T. Rampin

Molecular biological characterization of avian poxvirus strains isolated from different avian species

Fifteen strains of Avipoxvirus from different avian species were isolated and molecular biologically characterized. Most strains did not produce evident pocks on the chorioallantoic membranes of commercial and specific-pathogen free embryonated chicken eggs where, on the contrary, microscopic signs of viral growth were always detected. Polymerase chain reaction of highly conserved P4b gene was positive for all cases confirming to be a reliable diagnostic method for Avipoxvirus. Sequencing of these amplicons confirmed most strains clustered either with Fowlpox virus or with Canarypox virus whereas a possible new clade could be hypothesized for one strain from Japanese quail. Classification of Avipoxvirus strains by amplification of the newly identified locus fpv140 revealed major limitations as only five samples were positive. These results underline the importance to undertake similar studies on higher numbers of Avipoxvirus isolates and on wider genomic regions of this large viral group.

Avian mycobacteriosis in companion birds: 20-year survey.

The causative agents of avian mycobacteriosis in pet birds are rarely identified. The aim of this study is to add information about the etiology of avian mycobacteriosis. The identification of mycobacterium species in 27 cases of avian mycobacteriosis in pet birds was investigated by polymerase chain reaction (PCR) and sequencing of a rRNA hypervariable region. Avian mycobacteriosis appeared to be an infrequent diagnosis. Interestingly, a few cases of avian mycobacteriosis were recorded in very young birds. The most commonly affected species were the canary (Serinus canarius), the Eurasian goldfinch (Carduelis carduelis) and the red siskin (Spinus cucullatus). All but one bird were infected with Mycobacterium genavense. Mycobacterium avium was identified only in one case.

Adenoviral gizzard erosions in Italian chicken flocks

TYPE 1 avian adenoviruses belong to the genus Aviadenovirus within the adenovirus family. Five species of fowl adenovirus (fAdV) (designated by the letters A to E) are recognised within the Aviadenovirus genus based largely on molecular criteria, in particular restriction enzyme fragmentation

Epornitic of avian pox in common buzzards (Buteo buteo): virus isolation and molecular biological characterization

Six common buzzards from a bird rescue centre showed wart-like lesions on their toes. The lesions consisted of multiple crusty and proliferative nodules surrounded by skin swelling. Histologically, epithelial cell hypertrophy and hyperplasia with ballooning degeneration and large intracytoplasmic inclusion bodies consistent with avipoxvirus infection were seen. The virus was isolated in embryonated chicken eggs. Positive chorioallantoic membranes and samples of skin lesions were submitted for polymerase chain reaction. Molecular characterization based on the 4b core protein indicates a 100% homology of the isolated poxvirus with avian poxviruses belonging to subclade A2. However, analysis of fpv139 locus does not reveal similarities of the isolate with other avian poxviruses.

Mycobacterium genavense and Avian Polyomavirus co-infection in a European Goldfinch ( Carduelis carduelis )

Systemic mycobacteriosis associated with avian polyomavirus infection was diagnosed histologically in an 8-year-old, captive European goldfinch with a history of nervous signs. Severe mycobacterial lesions were observed in the central nervous system, lungs, cervical air sacs and adrenal glands, without involvement of the gastrointestinal tract. In addition to mycobacteriosis, intranuclear inclusions, typical of polyomavirus, were identified in the adrenal glands. Polymerase chain reaction assays were used to identify Mycobacterium genavense and finch polyomavirus as the causative agents. The absence of involvement of the gastrointestinal tract and the severity of the lesions in the respiratory tract suggested that inhalation may have been the primary route of infection with M. genavense.

Rhabdomyosarcoma of the pectoral muscles of a free-living European robin (Erithacus rubecula)

An adult free-living European robin (Erithacus rubecula) with a large, firm, subcutaneous mass on the pectoral muscle was examined. The bird was unable to fly and died spontaneously. Necropsy revealed a yellowish, bilobate mass almost completely replacing the pectoral muscles with extensive osteolysis of the keel bone. Histopathology revealed a poorly demarcated, highly cellular sarcomatous tumour with metastases to the lungs, pulmonary blood vessels and heart. Immunohistochemistry was negative for neuron-specific enolase, S-100 protein and the p-27 major capsid protein of avian leukosis viruses. The homogeneously positive immunolabelling for vimentin and scattered positivity for myoglobin and desmin suggested a diagnosis of rhabdomyosarcoma. A retrospective examination of the records for 194 birds of the thrush family, including 64 robins submitted over a 20-year period, showed no diagnoses of neoplasia.

Morphological and Immunohistochemical Observations on Leiomyoma of the Ventral Ligament of the Oviduct of the Hen

Leiomyomas of the ventral ligament (LVLs) of the oviduct from 2-year-old spent layers were examined. These tumours can be present either as single large masses or as multiple smaller nodules. The most common site of origin of the tumours was the centre of the free margin of the ventral ligament, but some small tumours were observed at the insertion of this ligament into the magnum of the oviduct. Most samples were highly vascular and some blood vessels within the tumours had vacuolation of the smooth muscle cells. These findings suggest that the proliferative processes leading to LVLs may include transformation of the blood vessels of the ventral ligament. Immunohistochemically, the tumour cells expressed vimentin, α-smooth muscle actin, desmin and heavy-caldesmon. These avian leiomyomas have been proposed as a model for similar tumours in other species.

Assessment of bovine herpesvirus 4 based vector in chicken.

The biological characteristics of BoHV-4 make it a good candidate as a gene delivery vector for vaccination purposes. These characteristics include little or no pathogenicity, unlikely oncogenicity, the ability to accommodate large amounts of foreign genetic material, the ability to infect several cell types from different animal species, such as sheep, goats, swine, cats, dogs, rabbits, mink, horses, turkeys, ferrets, monkeys, hamsters, rats, mice, and chickens. In this report, the feasibility to use BoHV-4 based vector in chicken was investigated. Although BoHV-4 was able to replicate, leading to a cytopathic effect in a chicken cell line and infect the chorion allantoic membrane of embryonated eggs, however it was not pathogenic even when a large dose of virus was injected into the chicken. An immune response could be produced against heterologous antigen delivered by a recombinant BoHV-4. These data suggest the feasibility of using BoHV-4 based vector for vaccination purposes in chickens.

Caecal coccidiosis in commercial male turkeys

Abstract An outbreak of coccidiosis with high mortality is reported in 30-day-old commercial turkeys. Grossly, a severe typhlitis with a large fibrino-necrotic core was present. Large numbers of oocysts were observed in caecal smears. The location and the severity of the lesions and the oocyst morphology were strongly suggestive of Eimeria adenoeides infection. This species has already been reported in turkey flocks in Italy, but it is rarely responsible for clinical coccidiosis and severe lesions with high mortality. Other caecal parasitic infections are considered in differential diagnosis.