Novel endotheliotropic herpesviruses fatal for Asian and African elephants.
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A highly fatal hemorrhagic disease has been identified in 10 young Asian and African elephants at North American zoos. In the affected animals there was ultrastructural evidence for herpesvirus-like particles in endothelial cells of the heart, liver, and tongue. Consensus primer polymerase chain reaction combined with sequencing yielded molecular evidence that confirmed the presence of two novel but related herpesviruses associated with the disease, one in Asian elephants and another in African elephants. Otherwise healthy African elephants with external herpetic lesions yielded herpesvirus sequences identical to that found in Asian elephants with endothelial disease. This finding suggests that the Asian elephant deaths were caused by cross-species infection with a herpesvirus that is naturally latent in, but normally not lethal to, African elephants. A reciprocal relationship may exist for the African elephant disease. (+info)
Involvement of DNA end-binding protein Ku in Ty element retrotransposition.
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Saccharomyces cerevisiae Ty elements are retrotransposons whose life cycles are strikingly similar to those of retroviruses. They transpose via an RNA intermediate that is converted to linear double-stranded cDNA and then inserted into the host genome. Although Ty integration is mediated by the element-encoded integrase, it has been proposed that host factors are involved in this process. Here, we show that the DNA end-binding protein Ku, which functions in DNA double-strand break repair, potentiates retrotransposition. Specifically, by using a galactose-inducible Ty1 system, we found that in vivo, Ty1 retrotransposition rates were substantially reduced in the absence of Ku. In contrast, this phenotype was not observed with yeast strains containing mutations in other genes that are involved in DNA repair. We present evidence that Ku associates with Ty1 viruslike particles both in vitro and in vivo. These results provide an additional role for Ku and suggest that it might function in the life cycles of retroelements in other systems. (+info)
Ultrastructure of porcine circovirus in persistently infected PK-15 cells.
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The ultrastructure of porcine circovirus was examined in persistently infected porcine kidney (PK)-15 cells. Virus-infected PK-15 cells had large numbers of intracytoplasmic inclusions, and a few cells had intranuclear inclusions. Intracytoplasmic inclusions were dispersed throughout the cytoplasm but were most numerous in the perinuclear cytoplasm. Inclusion were of various sizes, round to oval, and electron dense and were of two general types. Inclusions of the first type were small (0.1-0.5 microm diameter), not surrounded by trilaminar membranes, and granular with indistinct margins that blended with surrounding cytoplasm. Some contained 12+/-2-nm-diameter icosahedral virions in loose aggregates or rarely forming paracrystalline arrays. Small inclusions could be sites of viral assembly or maturation. Intracytoplasmic inclusions of the second type were larger (0.5-5.0 microm diameter) and more numerous and had abrupt margins surrounded by trilaminar membranes. They were more electron dense than small inclusions and were heterogeneous, containing various proportions of aggregated virions, electron-dense crystalline lamellae of 5 nm periodicity, and/or whorls of myelinoid membranes. Virions usually formed paracrystalline arrays and occasionally were loosely aggregated. Larger inclusions were typical of autophagolysosomes. Intranuclear inclusions were not membrane bound and were often associated with reticulated nucleoli or aggregates of heterochromatin. Some inclusions were irregularly shaped aggregates of indistinct, circular 10-12-nm-diameter viruslike particles. Others were 0.1-1.0 microm in diameter, round or ring shaped, dense, and finely granular, with sharply demarcated margins. (+info)
Electron microscopical observations of psittacine beak and feather disease in an Umbrella cockatoo (Cacatua alba).
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Psittacine beak and feather disease (PBFD) was diagnosed in an umbrella cockatoo (Cacatua alba) with severe feather dystrophy and loss. Electron microscopically, the intranuclear and intracytoplasmic inclusion bodies observed by light microscopy were composed of viral particles forming paracrystalline arrays, whorls, semicircles or concentric circles. Recovered viral particles from the skin and feather follicle tracts were icosahedral and 15 to 20 nm in diameter. (+info)
Detection of porcine circovirus from lesions of a pig with wasting disease in Japan.
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A wasting disease characterized by progressive weight loss and dyspnea has been observed in weaning pigs on a farm in Yamagata Prefecture in 1998. Histopathologic findings in an affected pig were bronchointerstitial pneumonia and intracytoplasmic clusters of basophilic inclusions in macrophages of lymph nodes, which were similar to those in pigs with postweaning multisystemic wasting syndrome (PMWS) recently reported in North America and Europe. Porcine circovirus (PCV)-like particles were observed in bronchial lymph node of the pig by electron microscopy, and PCV antigens were detected in the lesions by immunohistochemical staining. PCV DNA was also detected in the lung and tonsil by PCR, and restriction fragment length polymorphism analysis of the PCR products with HinfI showed the same type of the PCV associated with PMWS (pmws PCV). Homology of nucleotide sequences between the PCR product and corresponding regions of published pmws PCV genomes was very high. These results indicated that virus detected in this study was pmws PCV. To our knowledge, this is the first report on the presence of pmws PCV in Japan. (+info)
Herpesvirus infection in tortoises (Malacochersus tornieri and Testudo horsfieldii).
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Large numbers of pancake tortoises (Malacochersus tornieri) and Horsfield tortoises (Testudo horsfieldii) in three consignments imported into Japan died soon after arrival. Some tortoises in the first consignment were dead on arrival. Postmortem examination of two of the pancake tortoises and four of the Horsfield tortoises revealed necrotizing lesions of the oral mucosa in both species, primarily in the tongue. Eosinophilic to amphophilic inclusion bodies were visible in the nuclei of mucosal epithelial cells in the lesions. Similar inclusion bodies were observed in the liver, spleen, adrenal glands, stomach, lungs, kidneys, small and large intestines, pancreas, and cerebrum of the pancake tortoises and in the liver, spleen, and pancreas of the Horsfield tortoises. Electron microscopic examination of the cells containing inclusion bodies showed herpesvirus-like particles about 100 nm in diameter in the cytoplasm. Nested polymerase chain reaction analysis using a herpesvirus consensus primer method confirmed the presence of a characteristic herpesvirus base sequence in tissue from these lesions. (+info)
Measles inclusion-body encephalitis caused by the vaccine strain of measles virus.
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We report a case of measles inclusion-body encephalitis (MIBE) occurring in an apparently healthy 21-month-old boy 8.5 months after measles-mumps-rubella vaccination. He had no prior evidence of immune deficiency and no history of measles exposure or clinical disease. During hospitalization, a primary immunodeficiency characterized by a profoundly depressed CD8 cell count and dysgammaglobulinemia was demonstrated. A brain biopsy revealed histopathologic features consistent with MIBE, and measles antigens were detected by immunohistochemical staining. Electron microscopy revealed inclusions characteristic of paramyxovirus nucleocapsids within neurons, oligodendroglia, and astrocytes. The presence of measles virus in the brain tissue was confirmed by reverse transcription polymerase chain reaction. The nucleotide sequence in the nucleoprotein and fusion gene regions was identical to that of the Moraten and Schwarz vaccine strains; the fusion gene differed from known genotype A wild-type viruses. (+info)
Human granulocytic ehrlichiosis agent infection in a pony vaccinated with a Borrelia burgdorferi recombinant OspA vaccine and challenged by exposure to naturally infected ticks.
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A pony was vaccinated with recombinant OspA vaccine (rOspA) and then exposed 3 months later to Borrelia burgdorferi-infected ticks (Ixodes scapularis) collected in Westchester County, N.Y. At 2 weeks after tick exposure, the pony developed a high fever (105 degrees F). Buffy coat smears showed that 20% of neutrophils contained ehrlichial inclusion bodies (morulae). Flunixin Meglumine (1 g daily) was given for 2 days, and the body temperature returned to normal. PCR for ehrlichial DNA was performed on blood samples for 10 consecutive days beginning when the pony was first febrile. This pony was monitored for another 3.5 months but developed no further clinical signs. The 44-kDa immunodominant human granulocytic ehrlichiosis antigen gene was amplified by PCR and cloned into a pCR2.1 vector. DNA sequence analysis of this gene showed it was only 8 bp different (99% identity) from the results reported by others (J. W. Ijdo et al., Infect. Immun. 66:3264-3269, 1998). Western blot analysis, growth inhibition assays, and repeated attempts to isolate B. burgdorferi all demonstrated the pony was protected against B. burgdorferi infection. These results highlight the potential for ticks to harbor and transmit several pathogens simultaneously, which further complicates the diagnosis and vaccination of these emerging tick-borne diseases. (+info)