRACT FROM AUTHOR]

It is almost a decade since the highly pathogenic H5N1 avian influenza virus (A/H5N1) of clade 2.2.1 was introduced to Egypt in 2005, most likely, via wild birds; marking the longest endemic status of influenza viruses in poultry outside Asia. The endemic A/H5N1 in Egypt still compromises the poultry industry, poses serious hazards to public health and threatens to become potentially pandemic. The control strategies adopted for A/H5N1 in Egyptian poultry using diverse vaccines in commercialized poultry neither eliminated the virus nor did they decrease its evolutionary rate. Several virus clades have evolved, a few of them disappeared and others prevailed. Disparate evolutionary traits in both birds and humans were manifested by accumulation of clade-specific mutations across viral genomes driven by a variety of selection pressures. Viruses in vaccinated poultry populations displayed higher mutation rates at the immunogenic epitopes, promoting viral escape and reducing vaccine efficiency. On the other hand, viruses isolated from humans displayed changes in the receptor binding domain, which increased the viral affinity to bind to human-type glycan receptors. Moreover, viral pathogenicity exhibited several patterns in different hosts. This review aims to provide an overview of the viral evolution, pathogenicity and vaccine efficacy of A/H5N1 in Egypt during the last ten years. [ABSTRACT FROM AUTHOR]

Duck enteritis virus (DEV) is a double-stranded DNA virus belonging to the alphaherpesvirinae subfamily of the herpesviridae . Although vaccines were wildly used in controlling this disease, some infection could still not be prevented and led to significant economic losses as a result of mortality and decreased egg production. However, there is no antiviral drug against DEV. Resveratrol was identified to exert its antiviral activity by inhibiting the DEV replication in preliminary investigations. In the present study, we confirmed that resveratrol significantly reduced the mortality of ducklings which infected with a virulent strain of DEV. With resveratrol treatment, the survival rate increased by almost 80% at 8 days post infection (dpi). Pathological symptoms of ducklings caused by DEV were also relieved by resveratrol. The virus load in blood and tissues were effectively depressed when compared with the untreated group. In the assay of immune cytokines, the resveratrol exerted a dual-regulation effect. These results suggest that resveratrol is expected to be a new alternative control measure for DEV infection. [ABSTRACT FROM AUTHOR]

Monovalent H7 and H9 inactivated Avian Influenza Virus (AIV) vaccines were developed and its efficacy was compared with the locally available and imported vaccines including monovalent (Flu-Vac H7, Gallimune H9) and bivalent (Avi-Flu H7+H9, Otto-flu H7+H9) using inoculation in five broiler breeder flocks under field conditions. The sero conversion in the inoculates was studied using haemagglutination inhibition (HI) test. On day 21 post-vaccination; in case of H7N3 virus vaccines, the antibody titer; the Geometric Mean (GM) HI titer recorded were as 55.7 in group A (the group inoculated with Gallimmune; Merial vaccine) chickens, 52.0 in group B (the group inoculated with locallly manufactured Avi-Flu vaccine) 59.7 in group C (the group inoculated with locally manufactured Otto-Flu vaccine), 29.9 in group D (the group inoculated with newly developed local vaccine) and 2.5 in group E (un-inoculated control group). In case of H9N2 virus vaccines, on day 21 post vaccination, the GM HI titers of chicks in group A, B, C, D and E were recorded as 27.9, 68.6, 64.0, 24.3 and 2.5, respectively. This study indicated that the locally prepared AI vaccines also provoked quite good HI antibody titers in poultry flocks in Pakistan. [ABSTRACT FROM AUTHOR]

An outbreak of inclusion body hepatitis was noticed in 20% of the population of a flock of 20000 broiler chickens. The affected 14-day-old birds experienced 10% mortality during a period of one week. On 39 and 44 days of age, clinical infectious bursal disease and Newcastle disease with 5% and 15% mortalities occurred in the flock, respectively. Clinical signs of affected birds included depression, leg weakness and mild watery droppings. Grossly, only the affected liver was a friable and enlarged organ associated with petechial haemorrhages and multifocal gray-white to yellowish necrotic areas. Histopathologically, multifocal to coalescing necrosis of hepatocytes, remarkable large basophilic intranuclear inclusion bodies were diagnosed. In the present study, it seemed that the causative agent had produced acute disease without predisposing factors and it could be suggested that resulting immunosuppression was the trigger mechanism for subsequent infectious bursal disease (IBD) and Newcastle disease (ND) outbreaks. [ABSTRACT FROM AUTHOR]

Copyright of Avian Diseases is the property of American Association of Avian Pathologists, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Despite evidence for avian influenza A virus (AIV) transmission between wild and domestic ecosystems, the roles of bird migration and poultry trade in the spread of viruses remain enigmatic. In this study, we integrate ecosystem interactions into a phylogeographic model to assess the contribution of wild and domestic hosts to AIV distribution and persistence. Analysis of globally sampled AIV datasets shows frequent two-way transmission between wild and domestic ecosystems. In general, viral flow from domestic to wild bird populations was restricted to within a geographic region. In contrast, spillover from wild to domestic populations occurred both within and between regions. Wild birds mediated long-distance dispersal at intercontinental scales whereas viral spread among poultry populations was a major driver of regional spread. Viral spread between poultry flocks frequently originated from persistent lineages circulating in regions of intensive poultry production. Our analysis of long-term surveillance data demonstrates that meaningful insights can be inferred from integrating ecosystem into phylogeographic reconstructions that may be consequential for pandemic preparedness and livestock protection. [ABSTRACT FROM AUTHOR]

Copyright of Avian Diseases is the property of American Association of Avian Pathologists, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Avian Diseases is the property of American Association of Avian Pathologists, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: A rapid, sensitive, and specific molecular method for the diagnosis of infectious bronchitis virus (IBV) infection is important in curbing infectious bronchitis outbreaks in Morocco and other countries. Methods: In this study, an easy-to-perform SYBR green I real-time reverse transcriptase polymerase chain reaction (RT-PCR) targeting the nucleocapsid gene of IBV was developed and compared with conventional agarose gel-based RT-PCR for the detection of IBV infection. Results: We found that the SYBR green I real-time RT-PCR was at least 10 times more sensitive than the agarose gel electrophoresis detection method. The assay exhibited high specificity for IBV infection. All negative controls, such as Newcastle disease virus, infectious bursal disease virus, and avian influenza virus, were not detected. Conclusion: The SYBR green I real-time RT-PCR test described herein can be used to rapidly distinguish IBV from other respiratory pathogens, which is important for diagnosis and control of infectious bronchitis outbreaks in Morocco. The test is a valuable and useful method as a routine assay for diagnosis of clinical IBV infection in commercial chickens. [ABSTRACT FROM AUTHOR]

The infection of chickens with avian Hepatitis E virus (avian HEV) can be asymptomatic or induces clinical signs characterized by increased mortality and decreased egg production in adult birds. Due to the lack of an efficient cell culture system for avian HEV, the interaction between virus and host cells is still barely understood. In this study, four truncated avian HEV capsid proteins (ORF2-1 – ORF2-4) with an identical 338aa deletion at the N-terminus and gradual deletions from 0, 42, 99 and 136aa at the C-terminus, respectively, were expressed and used to map the possible binding site within avian HEV capsid protein. Results from the binding assay showed that three truncated capsid proteins attached to avian LMH cells, but did not penetrate into cells. However, the shortest construct, ORF2-4, lost the capability of binding to cells suggesting that the presence of amino acids 471 to 507 of the capsid protein is crucial for the attachment. The construct ORF2-3 (aa339-507) was used to study the potential binding of avian HEV capsid protein to human and other avian species. It could be demonstrated that ORF2-3 was capable of binding to QT-35 cells from Japanese quail and human HepG2 cells but failed to bind to P815 cells. Additionally, chicken serum raised against ORF2-3 successfully blocked the binding to LMH cells. Treatment with heparin sodium salt or sodium chlorate significantly reduced binding of ORF2-3 to LMH cells. However, heparinase II treatment of LMH cells had no effect on binding of the ORF2-3 construct, suggesting a possible distinct attachment mechanism of avian as compared to human HEV. For the first time, interactions between avian HEV capsid protein and host cells were investigated demonstrating that aa471 to 507 of the capsid protein are needed to facilitate interaction with different kind of cells from different species. [ABSTRACT FROM AUTHOR]

A novel strain of duck reovirus (DRV) associated with a high mortality in Pekin ducklings in China, 2013, was isolated and characterized. This strain (designated as HN5d) grew well in Vero cells and produced marked cytopathic effects. HN5d contains 10 dsRNA genome segments, a typical feature of avian orthoreovirus. Following cloning, sequencing, and sequence analysis of the genome segments, a unique deletion of 18 amino acids was found in the sigma C protein of HN5d when compared with that of the recent Chinese waterfowl reoviruses (e.g., DRV 091). Phylogenetic analysis of cDNA amplicons of segments encoding for the outer capsid proteins revealed that HN5d is a novel genotype 2 waterfowl reovirus isolate. Inoculation of Pekin ducklings with HN5d resulted in splenic necrosis, a typical feature of “Duck spleen necrosis disease” (DSND) discovered in China in 2006. Unlike the typical DSND, HN5d produced severer hemorrhagic and/or necrotic lesions in livers of experimentally infected ducklings. 20–30% of death was observed during the first 7 day in the experimentally exposed birds. These findings suggest that HN5d is a novel duck reovirus isolate with severer pathogenicity in Pekin ducklings. [ABSTRACT FROM AUTHOR]

Avian orthoreoviruses cause various diseases in wild birds and domesticated poultry. In this study we report the detection and genomic characterization of a partridge ( Perdix perdix ) origin reovirus strain, D1007/2008. The virus was isolated on cell culture from acute pneumonia and infra-orbital sinusitis. The 23,497 nucleotide long genome sequence was obtained by combined use of semiconductor and capillary sequencing. Sequence and phylogenetic analyses showed that the partridge reovirus strain was related to orthoreoviruses of gallinaceous birds. In fact, five (λB, λC, μB, σC, σNS) and one (σB) out of 10 genes clustered definitely with turkey or chicken origin orthoreoviruses, respectively, whereas in the λA, μA, μNS and σA phylogenies a more distant genetic relationship was observed. Our data indicate that the identified reovirus strain is composed of a mixture of chicken and turkey orthoreovirus related alleles. This finding implies that partridges may serve as natural reservoirs for orthoreoviruses of domesticated poultry. [ABSTRACT FROM AUTHOR]

Newcastle disease (ND) is a highly devastating disease for the poultry industry as it causes high economic losses. In this present study, a DNA vaccine containing the F and HN surface antigens of a highly virulent Newcastle disease virus (NDV), NDV/1/Chicken/2005 (FJ939313), was successfully generated. Cell transfection test indicated that the vaccine expressed the F and HN genes in Hep-2 cells. The main objective of this study was to compare the extent of protection induced by DNA vaccination after homologous and heterologous NDV-challenge as determined by the amount of NDV shedding after challenge. NDV-antibody-negative chickens were vaccinated either once, twice or thrice intramuscularly at 7, 14 and 21 days old and were challenged 14 days post vaccination with either homologous virus (vaccine-matched velogenic viscerotropic Newcastle disease virus (vvNDV) strain, FJ939313), phylogenetically related to group VII, or a phylogenetically divergent heterologous virus (unmatched vvNDV strain, AY968809), which belongs to genogroup VI and shows 84.1% nucleotide similarity to the NDV-sequences of the DNA vaccine. Our data indicate that birds, which received a single dose of the DNA vaccine were poorly protected, and only 30–40% of these birds survived after challenge with high virus shedding titre. Multiple administration of the DNA vaccine induced high protection rates of 70–90% with reduced virus shedding compared to the non-vaccinated and challenged birds. Generally, homologous challenge led to reduced tracheal and cloacal shedding compared to the heterologous vvNDV strain. This study provides a promising approach for the control of ND in chickens using DNA vaccines, which are phylogenetically closely related to the circulating field strains. [ABSTRACT FROM PUBLISHER]

The transmission routes of duck astrovirus CPH (DAstV/CPH) and its pathogenicity in duck embryos were investigated. Using a reverse transcription-polymerase chain reaction (RT-PCR) developed in this study, DAstV/CPH was detected in 23/50 fresh droppings of breeder ducks, 39/65 breeding eggs, 26/31 dead embryos, and 6/10 newly hatched ducklings, which were taken from a Pekin duck farm where DAstV/CPH had previously been identified. This finding, and the detection of DAstV/CPH in 36/130 dead-in-shell duck embryo samples collected from different hatcheries located in six provinces, suggests that the virus may be horizontally and vertically transmitted and associated with hatchability problems. Inoculation and repeated passages in embryonating duck eggs resulted in isolation of DAstV/CPH. The virus caused severe chorioallantoic membrane lesions as well as growth retardation and embryo mortality, indicating that DAstV/CPH is pathogenic for duck embryos. The effect of DAstV/CPH on hatching was confirmed by an embryo infection experiment in which 8/10 9-day-old duck embryos inoculated with the third passage of DAstV/CPH were unable to hatch, with most embryos succumbing in the final stage of incubation. The use of RT-PCR on the hatched ducklings provided evidence that the embryos could develop into infected ducklings. [ABSTRACT FROM PUBLISHER]

Studies carried out on cell permissivity are of great interest to understand virus replication and pathogenicity. We described the results of a comparative analysis of replication efficiency of two naturally occurring influenza A H9N2 variants isolated from poultry and wild birds, differing by only two substitutions Q226L and T384N, in the receptor-binding site of haemagglutinin and the 380 loop region of NA proteins, respectively. Considering the overall growth of both viruses, lung cultures ensured the most efficient growth of TUN12L226N384 strain with titres up to 109 TCID50/ml whereas small intestine culture was highly susceptible to the TUN51Q226T384 virus reaching a titre of 106 TCID50/ml. The lowest replication was shown in liver cells. The addition of trypsin was essential for the replication of either virus in primary fibroblasts, but it had a marginal positive effect on virus replication in the four other culture types with maximum titres of 108 TCID50/ml. This means that in chicken, the proteolytic activation of the H9N2 viruses with the cleavage motif RSSR may be mediated by other endoproteases than trypsin. Further investigations should concentrate on the production of the appropriate set of viruses by a reverse genetics approach and the examination of cellular protease expression in chicken tissues. This would lead to a more complete understanding of the tropism of low-pathogenic Influenza A viruses. [ABSTRACT FROM AUTHOR]

In 2014, the highly pathogenic avian influenza (HPAI) virus H5N8 triggered outbreaks in wild birds and poultry farms in South Korea. In the present study, we investigated the pathogenicity of the H5N8 HPAI virus, belonging to the clade 2.3.4.4, in different species of poultry. For this, we examined clinical signs and viral shedding levels following intranasal inoculation of the virus in 3-week-old commercial layer chickens and quails, 10-week-old Korean native chickens, and 8-week-old Muscovy ducks. Intranasal inoculation with 106.0 viruses at 50% egg-infective dose resulted in 100% mortality in the layer chickens (8/8) and quails (4/4), but 60% and 0% deaths in the Korean native chickens (3/5) and Muscovy ducks (0/4), respectively. In addition, transmission of the inoculated virus to contact-exposed birds was evident in all the species used in this study. Based on our results, we conclude that the H5N8 HPAI virus has lower pathogenicity and transmissibility in poultry species compared with previously reported H5N1 HPAI viruses. [ABSTRACT FROM AUTHOR]

To understand the cytogenetic characteristics of acute fibrosarcoma in chickens infected with the subgroup J avian leukosis virus associated with the v-src oncogene, we performed a karyotype analysis of fibrosarcoma cell cultures. Twenty-nine of 50 qualified cell culture spreads demonstrated polyploidy of some macrochromosomes, 21 of which were trisomic for chromosome 7, and others were trisomic for chromosomes 3, 4, 5 (sex chromosome w), and 10. In addition, one of them was trisomic for both chromosome 7 and the sex chromosome 5 (w). In contrast, no aneuploidy was found for 10 macrochromosomes of 12 spreads of normal chicken embryo fibroblast cells, although aneuploidy for some microchromosomes was demonstrated in five of the 12 spreads. The cytogenetic mosaicism or polymorphism of the aneuploidy in the acute fibrosarcoma described in this study suggests that the analysed cells are polyclonal. [ABSTRACT FROM AUTHOR]

Enteric disorders are an important cause of economic losses in broiler chickens worldwide. Several agents have been associated with enteric problems, such as viruses, bacteria, and parasites. In this study, broiler chickens showing signs of enteric disorders were subjected to molecular diagnosis for several viral agents and also for pathological examination for elucidating this problem. Thus, the chickens were screened for avian nephritis virus (ANV), chicken astrovirus (CAstV), avian rotavirus (ArtV), avian reovirus (AReoV), infectious bronchitis virus (IBV), fowl adenovirus group I (FAdV-1), and chicken parvovirus (ChPV). Postmortem examinations revealed a curving of the duodenal loop (J-like appearance) and intestines filled with liquid and gaseous content. Histopathological analysis of the duodenal loop showed pancreatic atrophy, acute mesenteritis, and enteritis. PCR results showed that ChPV was the sole viral agent detected in samples with lesions such as the curved duodenal loop and pancreatic atrophy. Molecular characterization of the nucleotide and deduced amino acid sequences revealed a high similarity with other strains of ChPV from Brazil, Canada, United States, Europe, and Asia. These findings suggest an association between ChPV and the development of enteritis, pancreatitis, and pancreatic atrophy, which may lead to curling of the duodenal loop. Together, these alterations may disrupt the normal functioning of the digestive system, diminishing digestion and the absorption of dietary nutrients and consequently leading to reduced weight gain, flock impairment, dwarfism, and an elevated feed conversion rate. [ABSTRACT FROM AUTHOR]

Duck Tembusu virus (DTMUV) is a newly emerging pathogenic flavivirus that has caused massive economic losses to the duck industry in China. DTMUV infection mainly results in significant decreases in egg production in egg-laying ducks within 1-2 weeks post infection. However, information on the comparative protein expression of host tissues in response to DTMUV infection is limited. In the present study, the cellular protein response to DTMUV infection in duck ovarian follicles was analyzed using nano- flow high-performance liquid chromatography-electrospray tandem mass spectrometry. Quantitative proteomic analysis revealed 131 differentially expressed proteins, among which 53 were up regulated and 78 were down regulated. The identified proteins were involved in the regulation of essential processes such as cellular structure and integrity, RNA processing, protein biosynthesis and modification, vesicle transport, signal transduction, and mitochondrial pathway. Some selected proteins that were found to be regulated in DTMUV-infected tissues were screened by quantitative real-time PCR to examine their regulation at the transcriptional level, western blot analysis was used to validate the changes of some selected proteins on translational level. To our knowledge, this study is the first to analyze the proteomic changes in duck ovarian follicles following DTMUV infection. The protein-related information obtained in this study may be useful to understand the host response to DTMUV infection and the inherent mechanism of DTMUV replication and pathogenicity. [ABSTRACT FROM AUTHOR]

Phylogenetic analysis of the highly pathogenic avian influenza (HPAI) H5 viruses causing recent outbreaks in Taiwan showed that they belonged to the Asian HPAI H5 lineage, clade 2.3.4.4 viruses, and were apparently introduced by migratory birds. These viruses reassorted with Eurasian influenza gene pool viruses and formed five genotypic variants. As Taiwan has a similar influenza ecosystem to southern China, the HPAI H5 lineage could become established and enzootic in the island. [ABSTRACT FROM AUTHOR]

In Egypt, avian influenza A subtype H5N1 and H9N2 viruses are enzootic in poultry. The control plan devised by veterinary authorities in Egypt to prevent infections in poultry focused mainly on vaccination and ultimately failed. Recently, widespread H5N1 infections in poultry and a substantial increase in the number of human cases of H5N1 infection were observed. We summarize surveillance data from 2009 through 2014 and show that avian influenza viruses are established in poultry in Egypt and are continuously evolving genetically and antigenically. We also discuss the epidemiology of human infection with avian influenza in Egypt and describe how the true burden of disease is underestimated. We discuss the failures of relying on vaccinating poultry as the sole intervention tool. We conclude by highlighting the key components that need to be included in a new strategy to control avian influenza infections in poultry and humans in Egypt. [ABSTRACT FROM AUTHOR]

The main objective of this study was to determine the effects of various levels of dietary Nigella sativa seeds on immune-responsiveness and pathogenesis of H9N2 avian influenza virus (AIV) in turkeys. The experiment was performed on 80 unvaccinated turkey poults, divided into four groups of 20 birds each. Group A was kept as a non-infected, non-treated negative control; group B was inoculated intranasally with H9N2 AIV (106 EID50) at 4 wk of age; groups C and D were fed on diets containing 1% and 3%Nigella sativa seeds, respectively, from d 1 through the entire experiment period and inoculated intranasally with H9N2 AIV (106 EID50) at the wk 4 of age. Infected birds showed clinical signs of differing severity, with the most prominent disease signs appearing in birds of the H9N2 group. All infected birds showed positive results for virus shedding; however, the pattern of virus shedding was different, with birds of group B showing more pronounced virus secretion than the birds in the groups C and D, which were fed different levels of N. sativa. Moreover, significantly higher antibody titer against H9N2 AIV in group D birds show the immunomodulatory nature of N. sativa. Similarly, increased IFN-γ mRNA expression suggest antiviral behavior of N. sativa, leading to suppressed pathogenesis of H9N2 viruses in N. sativa-fed birds.This study showed that dietary supplementation with N. sativa seed at the level of 3% would enhance immune responsiveness and suppress pathogenicity of influenza viruses in turkeys. [ABSTRACT FROM AUTHOR]

The article presents the March 2016 issue of the journal "Avian Diseases."

Outbreaks of salpingitis and peritonitis cause major economic losses due to high mortality, reduced egg-production, and culling. The aim of the present study was to characterize, in detail, lesions associated with increased mortality in layers due to avianpathogenic Escherichia coli (APEC) and to investigate the population structure of the E. coli involved, which is important for selection of optimal treatment and prophylactic strategies. Among 322 layers received from eight farms with increased mortality due to E. coli, three lesion types were observed; sepsis-like lesions, chronic salpingitis and peritonitis, and chronic salpingitis and peritonitis associated with sepsis-like lesions. One hundred isolates of E. coli obtained in pure culture from the different lesion types were selected for genetic characterization. Six out of 10 submissions (two farms with two submissions) were considered clonal as defined by more than 85% of the typed isolates of E. coli belonging to the same sequence-type (ST). B2 was the most-prevalent phylogroup, including the clonal complex of ST95. The most-important virulence genes of E. coli were demonstrated from both clonal and nonclonal outbreaks, and major differences as to phylogeny and virulence genes were not observed between the lesion types. Cannibalism was more-often observed during polyclonal outbreaks . A new pathotype of APEC is suggested based upon lesions and route of infection, high similarity of virulence genes including plasmid-associated genes, and high frequency of ST95 and other isolates belonging to phylogroup B2. Compared to the best-known pathotypes of E. coli, this needs further investigations, including infection experiments to show if single virulence factors can be pointed out that are specific for the salpingitis-peritonitis pathotype and possibly not found in other pathotypes of E. coli. Caracterización patológica y molecular de Escherichia coli asociada con el síndrome de salpingitis y peritonitis aviar. Los brotes de salpingitis y peritonitis causan importantes pérdidas económicas debido a la alta mortalidad, la reducción de la producción de huevos, y el sacrificio de aves afectadas. El objetivo del presente estudio fue caracterizar, en detalle, las lesiones asociadas con una mayor mortalidad en gallinas de postura ocasionadas por Escherichia coli patógena para las aves (con las siglas en inglés APEC) y para investigar la estructura de la población de E. coli implicada, lo cual es importante para la selección del tratamiento y estrategias profilácticas óptimas. De 322 gallinas de postura recibidas de ocho granjas que mostraban aumento de mortalidad por E. coli, se observaron tres tipos de lesiones; lesiones de tipo septicémico, salpingitis crónica con peritonitis y salpingitis y peritonitis crónicas asociadas con lesiones de tipo septicémico. Cien aislamientos de E. coli obtenidos en cultivo puro de los diferentes tipos de lesiones fueron seleccionados para su caracterización genética. Seis de diez casos diagnósticos (dos granjas enviaron dos casos) fueron considerados que provenían de un mismo clon que se define en que más del 85% de los aislamientos tipificados de E. coli pertenecen al mismo tipo de secuencia (ST). El filogrupo B2 fue el más prevalente, incluyendo el complejo clonal de ST95. Los genes de virulencia más importantes E. coli se demostraron de ambos brotes clonales y no clonales y las principales diferencias relacionadas con la filogenia y con los genes de virulencia no fueron observadas entre los tipos de lesiones. El canibalismo se observó más frecuentemente durante los brotes policlonales. Se sugiere un nuevo patotipo de Escherichia coli patógena para las aves con base a las lesiones y a la vía de infección, por la alta similitud de genes de virulencia incluyendo genes plásmidos asociados y por la alta frecuencia de ST95 y de otras cepas pertenecientes al filogrupo B2. En comparación con los patotipos más conocidos de E. coli, éste necesita más investigaciones, incluyendo experimentos de infección para mostrar si factores de virulencia individuales se pueden señalar como específicos para el patotipo asociado con salpingitis y peritonitis y, posiblemente que no se encuentren en otros patotipos de E. coli. [ABSTRACT FROM AUTHOR]

The article presents guidelines for authors of the journal "Avian Diseases."

Infectious bursal disease virus (IBDV) is an important pathogen of chickens causing negative economic impacts in poultry industries worldwide. IBDV has a variable range of virulence, with very virulent (vvIBDV) strains being responsible for the greatest losses from mortality and decreased performance. Previous vvIBDV studies using conventional broilers reported resistance to lethal effects and decreased performance as compared to specific-pathogen-free (SPF) layers, but the potential contribution of the conventional vs. SPF status to resistance has not been examined. In this study we compared differences in the acute pathologic effects of infection by the California rA strain of vvIBDV for SPF white leghorn egg-laying chickens and SPF white Plymouth Rock broiler chickens over a 7-day experimental period. Based on the clinical signs and mortality observed, as well as on the more-severe pathologic changes in lymphoid tissues and kidneys, white leghorns were shown to be more susceptible to the deleterious effects of vvIBDV infection than were white Plymouth Rocks. This study provides important information on the impact of chicken breed on susceptibility to vvIBDV and the absence of impact from conventional vs. SPF status on the outcome. El virus muy virulento de la enfermedad infecciosa de la bolsa produce una enfermedad y lesiones más severas en aves tipo Leghorn libres de patógenos específicos (LPE) en comparación con pollos de engorde LPE. El virus de la enfermedad infecciosa de la bolsa (con las siglas en Inglés IBDV) es un patógeno importante de los pollos que causa impacto económico negativo en la industria avícola en todo el mundo. El virus de Gumboro tiene un rango variable de virulencia, con cepas muy virulentas (vvIBDV) que son responsables de las mayores pérdidas por mortalidad y disminución del rendimiento. Estudios anteriores con cepas muy virulentas utilizando pollos de engorde convencionales mostraron que estas aves tenían resistencia a los efectos letales y a la disminución en el rendimiento en comparación con aves ligeras libres de patógenos específicos, pero no se ha examinado la contribución potencial de las aves convencionales en comparación con el estado libre de patógenos específicos. En este estudio, se compararon las diferencias en los efectos patológicos agudos de infección por la cepa muy virulenta de Gumboro California rA para aves de postura tipo Leghorn libres de patógenos específicos y en pollos de engorde Plymouth Rock libres de patógenos específicos durante un periodo experimental de siete días. Con base en los signos clínicos y en la mortalidad observada, así como en los cambios patológicos más severos en los tejidos linfoides y en los riñones, las aves Leghorn mostraron ser más susceptibles a los efectos patológicos por la infección por cepas muy virulentas del virus de Gumboro en comparación con las aves Plymouth Rock blancas. Este estudio proporciona información importante sobre el impacto de la raza de pollo en la susceptibilidad a un virus muy virulento de Gumboro y la ausencia de impacto de aves convencionales en comparación con el estado libre de patógenos específicos en el resultado. [ABSTRACT FROM AUTHOR]

Please see the PDF version of the front matter. [ABSTRACT FROM AUTHOR]

Chicken anemia virus (CAV) is a widespread chicken pathogen of significant economic importance. In 2013, broiler chicken flocks in Poland were examined for the presence of CAV, and phylogenetic relatedness between the strains was established. Ten cloacal swabs from each of 106 broiler flocks (birds aged 3-6 wk) were collected in different regions of the country and tested with the use of real-time PCR (all samples) and conventional PCR (those samples positive in real-time PCR) assays. The presence of CAV was detected in 16 of the flocks tested. Phylogenetic analysis clearly confirmed the existence of genetic diversity within the group of circulating CAV strains and their distinctiveness from vaccine strains used in Poland. Nota de investigación- Presentación y estudios filogenéticos del virus de la anemia infecciosa del pollo de parvadas de pollos de engorde en Polonia. El virus de la anemia del pollo (con las siglas en inglés CAV) es un patógeno de pollo ampliamente difundido de importancia económica significativa. En el año 2013, se examinaron parvadas de pollo de engorde en Polonia para detectar la presencia del virus de la anemia infecciosa, y se estableció una relación filogenética entre las cepas. Se recolectaron diez hisopos cloacales por parvada de un total de 106 parvadas de pollo de engorde (aves de entre tres a seis semanas) de diferentes regiones del país y se analizaron mediante el uso de PCR en tiempo real (todas las muestras) y mediante PCR convencional (solo las muestras positivas mediante el PCR en tiempo real). Se detectó la presencia del virus de la anemia en 16 de las parvadas analizadas. El análisis filogenético confirmó claramente la existencia de diversidad genética dentro del grupo de las cepas circulantes del virus de la anemia infecciosa y su diferenciación de las cepas vacunales utilizadas en Polonia. [ABSTRACT FROM AUTHOR]

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Please see the PDF version of these advertisements. [ABSTRACT FROM AUTHOR]

Background: Newcastle disease (ND), which is caused by the Newcastle disease virus (NDV), is one of the most important avian diseases in poultry. Since its discovery in 1926, ND has caused great economic losses to the world poultry industry and remains a threat to chickens and wild birds. Although a stringent vaccination policy is widely adopted to control ND, ND outbreaks still occur, and virulent NDV is sporadically isolated from chickens and wild birds. To study the pathogenesis of ND and provide tools to prevent its prevalence, novel antibody fragments should be developed. The variable domains of the heavy chain of the heavy-chain antibodies (VHH) are the smallest naturally occurring antibodies derived from camelid heavy-chain antibodies. The comparatively small size, high affinity, high solubility, low immunogenicity and ability to bind epitopes inaccessible to conventional antibodies of VHH make them ideal candidates for a considerable number of therapeutic and biotechnological applications. However, an anti-NDV VHH has not been reported to date. Results: In this study, a VHH yeast two-hybrid library was constructed from NDV vaccine immunized C. bactrianus, and seven VHH fragments to the haemagglutinin-neuraminidase (HN) protein of NDV were successfully screened and characterized for the first time. These selected VHH clones were all expressed as soluble protein in E. coli. ELISA, dot blot, immunocytochemistry and pull down results showed that the screened VHHs could interact with NDV virion, among which five had neutralizing activity. In addition, the seven VHHs could inhibit the haemagglutination activity of different NDV strains. Conclusions: We constructed an NDV-immunized VHH yeast two-hybrid library and screened and characterized seven VHHs targeting NDV HN protein for the first time. The seven VHHs may have great potential for NDV diagnosis, pathogenesis and therapeutics. [ABSTRACT FROM AUTHOR]

Since early 2014, several outbreaks involving novel reassortant highly pathogenic avian influenza ( HPAI) A(H5N8) viruses have been detected in poultry and wild bird species in Asia, Europe and North America. These viruses have been detected in apparently healthy and dead wild migratory birds, as well as in domestic chickens, turkeys, geese and ducks. In this study, we describe the pathology of an outbreak of H5N8 HPAIV in breeder ducks in the UK. A holding with approximately 6000 breeder ducks, aged approximately 60 weeks, showed a gradual reduction in egg production and increased mortality over a 7-day period. Post-mortem examination revealed frequent fibrinous peritonitis, with severely haemorrhagic ovarian follicles and occasional splenic and pancreatic necrosis and high incidence of mycotic granulomas in the air sacs and lung. Low-to-moderate levels of HPAI H5N8 virus were detected mainly in respiratory and digestive tract, with minor involvement of other organs. Although histopathological examination confirmed the gross pathology findings, intralesional viral antigen detection by immunohistochemistry was not observed. Immunolabelled cells were rarely only present in inflamed air sacs and serosa, usually superficial to granulomatous inflammation. Abundant bacterial microcolonies were observed in haemorrhagic ovaries and oviduct. The limited viral tissue distribution and presence of inter-current fungal and bacterial infections suggest a minor role for HPAIV H5N8 in clinical disease in layer ducks. [ABSTRACT FROM AUTHOR]

Highly virulent fowl aviadenoviruses (genus: Aviadenovirus) represent a significant risk in poultry farming that may contribute to increased mortality rates and may adversely affect the growth performance of poultry flocks. In this study, we performed the clinicopathological characterization of a FAdV strain SHP95 isolated from a commercial farm and its whole genome sequencing. The study revealed that the isolated strain is a highly virulent serotype 4 FAdV that can cause 100% mortality in day-old specific pathogen free (SPF) chickens with a dose of 2.5 × 105 TCID50. At a lower viral dose (1.5 × 104 TCID50), the infection in day-old SPF chickens caused 40% mortality and lesions characteristic for Hepatitis-hydropericardium syndrome (HHS). The viral strain was detectable by real time PCR in chicken organs, including the lymphoid organs until day 28 after infection. The whole genome assembly of strain SHP95 revealed a size of 45,641 bp, which encodes for 42 viral open reading frame (ORF). The comparative analysis in the genome shows 98.1% similarity between strain SHP95 and other FAdV-4 genomes reported. The major differences in the genome sequence between pathogenic and non-pathogenic fowl Adenovirus were identified in the right arm of the genome. [ABSTRACT FROM AUTHOR]