Search

Copyright of Journal of Management & Agribusiness / Jurnal Manajemen & Agribisnis is the property of IPB University 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.)

Infectious bronchitis virus (IBV) is an avian coronavirus (CoV) that belongs to the genus Gammacoronavirus and has been listed as an important disease by the World Organization for Animal Health (WOAH). It causes highly contagious respiratory, reproductive, and renal diseases in commercial poultry farms. Multiple IBV serotypes and genotypes have been identified in many countries and many detected variants do not provide cross-protection against infection, resulting in repeated outbreaks and significant economic losses worldwide. In addition, the high genetic mutations and recombination events in the prominent genomic regions of IBV, particularly in the spike glycoprotein (S) and nucleocapsid (N) proteins, are directly involved in the evolutionary processes of IBV and lead to increased pathogenicity and tissue tropism. The characterization of the different genotypes and the relationship between the structure, function, post-translational modifications (PTMs), and structural motifs will elucidate the mechanisms that promote replication and pathogenicity and affect the host's immune response during infection. In this review, we discuss the molecular features of various IBV genes and proteins that contribute to the infection process. We also highlight the common PTMs and structural motifs that occur during protein synthesis and are essential components of IBV ecology. [ABSTRACT FROM AUTHOR]

Traditional local chicken farming, as opposed to commercial poultry breeds, faces numerous disease-related challenges, with one of the prominent threats being the Newcastle disease virus. This case report describes 8-week-old local hens infected with the Newcastle disease virus detected through epidemiological aspect, pathological, and virology investigations. The morbidity of this farm was 65%, with 20% mortality and 30.7% case fatality rate. The anatomopathology and histopathology examination revealed pathological changes in various organs. Laboratory tests using the Haemmaglutination-Inhibition and Haemmaglutination assays confirmed the presence of the Newcastle disease virus. Based on clinical symptoms, anatomopathological findings, histopathological analysis, virus isolation, and identification, it is concluded that the affected hens were infected with viscerotropic velogenic Newcastle disease. [ABSTRACT FROM AUTHOR]

In this study, newcastle disease vaccine-chitosan nanoparticles (NDV-CS-NPs) are developed for the in ova vaccination of live NDV vaccine and immune response in chickens. Chitosan nanoparticles formed by ionic cross linked method, particles size of CS-NPs was 25 nm with recovery percent. NDV carrying chitosan nanoparticles (NDV-CS-NPs) was produced with good morphology and λ peak was 25 nm and examined under electron microscope (transmission electron microscope) TEM was appeared round shape and good dispersion. EID50 of NDV-CS-NPs was 105.7 /0.1ml. In this experiment, 500 fertile egg incubated at 37.5C0 and 55% humidity for 18day from incubation then candled and divided to 4 groups, G1 left without any treatment (C-), G2 treated with 0.1ml chitosan nanoparticles (CS-NPs) (C+), G3 treated with NDV vaccine (B1) EID50 108.7 (ordinary), while G4 treated with 0.1 ml of NDV-CS-NPs was 108.7. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agricultural, Environmental & Veterinary Sciences is the property of Arab Journal of Sciences & Research Publishing (AJSRP) 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.)

Highly pathogenic avian influenza (HPAI) A(H5) viruses belonging to clade 2.3.4.4c of the A/goose/Guangdong/1/96-like (Gs/GD) lineage caused severe global outbreaks in domestic birds from 2014 to 2015, that also represented the first incursions of Gs/GD viruses into Taiwan and the USA. However, few studies have investigated the circulation of clade 2.3.4.4c viruses after 2015. Here, we describe Gs/GD clade 2.3.4.4c and Mexican-like H5N2 viruses that were isolated in Taiwan during active surveillance conducted in chicken farms from February to March 2019. Phylogenetic analysis demonstrated two distinct genome constellations of the clade 2.3.4.4c H5 viruses, with the internal genes of one of the new genotypes closely related to a virus isolated from a pintail (Anas acuta) in Taiwan, providing the first direct evidence that migratory birds play a role in importing viruses into Taiwan. Our study also confirmed the co-circulation of Gs/GD clade 2.3.4.4c and Mexican-like H5 lineage viruses in Taiwan, presenting a rare case where Gs/GD viruses developed sustained transmission alongside another enzootic H5 lineage, raising the possibility that homosubtypic immunity may mask virus transmission, potentially frustrating detection, and the implementation of appropriate control measures. To eradicate H5 viruses from poultry in Taiwan, further studies on the effect of co-circulation in poultry of low pathogenic avian influenza and HPAI viruses are needed. Furthermore, only with continued surveillance efforts globally can we fully discern dispersal patterns and risk factors of virus transmission both to and within Taiwan. [ABSTRACT FROM AUTHOR]

The article focuses on Weblogs that disseminates rumors about the H5N1. The Web site of virologist Henry Niman is a virtual situation room for bird flu news, boasting color-coded maps tracking confirmed and suspected outbreaks of H5N1 in Indonesia, China and Europe. A newsfeed on the site, updated daily, offers commentary and background on reports culled from around the world. Revere, a prominent public health scientist and academic, maintains the highly regarded Web site Effect Measure. The Flu Wiki site acts a sort of homeland security guide for local communities on how to prepare for and cope with potential flu outbreaks. INSET: BEST OF THE BULLETIN ARCHIVE: Infectious disease.

Background: There is paucity of data on the virulence of highly pathogenic (HP) avian influenza viruses (AIV) H7 in ducks compared to HPAIV H5. Here, the virulence of HPAIV H7N1 (designated H7N1-FPV34 and H7N1-It99) and H7N7 (designated H7N7-FPV27) was assessed in Pekin and/or Muscovy ducklings after intrachoanal (IC) or intramuscular (IM) infection. Results: The morbidity rate ranged from 60 to 100% and mortality rate from 20 to 80% depending on the duck species, virus strain and/or challenge route. All Muscovy ducklings inoculated IC with H7N7-FPV27 or H7N1-FPV34 exhibited mild to severe clinical signs resulting in the death of 2/10 and 8/10 ducklings, respectively. Also, 2/10 and 6/9 of inoculated Muscovy ducklings died after IC or IM infection with H7N1-It99, respectively. Moreover, 5/10 Pekin ducklings inoculated IC or IM with H7N1-It99 died. The level of virus detected in the oropharyngeal swabs was higher than in the cloacal swabs. Conclusion: Taken together, HPAIV H7 cause mortality and morbidity in Muscovy and Pekin ducklings. The severity of disease in Muscovy ducklings depended on the virus strain and/or route of infection. Preferential replication of the virus in the respiratory tract compared to the gut merits further investigation. [ABSTRACT FROM AUTHOR]

Highlights • Study the pathogenicity of DTMUV from infection to recovery in duck spleen using HE staining. • Study the pathological change of duck spleen infected by DTMUV in using TEM for the first time. • Study the molecular mechanism of DTMUV infecting duck spleen from infection to recovery by RNA-seq. Abstract Duck Tembusu virus (DTMUV) is a novel member of flavivirus with the highest viral loads in the spleen. Six-month egg-laying shelducks were intramuscularly injected with DTMUV strain XZ-2012. Morphological analysis revealed the presence of vacuolar degeneration in the periellipsoidal lymphatic sheaths (PELS) of spleen white pulp following infection, especially from 12 hpi to 3 dpi. Ultrastructural images showed an obvious swelling of cells and their mitochondria and endoplasmic reticulum. Using RNA-seq analysis, the expression levels of RIG-I like receptors (RLRs), downstream IRF7 and proinflammatory cytokines IL-6 from RIG-I signaling pathway were non-apparently upregulated at 2 hpi and apparently at 3 dpi, while MHC-II expression was obviously downregulated at 2 hpi. The expression levels of downstream antiviral cytokines type-I IFNs, anti-inflammatory cytokines IL-10, cell adhesion molecules (CAMs), chemokines and their receptors associated with lymphocyte homing were significantly upregulated at 3 dpi. The population of lymphocyte was increased at 6 dpi. The immune function of spleen was recovered starting from 9 dpi. These findings of this study suggest that DTMUV invaded into the spleen via RIG-I signaling pathway and enhanced immune evasion by inhibiting MHC-II expression during the early stage of infection. Additionally, DTMUV induced PELS lesions through activating IL-6 expression. Furthermore, DTMUV increased the expression levels of RLRs, antiviral type-I IFNs, lymphocyte homing-related genes and proteins as well as the number of lymphocytes in the infected duck spleen. Taken altogether, this study provides new insights into the cellular and molecular mechanisms of DTMUV infection in duck spleen. [ABSTRACT FROM AUTHOR]

Highlights • CSFV non-structural proteins modulate TLR signaling pathways in pMDMs. • The expression of NS4B protein may disrupt TLR-TRIF signaling pathways in the pMDMs. • NS5A probably activates TLR-MyD88 signaling pathways in the pMDMs. Abstract Toll-like receptors (TLRs) are crucial activators of the innate immune response that play various roles in viral infection. Studies have confirmed that classical swine fever virus (CSFV) infection has significant effects on the expression of immune effectors participating in TLR signaling pathways; however, the involvement of CSFV-encoded proteins in TLR signaling pathways remains unclear. In this study, lentiviral individually expressing CSFV non-structural proteins (NSPs) were constructed to identify the "key proteins" that affect TLR gene expression and to analyze the impacts of these proteins on factors downstream of the TLR signaling pathways. The results indicated that Npro, NS2, NS3, NS3/4A, NS4B and NS5A all failed to induce the activation of NF-κB p65. Furthermore, NS4B was found to inhibit poly (I:C) stimulation-mediated activation of the TLR3 signaling pathway in porcine monocyte-derived macrophages (pMDMs), thereby suppressing the TRIF mRNA transcription, the IRF3 protein translation and the NF-κB p65 phosphorylation, and ultimately affecting the secretion of IL-6 and IFN-β; CSFV NS5A protein could significantly increase the activation of MyD88 and IRF7 as well as the consequent synthesis of IFN-α in pMDMs. The results suggest that CSFV NSPs affect TLR-mediated innate immune responses in pMDMs. [ABSTRACT FROM AUTHOR]

Highlights • 1 DEV infection increased the expression of duck IFN-β both in vivo and in vitro. • 2 DEV infection increased the expression of duck RIG-I both in vivo and in vitro. • 3 Duck RIG-I inhibited viral infection. • 4 The antiviral activity of duck RIG-I is STAT1-dependent. Abstract Retinoic acid-inducible gene I (RIG-I) is a nucleic acid sensor that plays a key role in host antiviral defenses. Duck viral enteritis (DEV) is a DNA virus that causes significant economic losses to the poultry industry worldwide. Although RIG-I is known to be involved in a common antiviral signaling pathway triggered by RNA viruses, its role in DEV infection remains unclear. In this study, we demonstrated that DEV infection increased the expression levels of interferon β (IFN-β) and RIG-I in ducks both in vivo and in vitro. Furthermore, overexpression of duck RIG-I significantly upregulated the expression of interferon-stimulated genes, including myxovirus resistance protein (Mx), Interferon-induced oligodenylate synthetase-like (OASL) and IFN-β. We therefore used overexpression and knockdown methods to determine if RIG-I affected DEV infection in ducks. Viral infection was inhibited by RIG-I, and enhanced by knockdown of RIG-I expression using small interfering RNA. RIG-I overexpression also activated signal transducer and activator of transcription 1 (STAT1), as a member of the JAK-STAT family. The combined results following STAT1 knockdown and RIG-I overexpression suggested that the antiviral activity of RIG-I was STAT1-dependent. Overall, these findings indicate that RIG-I effectively restricts DEV replication and may play a vital role in the host immune response to DEV infection in ducks. [ABSTRACT FROM AUTHOR]

The PA-X protein of influenza A virus has roles in host cell shut-off and viral pathogenesis. While most strains are predicted to encode PA-X, strain-dependent variations in activity have been noted. We found that PA-X protein from A/PR/8/34 (PR8) strain had significantly lower repressive activity against cellular gene expression compared with PA-Xs from the avian strains A/turkey/England/50-92/91 (H5N1) (T/E) and A/chicken/Rostock/34 (H7N1). Loss of normal PA-X expression, either by mutation of the frameshift site or by truncating the X-ORF, had little effect on the infectious virus titre of PR8 or PR8 7:1 reassortants with T/E segment 3 grown in embryonated hens' eggs. However, in both virus backgrounds, mutation of PA-X led to decreased embryo mortality and lower overall pathology; effects that were more pronounced in the PR8 strain than the T/E reassortant, despite the low shut-off activity of the PR8 PA-X. Purified PA-X mutant virus particles displayed an increased ratio of HA to NP and M1 compared to their WT counterparts, suggesting altered virion composition. When the PA-X gene was mutated in the background of poorly growing PR8 6:2 vaccine reassortant analogues containing the HA and NA segments from H1N1 2009 pandemic viruses or an avian H7N3 strain, HA yield increased up to 2-fold. This suggests that the PR8 PA-X protein may harbour a function unrelated to host cell shut-off and that disruption of the PA-X gene has the potential to improve the HA yield of vaccine viruses. [ABSTRACT FROM AUTHOR]

Highlights • A genotype VII Newcastle disease virus-like particles was constructed. • It can stimulate sufficient specific antibody response in commercial layers. • It conferred full protection and provide shorter virus shedding period. Abstract Newcastle disease (ND) is one of the most severe avian infectious disease inflicting a great loss on poultry industry worldwide. The control of ND relies on proper vaccination strategies. The vaccine strains of Newcastle disease virus (NDV) mainly belong to genotype I, II or III, which cannot fully prohibit virus shedding against the prevalent genotype VII virulent strain attack. To develop a safe, genotype matched vaccine candidate, we employed a bac-to-bac expression system and constructed a genotype VII NDV strain based virus-like particles (NDV VLPs). It was constructed with NDV M protein as the skeleton, and protective antigen F and HN proteins displayed on the surface. The NDV VLPs exhibited a similar appearance to the live NDV particles, but with denser F and HN proteins displayed on the surface. The immunization assay indicated that NDV VLPs stimulated a longer protection period, less tissue virus loading and shorter virus shedding period than the commercialized LaSota-formulated vaccine when challenged with genotype VII NDV strain. These results proposed the potential role of NDV VLPs as an alternative to current live genotype unmatched vaccine for the control and eliminate NDV in the avian flocks. [ABSTRACT FROM AUTHOR]

Newcastle disease (ND) is an economically important, contagious poultry viral disease reported across the globe. In India, ND is endemic and episodes of ND outbreaks despite strict vaccinations are not uncommon. We isolated and characterized seven ND viruses from vaccinated commercial poultry farms during severe disease outbreaks in Tamil Nadu, in Southern India, between April 2015 and June 2016. All the seven isolates were categorized as virulent by mean death time (48–54 hr) in embryonated chicken eggs. Also, their sequences carried the virulence signature of multi‐basic amino acid residues in their fusion protein cleavage site (RRQ/RR/KRF). Phylogenetic and evolutionary distance analyses revealed circulation of a novel sub‐genotype of genotype XIII, class II ND viruses, herein proposed as sub‐genotype XIIIe. The genetic divergence between the circulating virulent strains and the vaccine strains could possibly explain the disease outbreak in the vaccinated flocks. Further, our study signifies the need to implement routine epidemiological surveillance and to revisit the current vaccination program. [ABSTRACT FROM AUTHOR]

The H8 subtype viruses are rarely isolated from wild ducks. Shanghai is one of the important wintering or stopover sites on the East Asia-Australia Migration Flyway. An influenza virus, subtype H8N4, was firstly isolated from a common teal (Anas crecca) in Shanghai during 2017-2018 in this study. To clarify the genetic characteristics of the H8N4 virus, the whole genome sequences were analyzed. Phylogenetic analysis of the hemagglutinin and neuraminidase genes showed that they shared highest nucleotide identity (99.19%-99.64%) with the Japan duck-origin H8N4 virus collected in 2016 (A/duck/Aichi/231003/2016) and belonged to the Eurasian-like avian lineage. Six other genes of the H8N4 isolated virus were all highly similar to the corresponding genes of a wide range of AIV subtypes including H9N2, H5N7, H3N8, H1N2, H4N6 and H1N1. The results indicated that the H8N4 virus was a multiple reassortant virus. The study emphasized that the continuous surveillance of influenza virus in wild birds should be strengthened. [ABSTRACT FROM AUTHOR]

The avian adeno-associated virus (AAAV) is a replication-defective nonpathogenic virus that has been proved to be useful as a viral vector in gene delivery. In this study, the feasibility of AAAV for transgenic expression of duck hepatitis A virus (DHAV) VP3 structural protein and its ability to induce protective immunity in ducklings was assessed. The recombinant AAAV (rAAAV-VP3) expressing the VP3 protein was prepared by co-infection of Sf9 cells with recombinant baculovirus (rBac-VP3) containing VP3 gene flanked by inverted terminal repeats (ITRs) of AAAV and the other two recombinant baculovirus expressing AAAV functional and structural genes, respectively. The generation of rAAAV-VP3 was demonstrated by electron microscopy, immunofluorescence assay, and western blot analysis. One day old ducklings were inoculated with rAAAV-VP3 or commercial attenuated vaccine and then challenged with DHAV-1 strain SH two weeks post vaccination. Anti-DHAV-1 antibodies were detected in all vaccinated groups by ELISA, and the titers between the rAAAV-VP3 group and the attenuated vaccine group were not statistically significant. Real time RT-PCR analysis showed that the virus copy numbers in the livers of the PBS control group were significantly higher than that of the rAAAV-VP3 and attenuated vaccine groups. In conclusion, we demonstrated that the VP3 expression mediated by rAAAV in ducklings could induce protective immunity against DHAV challenge, and this could be a candidate vaccine for the control of duck viral hepatitis. [ABSTRACT FROM AUTHOR]

Chicken infectious anemia (CIA) is an immunosuppressive disease that causes great economic loss in poultry industry globally. This disease is caused by chicken anemia virus (CAV), an icosahedral and single-stranded DNA virus that is transmitted both vertically and horizontally. CAV, which belongs to the genus Gyrovirus has been reported in human, mouse and dog feces. Rapid identification of different strains of gyrovirus with high similarity to CAV has heightened public concern on this virus. Clinical symptoms of this disease such as intramuscular hemorrhage, weight loss, anemia and bone marrow aplasia are prominent in young chickens, while adult chickens experience subclinical symptoms. Biosecurity measures such as good management practice and vaccination have been the most reliable control strategy against this virus. Therefore, this study reviews the current state of CAV under the following subheadings (i) Chicken anemia virus (ii) Pathogenesis of CAV (iii) Serological evaluation of host antibodies to CAV (iv) Association of Marek's disease and infectious bursa disease with CAV infection (v) Genetic diversity and phylogenetics of CAV strains (vi) Current and future vaccine strategy in the control of CAV. In conclusion, improvement on DNA and recombinant vaccines strategy could curtail the economic impact of CAV on poultry birds. [ABSTRACT FROM AUTHOR]

Summary: Duck Tembusu virus (DTMUV) has been reported in ducks raised in farming system since its emergence in 2010. No information is available on DTMUV infection in free‐grazing ducks, which are commonly raised and widespread in several Asian countries. To determine the presence of DTMUV infection in free‐grazing ducks in Thailand, retrospective serum samples collected from 1,000 free‐grazing ducks during 2008–2015 were tested for DTMUV infection. Our result showed that 91 (9.10%) were positive for DTMUV neutralizing antibodies and DTMUV seropositive ducks have been detected in Thailand since 2008. To further investigate the seroprevalence and geographic distribution of DTMUV infection in free‐grazing ducks in Thailand, a cross‐sectional serological survey of DTMUV was conducted in 2016. Of 1,200 free‐grazing ducks in the 60 flocks from 20 provinces located in the major free‐grazing duck raising areas of Thailand, 365 (30.42%) were positive for DTMUV neutralizing antibodies and 56 flocks (93.33%) had at least one DTMUV seropositive duck. Additionally, DTMUV seropositive ducks were observed in all provinces tested. In conclusion, our data demonstrated the presence of DTMUV infection in free‐grazing ducks since 2008 and widespread DTMUV infection in free‐grazing ducks in Thailand with a relatively high seroprevalence. These findings suggest the potential role of free‐grazing ducks in the dissemination of DTMUV and highlight the necessity of systemic DTMUV surveillance in free‐grazing ducks in addition to farm ducks for early detection, prevention, and control of this emerging disease. [ABSTRACT FROM AUTHOR]

Protection against diseases caused by avian viruses is achieved by vaccination with different forms of vaccines, the best protection being attained using live vaccines. The live vaccine application is a very complex procedure that receives marginal attention, in spite of its crucial importance for vaccination success. As a result of our recent development focusing on the vaccine uptake evaluation using feathers, we put in practice that methodology in order to answer reservations regarding the vaccine application in several commercial flocks following vaccination. The present study describes five conundrums concerning Marek's Disease vaccination and four conundrums regarding Infectious laryngotracheitis (ILTV) vaccination, demonstrating the power and usefulness of this new approach to monitor vaccine application. We were able to detect various operational situations, including improper calibration of the Marek's disease virus (MDV) vaccination device, improper administration of the ILTV vaccine in drinking water, however we also demonstrated cases where adequate MDV vaccinations of various flocks were performed. Each case was described separately regarding the specific problem, the examination details and the conclusions drawn following the vaccine virus uptake in the feathers of the commercial chickens. [ABSTRACT FROM AUTHOR]

Highlights • This manuscript provides the first substantive review of Spotty Liver Disease (SLD) in context with the current knowledge about C. hepaticus , the recently discovered (2015) infectious cause of the disease. • The work also reflects in a comparative manner on earlier reports of a similar disease known as Avian Vibrionic Hepatitis (AVH) described in the 1950′s that had all the hallmarks of SLD, but for which an aetiological agent was not confirmed. • SLD is a significant infectious disease of layer poultry commercially farmed in barn or free-range systems that was described in the 1980s, however the recent discovery of the aetiological agent means that the pathobiology and epidemiological aspects of the agent remain to be fully elucidated. • Consequently, the review not only provides a comparative analysis of AVH and SLD, but also provides a comprehensive overview of the body of knowledge that has evolved since about the isolation, characterisation, pathobiology, genomics and epidemiology of C. hepaticus. Abstract Spotty Liver Disease is an acute infectious disease of layer chickens that was likely first described in the USA and Canada in the 1950s and 1960′s. The disease occurs almost exclusively in barn and free-range production systems. Outbreaks usually, but not exclusively occur in young layers (≅25 weeks) at peak of lay. Indicators of SLD include an acute drop in egg production of up to 35%, together with increased mortality of up to 15%. A presumptive diagnosis at post mortem is made with the detection of characteristic small yellow-white necrotic hepatic lesions, together with a fibrinous peri-hepatitis, excess pericardial and peritoneal fluid, and usually enteritis with diarrhoea. Histopathology reveals a multifocal acute hepatocellular necrosis with fibrin and occasional haemorrhage. Control measures trialled include use of antibiotics, improved biosecurity and hygiene, as well as management practices directed at reducing stress in flocks. However, none other than treatment with antibiotics has been consistently effective which suggested a bacterial aetiology. In 2015, a novel fastidious thermophilic, microaerobic campylobacter was isolated from symptomatic SLD flocks in the UK. Subsequently, an Australian group isolated and further characterised a genetically similar bacterium and named it Campylobacter hepaticus. The bacterium can be cultured from the liver and bile of infected birds, although recovery from non-sterile organs such as the caecum and duodenum remains elusive. Consequently, the route of transmission remains unconfirmed, although molecular detection by PCR of C. hepaticus DNA in the gastrointestinal tract and faeces of SLD infected birds is highly suggestive of a faecal-oral route. [ABSTRACT FROM AUTHOR]

Despite the purported role of avian pox (Avipoxvirus spp.) in the decline of endemic Hawaiian birds, few studies have been conducted on the dynamics of this disease, its impact on free‐living avian populations, or its interactions with avian malaria (Plasmodium relictum). We conducted four longitudinal studies of 3–7 yr in length and used generalized linear models to evaluate cross‐sectional prevalence of active pox infection and individuals with healed deformities that had recovered from pox. Our goal was to understand how species, season, elevation, malaria infection, and other biological characteristics influenced pox infection in ʻApapane, Hawaiʻi ʻAmakihi, ʻIʻiwi, and Japanese White‐eye across low‐, mid‐, and high‐elevation forests on the island of Hawaiʻi. We also used multi‐state capture‐recapture (longitudinal) models to estimate pox infection rates, recovery rates, and potential pox‐related mortality. Pox infection rates were typically highest in low‐elevation forests, followed by mid‐elevation forests, and lowest in high‐elevation forests. We also found seasonal changes in pox prevalence throughout the annual cycle; typically increasing from spring through summer, peaking in fall, and declining in winter. These seasonal changes occurred in low‐ and mid‐elevation forests, but not in high elevations where pox infection was low. Seasonal and elevation patterns of pox infection are like those for avian malaria, strongly implicating mosquito vectors, rather than other biting arthropods or contact transmission, as the primary source of transmitting both diseases. Most native Hawaiian birds recovered from pox infection within 6 months; frequently without permanent lesions. Contrary to our expectations, we found no direct evidence that pox is a substantial mortality factor in any of the three native bird species we studied. Birds with chronic malaria infection were more likely to have both active pox infection and healed pox lesions suggesting a synergistic interaction that may influence the evolution of pox virulence. Because pox infection can be assessed visually, and birds have a high recovery rate, this disease may be a sensitive indicator of the seasonal and annual risk of transmission of malaria in Hawaiʻi. [ABSTRACT FROM AUTHOR]

Highlights • Co-circulation of vaccine and field strains of IBV, Mg and Ms in poultry flocks. • Additional Mg gene analysis needed for differentiation of field versus vaccine Mg strains. • Field strains of Mg detected in flocks previously vaccinated against Mg. • MLST analysis showed the co-presence of field and vaccine-like Ms sequence types. • IBV 793B, Arkansas and D274 vaccine-like or field strains detected in flocks. Abstract Respiratory diseases continue to have a major impact on poultry health, welfare and productivity. However, little information is available on their current status in UK poultry flocks. We investigated the presence of four economically important respiratory pathogens in healthy or problematic flocks; infectious bronchitis virus (IBV), avian metapneumovirus (aMPV), Mycoplasma gallisepticum (Mg) and Mycoplasma synoviae (Ms). Samples from 131 UK poultry flocks were received during the 12 month study period. Oropharyngeal (OP) swabs were taken from eight birds per flock and accompanied with flock health information. The study included 118 chicken, 6 pheasant and 5 turkey flocks, and 1 quail and 1 partridge flock. Chicken flocks were of layers (n = 98), broilers (n = 15), breeders (n = 3) and undisclosed (n = 2). Flock ages ranged from 3 to 72 weeks old, and the average flock size was 17,633 birds. PCR detected 65 (49.6%), 59 (45%) and 8 (6.1%) flocks as positive for IBV, Mg/Ms and aMPV respectively. Analysis of the mgc2 gene of the Mg isolates revealed high similarities to Mg TS-11 and Mg 6/85. Further gene analysis found that the TS-11-like isolates were unrelated to the TS-11 vaccine. Multi-locus sequence typing (MLST) analysis identified the majority of positive Ms as ST21, along with ST2 (MS-H-like), ST6 and ST43. IBV S1 gene sequencing identified strains as 793B (66.7%), Arkansas (23.8%) and Massachusetts (9.5%). All aMPV positive samples belonged to subtype B. Findings indicate that over half of the flocks sampled were positive for at least one of the four vaccine or field strains of mycoplasmas or viruses. [ABSTRACT FROM AUTHOR]

Chicken infectious anaemia virus (CIAV) is a widely distributed immunosuppressive agent. SPF flocks and eggs used for vaccine production and diagnostics must be CIAV-free. Detection of CIAV infection in SPF flocks involves primarily serology or other invasive methods. In order to evaluate different types of samples for rapid detection of CIAV infection, a trial was conducted in serologically negative broiler breeder pullets vaccinated with a commercial live-attenuated CIAV vaccine. Controls and vaccinated groups were sampled before and after vaccination. Invasive and non-invasive samples were used for CIAV DNA detection by real-time PCR. Seroconversion occurred at 14 days post-inoculation (DPI) in the vaccinated group, whereas CIAV genome was detected by qPCR at 7 DPI in both invasive and non-invasive samples. Only invasive samples remained qPCR positive for CIAV DNA by 21 DPI despite seroconversion of the chickens. [ABSTRACT FROM AUTHOR]

In the present study the subtype B aMPV, strain aMPV/B/IT/GuineaFowl/1818/12, was detected in guinea fowls affected by respiratory signs, sequenced and molecularly characterized. Comparisons among several F and G gene full sequences of aMPVs subtype B, showed that no consistent pattern related to host-tropism could be identified. Moreover, analysis of partial G gene revealed the perfect identity of the guinea fowl strain with four Italian aMPVs isolated from turkeys or chickens in a time frame of three years, in the same geographic area. Phylogenetic analysis of both genes showed an evolutionary trend of subtype B circulating in Northern Italy from its first appearance in 1987, to date. The co-presence in the same geographic area of farms housing different avian species sensitive to aMPV, vaccinated with different vaccination programs or not vaccinated (like guinea fowls), and often belonging to the same integrate poultry company, could be a crucial factor for the establishment of an endemic infection. [ABSTRACT FROM AUTHOR]

Avian infectious bronchitis is a contagious viral disease of chicken. It is present everywhere in the world where poultry is reared. This study was designed to detect, isolate and sequence the circulating Infectious bronchitis viruses (IBVs) in poultry in Pakistan. Out of 905 clinical specimens tested, 358 were found positive for IBV, having serotype distribution of Mass (43%), 4/91 (51%), and different variants of IBV (5%), respectively. One of the variants recovered from broiler-breeder (BB) flock and designated as Pak-973, was further propagated and characterized on molecular basis. Virus neutralization test did not neutralize it with the reference antisera IBV serotypes M41, 4/91, D274, D1466 and IT-02, identifying it as a distinct serotype. Furthermore, Haemagglutination Inhibition test (HI) has proven useful in differentiating various serotype of IBV. In addition to this, partial Spike 1 (S1) gene was amplified by reverse transcriptase-PCR (RT-PCR) and subjected to sequencing for determining its genetic diversity. Sequenced data was submitted in the GenBank and the IBV isolate named as KX013102_NARC/973_Pakistan_2015. The phylogenetic analysis of Pak-973 showed a maximum homology of 93% with the Indian IBV variant KF360983_23/B/2008_India. However, an overall nucleotide homology with some other Indian isolates is between 82-93%. This study revealed the presence of IBV variant isolates in the field in Pakistan during 2015. [ABSTRACT FROM AUTHOR]

Eurasia highly pathogenic avian influenza virus (HPAIV) H5 clade 2.3.4.4 emerged in North America at the end of 2014 and caused outbreaks affecting >50 million poultry in the United States before eradication in June 2015. We investigated the underlying ecologic and epidemiologic processes associated with this viral spread by performing a comparative genomic study using 268 full-length genome sequences and data from outbreak investigations. Reassortant HPAIV H5N2 circulated in wild birds along the Pacific flyway before several spillover events transmitting the virus to poultry farms. Our analysis suggests that >3 separate introductions of HPAIV H5N2 into Midwest states occurred during March-June 2015; transmission to Midwest poultry farms from Pacific wild birds occurred ≈1.7-2.4 months before detection. Once established in poultry, the virus rapidly spread between turkey and chicken farms in neighboring states. Enhanced biosecurity is required to prevent the introduction and dissemination of HPAIV across the poultry industry. [ABSTRACT FROM AUTHOR]

The study was designed to investigate the presence and level of maternally derived antibodies (MDA) in broiler and pullet chicks to determine the right days and time of vaccination against Infectious bursal disease (IBD). A total of 150 day old broiler chicks and pullets chicks were obtained from reputable breeder farmers and the birds divided into 5 groups (A, B, C, D and E) comprising 30 chicks per group. Coefficient of variation (CV), central vaccination time (CVT), and vaccination days (VD) from mean MDA (passive immunity chicks derived from parents' stock) ELISA titres were also determined using Hipra calculator (a device online for determining vaccination day and time from mean ELISA titers). One milliliter of blood sample was collected from each broiler and pullet chick from all the groups to obtain sera. The antibody titre level of broiler chicks ranged from 1,962 ± 438 to 4,363 ± 974 while that of pullets ranged from 2,111 ± 471 to 4,526 ± 1011. The highest CV was 46% for broiler chicks from farm A and the highest CV for pullets was 42.5% from another breeder farm D. The CVT for broilers to be vaccinated with mild IBD vaccine was 19 days, it was 18 days for intermediate vaccine and for intermediate plus vaccines was 12 days. The CVT was 33 days for pullets to be vaccinated with mild vaccine, 31 days for intermediate vaccine, while with intermediate plus vaccines it was 20 days. While the vaccination days for broiler was 7 and 17 days and it was 10 and 25 days for pullets. From the study the presence and level of MDA in day old chicks has been established and was above 1000 ELISA titre in chicks from all the five breeder farms. [ABSTRACT FROM AUTHOR]

In the present study, the pathogenicity of fowl adenovirus (FAdV) serotype 4 strain HB1501 was systematically determined by using different doses and routes of inoculation in chickens and assessed the immune efficacy induced by fowl adenovirus serotype 4 (FAdV-4) strain SB15 in a vaccination trial. The results revealed that strain HB1501 was highly virulent in chickens, inflicting 30 to 100% mortality when administered by intramuscular and intravenous routes, and its pathogenicity was influenced markedly by the inoculation route. The inactivated oil-emulsion FAdV-4 vaccine derived from strain SB15 completely protected specific pathogen-free chickens against morbidity and mortality following infection with the virulent FAdV-4 strain HB1501. Importantly, no obvious clinical signs or gross lesions were observed and high antibody levels against FAdV were measured in the SB15-vaccinated chickens, indicating the potential of this strain to become an alternative vaccine candidate. This study provides detailed information on the pathogenicity of FAdV-4, which should be of great value to the control of hepatitis-hydropericardium syndrome. [ABSTRACT FROM AUTHOR]

Airborne transmission of H5N1 highly pathogenic avian influenza (HPAI) viruses has occurred among poultry and from poultry to humans during home or live-poultry market slaughter of infected poultry, and such transmission has been experimentally reproduced. In this study, we investigated simple, practical changes in the processing of H5N1 virus-infected chickens to reduce infectious airborne particles and their transmission. Our findings suggest that containing the birds during the killing and bleeding first step by using a disposable plastic bag, a commonly available cooking pot widely used in Egypt (halla), or a bucket significantly reduces generation of infectious airborne particles and transmission to ferrets. Similarly, lack of infectious airborne particles was observed when processing vaccinated chickens that had been challenged with HPAI virus. Moreover, the use of a mechanical defeatherer significantly increased total number of particles in the air compared to manual defeathering. This study confirms that simple changes in poultry processing can efficiently mitigate generation of infectious airborne particles and their transmission to humans. [ABSTRACT FROM AUTHOR]

Infectious laryngotracheitis (ILT) disease is an acute highly contagious viral disease leading to massive economic losses to the national poultry industry. This study aimed to identify the most accurate and rapid diagnostic methods to rescue layer poultry farms from intense outbreaks in Egypt. Fifty pathological specimens were collected and subjected to virus isolation (VI), histopathology, direct fluorescent antibody technique (FAT) and polymerase chain reaction (PCR). Egg inoculation revealed stunted growth and white pock lesions on chorioallantoic membranes (CAM) in 23 samples. Isolation and propagation of infectious laryngotracheitis virus (ILTV) in cell culture showed syncytia formation 5 days post infection in 20 inoculated samples. PCR resulted in successful amplification of a 647 bp fragment of the thymidine kinase (TK) gene in 25 field samples. Histopathological examination of inoculated CAM showed intranuclear inclusion bodies with infiltration of inflammatory cells. Direct FAT showed intra-cytoplasmic apple green reactions in 18 examined tracheal tissues. PCR has been shown to be more sensitive, accurate and rapid than VI, FAT and histopathological examination. [ABSTRACT FROM AUTHOR]

In 2017, highly pathogenic avian influenza A(H5N8) virus was detected in poultry in the Democratic Republic of the Congo. Whole-genome phylogeny showed the virus clustered with H5N8 clade 2.3.4.4B strains from birds in central and southern Asia. Emergence of this virus in central Africa represents a threat for animal health and food security. [ABSTRACT FROM AUTHOR]

Chicken anemia virus (CAV) is one of the commercially important diseases of poultry worldwide. In Egypt, CAV has been reported to be a potential threat to the commercial poultry sectors. Hence, this study was aimed at isolation and full genomic analysis of CAVs circulating in chicken populations in different geographical location in Egypt. A total of 42 samples were collected from broiler chicken flocks in 9 governorates in Egypt from 12 to 42 days of age. The mortality rate observed among chickens was ranging from 3% to 22%. Nineteen out of 42 farms were found positive for the CAV genome by polymerase chain reaction (PCR). Full genome sequencing was conducted for 18 positive samples. Genetic analysis revealed a high similarity of >99% in 11 viruses with the vaccine strain Del-Ros; while the other seven samples shared close similarity to CAV field strains isolated from China, Taiwan, and Brazil. The data also indicated Q139 and Q144 amino acids substitutions among the VP1 of Egyptian field strains, which are known to be important in virus replication and spread. Phylogenetic analysis of the sequenced viruses (n = 18) based on either the full gene nucleotide sequence or VP1 coding sequence, suggested the circulation of four distinct genotypes in Egypt designated as group A, B, C and D. Moreover, evidence of recombination was detected among four Egyptian CAVs located within group A. The findings of this study succeeded to elucidate the epidemiological and genetic features of CAVs circulating in Egypt, and underscores the important of CAVs surveillance. [ABSTRACT FROM AUTHOR]

Summary: The highly pathogenic avian influenza (HPAI) H5N1 viruses continue to cause major problems in poultry and can, although rarely, cause human infection. Being enzootic in domestic poultry, Egyptian isolates are continuously evolving, and novel clades vary in their pathogenicity in avian hosts. Considering the importance of domestic ducks as natural hosts of HPAI H5N1 viruses and their likelihood of physical contact with other avian hosts and humans, it is of utmost importance to characterize the pathogenicity of newly emerged HPAI strains in the domestic duck. The most recently identified Egyptian clade 2.2.1.2 HPAI H5N1 viruses have been isolated from naturally infected pigeons, turkeys and humans. However, essentially nothing is known about their pathogenicity in domestic ducks. We therefore characterized the pathogenicity of an Egyptian HPAI H5N1 isolate A/chicken/Faquos/amn12/2011 (clade 2.2.1.2) in Sudani duck, a domestic duck breed commonly reared in Egypt. While viral transcription (HA mRNA) was highest in lung, heart and kidney peaking between 40 and 48 hpi, lower levels were detected in brain. Weight loss of infected ducks started at 16 hpi and persisted until 120 hpi. The first severe clinical signs were noted by 32 hpi and peaked in severity at 72 and 96 hpi. Haematological analyses showed a decline in total leucocytes, granulocytes, platelets and granulocyte/lymphocyte ratio, but lymphocytosis. Upon necropsy, lesions were obvious in heart, liver, spleen and pancreas and consisted mainly of necrosis and petechial haemorrhage. Histologically, lungs were the most severely affected organs, whereas brain only showed mild neuronal degeneration and gliosis at 48 hpi despite obvious neurological clinical signs. Taken together, our results provide first evidence that this HPAI H5N1 isolate (clade 2.2.1.2) is highly pathogenic to Sudani ducks and highlight the importance of this breed as potential reservoir and disseminator of HPAI strains from this clade. [ABSTRACT FROM AUTHOR]

During the epizootic of highly pathogenic avian influenza subtype H5N8 in Serbia in the winter of 2016-2017, the highest percent of mortality due to this infection was recorded in mute swans (Cygnus olor). Besides mute swans, avian influenza virus subtype H5N8 was also diagnosed in a small number of hens in rural households. Pancreatic tissues from avian influenza H5N8 positive mute swans and hens that died during this outbreak were collected to determine the character of morphological lesions and the distribution of the viral antigen in this organ. Macroscopic examination of the pancreas of mute swans revealed hemorrhages as well as necrosis, while there were no macroscopic visible lesions in the pancreas of infected hens. Despite the different macroscopic finding, microscopic examination of the pancreas of both infected bird species revealed lesions in the form of acute pancreatitis and multifocal acinar necrosis. The viral antigen was abundantly expressed in the cytoplasm and nucleus of necrotic cells, as well as in macrophages in both examined bird species. Immunohistochemical expression of the viral antigen in the pancreas was strongly consistent with histological lesions. According to the above described findings, it could be concluded that highly pathogenic avian influenza virus H5N8 has a high affinity to pancreatic tissue in both mute swans and hens and the distribution and the character of the lesions in the pancreas are similar in both bird species. [ABSTRACT FROM AUTHOR]

Between 16 February and 15 May 2018, three highly pathogenic avian influenza (HPAI) A(H5N6) and 11 HPAI A(H5N8) outbreaks in poultry holdings, one HPAI A(H5N6) and one HPAI A(H5N8) outbreak in captive birds, and 55 HPAI A(H5N6) wild bird events were reported in Europe. There is no evidence to date that HPAI A(H5N6) viruses circulating in Europe are associated with clades infecting humans. Fewer HPAI wild bird cases have been detected than during the same period of previous year. Most of mortality events among wild birds involved single birds and species listed in the revised list of target species for passive surveillance. Raptor species constitute 74% of the HPAI‐infected wild birds found dead. Those raptor species probably became infected by hunting or scavenging HPAI virus‐positive birds, and so raptor cases may predominate later in the course of an HPAI epidemic. Despite the important HPAI virus incursion via wild birds there have been few associated HPAI A(H5N6) outbreaks in poultry. Fifteen low pathogenic avian influenza (LPAI) outbreaks were reported in three Member States. The risk of zoonotic transmission to the general public in Europe is considered to be very low. The situation in Africa and the Middle East should be closely monitored with regards to HPAI A(H5N1) and A(H5N8). Uncontrolled spread of the virus and subsequent further genetic evolution in regions geographically connected to Europe may increase uncertainty and the risk for further dissemination of virus. Long‐distance migrating wild birds from southern Africa, e.g. the common tern (Sterna hirundo), may be included in targeted active surveillance schemes at a few priority locations in Europe in order to detect HPAI A(H5)‐infected migrating birds early. However, the risk of HPAI introduction from non‐EU countries via migratory wild birds to Europe is still considered to be much lower for wild birds crossing the southern borders than for those crossing the north‐eastern borders. [ABSTRACT FROM AUTHOR]

Loop-mediated isothermal amplification (LAMP) methods to detect chicken infectious anemia virus (CIAV), reticuloendotheliosis virus (REV), and Marek’s disease virus (MDV), and a reverse transcription (RT)-LAMP assay to detect infectious bursal disease virus (IBDV), were developed. The CIAV-LAMP, REV-LAMP, MDV-LAMP, and IBDV-RT-LAMP methods were performed using four sets of six primers targeting the VP1 gene of CIAV, the gp90 gene of REV, the Meq gene of MDV, and the VP2 gene of IBDV. The results (a change in color) were observed visually. The methods showed high specificity and sensitivity. The detection limits were 50 genomic copies of CIAV, 16 genomic copies of REV, 20 genomic copies of MDV, and 250 genomic copies of IBDV. When used to test clinical samples, the results of the LAMP assays were in 100% agreement with a previously described PCR. Therefore, the LAMP assays are simple, rapid, highly sensitive, and specific methods for detecting four immune-suppressive viruses. [ABSTRACT FROM AUTHOR]

Egg drop syndrome virus (EDSV) is an economically important pathogen with a broad host range, and it causes disease that leads to markedly decreased egg production. Although EDSV is known to induce apoptosis in duck embryo fibroblasts (DEFs), the interaction between EDSV and its host needs to be further researched. Here, we provide the first evidence that EDSV infection triggers autophagy in DEFs through increases in autophagosome-like double-membrane vesicles, the conversion of LC3-I to LC3-II, and LC3 colocalization with viral hexon proteins. Conversely, P62/SQSTM1 degradation, LC3-II turnover, and colocalization of LAMP and LC3 confirmed that EDSV infection triggers complete autophagy. Furthermore, we demonstrated that inhibition of autophagy by chloroquine (CQ) and 3-methyladenine (3MA) or RNA interference targeting ATG-7 decreased the yield of EDSV progeny. In contrast, induction of autophagy by rapamycin increased the EDSV progeny yield. In addition, we preliminarily demonstrated that the class I phosphoinositide 3-kinase (PI3K)/Akt/mTOR pathway contributes to autophagic induction following EDSV infection. Altogether, these finding lead us to conclude that EDSV infection induces autophagy, which benefits its own replication in host cells. These findings provide novel insights into EDSV-host interactions. [ABSTRACT FROM AUTHOR]

An optoelectronic sensor is a rapid diagnostic tool that allows for an accurate, reliable, field-portable, low-cost device for practical applications. In this study, template-free In situ gold nanobundles (Au NBs) were fabricated on an electrode for optoelectronic sensing of fowl adenoviruses (FAdVs). Au NB film was fabricated on carbon electrodes working area using L(+) ascorbic acid, gold chroloauric acid and poly- l -lysine (PLL) through modified layer-by-layer (LbL) method. A scanning electron microscopic (SEM) image of the Au NBs revealed a NB-shaped Au structure with many kinks on its surface, which allow local electric field enhancement through light–matter interaction with graphene quantum dots (GQDs). Here, GQDs were synthesized through an autoclave-assisted method. Characterization experiments revealed blue-emissive, well-dispersed GQDs that were 2–3 nm in size with the fluorescence emission peak of GQDs located at 405 nm. Both Au NBs and GQDs were conjugated with target FAdVs specific antibodies that bring them close to each other with the addition of target FAdVs through antibody–antigen interaction. At close proximity, light–matter interaction between Au NBs and QDs produces a local electric signal enhancement under Ultraviolet–visible (UV–visible) light irradiation that allows the detection of very low concentrations of target virus even in complex biological media. A proposed optoelectronic sensor showed a linear relationship between the target FAdVs and the electric signal up to 10 Plaque forming unit (PFU)/mL with a limit of detection (LOD) of 8.75 PFU/mL. The proposed sensing strategy was 100 times more sensitive than conventional ELISA method. [ABSTRACT FROM AUTHOR]

Outbreaks of novel highly pathogenic avian influenza viruses have been reported in poultry species in the United States since 2014. These outbreaks have proven the limitations of biosecurity control programs, and new tools are needed to reinforce the current avian influenza control arsenal. Some enzootic countries have implemented inactivated influenza vaccine (IIV) in their control programs, but there are serious concerns that a long-term use of IIV without eradication may result in the selection of novel antigenically divergent strains. A broadly protective vaccine is needed, such as live-attenuated influenza vaccine (LAIV). We showed in our previous studies that pc4-LAIV (a variant that encodes a C-terminally truncated NS1 protein) can provide significant protection against heterologous challenge virus in chickens vaccinated at 2–4 weeks of age through upregulation of innate and adaptive immune responses. The current study was conducted to compare the performances of pc4-LAIV and IIV in young chickens vaccinated at 1 day of age. A single dose of pc4-LAIV was able to induce stronger innate and mucosal IgA responses and protect young immunologically immature chickens better than a single dose of IIV. Most importantly, when 1-day-old chickens were intranasally primed with pc4-LAIV and subcutaneously boosted with IIV three weeks later, they showed a rapid, robust, and highly cross-reactive serum antibody response and a high level of mucosal IgA antibody response. This vaccination regimen warrants further optimization to increase its range of protection. [ABSTRACT FROM AUTHOR]

The antiviral cytokine interferon-alpha (IFN-α) plays a critical role in the innate immune system. Previous studies have shown that recombinant chicken IFN-α inhibits avian influenza virus (AIV) replication in vivo; however, the antiviral effect of recombinant duck IFN-α (rDuIFN-α) on highly pathogenic AIV remains unknown. In this study, the duck IFN-α gene was cloned, expressed, and purified. The antiviral effects of the resulting rDuIFN-α were further evaluated in vitro and in vivo. Our results showed that rDuIFN-α inhibited the replication of vesicular stomatitis virus (VSV) and AIV in duck embryo fibroblasts in vitro, with antiviral activities against VSV and AIV of 2.1 × 105 and 4.1 × 105 U/mg, respectively. We next investigated the anti-H5N1 AIV effect of intramuscular injection of rDuIFN-α in vivo. rDuIFN-α reduced viral titers in the brains, lungs, and spleens of 2-day-old (2D) ducks compared with that in the virus-challenged control group, and pretreatment with rDuIFN-α reduced mortality from 60% to 10% in 2D ducks. Moreover, rDuIFN-α increased the expression of IFN-stimulated genes in the brains and spleens of 2D ducks. Our results demonstrate that rDuIFN-α blocks VSV and H5N1 influenza virus infection in vitro and exhibits antiviral effects against H5N1 influenza virus infection in 2D ducks. [ABSTRACT FROM AUTHOR]

During surveillance for avian influenza viruses, three H5N6 viruses were isolated in chickens obtained from live bird markets in eastern China, between January 2015 and April 2016. Sequence analysis revealed a high genomic homology between these poultry isolates and recent human H5N6 variants whose internal genes were derived from genotype S H9N2 avian influenza viruses. Glycan binding assays revealed that all avian H5N6 viruses were capable of binding to both human-type SAα-2,6Gal receptors and avian-type SAα-2,3Gal receptors. Their biological characteristics were further studied in BALB/c mice, specific-pathogen-free chickens, and mallard ducks. All three isolates had low pathogenicity in mice but were highly pathogenic to chickens, as evidenced by 100% mortality 36-120 hours post infection at a low dose of 103.0EID50 and through effective contact transmission. Moreover, all three poultry H5N6 isolates caused asymptomatic infections in ducks, which may serve as a reservoir host for their maintenance and dissemination; these migrating waterfowl could cause a potential global pandemic. Our study suggests that continuous epidemiological surveillance in poultry should be implemented for the early prevention of future influenza outbreaks. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the effects of a new multispecies probiotic containing four Bacillus species and Saccharomyces boulardii (Microguard®) with a commercial probiotic (Protexin®) and a commonly used antibiotic in broilers. Six hundred one-day-old male Ross 308 broilers were randomized to six experimental treatments, with five replicates of 20 chicks each, for 42 days, receiving an ad libitum cornsoybean basal diet. Treatments were added to the basal diet and consisted of tetracycline as an antibiotic growth promoter (500 g/ton), three dosages of Microguard (50, 100 and150 g/ton) or Protexin (100 g/ton). The control group received the basal diet with no additive. The group fed with Microguard at 150 g/ton showed increased final bodyweight, weight gain, high density lipoprotein, triglyceride, and antibody titres against Newcastle disease (ND) and avian influenza (AI) levels. Improved feed conversion ratio, increased villus height, and villus highest crypt depth ratio, along with lower plasma gamma-glutamyl transpeptidase, alkaline phosphatase, alanine aminotransferase, were found in probiotic-supplemented broilers. Carcass yield, liver weights, breast muscle values, and abdominal fat weights were reduced in groups fed with 100 or 150 g/ton of Microguard. Caecal coliforms, Salmonella and Escherichia coli numbers decreased in groups fed with 100 or 150 g/ton of Microguard. These results show that Microguard at 150 g/ton is a promising probiotic to replace antibiotics in broiler feed as a growth-promoter while enhancing immune system responses and inducing beneficial modulations in the caecal microflora. [ABSTRACT FROM AUTHOR]

Infectious bursal disease (IBD) is an immunosuppressive, acute and highly contagious illness of growing-poultry stock infected with infectious bursal disease virus (IBDV). It is common in Pakistan, causing potential economic losses throughout the year. The objective of the study is to propose a rapid, sensitive and specific diagnostic tool, and compare it with existing commonly used reverse transcriptase polymerase chain reaction (RT-PCR) method for IBDV. Different primers were used for RT-PCR and reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) to target the IBD virus. RT-LAMP primers showed prodigious specificity without cross reaction to the other animal pathogens. Moreover, RT-LAMP was found to have 10 times higher selectivity for IBDV identification as compared to RT-PCR. RT-LAMP detected 9.2% more field samples than RT-PCR. Sequences of PCR products were determined and phylogenetic analysis of research isolates revealed its maximum similarity with indigenous and Indian IBDV isolates. RT-LAMP was found to be simple, specific, less laborious and a better technique as compared to RT-PCR for quick analysis. In general, RT-LAMP was declared positive on observing turbidity or adding fluorescence staining reagent such as SYBR Green I. The options of direct use of field sample homogenate and viewing directly the peaks in the graph shown on a monitor/laptop have made it much more convenient and time saving than gel based RT-PCR. [ABSTRACT FROM AUTHOR]

Newcastle disease virus (NDV) live vaccines are supplied in lyophilized form and usually administered through conventional routes (drinking water, spray, or eye drop) following reconstitution in a diluent. Virus inactivation due to physico-chemical properties of the diluent at the time of administration may lead to vaccine failure. The present study aimed to evaluate the survival of NDV live vaccine strain immersed in 5 pH-amended water samples (pH 5.00, pH 6.00, pH 7.00, pH 8.00, and pH 9.00) by sequential determination of virus infectivity on Vero cells for 3 hours. Minimum reduction in virus infectivity was recorded in the water with neutral or slightly alkaline pH, while the virus was relatively less stable at extreme pH conditions. Maximum reduction of infectivity was observed in the water with pH 9.00 in which the virus was completely inactivated within 3 hours. Addition of stabilizers (Cevamune® or skimmed milk) slightly altered the pH and total dissolved solids (TDS) values of the virus-charged water samples. In the stabilizer-added water samples, minimum reduction in infectivity was observed in the water with neutral pH, followed by the ones with a pH of 8.00, 6.00, 5.00, and 9.00. In all types of water samples, T-90 values (time required for 90% reduction in virus infectivity) were highest (485 minutes) at neutral pH (pH 7.00) and lowest (102 to 134 min) at an extreme alkaline condition (pH 9.00). Results of the present study indicate that water with a pH range of 7.00 to 8.00 is suitable for administration of NDV live vaccines. However, the addition of Cevamune® or skimmed milk may have beneficial effects on preserving the infectivity of the virus, even at extreme pH conditions. [ABSTRACT FROM AUTHOR]

Traditional approaches to assess the immune response of chickens to infection are through animal trials, which are expensive, require enhanced biosecurity, compromise welfare, and are frequently influenced by confounding variables. Since the chicken embryo becomes immunocompetent prior to hatch, we here characterized the transcriptional response of selected innate immune genes to Newcastle disease virus (NDV) infection in chicken embryos at days 10, 14, and 18 of embryonic development. The results suggest that the innate immune response 72 h after challenge of 18-day chicken embryo is both consistent and robust. The expression of CCL5, Mx1, and TLR3 in lung tissues of NDV challenged chicken embryos from the outbred Kuroiler and Tanzanian local ecotype lines showed that their expression was several orders of magnitude higher in the Kuroiler than in the local ecotypes. Next, the expression patterns of three additional innate-immunity related genes, IL-8, IRF-1, and STAT1, were examined in the highly congenic Fayoumi (M5.1 and M15.2) and Leghorn (Ghs6 and Ghs13) sublines that differ only at the microchromosome bearing the major histocompatibility locus. The results show that the Ghs13 Leghorn subline had a consistently higher expression of all genes except IL-8 and expression seemed to be subline-dependent rather than breed-dependent, suggesting that the innate immune response of chicken embryos to NDV infection may be genetically controlled by the MHC-locus. Taken together, the results suggest that the chicken embryo may represent a promising model to studying the patterns and sources of variation of the avian innate immune response to infection with NDV and related pathogens. [ABSTRACT FROM AUTHOR]

In early 2004 highly pathogenic avian influenza (HPAI) H5N1 virus caused major outbreaks of disease in poultry in Indonesia. The disease was first reported in West Timor in eastern Indonesia in the same year, resulting in the death of approximately one hundred chickens from both commercial and backyard farms; however no evidence of disease has subsequently been reported in West Timor since 2007. A targeted survey was undertaken in 2013 in 2 districts of West Timor. Three hundred village and commercial poultry (292 chickens and 8 Muscovy ducks) from 10 villages and 5 live bird markets (LBMs) were sampled between August and October 2013. Swabs of the cloaca and trachea of the sampled birds were tested using the Anigen ® Rapid Test (Bionote). All samples were negative on testing (0%; 95%CI: 0.0–1.2%). From these results it was concluded with a high level of confidence (100%, 95%CI: 99.988, 100) that this population is not infected, and these results, along with a lack of clinical evidence of disease, support the conclusion that West Timor was free from HPAI infection at the time of the survey. [ABSTRACT FROM AUTHOR]

Marek’s disease is a lymphoproliferative disease causing a serious threat in poultry production. Field strains of Marek’s disease virus (MDVs) are continuously re-emerging, causing great economical losses to the poultry industry worldwide in spite of the intensive vaccination and restrictive management policy used. Histopathological and molecular characterizations of MDVs are essential for monitoring the changes of viruses and evaluating the effectiveness of existing vaccines. During 2016, 190 visceral tumour tissues representing 30 vaccinated chicken flocks from the Gifu prefecture, Japan, were analysed. A pathological examination revealed the presence of lymphoproliferative lesions in the visceral organs. Polymerase chain reaction screening of tissue specimens using specific primers for avian leucosis virus, reticuloendotheliosis virus, and MDV was positive only for MDV. The polymerase chain reaction products of meq, pp38, virus-induced IL-8 homology, and glycoprotein MDV genes were sequenced and used for homology, phylogenetic, and similarity level analysis with the published reference of MDVs in the database. The results revealed high similarity between the field isolates, vv and vv+ strains of MDV from the USA and China. Several point mutations in the nucleotide sequence of the field isolates and their deduced amino acid sequences were detected in those genes. The present molecular analyses indicated that nucleotide and amino acid changes could be valuable criteria for differentiation and determination of the pathogenicity and oncogenicity of MDVs according to the Avian Disease and Oncology Laboratory pathotyping in vivo studies. Furthermore, the results suggest that development of a new vaccine must be considered to overcome this devastating avian oncogenic viral disease. [ABSTRACT FROM PUBLISHER]

With increasing frequency, avian Metapneumovirus (aMPV) is reported to induce respiratory signs in chickens. An adequate knowledge of current aMPV prevalence among Italian broilers is lacking, with little information available on its economical and health impact on the poultry industry. In order to collect preliminary data on the epidemiological context of aMPV in broiler flocks, a survey was performed in areas of Northern Italy with high poultry density from 2014 to 2016. Upper respiratory tract swabs were collected and processed by A and B subtype-specific multiplex real-time reverse transcription PCR (RT-PCR). Samples were also screened for infectious bronchitis virus (IBV) by generic RT-PCR and sequencing. Productive data and respiratory signs were detailed where possible. The high prevalence of aMPV was confirmed in broilers older than 26 d and also attested in IBV-negative farms. All aMPV detections belonged to subtype B. Italian strain genetic variability was evaluated by the partial attachment (G) gene sequencing of selected strains and compared with contemporary turkey strains and previously published aMPV references, revealing no host specificity and the progressive evolution of this virus in Italy. [ABSTRACT FROM AUTHOR]