Purification and characterization of the aetiological agent of hydropericardium hepatitis syndrome from infected liver tissues of broiler chickens

Hydropericardium hepatitis syndrome in broiler chickens is an acute, infectious disease characterized by high mortality, excess pericardial fluid and multifocal hepatic necrosis. The aetiological agent was purified to homogeneity from infected liver tissues from field outbreaks. Electron-microscopic and serological confirmation of the virus were undertaken and the disease was reproduced experimentally in broiler chicks. The results indicated that an adenovirus, fowl adenovirus serotype 4, was alone responsible for the disease in the materials studied.

[Adenovirus KR95, isolated from chickens during an outbreak of hydropericarditis, is the pathogen of this disease]

Virus agent KR95 was isolated from the liver of dieoff chickens during an outbreak of hydropericarditis syndrome at a poultry farm in Russia. Electron microscopic examination of the virus morphology, comparative restriction cleavage map construction, DNA-DNA hybridization, and analysis of structural proteins from purified and disrupted virions showed that the agent is to be classified as type 1 avian adenovirus.

[Adenovirus infections in psittacines]

Diagnostic investigations were carried out in a fatal disease of several African Grey Parrots (Psittacus erithacus) and Cape Parrots (Poicephalus robustus) in a large breeding plant. Electron microscopically examination of liver and intestine, the organs with the most prominent pathomorphological changes, regularly revealed adenoviruses. Necrotizing hepatitis and catarrhal to haemorrhagic enteritis dominated on histopathological examination. Numerous basophilic intranuclear inclusion bodies in hepatocytes and enterocytes and their ultrastructural characteristics underline the etiological role of the detected adenoviruses. Adenoviruses were isolated from livers of three different birds and once from the intestine. Serologically the isolates were classified as fowl adenovirus serotype 4 (FAV4). Restriction enzyme analysis of two isolates showed the identity with the FAV4 reference strain KR5.

DNA in situ hybridization for the rapid diagnosis of massive necrotizing avian adenovirus hepatitis and pancreatitis in chicks

The present study describes the use of DNA in situ hybridization for the rapid diagnosis of massive necrotizing adenovirus hepatitis and pancreatitis in broiler chicks. A light microscope and DNA probes were used to identify avian adenovirus in replicate sections of formalin-fixed paraffin-embedded liver and pancreas from field and experimental chicks. Avian adenovirus infection was confirmed by transmission electron microscopy and virus isolation.

The avian adenovirus penton: two fibres and one base

The penton capsomer of mammalian adenoviruses consists of a trimeric, long and thin fibre inserted into a pentameric base. The avian adenoviruses possess a penton which presents another symmetry mismatch: each pentameric base is associated with two fibres. Here we have studied the morphology of the penton of CELO virus, an avian adenovirus, and we have determined the sequence of both fibres, one long and one short. The short fibre is probably associated with the base in the same way as the mammalian viral fibres and we will discuss how the long fibre could be attached. The shafts of all known adenovirus fibres consist of a series of 15-residue repeats. The avian virus fibres show a more complicated and less regular shaft repeat structure with single, double and triple repeats. The sequences of the receptor binding (head) domains of both fibres are very different from all other known fibre head domains and very different from each other, suggesting that the two fibres might bind to different receptors. The genome organization of the sequenced region is rather different from that in human adenoviruses. In particular, a region homologous to the human virus E3 region was not found at the position where it normally occurs in the human virus genome.

Hemorrhagic enteritis by adenovirus-like particles in turkeys: a possible pathogenic mechanism

This paper describes an outbreak of hemorrhagic enteritis due to adenovirus in turkeys in Spain. Diagnosis of the disease was confirmed by histopathological examination and the observation of adenovirus in spleen mononuclear cells and intestinal infiltrate. Evidence was also found of intravascular coagulation, which may give rise to the bleeding considered characteristic of this disease.

Inclusion body hepatitis in Gambel's quail (Callipepla gambelii)

An acute necrotizing hepatitis in 1- to 3-wk-old Gambel's quail (Callipepla gambelii) caused by an adenovirus is described. The infection caused high mortality in captive raised, orphan chicks at two wildlife rehabilitation facilities in Arizona (USA). Gross lesions varied from pale livers to multiple, pinpoint, white foci scattered throughout the livers. Microscopically, scattered foci of hepatocellular necrosis were present. Intact hepatocytes at teh periphery of necrotic foci had eosinophilic and basophilic intranuclear inclusion bodies.

Liquid crystalline DNA in fowl adenovirus

Fowl adenovirus particles were studied using negative stain electron microscopy. Upon preparation, some particles collapsed and showed their internal structure. The DNA could be observed as thin parallel lines with a spacing of 25 A, very similar to images of the liquid crystalline DNA in bacteriophage heads and in herpes virus.

Inclusion bodies containing adenovirus-like particles in the intestine of a psittacine bird affected by inclusion body hepatitis

This paper reports a case of inclusion body hepatitis with intranuclear inclusion bodies in the liver and the intestine of a Yellow-naped Amazon parrot (Amazona ochrocephala). Structurally, basophilic intranuclear inclusion bodies were found in hepatic cells and enterocytes. Ultrastructurally, icosahedral adenovirus-like particles, 60-75 nm in diameter, were found in the same cells.

Characterization of the structural proteins of hemorrhagic enteritis virus

The structural proteins of hemorrhagic enteritis (HEV), a turkey adenovirus, were analyzed by polyacrylamide gel electrophoresis (PAGE) and Western blotting using polyspecific, monospecific and monoclonal antibodies for detection. In purified HEV preparations, eleven polypeptides with apparent molecular weights ranging from 96,000 to 9,500 (96k to 9.5k), were specifically recognized by convalescent turkey serum. Six of these polypeptides were further characterized by PAGE, Western blotting, ELISA, sucrose gradient centrifugation and electron microscopy. The 96k polypeptide was identified as the hexon polypeptide which is a monomer of the major outer capsid or hexon protein. The 51/52k and 29k polypeptides, identified as the penton base and fiber polypeptides respectively, were the components of the vertex or penton protein. The 57k polypeptide was identified as a homologue of the human adenovirus type 2 (Ad 2) IIIa protein with which it shares a common epitope. Two core proteins with molecular weights of 12.5 and 9.5k were present in purified HEV nucleoprotein cores. The proteins of two HEV isolates, one apathogenic (HEV-A) and one virulent (HEV-V), resembled each other in most respects. However, differences between HEV-A and HEV-V were found in electrophoretic migration of the penton base protein both under native and denatured conditions, and in the electrophoretic migration of the 43/44k polypeptide. Moreover, homologous antiserum against the fiber protein reacted stronger than heterologous antiserum in an ELISA. Single fibers were detected by electron microscopy attached to the penton base proteins of HEV virions and in isolated pentons. The feature of having single fibers is shared with the mammalian adenoviruses and the avian egg drop syndrome 1976 virus (EDS 76 V), but not with the fowl adenoviruses which have double fibers attached to their penton base proteins.

Respiratory adenovirus-like infection in a rose-ringed parakeet (Psittacula krameri)

Intranuclear inclusions were observed under light microscopy in the bronchial epithelial cells of a recently purchased female rose-ringed parakeet that died of chlamydiosis. Transmission electron microscopy revealed the presence of numerous particles of adenovirus morphology. A latent adenovirus infection may have become more severe following chlamydiosis and the stress of handling.

Identification and characterization of viral polypeptides from type-II avian adenoviruses

The polypeptides of serologically related viruses of hemorrhagic enteritis (HE) in turkeys, marble spleen disease (MSD) in pheasants, and splenomegaly in chickens (SMC) were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and analyzed by protein immunoblotting with polyclonal antibodies to HE virus (HEV). The viral polypeptides II, III, IV, V, VI, and VII were detected on SDS-PAGE with the size range from 18 to 97 kDa in HEV. Viral polypeptides II, III, V, VI, and VII were detected in MSD virus and virus of SMC. Protein immunoblotting of viral proteins with anti-HEV serum revealed antigenic differences between the 3 viruses of avian adenovirus type-II examined. The differences were that the polypeptides II, III, IV, V, VI, and VII were identified in HEV and the polypeptides II, V, VI, and VII were identified in MSD virus and virus of SMC. The bands of penton base (polypeptide III) and fiber (polypeptide IV) were seen in HEV only by protein immunoblotting.

Studies on the aetiology of hydropericardium syndrome (Angara disease) in broilers

The study was carried out to determine the aetiological agent(s) associated with hydropericardium syndrome (Angara disease) in broilers in Pakistan. The results indicate that in addition to adenovirus some other agent is involved in causing the disease but that this agent requires co-infection by an adenovirus for the reproduction of the typical signs of the syndrome. The nature of this agent remains unknown because no discrete virus or virus-like particle could be seen by electron microscopy.

Avian adenovirus isolated from pigeons affected with inclusion body hepatitis

Avian adenoviruses were isolated from two pigeons affected with inclusion body hepatitis (IBH) by using chicken embryo liver cell cultures. One of the isolates, designated strain S-PL1, replicated in the cell nuclei forming intranuclear inclusion bodies, showed adenovirus-like morphology by electron microscopy, and cross-reacted serologically with strain SR-48 known as serotype 2 of fowl adenovirus. The strain S-PL1 killed day-old chicks by subcutaneous inoculation, and its 50% chicken lethal dose was 10(3.8) plaque forming units per bird. Severe lesions characterized with IBH and pancreatitis, were produced in chicks inoculated with the virus. Intranuclear inclusion bodies were also recognized in the liver, pancreas, kidney, proventriculus, small intestine, and caecum. By indirect immunofluorescence test, intranuclear viral antigens were detected in the liver, pancreas and other tissues.

Propagation of group II avian adenoviruses in turkey and chicken leukocytes

An avirulent hemorrhagic enteritis virus isolate (HEV-A) as well as a virulent one (HEV-V), both belonging to the group II avian adenoviruses, were successfully propagated in turkey leukocyte cell cultures. HEV antigens were detected as early as 12 hr after infection of the cells, using HEV-specific monoclonal antibodies in a fluorescent antibody test, and virus particles were observed by electron microscopy in the nuclei of infected cells at 18 to 24 hr after infection. Electron microscopy revealed the presence of HEV in the nuclei of nonadherent cells, as well as in adherent cells. The nonadherent infected cells had the characteristics of immature mononuclear leukocytes, whereas the adherent cells had monocyte-macrophage characteristics. HEV produced in turkey leukocytes was mostly cell-associated, particularly with the nonadherent cells. HEV-A could be serially passed in turkey blood leukocyte cultures at least seven times. Various methods employed to culture virus indicated that cells grown in spinner cultures were superior to cells grown in stationary cultures. In contrast to the successful infection of HEV in turkey leukocytes, the infection of chicken leukocytes with either HEV or splenomegaly virus of chickens, or turkey leukocytes with splenomegaly virus, was poor.

A review of marble spleen disease of ring-necked pheasants

Marble spleen disease (MSD) is a contagious disease of captive-reared ring-necked pheasants (Phasianus colchicus) characterized by variable mortality and high morbidity. The etiologic agent is a type II avian adenovirus closely related to hemorrhagic enteritis virus of turkeys and splenomegaly virus of chickens. Gross lesions of MSD consist of enlargement and mottling of the spleen and pulmonary edema. Microscopic alterations are most pronounced in the spleen and are characterized by reticuloendothelial (RE) cell hyperplasia and lymphoid necrosis. Intranuclear viral inclusions occur within hyperplastic RE cells. Serologic detection of MSD is routinely accomplished using an agar gel precipitin test. Oral vaccination with hemorrhagic enteritis virus or avirulent strains of MSD virus is effective in preventing MSD. There is no specific treatment available for MSD but supportive care, strict sanitation and good management practices are helpful in reducing mortalities and limiting the spread of an epizootic.

Viral agents associated with outbreaks of diarrhea in turkey flocks in Quebec

The relative importance of various enteric viruses associated with diarrhea of turkey poults was investigated by an evaluation of specimens received since 1982. Specimens originated from one to eight week old turkey poults, with mild to severe diarrhea, from 114 flocks in 42 commercial operations located in southern Quebec. The acute phase of enteritis occurred usually in poults between two and four weeks of age. Clarified intestinal contents were examined by direct electron microscopy and enzyme immunoassays. Enzyme-linked immunosorbent assays were performed with antisera to bovine rotavirus group antigen, avian reovirus types 1 to 5, and the prototype strain of the turkey enteric coronavirus. The presence of viruses could be demonstrated by electron microscopy in 55.3% of the specimens, and at least five different viruses were incriminated either alone or in combination. The coronavirus was by far the most common enteric virus with a prevalence of 47.5%. By enzyme-linked immunosorbent assay, rotavirus, reovirus and turkey coronavirus were detected in 14.5%, 18.1% and 61.4% of the specimens, respectively. By electron microscopy, 56.6% of these cases were positive for at least one virus.

Inclusion body hepatitis in bobwhite quail (Colinus virginianus)

Farm-reared bobwhite quails less than 3 weeks of age experienced high mortality (250 of 400). At necropsy, these birds had multiple 1-to-2-mm pale foci throughout their livers. Histologically, these foci varied from acute hepatocellular necrosis without an inflammatory response to necrosis with infiltrates of mononuclear inflammatory cells and some heterophils. Hepatocytes adjacent to affected areas had large basophilic intranuclear inclusions. A group I avian adenovirus was isolated from affected livers.

Study of avian adenovirus DNA infectivity in chick embryos

Inoculation of CELO adenovirus deproteinized DNA into the allantoic cavity of 9-day-old chick embryos (CE) induced the synthesis of infectious viral particles. The produced virions appeared to be identical with CELO adenovirions in terms of morphology, electrophoretic and immunochemical properties of hexon major capsid protein and also of DNA dot-hybridization. High infectivity of CELO DNA (minimal infective dose equaled 40 ng) may be also related, at least in part, to the absence of deoxyribonuclease activity in the allantoic fluid (AF).

Viral hepatitis in domestic geese in Saskatchewan

Up to 25% mortality occurred in goslings between 8 and 28 days of age in three sequential hatches from a closed breeder flock on a single farm. The birds died suddenly with minor ascites, subcutaneous and myocardial hemorrhages, and pale, mottled livers with petechial hemorrhages. Liver necrosis associated with intranuclear inclusion bodies was seen on histology. Virus particles were found on examination of the inclusion bodies with an electron microscope. Liver homogenates caused variable mortality 7 to 17 days postinoculation in goose embryos, some of which had hepatic necrosis and intranuclear inclusion bodies. Experimental goslings inoculated with material from these infected embryos died from hepatitis.

Structural organization and polypeptide composition of the avian adenovirus core

CELO virus (fowl adenovirus 1) contained three core polypeptides of molecular weights 20,000, 12,000, and 9,500. The core was similar to that of human adenoviruses, with some evidence of compact subcore domains. Micrococcal nuclease digestion of CELO virus cores produced a smear of DNA fragments of gradually decreasing size, with no nucleosome subunit or repeat pattern. Moreover, when digested cores were analyzed without protease treatment, there was again no evidence of a nucleosome substructure; neither DNA fragments nor core proteins entered a 4% polyacrylamide gel. The organization of the core is thus quite unlike that of chromatin. Restriction endonuclease analysis of the DNA from digested cores showed that the right end was on the outside of the core. We suggest that adenovirus DNA is condensed into the core by cross-linking and neutralization by the core proteins, beginning with the packaging sequence at the center of the core and ending with the right end of the DNA on the outside.

Purification and hemagglutinating properties of egg drop syndrome 1976 virus

We purified three populations of virus particles, F7, F9 and F17, with buoyant densities of 1.34, 1.33 and 1.29 g/ml, respectively, in CsCl equilibrium density gradients from cultures of chick embryo liver cells infected with the H-162 strain of the virus of egg drop syndrome 1976. F9 particles were infectious complete virions and most F17 particles were empty particles. F7 particles were less infectious, and had little capacity of hemagglutination (HA). HA titers were the same at 4 degrees and 37 degrees C and maximal between pH 6.4 and 8.4 and ionic strength from 0.14 to 0.54 M of NaCl. HA titer was inversely proportional to erythrocyte concentration. Potassium periodate destroyed markedly the infectivity of the virus and partially its HA activity at 37 degrees C. HA activity was stable at 56 degrees C or lower temperatures and destroyed at 80 degrees C. Trypsin, alpha-chymotrypsin, papain, ficin and neuraminidase had no effect on HA activity. Alpha-chymotrypsin destroyed the receptor for the virus on chicken erythrocytes, whereas trypsin and neuraminidase did not affect the receptor.

Hemorrhagic enteritis in captive American kestrels (Falco sparverius)

Hemorrhagic enteritis and hepatitis of suspected adenovirus etiology were the apparent cause of death of nine captive American kestrels. Cloacal hemorrhage was the only prominent gross lesion: disseminated hepatocellular necrosis, and intranuclear inclusion bodies were evident microscopically. Electron microscopy revealed numerous adenovirus-like particles associated with the hepatic lesions. Attempts to serologically identify the agent were unsuccessful.

The fibers of fowl adenoviruses

Purified virions from 14 strains of fowl adenoviruses (FAV) representing 11 serotypes were examined by electron microscopy. Pentons of all strains turned out to have two projections at their penton bases. It is shown that the double fibers also protrude from the intact virion. The length of both fibers was measured on free pentons and is given for each serotype. Double fibers seem to be a common feature of FAV. The serologically unrelated Egg Drop Syndrome (EDS) avian adenovirus strain 127 was confirmed to have single fibers only.

Some biological and physico-chemical properties of egg drop syndrome (EDS) avian adenovirus strain B8/78

The EDS adenovirus produced either in the allantoic cavity of embryonated duck eggs (A0 virus) or in chicken embryo liver cell cultures (TC0 virus) were comparatively studied by gradient ultracentrifugation in CsCl. The A0 viral particles banded at densities of 1.36 and 1.31 g/ml, whereas, the TC0 viral particle were found at densities of 1.33 and 1.31 g/ml, respectively. The heavy populations contained infectious and hemagglutinating particles if they were not pelleted and sonicated before gradient ultracentrifugation. Pelleting or sonicating the viral particles resulted in loss of hemagglutinating activity of the heavy populations. The light particles were hemagglutinating but not infectious regardless of the previous treatment. The pH- and heat-sensitivity of the B8/78 virus strain was similar to those described for CEL0 (FAV-1) adenovirus (5). The B8/78 virus strain replicated well in tissue cultures of chicken and goose origin causing the formation of intranuclear inclusion bodies in the infected cells.

Outbreaks of egg-drop syndrome-1976 in Japan and its etiological agent

A condition similar to egg-drop syndrome-1976 (EDS-76) occurred in 14 broiler breeding flocks in 2 farms in Japan from December 1978 to January 1980, and it was diagnosed as EDS-76 by serologic and virological investigations. Egg production fell suddenly when the hens were 30 to 55 weeks of age, and the depression lasted 3 to 7 weeks. Production fell 6 to 25%. Depressed egg production was accompanied by the laying of shell-less, soft-shelled, and thin-shelled eggs associated with loss of egg-shell pigment. Eleven isolates of hemagglutinating adenovirus were isolated from cloacal swabs (10 isolates) and a uterus (1 isolate) of hens in one farm. One isolate, cloned and named JPA-1, had the same antigenicity in serologic tests and the same biological and physicochemical properties as the BC14 strain of EDS-76 virus.

Pathology of adenoviral infection in turkeys (Meleagris gallopavo) with respiratory disease and colisepticemia

Nuclear inclusion bodies typical of the adenovirus group were widespread in in the spleen and other tissues of 8-week-old turkeys with severe respiratory disease and concomitant evidence of colisepticemia. Adenoviral virions were seen in affected nuclei of splenic tissue and in negatively stained preparations of ground spleen. In splenic tissue, inclusions were most prominent in reticular cells and macrophages in the periarterial lymphoid sheaths, the red pulp and the marginal zones of the periarteriolar reticular sheaths. Marked reticuloendothelial hyperplasia, lymphoid atrophy and granulocytic splenitis characterized the splenic changes. There were inclusions in the respiratory tract, intestinal tract, liver, kidney and pancreas. Inoculation of young turkeys, especially when immunosuppressed, resulted in evidence of infection and respiratory disease. The viruses produced cytopathic changes in primary turkey kidney cell cultures but did not affect embryonating chicken eggs. Concentrated viral suspensions induced precipitin lines in agar gel immunodiffusion tests with known antisera against known turkey adenoviruses but did not show an antigenic relationship to chicken adenoviruses.

Further studies on the classification of fowl adenoviruses

In addition to the 8 fowl adenovirus serotypes described previously, 3 new serotypes were recognized. Two, A-2 and C2-B, were isolated in the U.S.A., and one, 380, in Northern Ireland. In addition another isolate, X-11, has a broader antigenicity than YR-36 and therefore should be used instead of YR-36 as prototype strain. It is concluded that there are at least 11 distinct fowl adenovirus serotypes on the basis of the serum-neutralization test.

Physicochemical characterization and pathogenicity studies of two turkey adenovirus isolants

Two turkey adenoviruses were isolated from poults with respiratory disease, and their physicochemical properties were studied. The virus particles were unenveloped. contained DNA genome, replicated within the nuclei of infected cells, and were icosahedral in shape. Pathogenicity studies in poults indicated that North Carolina Kennedy isolant was a pathogen of relatively low virulence whereas the North Carolina Jackson isolant was nonpathogenic in commercial turkey poults.

Adenovirus of ring-necked pheasants: purification and partial characterization of marble spleen disease virus

A method for purification of marble spleen disease virus (MSDV) from the spleens of infected turkeys and pheasants is described. It combines chloroform or fluorocarbon extraction with subsequent purification by centrifugation on a cushion of cesium chloride (CsCl). Further purification of MSDV was accomplished with a CsCl equilibrium density gradient. A viral buoyant density of approximately 1.32 to 1.33 g/cm3 was determined. Negative-stain electron microscopy revealed that virus isopycnically banded by CsCl gradient had non-enveloped icosahedral capsids composed of 252 capsomeres. The direct colorimetric diphenylamine assay indicated that MSDV has deoxyribonucleic acid as its nucleic acid. The above evidence demonstrates that MSDV is an avian adenovirus, the first recognized in the ring-necked pheasant (Phasianus colchicus L.).

Demonstration of an avian adenovirus as the causative agent of marble spleen disease

A purification procedure, using chloroform or fluorocarbon extraction and centrifugation on a cushion of cesium chloride (CsCL), was designed to isolate the causative virus of marble spleen disease. Virus was purified, inoculated into turkeys, and subsequently reisolated by purification from the spleen of inoculated turkeys, thus fulfilling Koch's postulates. Splenic antigen was detected by the agar gel precipitin test, and viral inclusions with viral particles were observed by light and electron microscopy. Results of further studies indicated splenic lymphoreticulum cell hyperplasia was a sensitive indicator of marble spleen disease virus (MSDV) infection. Direct fluorescent antibody staining revealed nuclear fluorescence in virus-infected splenic cells from turkeys inoculated with purified MSDV. With negative stain electron microscopy, MSDV was observed to be 90 nm across with an icosahedral capsid composed of 252 capsomeres. This morphologic feature was consistent with that of an avian adenovirus. Serologic evidence for classification of MSDV as an adenovirus was the cross reaction of MSDV antigen with antiserum to turkey adenovirus serotypes TA-1 and TA-2 in the agar gel precipitin test.

Hemagglutinating properties of CELO, an oncogenic avian adenovirus

Chicken-embryo-lethal-orphan (CELO) virus, Phelps strain, agglutinated erythrocytes at 37 C. The hemagglutinating activity, which is a function of complete and incomplete virus particles, was sensitive to heat but not to pH. The soluble components of the virus were similar in sedimentation characteristics to those obtained from human adenovirus type 1. The effects of chemical and physical agents on CELO hemagglutinin, CELO infectivity, and red-cell receptors suggested that the last were protein in nature and that cell-virus attachment was mediated by amino groups on the virion. The attachment of virus to red blood cells via the penton projection was demonstrated by electron microscopy.