Novel avian bornavirus in a nonpsittacine species (Canary; Serinus canaria) with enteric ganglioneuritis and encephalitis.

A canary bird (Serinus canaria) died with nonsuppurative ganglioneuritis of the proventriculus and gizzard and encephalitis, lesions comparable to proventricular dilatation disease (PDD) of psittacine birds. Recently, several genotypes of a novel avian bornavirus have been linked to PDD. In the canary, bornaviral antigen was detected by immunohistochemistry in both neural and extraneural tissues. The widespread viral dissemination was confirmed by reverse transcription-PCR. Sequence analysis revealed a unique genotype of avian bornavirus. This observation suggests that bornaviruses are natural pathogens of several avian species and that the family Bornaviridae comprises more viral genotypes (or viral species) than previously assumed.

Avian bornaviruses in psittacine birds from Europe and Australia with proventricular dilatation disease.

To determine whether avian bornaviruses (ABVs) were a factor in proventricular dilatation disease (PDD), we used immunohistochemistry, reverse transcription-PCR, and nucleotide sequence analysis to examine paraffin wax-embedded or frozen tissue samples of 31 psittacine birds with this disease. PDD is a fatal disease of psittacine birds associated with nonsuppurative encephalitis and ganglioneuritis of the upper intestinal tract. Tissue samples had been collected from 1999 through 2008 in Austria, Switzerland, Hungary, and Australia. Immunohistochemical demonstration of viral antigen within the brain and vegetative nerve system of the gastrointestinal tract provides strong evidence for a causative role of ABVs in this condition. Partial sequences of nucleoprotein (p40) and matrix protein (gp18) genes showed that virus in most of our cases belonged to the ABV-2 and ABV-4 groups among the 5 genogroups described so far. Viral sequences of 2 birds did not match any of the described sequences and clustered together in a new branch termed ABV-6.

Emergence of canine distemper in Bavarian wildlife associated with a specific amino acid exchange in the haemagglutinin protein.

A widespread, severe outbreak of canine distemper encephalitis was observed in wildlife in Southern Bavaria in the spring and summer of 2008. The haemagglutinin (HA) genes of six representative canine distemper virus (CDV) samples originating from five red foxes and one badger during this outbreak had a Y549H amino acid substitution in the HA protein compared to sequences from two captive domesticated ferrets which succumbed to CDV in the same area 2 years earlier. As this specific substitution at the receptor-binding site has been hypothesised to contribute to the emergence of CDV and its spread to novel hosts, the outbreak in wildlife in Southern Bavaria might, directly or indirectly, be associated with a Y549H amino acid exchange.

Analysis of the variability of CMV strains in the RL11D domain of the RL11 multigene family.

Human cytomegalovirus (CMV) contains one of the largest genomes within the herpesvirus family and includes 12 multigene families. One of these is the RL11 family, whose members encode a characteristic domain, called RL11D. In the present study, the sequence variability of RL11D within the UL1, UL4, UL6, UL7, and UL10 genes of the RL11 family was investigated. For this purpose, these genes were analyzed in 70 clinical isolates obtained from urine, bronchoalveolar lavage, and blood of different patients. Substantial genetic variability among the clinical isolates was observed in all five genes analyzed. Based on phylogenetic analysis of variations in RL11D, the clinical isolates could be classified into three genotypes for UL1, 7, and 10 and, four genotypes for UL4 and 6. Further analysis showed statistically significant linkages between the following pairs of genes: UL6/UL7, UL4/UL7, UL1/UL4, and UL4/UL6. The data show that CMV strains exhibit a high interstrain variability in the RL11D domain of various RL11 family genes. Sequence variations, however, can be clearly grouped into a limited number of distinct genotypes. The genetic linkages found probably reflect a low frequency of recombination between genes that are arranged in close proximity on the viral genome.