Canary Bornavirus (Orthobornavirus serini) Infections Are Associated with Clinical Symptoms in Common Canaries (Serinus canaria dom.).

While parrot bornaviruses are accepted as the cause of proventricular dilatation disease (PDD) in psittacine birds, the pathogenic role of bornaviruses in common canaries is still unclear. To answer the question of whether canary bornaviruses (species Orthobornavirus serini) are associated with a PDD-like disease in common canaries (Serinus canaria f. dom.), the clinical data of 201 canary bird patients tested for bornaviruses using RT-PCR assays, were analyzed for the presence of PDD-like gastrointestinal or central nervous system signs and for other viruses (mainly circovirus and polyomavirus), yeasts and trichomonads. Canary bornavirus RNA was detected in the clinical samples of 40 out of 201 canaries (19.9%) coming from 28 of 140 flocks (20%). All nucleotide sequences obtained could unequivocally be determined as canary bornavirus 1, 2, or 3 supporting the current taxonomy of the species Orthobornavirus serini. PDD-like signs were found associated with canary bornavirus detection, and to a lesser extent, with circoviruses detection, but not with the detection of polyomaviruses, yeasts or trichomonads. The data indicate that canary bornaviruses contribute to a PDD-like disease in naturally infected canaries, and suggest a promoting effect of circoviruses for the development of PDD-like signs.

Molecular identification of novel and genetically diverse adenoviruses in Passeriform birds.

Knowledge about adenoviruses in birds of the order Passeriformes is very scarce. Based on molecular characterizations, only two siadenoviruses, great tit adenovirus 1 and Gouldian finch adenovirus, have been described so far occurring in great tits and Gouldian finches, respectively. Assuming a broader occurrence of adenoviruses, various passeriform birds including pet, zoo, and wild birds were examined using a broad-range PCR targeting a fragment of the adenovirus DNA polymerase gene. Adenoviruses were detected in 25 individual birds belonging to 13 species and seven zoological families (Ploceidae, Fringillidae, Estrildidae, Paridae, Sylviidae, Turdidae, Muscicapidae). The putative viruses were further characterized by sequencing the PCR products and phylogenetic analyses. DNA of adenoviruses affiliating to 3 genera including aviadenovirus, siadenovirus, and atadenovirus was found. Viruses with sequences identical or closely related to great tit adenovirus 1 and Gouldian finch adenovirus 1 were detected in a great tit and in two zebra finches, respectively. Based on polymerase amino acid sequence comparisons, the viruses found in the remaining 22 birds revealed phylogenetic distances larger than 15% to adenoviruses known so far suggesting that they may belong to at least 14 different virus species. In some bird species (great tit, zebra finch, vitelline masked weaver) varying adenovirus genera were detected. These results suggest a broad variety of adenoviruses circulating in passeriform birds.