Observations on host range and control of goose virus hepatitis

A number of experiments were done with a strain of goose hepatitis virus (isolated from sick goslings in the Netherlands in 1969. This virus was easily grown in embryonating eggs of the Muscovy duck (Cairina moschata) as well as in embryonating goose eggs. It also proved possible to adapt it to White Pekin duck eggs. The susceptibility of embryonating eggs obtained by crossing Muscovy drakes with Pekin ducks was intermediate between that of eggs from the two parental breeds. It was not possible to adapt goose hepatitis virus to growth in chicken embryos. The sensitivity of goslings to the goose hepatitis virus was found to vary considerably according to the farms from which they came. These differences were caused by variations 'in the quantity of parentally derived antibodies. One day-old Muscovy ducklings appeared to be at least as sensitive to the virus as goslings. However, disease symptoms could not be produced with goose hepatitis virus in Pekin ducklings nor in ducklings obtained by crossing Muscovy drakes and Pekin ducks. Treatment with homologous immune serum protected susceptible goslings and Muscovy ducklings against the disease. Under farm conditions, mortality was reduced from 30 to 3%. A breeding flock of adult Muscovy ducks, which had by serum therapy survived a goose hepatitis infection at an early age, produced ducklings resistant to the goose hepatitis virus. Over 100 flocks of geese, totalling more than 6,000 birds, were actively immunized with goose hepatitis Virus. The progeny produced in the following breeding season resisted, almost without exception, a challenge at one day of age with virulent goose hepatitis virus.     

Serological survey for the prevalence of antibodies to egg drop syndrome 1976 virus in domesticated and wild birds in Israel

A serological survey of chicken, turkey, goose and duck flocks for the presence of antibodies to egg drop syndrome virus 1976 (EDS 76) has been carried out in Israel. In most of the chicken flocks sampled egg production was not normal, but no antibodies against this virus were detected. Likewise, turkey breeding flocks were similarly negative. All Pekin duck flocks tested showed some serological activity. Muscovy ducks that were reared in direct or indirect contact with Pekin ducks had haemagglutination-inhibition antibodies to EDS 76 virus. Seven cattle egrets trapped on a duck farm were serologically positive. No antibodies were detected in a collection of water fowl raised in a zoological garden.     

Isolation and molecular characterization of a new Muscovy duck parvovirus from Muscovy ducks in the USA.

Between 1997 and 1999 several cases of a new disease in Muscovy ducks were reported in Pennsylvania, USA. The cases were characterized by locomotor dysfunction, weakness, recumbency, 40 to 60% morbidity and 10 to 40% mortality. The most characteristic microscopic lesions were moderate to severe degenerative rhabodomyopathy. In order to characterize the aetiological agent, virus isolation was attempted from the spleen, liver, heart, skeletal muscle and intestine by inoculation of 14-day-old Muscovy duck embryos with tissue homogenates. Deaths occurred on the second egg passage and parvoviruses were isolated by serial passage of allantoic fluid from dead embryos and then in Muscovy duck embryo fibroblast (MDEF) cultures. Parvovirus particles were observed in allantoic fluids and supernatants of MDEF cultures by transmission electron microscopy. Two genomic fragments, comprising 1108 nucleotides of the right open reading frame that codes for the structural viral proteins 1, 2 and 3, were amplified by polymerase chain reaction from one of the isolates, Muscovy duck parvovirus (MDPV)/PSU-31010. Comparison of this fragment with available sequences of other MDPV and related goose parvovirus (GPV) isolates showed that it had only 84.5% sequence identity with other MDPV isolates and 84.6% identity with the GPV isolates. This region shares over 99% identity among previously sequenced MDPV isolates and 95% identity among the related GPV isolates. This suggests that MDPV/PSU-31010 is divergent from all other sequenced MDPV and GPV isolates, and may represent a new group of avian parvoviruses.     

Evolutionary comparison of the avian IgL locus: combinatorial diversity plays a role in the generation of the antibody repertoire in some avian species

Immunoglobulin light chain (IgL) diversity is generated in the chicken by recombination between the single functional variable (VL) and joining (JL) gene segments and subsequent somatic diversification of the rearranged VL region. In order to determine whether these events are a general feature of avian IgL genes, we analyzed the organization and recombinatorial characteristics of the IgL loci of several other avian species. Southern blot analysis of bursal and germline DNA using chicken VL and constant (CL) probes revealed that the IgL loci of quail, mallard duck, pigeon, turkey, cormorant, and hawk consist of a family of VL elements, but undergo a single major rearrangement event similar to that observed in chickens. In contrast, several rearrangements were observed in the Muscovy duck locus. A phage clone containing a 26 kb insert that hybridized to VL and CL probes was isolated from a Muscovy duck erythrocyte DNA genomic library. Nucleotide sequencing revealed that the clone contained a single JL-CL region flanked on the 5' side by five VL segments. Unlike the chicken, two of the VL segments (VL1, VL5) appear to be functional. The remaining three VL segments are pseudogenes that lack promoter and leader sequences, but one of these (psi VL3) has recombination signal sequences. Overall, these data indicate that rearrangement of one VL gene segment is a general feature of the IgL locus in many avian species. In these species, the presence of a family of VL elements that do not rearrange suggests that a pseudogene pool may be available for somatic diversification by gene conversion. The organization of the Muscovy duck IgL locus suggests that additional combinatiorial diversity has evolved independently in some avian species.     

Characterization of a herpesvirus isolated from domestic geese in Australia

A herpesvirus (GHV 552/89) associated with high mortality in a flock of domestic geese in Australia was compared with duck virus enteritis (DVE) herpesvirus by cross-protection studies in domestic geese, Muscovy ducks and commercial Pekin ducks. In DVE-vaccinated geese, Muscovy ducks and Pekin ducks, mortality levels of 100, 50 and 0%, respectively, were recorded following challenge with GHV 552/89. Conversely, in geese, Muscovy ducks and Pekin ducks immunized with inactivated GHV 552/89, 100% mortality was observed in the geese and Muscovy ducks, and 80% in the Pekin ducks following challenge with DVE virus. The isolate was also compared with six other avian herpesviruses using cross-neutralization tests in cell cultures. No detectable cross-neutralization occurred with any of the avian herpesviruses tested. Further characterization of GHV 552/89 was undertaken by comparing its genome with strains of DVE herpesvirus using restriction endonuclease analysis of the viral DNA and a polymerase chain reaction (PCR) test. Following digestion with HindIII, the DNA fragment pattern of GHV 552/89 was found to be completely different from the DVE viruses. Similarities were found between the digestion patterns of a UK and a US DVE isolate, but both were distinguishable from a UK vaccine strain. The results of the PCR analysis and comparison using two DVE-specific primer sets did not produce specific amplification products of expected molecular weights (603 and 446 base pairs) from the GHV 552/89 genome. The PCR products derived from the DVE strains were similar to those derived from the DVE control DNA. From the results of this study, it is concluded that the goose herpesvirus GHV 552/89 is antigenically and genomically distinct from DVE herpesvirus.     

Structural and biological characteristics of reoviruses isolated from Muscovy ducks (Cairina moschata)

Two Muscovy duck reoviruses, strains y1/79 and 1625/87, were investigated with regard to their genome organization, polypeptide pattern, serotype specificity, and pathogenicity. Electrophoretic analysis of the genome revealed the migration pattern of avian reoviruses. In spite of general conformity, great polymorphism was detected in the electrophoretic mobility of individual genome segments of the two strains sharing only three segments of identical size (L1, M2, M3). Only one segment (M3) migrated into the same position as the corresponding segment of prototype chicken reovirus S1133. The basic electrophoretic mobility pattern of the immunopre‐cipitated polypeptides, eight structural and two non‐structural, closely resembled that of the chicken reovirus. However, considerable strain‐specific variation was also seen at the protein level, with the σ_c polypeptides exhibiting the most obvious migration differences. Based on the results of cross‐neutralization assays the two Muscovy duck reovirus strains were grouped into one serotype, with no cross‐reactivity to the chicken serotype S1133. In experimental infections, despite virus replication proved by faecal virus excretion and antibody response, only strain y1/79 was pathogenic for 16‐day‐old Muscovy ducklings, thus making strain 1625/87 a possible candidate as vaccine strain.     

Peptide Epitope Binding Specificity and Vk and Vh Gene Usage in a Monoclonal IgM Natural Autoantibody to T Cell Receptor CDR1 from a Viable Motheaten Mouse

Autoantibodies (AAbs) to T cell receptor (TCR) determinants are produced in humans during the course of rheumatoid arthritis and systemic lupus erythematosus as well as in retroviral infections. We have examined the binding specificity of a panel of monoclonal antibodies derived from mutant viable motheaten (mev) mice against several TCR peptide determinants representing the complementary determining region 1 (CDR1) regions of various Vβ families, and have identified one mAb, UN37-5, that shows high affinity binding with specificity for two CDR1 peptide determinants. The light and heavy chain V genes of UN37-5 were sequenced and compared to known V genes. The UN37-5 V_H gene sequence represents the V_HJ606 family and is most similar to a previously reported V_H gene derived from a germline DNA fragment representing a unique J606 family V_H gene. This germline V_H gene is also used by previously characterized mev derived mAbs directed against thymocyte and RBC antigens. The UN37-5 V_L gene sequence represents the Vk 4/5 gene family. It has 87% homology with the Vk Ox-1 germline gene. The UN37-5 Vk sequence has greater than 95% identity at the amino acid level with Vk_Lchains from IgM hybridomas specific for DNA and the influenza virus hemagglutinin. The specificity of this AAb is determined by the V_H CDR3 and a Vk chain which has not been utilized in previously reported mev autoantibodies.     

Avian embryo susceptibility to Italian H7N1 avian influenza viruses belonging to different genetic lineages

Summary.  In the present paper we report of the results of an immunohistochemical investigation to assess tissue tropism and viral replication in developing chicken, turkey, Muscovy duck and mallard duck embryos, of Italian H7N1 isolates belonging to different genetic lineages. LPAI isolates were chosen on the basis of the location in the phylogenetic tree: a progenitor strain, A/ty/Italy/977/V99, (exhibiting no additional glycosylation site, nAGS), strain A/ty/Italy/2379/V99 (AGS in position 123) and strain A/ty/Italy/3675/V99 (AGS in position 149) were selected. The latter two strains belonged to distinct lineages originating from the pool of progenitor strains. HPAI isolate A/ty/Italy/4580/V99 was also included in the study. All the embryos tested supported the growth of HPAI. The LPAI isolates replicated readily in the allantoic layer of the CAM of all the species tested, and did not grow in the developing chicken, turkey and Muscovy duck embryos. In contrast, they replicated to different extents in the respiratory tract of the developing mallard embryo, which also presented lower mortality rates than the other species. We conclude from these findings that the pathogenesis of LPAI infections in mallard embryos is different to that observed in other species, and should be investigated further. Received February 12, 2002; accepted April 17, 2002 Published online July 19, 2002     

Virus hepatitis of geese. 3. Properties of the causal agent

Characteristics of the goose hepatitis virus strain SHM 319 were studied in goose embryos and tissue cultures of avian origin. The virus was found to be resistant to both ether and sodium deoxycholate (0.25%). The growth of the virus was inhibited by 5-iodo-2-deoxyuridine. Virus infectivity was not affected by heating at 56 degrees C for 3 hours, exposure to pH 3.0, formalin (1:1000), and other inactivating chemicals. Cell culture systems of three avian species were inoculated with GVH-SHM 319. Extensive cytopathic effect was produced only in goose cell cultures. No virus replication was observed in chicken or White Pekin duck cells. Fluorescent antibody staining revealed granular nuclear staining in infected susceptible tissue cultures. May-Grunwald-Giemsa-staining of infected tissue culture cells showed formation of mainly intranuclear inclusion bodies. Millipore filtration procedures revealed a particle size less than 50 nm. Hemagglutination was not observed. Precipitating antibodies could not be detected in GHV hyperimmunized birds. Neutralization tests could not demonstrate a relationship to known viruses of waterfowl, including duck virus enteritis and duck virus hepatitis. A certain discrepancy in the neutralization test with Hungarian goose sera is discussed.     

Cloning and sequence analysis of κ and γ cynomolgus monkey immunoglobulin cDNAs

One γ heavy chain and 10 κ light chain cynomolgus monkey (Macaca fasicularis) immunoglobulin cDNAs have been cloned and sequenced. Comparisons of the variable (V) regions to human antibody sequences have revealed extensive identity, exhibiting 93% at the amino acid level for the V_H framework regions, and 88–99% for the V_κ frameworks. Identification of very few cynomolgus monkey-specific framework region residues suggests a role for cynomolgus monkey antibodies as donators of variable regions to chimeric monoclonal antibodies for utilisation in human therapy with human constant (C) regions. The cynomolgus monkey C_κ region exhibited 83% amino acid identity to its human counterpart, and the C_γ region was 95, 93, 95, and 95% similar to the human C_γ1, C_γ2, C_γ3, and C_γ4 regions, respectively. Evolutionary analysis of the C_γ genes, using the silent molecular clock, suggests that the divergence between cynomolgus monkey and human occurred before the time at which the ancestral γ gene diverged into the multiple isotypes observed in humans.     

ALlometric growth of histochemical types of muscle fibers in ducks

Radial growth (fiber cross sectional area) was measured at the midlength of sartorius muscles in Pekin and Muscovy breeds of domestic ducks. Pekins exhibited faster early growth (up to 7 weeks after hatching) while Muscovies exhibited greater divergence between sexes (after 7 weeks). In both sexes of both breeds, radial growth of strong-ATPase fibers failed to keep pace with that of weak-ATPase fibers; allometric growth ratio, k = 0.64 in Muscovy males, k = 0.65 in Muscovy females, k = 0.61 in Pekin males and k = 0.61 in Pekin females (P less than 0.005). At 7 weeks, strong-ATPase fibers showed a greater range in their potential for aerobic metabolism, as judged by cytophotometry of their reactions for succinate dehydrogenase (SDH). Thus, in strong-ATPase fibers, cross sectional area was inversely related to SDH reaction in both Pekin and Muscovy breeds (r = -0.76 and r = -0.43, respectively). Further evidence was found for developmental changes in muscle structure caused by changes in relative fiber length, as proposed by MacCallum in 1898.     

Large-scale survey of Cryptosporidium spp. in chickens and Pekin ducks (Anas platyrhynchos) in Henan,China: prevalence and molecular characterization

Few data are available on the molecular characterization of Cryptosporidium spp. in chickens and ducks in China. In this study, 2579 faecal samples from 46 chicken farms and eight Pekin duck farms in 21 prefectures in Henan Province were examined. The overall infection rate of Cryptosporidium was 10.6% (163/1542) in layer chickens (10 out of 17 farms), 3.4% (16/473) in broilers (five out of 29 farms), and 16.3% (92/564) in Pekin ducks (four out of eight farms), respectively. The highest infection rates were observed in 31-day-old to 60-day-old layer chickens (24.6%) and 11-day-old to 30-day-old Pekin ducks (40.3%). The season of highest prevalence in chickens was spring (15.6%) and the lowest was winter (P<0.01). One hundred and eighty-seven Cryptosporidium-positive samples were analysed by polymerase chain reaction (PCR)–restriction fragment length polymorphism analysis of the small subunit rRNA gene, and 55 were further analysed by DNA sequencing of the PCR products. Two Cryptosporidium species were identified: Cryptosporidium baileyi (184/187) on 15 chicken farms and four duck farms, and Cryptosporidium meleagridis (3/187) on three layer chicken farms. C. baileyi was the predominant Cryptosporidium species, found in all age groups of chickens and all Cryptosporidium-positive ducks examined, whereas C. meleagridis was only identified in 31-day-old to 120-day-old layer chickens. Considering the large size of the chicken industry and the close contact between chickens and humans, and that C. meleagridis is the third most common Cryptosporidium parasite in humans, then C. meleagridis could potentially become an emerging zoonosis in some areas in China.     

The Pekin duck programmed death‐ligand 1: cDNA cloning,genomic structure,molecular characterization and mRNA expression analysis

Programmed death ligand‐1 (PD‐L1) plays an important role in the attenuation of adaptive immune responses in higher vertebrates. Here, we describe the identification of the Pekin duck PD‐L1 orthologue (duPD‐L1) and its gene structure. The duPD‐L1 cDNA encodes a 311‐amino acid protein that has an amino acid identity of 78% and 42% with chicken and human PD‐L1, respectively. Mapping of the duPD‐L1 cDNA with duck genomic sequences revealed an exonic structure of its coding sequence similar to those of other vertebrates but lacked a noncoding exon 1. Homology modelling of the duPD‐L1 extracellular domain was compatible with the tandem IgV‐like and IgC‐like IgSF domain structure of human PD‐L1 (PDB ID: 3BIS). Residues known to be important for receptor binding of human PD‐L1 were mostly conserved in duPD‐L1 within the N‐terminus and the G sheet, and partially conserved within the F sheet but not within sheets C and C'. DuPD‐L1 mRNA was constitutively expressed in all tissues examined with highest expression levels in lung and spleen and very low levels of expression in muscle, kidney and brain. Mitogen stimulation of duck peripheral blood mononuclear cells transiently increased duPD‐L1 mRNA expression. Our observations demonstrate evolutionary conservation of the exonic structure of its coding sequence, the extracellular domain structure and residues implicated in receptor binding, but the role of the longer cytoplasmic tail in avian PD‐L1 proteins remains to be determined.     

Secretory immune system of the duck ( Anas platyrhynchos ). Identification and expression of the genes encoding IgA and IgM heavy chains

IgA has not previously been identified in waterfowl. Studies instead revealed physical and antigenic similarities between duck bile immunoglobulin (Ig) and serum IgM. Here, a differential screening approach was used to clone, from a duck spleen library, the cDNA encoding the heavy (H) chains of IgM and the Ig, identified here as IgA, occurring in duck secretions. Phylogenetic comparisons of inferred amino acid sequences of entire H chain constant (C) regions and of individual domains revealed that the duck μ chain was closest to chicken μ (54 % overall identity), and duck α was closest to chicken α (50 % identity). Comparison of the μ and α C regions revealed areas of up to 65 % amino acid similarity within the C4 domains, accounting for the previously noted antigenic overlap of duck IgM and IgA. Messages for α and μ were detected in duck lymphoid organs but the α message was most abundant in the respiratory, alimentary and reproductive tracts. The α message first appeared around 14 days of age and reached adult levels of expression only at 35 – 50 days. The results indicate that the duck has a mucosal immune system which utilizes IgA; however, the delayed expression and secretion of duck IgA explains the susceptibility of ducklings to mucosal pathogens. Since the waterfowl are among the most primitive extant birds, the recognition of IgA in the duck supports the conclusion that IgA occurs throughout the class Aves and also existed in the common ancestors of birds and mammals.     

Genomic sequence of an avian paramyxovirus type 1 strain isolated from Muscovy duck (Cairina moschata) in China

The complete sequence of an avian paramyxovirus type 1 (APMV-1) strain, FP1/02, isolated from Muscovy duck in China, was determined. Sequence analysis indicated that the complete genome of strain FP1/02 contained 15,192 nucleotides (nt), following the rule of six. The genome contained an extra 6-nt insertion in the non-coding region of the NP gene when compared with other APMV-1 strains, such as strains La Sota and Beaudette C. The cleavage site of the F protein was (112)R-R-Q-K-R↓F(117), indicating that the FP1/02 strain was virulent, but the morbidity and mortality varied with the species of duck. Genotypic analysis based on the F gene revealed that APMV-1 FP1/02 was a member of genotype VII. Phylogenetic analysis showed that the FP1/02 strain shared high identity with other APMV-1 strains such as ZJ1, SF02 and NA-1 isolated from geese.     

Cloning, in vitro expression and bioactivity of duck interleukin-2

In this report, the cDNA sequences of Shaoxing (SX) and Muscovy (MV) duck IL-2 were cloned, then recombinant duck IL-2 (rduIL-2) was produced in prokaryotic expression system. In vitro bioactivity of rduIL-2 was determined by lymphocyte proliferation assay and in vivo bioactivity of rduIL-2 was assessed by vaccine immunization. Monoclonal antibodies (mAbs) and polyclonal antibodies (pAbs) specific for rduIL-2 were generated and characterized by ELISA, Western blot and neutralizing assays. The cDNA contains an open reading frame (ORF) of 420-base pairs encoding a protein of 140 amino acids (aa) with a putative signal peptide of 21aa. The His-duIL-2 fusion protein was recognized in Western blot by mAb against chicken IL-2 (chIL-2), but not by mAbs against human IL-2 and mouse IL-2. Recombinant duIL-2 induces in vitro proliferation of Con A-stimulated duck splenocytes in MTT assay and strengthens duck immune responses induced by vaccinating the inactivated oil emulsion vaccine against avian influenza virus. Polyclonal antibodies and mAb 2B3 against rduIL-2 were shown to have effective neutralizing ability by inhibiting the biological activities of both recombinant duIL-2 and endogenous duIL-2. Despite the fact that duck and chicken IL-2s only share identity of 55.0-56.7% in amino acid sequence, duck and chicken IL-2 molecules displayed similar cross-priming activity in in vitro lymphocyte proliferation assays. The results, at the first time, indicated that rduIL-2 has the potential to be used as an immunoadjuvant for enhancing vaccine efficacy and an immunotherapeutic, and the mAbs against rduIL-2 further facilitate basic immunobiological studies of the role of IL-2 in avian immune system.