Velogenic Newcastle disease in imported caged birds.
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Velogenic Newcastle disease was diagnosed in pet birds intended for importation into Canada. Virological and histopathological examination confirmed the presence of the disease. The group of birds was denied entry into Canada. Similar birds illegally imported are a potential source of velogenic Newcastle disease virus and are a threat to domestic poultry. (+info)
Detection and heterogeneity of herpesviruses causing Pacheco's disease in parrots.
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Pacheco's disease (PD) is a common, often fatal, disease of parrots. We cloned a virus isolate from a parrot that had characteristic lesions of PD. Three viral clones were partially sequenced, demonstrating that this virus was an alphaherpesvirus most closely related to the gallid herpesvirus 1. Five primer sets were developed from these sequences. The primer sets were used with PCR to screen tissues or tissue culture media suspected to contain viruses from 54 outbreaks of PD. The primer sets amplified DNA from all but one sample. Ten amplification patterns were detected, indicating that PD is caused by a genetically heterogeneous population of viruses. A single genetic variant (psittacid herpesvirus variant 1) amplified with all primer sets and was the most common virus variant (62.7%). A single primer set (23F) amplified DNA from all of the positive samples, suggesting that PCR could be used as a rapid postmortem assay for these viruses. PCR was found to be significantly more sensitive than tissue culture for the detection of psittacid herpesviruses. (+info)
Population genetic structure and vocal dialects in an amazon parrot.
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The relationship between cultural and genetic evolution was examined in the yellow-naped amazon Amazona auropalliata. This species has previously been shown to have regional dialects defined by large shifts in the acoustic structure of its learned contact call. Mitochondrial DNA sequence variation from a 680 base pair segment of the first domain of the control region was assayed in 41 samples collected from two neighbouring dialects in Costa Rica. The relationship of genetic variation to vocal variation was examined using haplotype analysis, genetic distance analysis, a maximum-likelihood estimator of migration rates and phylogenetic reconstructions. All analyses indicated a high degree of gene flow and, thus, individual dispersal across dialect boundaries. Calls sampled from sound libraries suggested that temporally stable contact call dialects occur throughout the range of the yellow-naped amazon, while the presence of similar dialects in the sister species Amazona ochrocephala suggests that the propensity to form dialects is ancestral in this clade. These results indicate that genes and culture are not closely associated in the yellow-naped amazon. Rather, they suggest that regional diversity in vocalizations is maintained by selective pressures that promote social learning and allow individual repertoires to conform to local call types. (+info)
Tyzzer's disease in a neonatal rainbow lorikeet (Trichoglossus haematodus).
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A captive-born 8-day-old male rainbow lorikeet (Trichoglossus haematodus) was found dead. Histologically, there were necrotizing hepatitis, myocarditis, and ventriculitis. Silver stain revealed argyrophilic filamentous bacilli within hepatocytes, smooth myofibers of the gizzard, and cardiac myofibers surrounding foci of necrosis. Immunohistochemistry using anti-Clostridium piliforme RT and MSK strain antisera reacted positively against bacilli within hepatocytes, cardiac myofibers, smooth myofibers of the gizzard, and splenic and intestinal macrophages. Polymerase chain reaction (PCR) assay of paraffin-embedded liver, heart, gizzard, spleen, and small intestine amplified the 196-bp DNA fragment specific to 16S ribosomal RNA of C. piliforme. The results of histopathology, immunohistochemistry, and PCR are consistent with C. piliforme infection in this lorikeet. (+info)
Lactobacillus psittaci sp. nov., isolated from a hyacinth macaw (Anodorhynchus hyacinthinus).
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A Gram-positive, non-spore-forming, catalase-negative, facultatively anaerobic coccibacillus to rod-shaped bacterium isolated from a parrot was characterized using phenotypic and molecular taxonomic methods. The unknown bacterium phenotypically resembled lactobacilli and comparative 16S rRNA gene sequencing demonstrated that the organism represents a distinct subline within the Lactobacillus delbrueckii rRNA cluster of the genus. 16S rRNA sequence divergence values of > 6% with recognized Lactobacillus species clearly demonstrated the phylogenetic separateness of the parrot bacterium. On the basis of phylogenetic evidence and the phenotypic distinctiveness of the unknown bacterium, a new species, Lactobacillus psittaci sp. nov., is proposed. The type strain of Lactobacillus psittaci is CCUG 42378T (= CIP 106492T). (+info)
Duplication and concerted evolution of the mitochondrial control region in the parrot genus Amazona.
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We report a duplication and rearrangement of the mitochondrial genome involving the control region of parrots in the genus Amazona. This rearrangement results in a gene order of cytochrome b/tRNA(Thr)/pND6/pGlu/CR1/tRNA(Pro)/NADH dehydrogenase 6/tRNA(Glu)/CR2/tRNA(Phe)/12s rRNA, where CR1 and CR2 refer to duplicate control regions, and pND6 and pGlu indicate presumed pseudogenes. In contrast to previous reports of duplications involving the control regions of birds, neither copy of the parrot control region shows any indications of degeneration. Rather, both copies contain many of the conserved sequence features typically found in avian control regions, including the goose hairpin, TASs, the F, C, and D boxes, conserved sequence box 1 (CSB1), and an apparent homolog to the mammalian CSB3. We conducted a phylogenetic analysis of homologous portions of the duplicate control regions from 21 individuals representing four species of Amazona (A. ochrocephala, A. autumnalis, A. farinosa, and A. amazonica) and Pionus chalcopterus. This analysis revealed that an individual's two control region copies (i.e., the paralogous copies) were typically more closely related to one another than to corresponding segments of other individuals (i.e., the orthologous copies). The average sequence divergence of the paralogous control region copies within an individual was 1.4%, versus a mean value of 4.1% between control region orthologs representing nearest phylogenetic neighbors. No differences were found between the paralogous copies in either the rate or the pattern in which the two copies accumulated base pair changes. This pattern suggests concerted evolution of the two control regions, perhaps through occasional gene conversion events. We estimated that gene conversion events occurred on average every 34,670 +/- 18,400 years based on pairwise distances between the paralogous control region sequences of each individual. Our results add to the growing body of work indicating that under some circumstances duplicated mitochondrial control regions are retained through evolutionary time rather than degenerating and being lost, presumably due to selection for a small mitochondrial genome. (+info)
Hepatic hyaline globules in an Eclectus parrot (Eclectus roratus).
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Hepatic hyaline globules, similar to those reported in some human livers, were observed in liver tissue from an Eclectus parrot (Eclectus roratus). The cytoplasmic inclusions were periodic acid-Schiff positive and diastase resistant and failed to stain by acid-fast or Congo red techniques. Ultrastructurally, the hepatic globules were composed of granular amorphous material with small peripheral striations that extended into the cytoplasm. (+info)
Molecular identification of Candida parapsilosis from crop mucosa in a cockatiel.
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A 2-month-old cockatiel was evaluated for diarrhea, dyspnea, and death. Histologic examination of lesions in the crop mucosa revealed hyperkeratosis and the presence of blastoconidia and hyphae. Positive immunohistochemical staining of the organisms was achieved with an antibody directed against Candida spp. Polymerase chain reaction amplification of DNA from crop lesion material with internal transcribed spacer 2 (ITS2) primers yielded fragments of approximately 300 bp, which demonstrated 95% DNA homology with the corresponding sequence from a strain of Candida parapsilosis deposited in the GenBank data base. The Candida species in the lesion of the crop mucosa was therefore identified by DNA sequence analysis as C. parapsilosis. (+info)