Poultry Viruses Research Articles

Serological Diagnosis of Influenza A Subtype H1 on Family Poultry of Belo Horizonte, Minas Gerais and Santa Maria, Rio Grande Do Sul, in Brazil.

ABSTRACT Serum samples (n=687) from Gallus gallus domesticus were collected for the investigation of antibodies to avian influenza virus (AIV-A) in the family poultry of the surrounding counties of Santa Maria/RS and the metropolitan region of Belo Horizonte/MG, totaling twenty different counties. Additional samples of seventeen (n=17) free-flying ducks (C. moschata pure or hybrid with Anas platyrhynchos) were collected in Belo Horizonte. The chosen tests for the survey were performed as described by the World Organization for Animal Health (OIE), including agar gel immunodiffusion (AGID) for antibodies to AIV-A nucleoprotein (N) and haemagglutination- inhibition (HI) for antibodies to subtype H1. Out of the 704 serum tests performed by AGID, eight (8/704) were revealed positive for antibodies to AIV-A N protein, with six (6/704) retested positive for subtype H1. Two sera tested positive by AGID were shown to be non reactive to the H1 subtype, suggesting specificity to another subtype. A low occurrence of antibodies to influenza A (1.13%) was found, and mostly (75%) specific to subtype H1. This represents an approximately 0,85% overall occurrence for subtype H1 antibodies, with an unknown subtype specific antibodies detected in one free-flying anatid. The low occurrence of antibodies in the family poultry may suggest a low AIV-A activity during the period of study, information which remains to be confirmed by virus detection.

The Seroprevalence Study of Reticuloendotheliosis Virus Infection in Chicken in Bangladesh

We showed seroprevalence of Reticuloendotheliosis virus (REV) in poultry in selected areas of Bangladesh.Total 3,555 serum samples were collected between 2014 and 2016 from 10 districts, 6 types of chicken and 144 flocks, tested for the specific antibodies directed against REV by indirect Enzyme Linked Immunosorbent Assay (ELISA). The overall seroprevalence of REV in the chickens tested were 21.13% (751/3,555) and 73.61% (106/144) flocks were seropositive. According to district, Gazipur had the highest (49.50%) and Khulna had the lowest (9.09%) seropositive rates.Additionally, the prevalence rates were highest 38.21% during onset of laying period, age between 19 and 24 weeks. The positivity rates were almost same round the year like 22.96% in summer, 20.70% in rainy and 20.43% in winter seasons.Furthermore, the seropositive rates in broiler flocks, broiler breeder flocks, commercial layer flocks, layer breeder flocks, sonali flocks, and domestic chicken flocks were 6.86%, 42.15%, 25.84%, 33.59%, 9.40%, and 6.49%, respectively. Conclusion: These results indicate that REV infections are widespread ubiquitous in all types of chickens and may appear as a potential threat for the rapidly growing poultry industry in Bangladesh. This is the first seroprevalencestudy on REV infections in chicken in Bangladesh.More prevalence study, molecular characterization and vaccine production from local isolates are emergency requirements to combat REV. The quality verification of imported vaccine must be strongly adopted.

Avian leukosis virus subgroup – J as a contaminant in live commercially available poultry vaccines distributed in Nigeria

Globally, vaccines are used to prevent and control the menace of infectious diseases in livestock with some reported to be inadvertently contaminated with extraneous agents (EAs). With the aim of screening and characterizing for some selected EAs, 44 live viral poultry vaccines were randomly selected based on availability. The vaccines comprised 14 manufacturers in 10 different countries including Nigeria were screened by Polymerase Chain Reaction. In 9% (4/44) of the vaccines, contamination with only avian leukosis virus (ALV) subgroup J (ALV-J) was recorded. Other exogenous ALV subgroups, chicken infectious anemia and infectious laryngotracheitis viruses were absent. The EAs was found in infectious bursal disease (n = 1), Fowlpox (n = 2) and Mareks disease (n = 1) vaccines. Phylogenetic analysis of the ALV-J env gene showed clustering with contemporary group I and II. The result underscores the importance of screening vaccines to avoid the introduction and spread of EAs that could pose a threat to poultry production.

Genetic characteristics of H9N2 avian influenza viruses isolated from free-range poultry in Eastern China, in 2014-2015.

Circulating H7N9 influenza viruses in live poultry markets continue to pose a threat to human health. Free-range poultry, one of the sources for these markets, are common in China as well as in many developing countries. Because the H9N2 virus could be a source of internal genes for the H7N9 virus, we conducted surveillance in free-range poultry and live poultry markets to study the evolution of H7N9 and H9N2 viruses in Eastern China. We found 28 samples positive for the H9N2 virus (a rate of 3.2%), but no positive samples for the H7N9 virus. Six representative H9N2 isolates were sequenced and analyzed, and the results showed that these viruses shared high nucleotide identities (99.0 to 100%) and were in a same branch in the phylogenetic trees. All these 6 viruses are closely clustered with Zhejiang H9N2 chicken isolates, and belonged to genotype G57, along with some novel H7N9 strains and H9N2 strains circulating in humans in China. We hope that surveillance of AIVs in free-range poultry will be strengthened for further identification more genetic diversity.

Isolation and genetic characterization of H13N8 low pathogenic avian influenza virus from migratory birds in eastern China.

Low pathogenic avian influenza virus (LPAIV) is an important zoonotic pathogen. Migratory birds are the natural reservoir for all 16 haemagglutinin (HA) and nine neuraminidase (NA) subtypes of LPAIV. Surveillance of LPAIV in migratory waterfowl and poultry is important for animal and public health. An understanding of the ecology and epidemiology of LPAI viruses in their reservoirs is beneficial for routine surveillance projects. Here, we report the isolation of an H13N8 LPAIV from black-tailed gulls in eastern China. Full genome sequences of this isolate were determined. Genetic analysis of the HA and NA segments of this isolate showed that this H13N8 LPAIV was derived from the Eurasian lineage. Additionally, we speculate that this H13N8 LPAIV was a reassortant between the North American and Eurasian lineages. Interestingly, we identified amino acid motifs responsible for increased virulence or transmission of influenza viruses in mammals. We also found weak but measurable haemagglutination inhibition antibody titers against H13N8 virus in serum samples collected from chickens. These results suggest that continued surveillance for LPAI viruses in migratory birds and poultry is required.

Synthesis of new quinoline scaffolds via a solvent-free fusion method and their anti-microbial properties

Purpose: To develop a robust and simple fusion-based methodology for the synthesis of various 5-(-3- nitrophenyl) pyrimido[5,4-c] quinoline-2,4(1H,3H)-diones (5 – 9). Method: The synthesis involved formation of a Knoevenagel product using barbituric acid and 3- nitrobenzaldehyde which cyclized on fusing with various sulfanilamides in a sealed tube at 170 – 212°C. This resulted in the synthesis of the target quinolines (5 – 9). To evaluate their antibacterial and antiviral properties, the synthesized quinolines were tested against four gram-negative bacterial strains and four poultry viruses. The MIC and IC 50 of each active compound were calculated. Results: Data from NMR, mass spectrometry and elemental analysis confirmed the formation of quinoline scaffolds. Antibacterial screening revealed that all the compounds had antibacterial activities. However, the minimum inhibitory concentration (MIC) of compounds 6 – 8 and 9 against Proteus vulgaris and Klebsiella pneumoniae showed that these compounds were more active than the standard drug ampicillin. Antiviral studies and IC 50 values showed that compounds 5 – 9 were effective against Newcastle disease virus (NDV) and infectious bursal disease virus (IBDV), while compounds 5, 6 and 8 were active against avian influenza virus subtype H9N2 (AIV); compounds 7 and 8 were active against infectious bronchitis virus (IBV). Conclusion: A simple strategy of fusion of Knoevenagel product with aromatic amines can be used to synthesize highly functionalized quinoline scaffolds which are potential drug candidates for development of new antibacterial and antiviral agents. Keywords: Quinoline scaffolds, Barbituric acid, Knoevenagel condensation, Antiviral, Antibacterial

Highly pathogenic avian influenza A/H5N1 Clade 2.3.2.1c virus in poultry in Cameroon, 2016–2017

ABSTRACTIn May 2016, highly pathogenic avian influenza virus of the subtype A/H5N1 was detected in Cameroon in an industrial poultry farm at Mvog-Betsi, Yaoundé (Centre region), with a recorded sudden increase of deaths among chickens, and an overall mortality rate of 75%. The virus spread further and caused new outbreaks in some parts of the country. In total, 21 outbreaks were confirmed from May 2016 to March 2017 (six in the Centre, six in the West, eight in the South and one in the Adamaoua regions). This resulted in an estimated total loss of 138,252 birds (44,451 deaths due to infection and 93,801 stamped out). Only domestic birds (chickens, ducks and geese) were affected in farms as well as in poultry markets. The outbreaks occurred in three waves, the first from May to June 2016, the second in September 2016 and the last wave in March 2017. The topology of the phylogeny based on the haemagglutinin gene segment indicated that the causative H5N1 viruses fall within the genetic clade 2.3.2.1c, within the same group as the A/H5N1 viruses collected in Niger in 2015 and 2016. More importantly, the gene constellation of four representative viruses showed evidence of H5N1/H9N2 intra-clade reassortment. Additional epidemiological and genetic data from affected countries in West Africa are needed to better trace the origin, spread and evolution of A/H5N1 in Cameroon.RESEARCH HIGHLIGHTSHPAI A/H5N1 was detected in May 2016 in domestic chickens in Yaoundé-Cameroon.Twenty-one outbreaks in total were confirmed from May 2016 to March 2017.The causative H5N1 viruses fall within the genetic clade 2.3.2.1c.The viral gene constellation showed evidence of H5N1/H9N2 intra-clade reassortment.

The Multifaceted Zoonotic Risk of H9N2 Avian Influenza.

Poultry-adapted H9N2 avian influenza viruses (AIVs) are commonly found in many countries in Asia, the Middle East, Africa, and Europe, and although classified as low pathogenic viruses, they are an economically important disease. Besides the importance of the disease in the poultry industry, some H9N2 AIVs are also known to be zoonotic. The disease in humans appears to cause primarily a mild upper respiratory disease, and doesn’t cause or only rarely causes the severe pneumonia often seen with other zoonotic AIVs like H5N1 or H7N9. Serologic studies in humans, particularly in occupationally exposed workers, show a large number of people with antibodies to H9N2, suggesting infection is commonly occurring. Of the four defined H9N2 poultry lineages, only two lineages, the G1 and the Y280 lineages, are associated with human infections. Almost all of the viruses from humans have a leucine at position 226 (H3 numbering) of the hemagglutinin associated with a higher affinity of binding with α2,6 sialic acid, the host cell receptor most commonly found on glycoproteins in the human upper respiratory tract. For unknown reasons there has also been a shift in recent years of poultry viruses in the G1 and Y280 lineages to also having leucine instead of glutamine, the amino acid found in most avian viruses, at position 226. The G1 and Y280 poultry lineages because of their known ability to infect humans, the high prevalence of the virus in poultry in endemic countries, the lack of antibody in most humans, and the shift of poultry viruses to more human-like receptor binding makes these viruses a human pandemic threat. Increased efforts for control of the virus, including through effective vaccine use in poultry, is warranted for both poultry and public health goals.

Virucidal Efficacy of a Quaternary Ammonium Compound with Food Additive–Grade Calcium Hydroxide Toward Avian Influenza Virus and Newcastle Disease Virus on Abiotic Carriers

The virucidal efficacies of a 0.2% food additive-grade calcium hydroxide [FdCa(OH)2] solution, a quaternary ammonium compound (QAC) diluted at 1:500 (QACx500), and their mixture [Mix500; FdCa(OH)2 powder added at a final concentration of 0.2% to QACx500] were investigated as fomites for avian influenza virus (AIV) and Newcastle disease virus (NDV) on abiotic carriers (steel, rubber, and plastic) at two different temperatures (room temperature [RT; 25 ± 2 C] and 2 C). These viruses were seeded on coupons (5 cm×5 cm) of rubber, steel, or plastic with 5% fetal bovine serum. After complete drying, the coupons were covered with the test solutions at RT or 2 C. After fixed incubation periods, viruses were recovered from the coupons and titrated. At RT, Mix500 required a short time (3 min) to inactivate AIV and NDV to effective levels (≥3 log virus reduction) on rubber, steel, and plastic carriers compared with QAC or FdCa(OH)2. At low temperature, QACx500 inactivated AIV on steel and plastic carriers to effective levels within 60 min, whereas Mix500 did so within 10 min. QACx500 and FdCa(OH)2 solutions could inactivate NDV on steel and plastic carriers within 20 and 10 min, respectively, and Mix500 could do so within 3 min. Viruses on the carriers required longer incubation periods for inactivation at 2 C than at 25 C. These results demonstrate desirable synergistic virucidal effects of Mix500 for important poultry viruses on abiotic carriers, while indicating high applicability within poultry farming.

H9N2 influenza viruses from Bangladesh: Transmission in chicken and New World quail.

The H9N2 influenza viruses that have become established in Bangladeshi live poultry markets possess five gene segments of the highly pathogenic H7N3 avian influenza virus. We assessed the replication, transmission, and disease potential of three H9N2 viruses in chickens and New World quail. Each virus replicated to high titers and transmitted by the airborne route to contacts in both species. Infected chickens showed no disease signs, and the viruses differed in their disease potential in New World quail. New World quail were more susceptible than chickens to H9N2 viruses and shed virus after airborne transmission for 10 days. Consequently, New World quail are a potential threat in the maintenance and spread of influenza virus in live poultry markets.

Detection of non-notifiable H4N6 avian influenza virus in poultry in Great Britain

A 12-month pilot project for notifiable avian disease (NAD) exclusion testing in chicken and turkey flocks in Great Britain (GB) offered, in partnership with industry, opportunities to carry out differential diagnosis in flocks where NAD was not suspected, and to identify undetected or undiagnosed infections. In May 2014, clinical samples received from a broiler breeder chicken premises that had been experiencing health and production problems for approximately one week tested positive by avian influenza (AI) real-time reverse transcription polymerase chain reaction (RRT-PCR). Following immediate escalation to an official, statutory investigation to rule out the presence of notifiable AI virus (AIV; H5 or H7 subtypes), a non-notifiable H4N6 low pathogenicity (LP) AIV was detected through virus isolation in embryonated specific pathogen free (SPF) fowls’ eggs, neuraminidase inhibition test, cleavage site sequencing and AIV subtype H4-specific serology. Premises movement restrictions were lifted, and no further disease control measures were implemented as per the United Kingdom (UK) legislation. Phylogenetic analysis of the haemagglutinin and neuraminidase genes of the virus revealed closest relationships to viruses from Mallard ducks in Sweden during 2007 and 2009. In June 2014, clinical suspicion of NAD was reported in a flock of free-range laying chickens elsewhere in GB, due to increasing daily mortality and reduced egg production over a five-day period. An H4N6 LPAIV with an intravenous pathogenicity index of 0.50 was isolated. This virus was genetically highly similar, but not identical, to the virus detected during May 2014. Full viral genome analyses showed characteristics of a strain that had not recently transferred from wild birds, implying spread within the poultry sector had occurred. A stalk deletion in the neuraminidase gene sequence indicated an adaptation of the virus to poultry. Furthermore, there was unexpected evidence of systemic spread of the virus on post-mortem. No other cases were reported. Infection with LPAIVs often result in variable clinical presentation in poultry, making detection of disease more difficult.

Diagnostic and Vaccination Approaches for Newcastle Disease Virus in Poultry: The Current and Emerging Perspectives.

Newcastle disease (ND) is one of the most devastating diseases that considerably cripple the global poultry industry. Because of its enormous socioeconomic importance and potential to rapidly spread to naïve birds in the vicinity, ND is included among the list of avian diseases that must be notified to the OIE immediately upon recognition. Currently, virus isolation followed by its serological or molecular identification is regarded as the gold standard method of ND diagnosis. However, this method is generally slow and requires specialised laboratory with biosafety containment facilities, making it of little relevance under epidemic situations where rapid diagnosis is seriously needed. Thus, molecular based diagnostics have evolved to overcome some of these difficulties, but the extensive genetic diversity of the virus ensures that isolates with mutations at the primer/probe binding sites escape detection using these assays. This diagnostic dilemma leads to the emergence of cutting-edge technologies such as next-generation sequencing (NGS) which have so far proven to be promising in terms of rapid, sensitive, and accurate recognition of virulent Newcastle disease virus (NDV) isolates even in mixed infections. As regards disease control strategies, conventional ND vaccines have stood the test of time by demonstrating track record of protective efficacy in the last 60 years. However, these vaccines are unable to block the replication and shedding of most of the currently circulating phylogenetically divergent virulent NDV isolates. Hence, rationally designed vaccines targeting the prevailing genotypes, the so-called genotype-matched vaccines, are highly needed to overcome these vaccination related challenges. Among the recently evolving technologies for the development of genotype-matched vaccines, reverse genetics-based live attenuated vaccines obviously appeared to be the most promising candidates. In this review, a comprehensive description of the current and emerging trends in the detection, identification, and control of ND in poultry are provided. The strengths and weaknesses of each of those techniques are also emphasised.

A comparative pathogenicity analysis of two adenovirus strains, 1/A and 8a/E, isolated from poultry in Poland

Fowl adenoviruses (FAdVs) are the causative agents of multietiological syndromes and diseases in poultry flocks. During a routine diagnostic examination, two FAdVs strains were isolated. Molecular typing of these isolates based on the partial loop L1 HVR1-4 region of the hexon gene sequence revealed the presence of different FAdV isolates: 1/A-61/11z (GenBank accession number KX247012, APP94082), and 8a/E-6/12j (GenBank accession number: KP890032, ALB00550), and comparative genome analysis indicated small differences between these two viruses. The next step of the study was the estimation of the pathogenicity of these isolates in specific-pathogen-free (SPF) chickens. Chickens were divided into three groups, with 20 chickens per group infected intraperitoneally on the first day after hatching. Group I consisted of chickens infected with strain FAdV-1/A-61/11z, group II consisted of chickens infected with strain FAdV-8a/E-6/12j, and group III consisted of uninfected birds. Clinical signs observed in infected chickens included poor growth, apathy, prostration, ruffled feathers, crouching position, and huddling behavior. The mortality rate in chickens infected with FAdV-1/A-61/11z was 10% at 10 days postinfection (dpi), and no mortality was observed in chickens infected with the FAdV-8a-6/12j strain. The mean real-time PCR threshold cycle (Ct) value was 39.70%. The detection limit of these assays was 8 copies, with an efficiency of 91.03% and 95.17% and regression square (R2) values of 0.991 and 0.997, respectively, with a mean pathogen load of 4.8 × 106.0 copies/µl. The assays did not demonstrate cross-reactivity between types 1/A and 8a/E and non-targeted poultry viruses. Adenoviral DNA was detected in the liver, spleen, kidney, gizzard, intestine, bursa of Fabricius, and thymus of every examined dead and euthanized chicken from groups I and II between the third and fourth week postinfection. This is the first study conducted on the pathogenic and apathogenic strains FAdV-1/A and FAdV-8a/E, showing the presence of the virus in multiple tissues in chickens in Poland. This study revealed that it is very likely that the FAdV-1/A-61/11z strain is able to cause clinical inclusion body hepatitis (IBH) in chickens and that it is slightly more virulent than the FAdV-8a/E-6/12j strain, although both are primary pathogens of the disease.

Excess lung cancer occurrence in poultry plants. Occupational risk factors: Findings for oncogenic viruses exposure and other occupational exposures

Certain viruses naturally infect and cause cancer in chickens and turkeys. Humans are widely exposed. The viruses cause cancer in primates, and transform human cells in vitro, but it is not known if they cause cancer in humans, mainly because of the lack of epidemiologic evidence. We conducted cohort mortality studies of workers in poultry slaughtering/processing plants across the United States, because they have the highest human exposures. An excess of lung cancer and other deaths was recorded in the poultry workers. Here, we report on a case-cohort study of the lung cancer deaths nested within these cohorts, that was conducted to provide epidemiologic evidence linking these viruses with human cancer occurrence, while adjusting for possible confounders, including workplace chemical carcinogens. We obtained interviews for 339 lung cancer deaths and 457 controls, selected from our combined cohorts of 30,411 poultry plant workers and 16,405 non-poultry workers, belonging to United Food & Commercial Workers unions. Data was analyzed by both logistic regression and Cox regression, adjusting for smoking and other confounders. Lung cancer risk was independently associated with tasks or work areas indicative of exposure to both poultry oncogenic viruses and to workplace chemical carcinogens. The study provides an incremental piece of evidence (epidemiologic), indirectly linking the oncogenic viruses of poultry with the occurrence of cancer in humans, and thus may have public health implications, but the limitations highlighted must be considered. Confirmatory studies, particularly molecular studies providing definitive proof of poultry oncogenic retrovirus integration in human DNA are needed, before the findings observed in this study can be put into proper perspective.

Live Poultry Trading Drives China's H7N9 Viral Evolution and Geographical Network Propagation.

The on-going reassortment, human-adapted mutations, and spillover events of novel A(H7N9) avian influenza viruses pose a significant challenge to public health in China and globally. However, our understanding of the factors that disseminate the viruses and drive their geographic distributions is limited. We applied phylogenic analysis to examine the inter-subtype interactions between H7N9 viruses and the closest H9N2 lineages in China during 2010–2014. We reconstructed and compared the inter-provincial live poultry trading and viral propagation network via phylogeographic approach and network similarity technique. The substitution rates of the isolated viruses in live poultry markets and the characteristics of localized viral evolution were also evaluated. We discovered that viral propagation was geographically-structured and followed the live poultry trading network in China, with distinct north-to-east paths of spread and circular transmission between eastern and southern regions. The epicenter of H7N9 has moved from the Shanghai–Zhejiang region to Guangdong Province was also identified. Besides, higher substitution rate was observed among isolates sampled from live poultry markets, especially for those H7N9 viruses. Live poultry trading in China may have driven the network-structured expansion of the novel H7N9 viruses. From this perspective, long-distance geographic expansion of H7N9 were dominated by live poultry movements, while at local scales, diffusion was facilitated by live poultry markets with highly-evolved viruses.

Potential of genotype VII Newcastle disease viruses to cause differential infections in chickens and ducks.

Newcastle disease (ND), caused by ND virus (NDV), is one of the most infectious and economically important diseases of the poultry industry worldwide. While infections are reported in a wide range of avian species, the pathogenicity of chicken-origin virulent NDV isolates in ducks remains elusive. In this study, two NDV strains were isolated and biologically and genetically characterized from an outbreak in chickens and apparently healthy ducks. Pathogenicity assessment indices, including the mean death time (MDT), intracerebral pathogenicity index (ICPI) and cleavage motifs in the fusion (F) protein, indicated that both isolates were velogenic in nature. While these isolates carried pathogenic characteristics, interestingly they showed differential pathogenicity in ducks. The chicken-origin isolate caused high (70%) mortality, whereas the duck-origin virus resulted in low (20%) mortality in 4-week-old ducks. Intriguingly, both isolates showed comparable disease pathologies in chickens. Full-genome sequence analysis showed that the virus genome contains 15192 nucleotides and carried features that are characteristic of velogenic strains of NDV. A phylogenetic analysis revealed that both isolates clustered in class II and genotype VII. However, there were several mutations in the functionally important regions of the fusion (F) and haemagglutinin-neuraminidase (HN) proteins, which may be responsible for the differential pathogenicity of these viruses in ducks. In summary, these results suggest that NDV strains with the same genotype show differential pathogenicity in chickens and ducks. Furthermore, chicken-origin virulent NDVs are more pathogenic for ducks than duck-origin viruses. These findings propose a role for chickens in the evolution of viral pathogenicity and the potential genetic resistance of ducks to poultry viruses.

Molecular epidemiological survey and complete genomic phylogenetic analysis of H6 subtype avian influenza viruses in poultry in China from 2011 to 2016

To investigate the prevalence and evolution of the H6 subtype avian influenza viruses (AIVs) circulating in poultry in China from 2011 to 2016, 11 molecular epidemiological surveys was performed in this study. In total, 893 H6 subtype viral strains were isolated from 67,639 swab samples and 360 environmental samples. From these strains, 35 representative strains were selected and their whole genomic sequences determined. According to a phylogenetic analysis and molecular characterization, all 35 viral strains belonged to the Eurasian avian lineage. All of them were categorized as ‘low pathogenic’ and a few strains had some bioinformatical mutations. This epidemiological survey shows that the prevalence of H6 subtype AIVs increased from 2012 to 2016 in China, and suggests that infections by H6 subtype AIVs in China has increased in recent years.

Geographical and Historical Patterns in the Emergences of Novel Highly Pathogenic Avian Influenza (HPAI) H5 and H7 Viruses in Poultry.

Over the years, the emergence of novel H5 and H7 highly pathogenic avian influenza viruses (HPAI) has been taking place through two main mechanisms: first, the conversion of a low pathogenic into a highly pathogenic virus, and second, the reassortment between different genetic segments of low and highly pathogenic viruses already in circulation. We investigated and summarized the literature on emerging HPAI H5 and H7 viruses with the aim of building a spatio-temporal database of all these recorded conversions and reassortments events. We subsequently mapped the spatio-temporal distribution of known emergence events, as well as the species and production systems that they were associated with, the aim being to establish their main characteristics. From 1959 onwards, we identified a total of 39 independent H7 and H5 LPAI to HPAI conversion events. All but two of these events were reported in commercial poultry production systems, and a majority of these events took place in high-income countries. In contrast, a total of 127 reassortments have been reported from 1983 to 2015, which predominantly took place in countries with poultry production systems transitioning from backyard to intensive production systems. Those systems are characterized by several co-circulating viruses, multiple host species, regular contact points in live bird markets, limited biosecurity within value chains, and frequent vaccination campaigns that impose selection pressures for emergence of novel reassortants. We conclude that novel HPAI emergences by these two mechanisms occur in different ecological niches, with different viral, environmental and host associated factors, which has implications in early detection and management and mitigation of the risk of emergence of novel HPAI viruses.

Chicken Interferon-induced Protein with Tetratricopeptide Repeats 5 Antagonizes Replication of RNA Viruses

The intracellular actions of interferon (IFN)-regulated proteins, including IFN-induced proteins with tetratricopeptide repeats (IFITs), attribute a major component of the protective antiviral host defense. Here we applied genomics approaches to annotate the chicken IFIT locus and currently identified a single IFIT (chIFIT5) gene. The profound transcriptional level of this effector of innate immunity was mapped within its unique cis-acting elements. This highly virus- and IFN-responsive chIFIT5 protein interacted with negative sense viral RNA structures that carried a triphosphate group on its 5′ terminus (ppp-RNA). This interaction reduced the replication of RNA viruses in lentivirus-mediated IFIT5-stable chicken fibroblasts whereas CRISPR/Cas9-edited chIFIT5 gene knockout fibroblasts supported the replication of RNA viruses. Finally, we generated mosaic transgenic chicken embryos stably expressing chIFIT5 protein or knocked-down for endogenous chIFIT5 gene. Replication kinetics of RNA viruses in these transgenic chicken embryos demonstrated the antiviral potential of chIFIT5 in ovo. Taken together, these findings propose that IFIT5 specifically antagonize RNA viruses by sequestering viral nucleic acids in chickens, which are unique in innate immune sensing and responses to viruses of both poultry and human health significance.

Co-infection of fowl adenovirus with different immunosuppressive viruses in a chicken flock

In poultry, fowl adenovirus (FAdV) and immunosuppressive virus co-infection is likely to cause decreased egg production, inclusion body hepatitis, and pericardial effusion syndrome. In this study, fowl adenovirus infection was found in parental and descendent generations of chickens. We used quantitative polymerase chain reaction (PCR) and dot blot hybridization to detect the infection of reticuloendotheliosis (REV), avian leukosis virus (ALV), and chicken infectious anemia virus (CIAV) in 480 plasma samples. The test samples were 34.58% FADV-positive, 22.29% REV-positive, 7.5% CAV-positive, and 0.63% ALV-positive. Sequence analysis showed that FADV belonged to serotype 7, which can cause inclusion body hepatitis. The ALV strain was ALV-A, in which the homology of gp85 gene and SDAU09C1 was 97.3%. The positive rate was lower because of the purification of avian leukemia, whereas the phylogenetic tree analysis of REV showed that the highest homology was with IBD-C1605, which was derived from a vaccine isolate. Through pathogen detection in poultry we present, to our knowledge, the first discovery of fowl adenovirus type 7 infection in parental chickens and found that there was co-infection of FAdV and several immunosuppressive viruses, such as the purified ALV and CIAV. This indicates that multiple infection of different viruses is ever-present, and more attention should be given in the diagnosis process.