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

Abstract

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.

Keywords: Macrorhabdus; avian bornavirus; canary bornavirus; circovirus; coinfection; domestic canary; natural infection; pathogenicity; polyomavirus; proventricular dilatation disease.

Figure 1

Phylogenetic relationship based on CLUSTALW alignments and neighbor-joining analyses including bornavirus partial N gene nucleotide sequences (0.35 bp) from 31 canaries (this study, strain names with GenBank accession numbers in brackets are given) and representatives of the 9 species included in the genus Orthobornavirus (GenBank accession numbers starting with letters are given). Representatives of the three viruses included in the species Orthobornavirus serini are highlighted by black boxes. Red circles, blue squares, as well as green or orange triangles, mark origin from the same flocks. The other canary-bornavirus strain sequences of this tree originated from different flocks. Sequences obtained in this investigation are available in GenBank under the accession numbers OP150416-OP150446.