33 research outputs found
Complete Genome Sequence of Avian Paramyxovirus (APMV) Serotype 5 Completes the Analysis of Nine APMV Serotypes and Reveals the Longest APMV Genome
Avian paramyxoviruses (APMV) consist of nine known serotypes. The genomes of representatives of all APMV serotypes except APMV type 5 have recently been fully sequenced. Here, we report the complete genome sequence of the APMV-5 prototype strain budgerigar/Kunitachi/74.APMV-5 Kunitachi virus is unusual in that it lacks a virion hemagglutinin and does not grow in the allantoic cavity of embryonated chicken eggs. However, the virus grew in the amniotic cavity of embryonated chicken eggs and in twelve different established cell lines and two primary cell cultures. The genome is 17,262 nucleotides (nt) long, which is the longest among members of genus Avulavirus, and encodes six non-overlapping genes in the order of 3'N-P/V/W-M-F-HN-L-5' with intergenic regions of 4-57 nt. The genome length follows the 'rule of six' and contains a 55-nt leader sequence at the 3'end and a 552 nt trailer sequence at the 5' end. The phosphoprotein (P) gene contains a conserved RNA editing site and is predicted to encode P, V, and W proteins. The cleavage site of the F protein (G-K-R-K-K-R downward arrowF) conforms to the cleavage site motif of the ubiquitous cellular protease furin. Consistent with this, exogenous protease was not required for virus replication in vitro. However, the intracerebral pathogenicity index of APMV-5 strain Kunitachi in one-day-old chicks was found to be zero, indicating that the virus is avirulent for chickens despite the presence of a polybasic F cleavage site.Phylogenetic analysis of the sequences of the APVM-5 genome and proteins versus those of the other APMV serotypes showed that APMV-5 is more closely related to APMV-6 than to the other APMVs. Furthermore, these comparisons provided evidence of extensive genome-wide divergence that supports the classification of the APMVs into nine separate serotypes. The structure of the F cleavage site does not appear to be a reliable indicator of virulence among APMV serotypes 2-9. The availability of sequence information for all known APMV serotypes will facilitate studies in epidemiology and vaccinology
Characteristics of three strains of avian adenoviruses isolated in Queensland. II. Biochemical, biophysical, and electron microscope studies
Three strains of adenovirus were relatively stable to the effects of chloroform, extreme pH, trypsin, heat, lyophilization, and ultrasonication. The structure of the viruses and their mode of replication in cell cultures confirmed these viruses to be members of the avian adenoviruses
Characteristics of three strains of avian adenoviruses isolated in Queensland. I. Biological properties
Three strains of avian adenovirus were isolated and studied in cell cultures, chicken embryos, and chickens. One strain (ADAM-1) was isolated from the bursa of Fabricius of a chicken with Marek's disease, and the others (ADAM-2 and ADAM-3) from one-day-old chicks with respiratory signs. Experimentally, ADAM-1 produced no clinical signs or lesions except atrophy of the bursa of Fabricius. ADAM-2 caused mild respiratory signs in young chickens when inoculated intratracheally. The behavior of the three viruses in cell cultures and chick embryos was similar to that described for other avian adenoviruses (CELO). In a serological survey using the agar-gel precipitation test, 3-30% of sera tested gave a positive reaction
A pathogenic paramyxovirus from a budgerigar (Melopsittacus undulatus)
An outbreak of acute enteritis with high mortality among caged budgerigars (Melopsittacus undulatus) in a bird sanctuary was investigated. An agent with the properties of a paramyxovirus, but distinct from Newcastle disease virus and myxovirus Yucaipa, was isolated from one budgerigar. Inoculation of the virus intranasally, orally or intra abdominally, in young budgerigars produced an acute, fatal enteritis. Birds surviving the original outbreak developed antibodies to the virus. The virus was not pathogenic for chick embryos, young or mature chickens, or pigeons. Hemadsorption was demonstrated in infected cell cultures, but no hemagglutinin was detected