Genetic Characterization of a Herpesvirus Isolate from a Superb Starling (Lamprotornis superbus) as a Psittacid Herpesvirus Genotype 1
Department of Large Animal Medicine and Surgery, Texas A&M University, College Station, TX 77843-4475, USA. Avian Diseases
(Impact Factor: 1.24).
01/2004; 48(1):212-4. DOI: 10.1637/7078
Four genotypes of the psittacid herpesvirus (PsHV) cause Pacheco disease in parrots. Viruses that are serologically cross-reactive to the PsHVs have also been isolated from passerine species. DNA was amplified from a herpesvirus isolated from a superb starling (Lamprotornis superbus) with PsHV-specific primers and polymerase chain reaction. A comparison of the partial sequence of the UL 16 gene from this herpesvirus with sequences from viruses of known PsHV genotypes showed that the herpesvirus from the superb starling was a PsHV genotype 1 virus. This finding expands the range of birds that are known to be susceptible to PsHV genotype 1 infections and suggests that PsHVs should be considered as a differential in passerines with herpesvirus infections.
Available from: tamu.edu
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ABSTRACT: Internal papillomatous disease (IPD) is characterized by mucosal papillomas occurring primarily in the oral cavity and cloaca of Neotropical parrots. These lesions can cause considerable morbidity, and in some cases result in mortality. Efforts to demonstrate papillomavirus DNA or proteins in the lesions have been largely unsuccessful. However, increasing evidence suggests that mucosal papillomas may contain psittacid herpesviruses (PsHVs). In this study, PsHV 1 genotype 1, 2, and 3 DNA was found in 100% of mucosal papillomas from 30 Neotropical parrots by PCR using PsHV specific primers. However, Psittacus erithacus papillomavirus and finch papillomavirus DNA were not detected. Additionally, a novel PsHV sequence related to, but phylogenetically distinct from PsHV 1, was identified in 4 African grey parrots (Psittacus erithacus), two of which exhibited papillomas. These findings suggest that mucosal papillomas may develop in parrots latently infected with PsHV. Tumors of the bile and pancreatic ducts have also been observed in parrots with IPD. Other mucosal tumors including carcinomas of the proventriculus and ventriculus may be coincident with bile duct tumors, but cloacal carcinomas usually develop as solitary lesions. To test whether PsHV was associated with these tumors, the fresh tissues from 11 parrots and the formalin-fixed paraffin-embedded (FFPE) tissues of 5 parrots exhibiting mucosal tumors were examined by PCR. All tumors were found to contain PsHV 1 genotype 3 DNA except one bird with a cloacal carcinoma that contained genotype 4. Histologically normal tissues available from six parrots did not contain PsHV DNA. Experiments were performed using the FFPE tissues of 5 parrots with IPD related tumors known to contain PsHV by PCR, to show that the virus was in significantly higher concentration in the neoplastic tissue compared to adjacent histologically normal tissue. Neoplastic and adjacent unaffected cells were dissected from the tissues using laser capture microdissection and the DNA was examined by PCR. In situ hybridization using PsHV specific probes and direct in situ PCR were also performed on the tissues. A strong association was shown between infection by PsHV 1 genotype 3 and birds manifesting IPD related tumors and other neoplasms of the digestive tract.
Available from: William Wigle
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ABSTRACT: Psittacid herpesvirus-1 (PsHV-1) is the cause of an acute fatal disease in parrots and is implicated as the cause of papillomatous lesions of the digestive tract. Not all infections cause disease and some parrots are infected asymptomatically. Latently infected parrots are potential sources for virus dissemination. Tissues from parrots that died spontaneously with a history of coming from flocks where a PsHV-1 outbreak had occurred were examined for PsHV-1 DNA. Fourteen of 16 parrots examined were infected with at least 1 variant of PsHV-1; of these 13 (93%) had viral DNA in either or both the oral and cloacal mucosa, suggesting that most latently infected parrots could be detected by sampling these sites. Nine of 9 parrots shown to be infected 5 years prior to this study were positive again on repeat sampling and were infected with the same virus genotype. Opportunistic sampling of parrots submitted for diagnostic necropsy indicated that the prevalence of PsHV-1 in parrots in the sampled population was approximately 9.3%. PsHV-1 genotypes 1, 2, and 3 were found in these birds, but genotype 4 was not. Six necropsy specimens were found to be infected with two PsHV-1 genotypes and it was concluded that infection with one serotype did not protect against infection with another. Psittacid herpesvirus 2 (PsHV-2) was identified in 4 African grey parrots and a blue and gold macaw. Prior to this study PsHV-2 had only been found in African grey parrots.
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ABSTRACT: An epizootic of Pacheco's disease is reported from a zoo bird population. The infection was introduced by wild-captured Patagonian conures (Cyanoliseus patagonus) despite 61 days of quarantine. The disease affected several parrot species and, interestingly, three out of seven bearded barbets (Lybius dubius). The mortality rate was 30.93%. Autopsy revealed abdominal hyperaemia with liver haemorrhages and, in less rapid cases, yellowish discoloration and fragility of the liver. Death was caused by the collapse of circulation. Histopathology demonstrated liver cell necrosis, disintegration of the lobular structure, and a few intranuclear inclusion bodies. Icosahedral virions were detected by electron microscopy. The virus was isolated in the allantoic cavity of embryonated chicken eggs as well as in chicken embryo fibroblast cell culture. A 281-bp-long fragment of psittacid herpesvirus DNA was detected by PCR in cell culture material and liver samples of the affected birds. To our knowledge this is the first report of Pacheco's disease in bearded barbets as well as the first occurrence of Pacheco's disease in Hungary.
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