Molecular epidemiology of fowl adenoviruses in Greece

Outbreaks of inclusion body hepatitis (IBH) and adenoviral gizzard erosion have been anecdotally reported in Greece since approximately 2011. However, a relevant increase in clinical outbreaks compatible with IBH has been described since 2014. Unfortunately, with limited exceptions, only serological assays were performed, and involved strains were not properly characterized. In the present study, 35 outbreaks were investigated in the period between July 2017 and February 2018 in Greece. In addition to clinical and histopathological diagnosis, fowl adenovirus (FAdV) presence was investigated by PCR and sequencing. Thirty-four out of 35 samples tested FAdV positive. Twenty-nine (85.29%) and 5 (14.71%) strains were classified as FAdV-E and FAdV-D, respectively. Fowl adenovirus-E strains were genetically homogeneous and formed an independent cluster of Greek-only sequences, including the sole previously available sequence, suggesting the prolonged circulation of this species in Greece. On the contrary, FAdV-D strains were more heterogeneous and closely related to strains sampled in other European countries, testifying the occurrence of multiple introduction events. The evaluation of phylogenetic relationships, geographic clustering, age of infection, and origin of the broiler breeder flocks suggests that both vertical and horizontal transmission are important in FAdV epidemiology in Greece and highlights the limited efficacy of currently implemented control measures. Of note, a significantly higher mortality was observed in precociously infected flocks, likely because of the higher susceptibility of younger animals. This evidence stresses the need of preventing vertical and/or early infection to limit the economic impact of adenovirus-induced diseases.

Hematochezia and thrombocytopenia in a 3-day-old infant: Congenital adenoviral infection

Neonatal adenovirus infection is infrequent, but in most cases the outcome of the infection is fatal. In this case report we describe the hospital course of a 3 day old newborn patient presenting with bloody stools and thrombocytopenia that remained clinically stable and had a benign course following Adenovirus 40/41 infection detected in stool. Neonatal adenovirus infection should be considered in the differential diagnosis of neonatal sepsis and pneumonia but also in patients that present with hematochezia, thrombocytopenia and/or other less specific signs and symptoms of viral illness.

Triple infection with agamid adenovirus 1, Encephaliton cuniculi-like microsporidium and enteric coccidia in a bearded dragon (Pogona vitticeps)

A 2-month-old juvenile central bearded dragon was presented for anorexia and cachexia. Another specimen from the same cage had died suddenly 2 weeks prior. Fecal analysis revealed a high quantity of Isospora amphiboluri and a few pinworm eggs. Other examinations were not performed and the animal died a few days later despite supportive care. A third individual from the same cage presented with anorexia and a distended cœlom and was euthanized. In this third dragon, histological examination revealed intestinal coccidiosis, basophilic intranuclear inclusions compatible with adenovirus infection, acute hepatic necrosis with intrahepatocytic and intraenteritic organisms typical of microsporidia and renal gout. A PCR confirmed the diagnosis of adenovirosis. Sequencing showed that the PCR product was 100% identical to the corresponding portion of the agamid adenovirus 1 genome. A PCR for the detection of Encephalitozoon (E.) cuniculi was positive. Partial sequencing revealed 100% identity to an E. cuniculi-like organism previously found in bearded dragons. In cases where environmental factors such as poor hygiene or stress can be excluded, the presence of opportunistic pathogens in high numbers can be due to a systemic (viral) infection with temporary immunosuppression.

Sheep lung segmental delivery strategy demonstrates adenovirus priming of local lung responses to bacterial LPS and the role of elafin as a response modulator

Viral lung infections increase susceptibility to subsequent bacterial infection. We questioned whether local lung administration of recombinant adenoviral vectors in the sheep would alter the susceptibility of the lung to subsequent challenge with bacterial lipopolysaccharide (LPS). We further questioned whether local lung expression of elafin, a locally produced alarm anti-LPS/anti-bacterial molecule, would modulate the challenge response. We established that adenoviral vector treatment primed the lung for an enhanced response to bacterial LPS. Whereas this local effect appeared to be independent of the transgene used (Ad-o-elafin or Ad-GFP), Ad-o-elafin treated sheep demonstrated a more profound lymphopenia in response to local lung administration of LPS. The local influence of elafin in modulating the response to LPS was restricted to maintaining neutrophil myeloperoxidase activity, and levels of alveolar macrophage and neutrophil phagocytosis at higher levels post-LPS. Adenoviral vector-bacterial synergism exists in the ovine lung and elafin expression modulates such synergism both locally and systemically.

[Mixed infection and risk factors in children with severe adenovirus pneumonia]

OBJECTIVE

To investigate the mixed infection and analyze risk factors in children with severe adenovirus pneumonia.

METHODS

A retrospective analysis was performed on the clinical data of 756 children with adenovirus pneumonia between June 2009 and June 2011. Pathogens and risk factors were studied in 216 severe cases.

RESULTS

Of the 216 severe cases, 138 (63.9%) were aged from 6 months to 2 years, and 161 (74.5%) developed the disease in the winter and spring; 177 (81.9%) were affected by 1-4 pathogens besides adenovirus, including 74 cases (34.3%) infected with one pathogen as an addition. A total of 334 pathogen strains were identified from the respiratory secretions and sera of the 216 cases. Of them, 163 (48.8%) were bacterial strains, dominated by Gram-negative bacteria (124 strains), 108 (32.3%) were viral strains, and 40 (12.0%) were fungal strains. Multivariate logistic regression analysis indicated that congenital heart disease, congenital airway abnormalities, nutritional anemia, recurrent pulmonary infection, and surgical history were the independent risk factors for severe adenovirus pneumonia in children, with odds ratios of 3.3, 11.1, 7.2, 14.3 and 12.9 respectively (P<0.05).

CONCLUSIONS

Severe adenovirus pneumonia is mostly seen in children aged from 6 months to 2 years and occurs frequently in the winter and spring. Many cases are also infected with other pathogens, most commonly Gram-negative bacteria. Congenital heart disease, congenital airway abnormalities, nutritional anemia, recurrent pulmonary infection and surgical history are the independent risk factors for severe adenovirus pneumonia in children.

Proanthocyanidin-enriched extract from Myrothamnus flabellifolia Welw. exerts antiviral activity against herpes simplex virus type 1 by inhibition of viral adsorption and penetration

AIM OF THE STUDY

Extracts from the aerial parts of the South African resurrection plant Myrothamnus flabellifolia Welw. have been used traditionally against infections of the upper respiratory tract and skin diseases. A polyphenol-enriched extract was investigated for potential antiviral effects against herpes simplex virus type 1 (HSV-1) and adenovirus, and the underlying mode of action was to be studied.

MATERIALS AND METHODS

Antiviral effects of an acetone-water extract (MF) from Myrothamnus flabellifolia on HSV-1 and adenovirus type 3 were tested in infected Vero cells by plaque reduction assay, MTT test and immunofluorescence. The influence of the extract on the HSV-1 envelope glycoprotein D was shown by Western blot. Organotypic full thickness skin models consisting of multilayer skin equivalents were used for the investigation of MF effects on HSV-1 replication.

RESULTS

MF exhibited strong antiviral activity against HSV-1. The HSV-1-specific inhibitory concentration (IC(50)) was determined as 0.4 μg/mL and the cytotoxic concentration (CC(50)) against Vero cells as 50 μg/mL. A selectivity index (SI) (ratio of CC(50) to IC(50)) of approximately 120 was calculated when MF was added to the virus inoculum for 1h at 37°C prior to infection. The replication of adenovirus 3 was not affected by MF. MF abolished virus entry into the host cell by blocking viral attachment to the cell surface. When added after attachment at a concentration of >6 μg/mL, the extract also inhibited penetration of HSV-1 into the host cell. Polyphenolic compounds from MF directly interacted with viral particles, leading to the oligomerisation of envelope proteins as demonstrated for the essential viral glycoprotein D (gD). Using organotypic full thickness tissue cultures, it was shown that treatment of HSV-1 infected cultures with the MF resulted in reduced viral spread.

CONCLUSIONS

A polyphenol-enriched extract from Myrothamnus flabellifolia strongly acts against HSV-1 by blocking viral entry into the cells.

Viral cytopathic changes in urine cytology of ileal conduit attributed to adenovirus: Report of a case

Urine cytology from ureteral diversions utilizing intestinal segment as reservoir or conduit, constructed during cystectomy performed usually for advanced bladder neoplasia, differs from bladder urine cytology in that the presence of abundant intestinal mucosal cells with degenerative and inflammatory changes interferes with the recognition of other important cellular changes, particularly of recurrent neoplasia in the upper urinary tract, not to mention other less frequent yet note worthy pathologic changes, such as viral type indigenous to the urinary tract. When confronted with diseases involving the intestinal segment, such as viral enteritides, the diagnostic problem becomes more complex and special effort is needed to recognize and characterize them correctly, differentiating them from other pathologies or artifacts seen in such specimens. We report one such case in which viral changes affecting columnar intestinal epithelium were identified and by immunocytochemistry characterized as adenoviral involving primarily cells of the intestinal conduit. We discuss the significance of such infection in comparison to other viral changes indigenous to the urinary tract, which could also occur in such specimens.

Detection of microorganisms in the tracheal aspirates of preterm infants by polymerase chain reaction: association of adenovirus infection with bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is recognized as an important cause of morbidity and mortality in preterm infants. Because the role of congenital infections in BPD has been debated, the purpose of this study was to test the hypothesis that detection of infectious agents in tracheal aspirate samples was associated with the development of BPD. Tracheal aspirate samples were obtained within the 1st week of life and screened by polymerase chain reaction for adenovirus, cytomegalovirus, parvovirus, enteroviruses, Ureaplasma urealyticum, Mycoplasma hominis, Mycoplasma pneumoniae, and Chlamydia species. BPD was defined as persistent oxygen dependence at 28 d of age and 36 wk postconceptional age (PCA). Infants that expired before these time points were excluded from statistical analysis. Out of 89 infants studied, at 28 d of life, 13 had expired, 45 had BPD, and 31 had no BPD (controls). At 36 wk PCA, 15 infants expired, 39 still had BPD, and 35 did not. A significant increase in the frequency of adenovirus genome was identified in BPD patients compared with controls, both at 28 d of life (12/45 = 27% versus 1/31 = 3%: p< or =0.01) and at 36 wk PCA (10/39 = 29% versus 2/35 = 6%: p = 0.01). Other microorganisms were rarely detected and not associated with the development of BPD. This is the first study reporting the frequency of detection of adenovirus DNA in tracheal aspirate samples obtained during the 1st week of life from infants with BPD and suggests that prenatal acquisition may be important in the development of BPD.

Quantitative colorimetric microneutralization assay for characterization of adenoviruses

A microneutralization assay that automates the reading and interpretation of viral infectivity and neutralization data was developed for the characterization of adenoviruses (AV). Virus, serum, and cells were added to 96-well plates, incubated for 7 days, and stained with vital stain. The A550 of solubilized dye was read in a plate reader interfaced to a personal computer which analyzed the results. Correlation of A550 values with visual observation of cytopathic effect was extremely good (r = 0.977625). Clinical isolates of 17 AV from 11 patients were characterized by colorimetric neutralization assay. Prototype AV titers tested were comparable to those determined by tube methods. Prototype homotypic antiserum titers were comparable to or greater than those determined by standard tube neutralization.

Genome analysis of South American adenovirus strains of serotype 7 collected over a 7-year period

DNA restriction analysis was carried out on a sample of 212 epidemiologically unrelated adenovirus (Ad) strains of serotype 7 isolated in Chile, Uruguay, and Argentina from nasopharyngeal aspirates of children with acute lower respiratory disease between 1984 and 1990. The identified genome types were Ad7b (n = 12), Ad7c (n = 21), and Ad7h (n = 179). The analysis of the occurrence of the three genome types throughout the study period revealed that Ad7c was the predominant virulent variant in 1984 and indicated that a shift to genome type 7h took place in 1986. Ad7b cocirculated with the other genomic variants at a relatively low frequence.

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.

Bacterial flora of Tasmanian SIDS infants with special reference to pathogenic strains of Escherichia coli

The general bacterial flora of 38 Tasmanian SIDS infants was examined together with faecal flora of 134 comparison infants ranging in age from birth to 6 months. The microflora of all specimens received was investigated with special emphasis on the toxigenic Escherichia coli (TEC). Samples were examined for verocytotoxigenic E. coli, free faecal verocytotoxin (FVT), heat labile toxin (LT) and heat stable toxin (ST) producers with the use of a Vero cell assay and commercial kits. The findings of this study revealed a high isolation rate (39%) of TEC from SIDS infants as compared to 1.5% from the healthy comparison infants. Atypical E. coli strains were also identified during the study, including E. coli A-D. An analysis of the same specimens for rotaviral and adenoviral antigens indicated that 30% of the SIDS cases were positive as compared to 20% in the comparison group.

Histochemical/histoenzymic studies in broiler chicks fed aflatoxin, ochratoxin and inoculated with inclusion body hepatitis virus singly and in concurrence

The effect of feeding mycotoxins, i.e. aflatoxin B1 (1.25 ppm from 3 to 38 days of age) and ochratoxin A (0.5 ppm from 3 to 38 days of age) along with inclusion body hepatitis virus (IBHV) inoculation (at 10 days of age) singly and in combination was studied in broiler chicks. Birds in combined treatment groups, i.e. aflatoxin fed and virus inoculated and ochratoxin fed and virus inoculated, showed more changes in activities of phosphatases (AKPase, ATPase, G-6-Pase and ACPase) in liver and kidney tissues than their respective individual treatment groups with a few exceptions. Reduction in the activities of oxido-reductases in liver and kidney tissues were almost comparable in different treatment groups. The increase in muco-polysaccharides reaction was more marked in both the combined treatment groups than the single treatment groups. Intensity of lipid reaction was more in ochratoxin virus combination group than either alone.

Laboratory testing in patients with morbilliform viral eruptions

The explosion of immunologic testing capabilities over the past 20 years has enabled clinicians to accurately diagnose many conditions that previously were very difficult to identify solely on a clinical basis. Among these disorders are the viral exanthems. Infections with some of these viruses are of relatively little import (erythema infectiosum), whereas others have more significant consequences (HIV, cytomegalovirus). Clinical suspicions may be pursued more fully now, sometimes even in an office setting.

Biological characterisation of an Indian isolate of egg drop syndrome-76 virus

An isolate of egg drop syndrome-76 virus replicated best in primary chicken embryo liver cells and less well in duck embryo liver cells, duck embryo fibroblast cells and chicken embryo kidney cells. The cytopathic effect in chicken embryo liver cells was marked by the presence of round and refractile cells and detachment of cells from the glass surface. The intranuclear eosinophilic inclusion bodies were observed by 24 to 48 hours after infection. No virus multiplication was observed in primary quail embryo fibroblast cells, chicken embryo fibroblast cells or mammalian cells like Vero, BHK-21 and MDBK. Duck embryos supported the maximum growth of the virus, with allantoic fluid having the highest haemagglutinin titre, followed in order by chorioallantoic membrane, skin and internal organs. Chicken and quail embryos did not support the growth of the virus.

Immunohistological detection of human herpes virus 6 in formalin-fixed, paraffin-embedded lung tissues

Human herpes virus type 6 (HHV-6) infection is widespread in healthy individuals. The only definite disease association is with exanthem subitum in infants though the virus has been linked with a variety of other diseases including interstitial pneumonitis in bone marrow allograft recipients. In order to investigate the role of HHV-6 in the latter disease we have developed an optimised staining method for the demonstration of specific antigen in routinely processed post-mortem tissues. Formalin-fixed, paraffin-embedded lung tissue from 8 immunocompromised patients who died from interstitial pneumonitis was subjected to immunoperoxidase staining with monoclonal antibodies against HHV-6, cytomegalovirus (CMV), and adenovirus, using a modified avidin-biotin complex (ABC) method. Staining for HHV-6 was obtained in 6 of the 8 patients studied and was present in pneumocytes and macrophages. CMV and adenovirus antigens were identified in 4 and 6 patients, respectively. Whilst the lung tissue of 6 patients contained more than one virus, there was no evidence of cross-reactivity between the monoclonal antibodies. We demonstrated that accurate localisation of HHV-6 using monoclonal antibodies is possible in post-mortem lung tissue and conclude that either HHV-6 alone or in combination with other viruses may play a role in the development of interstitial pneumonitis following bone marrow transplantation or chemotherapy.

Evaluation of the interaction of Eimeria meleagrimitis with hemorrhagic enteritis virus or marble spleen disease virus in turkeys

The interaction of Eimeria meleagrimitis with hemorrhagic enteritis virus (HEV) or marble spleen disease virus (MSDV) was studied in 4-week-old female turkeys. Birds given either virus in combination with the coccidia showed greater weight gain than did birds given HEV alone. A combination of MSDV and E. meleagrimitis resulted in significantly lower oocyst production when oocysts were counted from individual birds. Levels of serum glucose, serum albumin, and total protein were reduced in birds given HEV either alone or in combination with E. meleagrimitis. Birds receiving E. meleagrimitis alone or in combination with either MSDV or HEV exhibited higher blood urea nitrogen (BUN) levels than birds in all other treatments. Birds receiving HEV or the combination of E. meleagrimitis and either HEV or MSDV had significantly lower serum triglycerides and cholesterol. Serum amylase was lower in poults receiving HEV alone or combined with E. meleagrimitis, and serum alkaline phosphatase was lower in the HEV-only treatment.

[Mycoplasma sp. in the respiratory tract of hospitalized children]

Mycoplasma pneumoniae is one of the most common bacteria causing respiratory diseases in other countries, specially in older children, adolescents and young adults and less frequently in the age group studied here, nevertheless the determination of its presence in this group was considered important. Two hundred and fifty throat swabs were taken from children, under five years of age, hospitalized with a diagnosis of acute respiratory infections (ARI) and to 50 children, same age, with no ARI (controls). The samples were placed in transport media and were incubated at 37 degrees C during 7 to 15 days. They were reinoculated in PPLO agar and typical colonies were looked for, 5 to 8 days later. The organisms were identified by biochemical tests. Eight Mycoplasma sp (3.2%) were obtained, five of them were M. pneumoniae (2.0%) and three M. hominis (1.2%). Only in 2 cases adenoviruses with M. hominis were found in the absence of other pathogens. It was shown that M. pneumoniae also infects children under five years old, so its present should be suspected, specially when the patient's health does not improve with the installed treatment. Some important suggestions for the isolation of mycoplasma are given.

Monitoring foreign gene expression by a human adenovirus-based vector using the firefly luciferase gene as a reporter

We have constructed a helper-independent adenovirus type 5-luciferase recombinant (Ad5-Luc 3) containing the firefly luciferase gene flanked by simian virus 40 (SV40) regulatory sequences inserted in the early region 3 (E3) of the Ad5 genome. Expression of luciferase in cells infected with Ad5-Luc3 was relatively efficient. In HeLa cells approximately 20 micrograms luciferase per 10(6) cells was made by 36 h post-infection and a 62 kilo-Dalton (kDa) luciferase band was clearly visible in a [35S]methionine-labeled Ad5-Luc 3-infected cell extract analyzed directly by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The results of experiments in which cultured cells were infected with Ad5-Luc 3 in the presence or absence of 1-beta-D-arabinofuranosyl cytosine (AraC) showed that the majority of luciferase expression was dependent on viral DNA replication. This suggested that the enzyme was probably translated primarily from mRNA derived from transcripts expressed from the major late promoter of Ad5. An anti-luciferase antibody was raised in a rabbit and used to further characterize the luciferase expressed in HeLa cells infected with Ad5-Luc 3 by immunoprecipitations and Western blot analyses. The half-life of luciferase expressed in HeLa cells infected with Ad5-Luc 3 was calculated to be approximately 6-8 h by pulse chase analysis. Luciferase is likely to be a useful marker for monitoring virus dissemination and gene expression in experimental animals because assays for enzymatic activity are extremely sensitive and backgrounds are low in all tissues. In mice inoculated intraperitoneally (i.p.) with Ad5-Luc 3, luciferase activity was detected in the liver, spleen, kidney, and lung. A single i.p. inoculation of mice with Ad5-Luc 3 was sufficient to raise anti-luciferase antibody and Ad5 neutralizing antibody which persisted for at least 8 weeks. Even in the presence of circulating anti-luciferase and Ad5 neutralizing antibodies, luciferase activity could be detected in the livers, spleens, and kidneys of mice inoculated i.p. a second time with Ad5-Luc 3.

Necrotizing pancreatitis and gizzard erosion associated with adenovirus infection in chickens

Cases of focal necrotic pancreatitis and gizzard erosion in chickens are reported. Intranuclear inclusion bodies were seen in necrotic pancreatic acinar cells and necrotic epithelial cells of the gizzard, and electron microscopy demonstrated virus particles in affected gizzard epithelium. Adenovirus antigens were detected immunohistochemically in these intranuclear inclusion bodies. These findings suggest that the necrotizing pancreatitis and gizzard erosion were associated with adenovirus infection.

Experimental infection of weaned calves and lambs with two strains of bovine adenovirus type 2

The pathogenicity of two genetically different strains of bovine adenovirus type 2 (BAV-2) was tested in a double cross experimental infection of weaned lambs and calves. One of the virus strains was isolated from cattle and represented BAV-2 subgroup "A", while the other was isolated from sheep and belonged to subgroup "B" (Belák et al., 1983). The two virus strains caused infection both in lambs and calves; the viruses were repeatedly reisolated and definite seroconversion was found in all four groups. However, remarkable differences were observed in the pathogenicity: the most intensive virus multiplication and shedding, the most severe clinical symptoms and histopathological lesions were observed in the lamb group infected with the ovine isolate.

Physical mapping and homology studies of egg drop syndrome (EDS-76) adenovirus DNA

Homologous sequences between EDS-76 adenovirus strain 127 DNA and bovine adenovirus DNA were found by the Southern blotting technique and no homology with CELO virus DNA could be detected. These data suggest a genetic similarity between EDS-76 virus and bovine adenoviruses. The fragments generated form EDS-76 adenovirus DNA by eight restriction endonucleases were physically mapped.