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Poult enteritis and mortality syndrome (PEMS) is an acute, infectious intestinal disease of turkey poults, characterized by high mortality and 100% morbidity, that decimated the turkey industry in the mid-1990s. The etiology of PEMS is not completely understood. This report describes the testing of various filtrates of fecal material from control and PEMS-affected poults by oral inoculation into poults under experimental conditions, the subsequent isolation of a reovirus, ARV-CU98, from one of the PEMS fecal filtrates, and in vivo and in vitro studies conducted to determine the pathogenicity of ARV-CU98 in turkey poults. In order to identify a filtrate fraction of fecal material containing a putative etiologic agent, poults were challenged in two independent experiments with 220- and 100-nm filtrates of fecal material from PEMS-negative and PEMS-positive poults. The 100-nm filtrate was chosen for further evaluation because poults inoculated with this filtrate exhibited mortality and significantly lower (P < or = 0.05) body weight and relative bursa weight, three clinical signs associated with PEMS. These results were confirmed in a third experiment with 100-nm fecal filtrates from a separate batch of PEMS fecal material. In Experiment 3, body weight and relative bursa and thymus weights were significantly lower (P < or = 0.05) in poults inoculated with 100-nm filtrate of PEMS fecal material as compared with poults inoculated with 100-nm filtrate of control fecal material. Subsequently, a virus was isolated from the 100-nm PEMS fecal filtrate and propagated in liver cells. This virus was identified as a reovirus on the basis of cross-reaction with antisera against avian reovirus (FDO strain) as well as by electrophoretic analysis and was designated ARV-CU98. When inoculated orally into poults reared under controlled environmental conditions in isolators, ARV-CU98 was associated with a higher incidence of thymic hemorrhaging and gaseous intestines. In addition, relative bursa and liver weights were significantly lower (P < or = 0.05) in virus-inoculated poults as compared with controls. Virus was successfully reisolated from virus-challenged poults but not from control birds. Furthermore, viral antigen was detected by immunofluorescence in liver sections from virus-challenged poults at 3 and 6 days postinfection and virus was isolated from liver at 6 days postinfection, suggesting that ARV-CU98 replicates in the liver. In addition to a decrease in liver weight, there was a functional degeneration as indicated by altered plasma alanine aminotransferase and aspartate aminotransferase activities in virus poults as compared with controls. Although this reovirus does not induce fulminating PEMS, our results demonstrated that ARV-CU98 does cause some of the clinical signs in PEMS, including intestinal alterations and significantly lower relative bursa and liver weights. ARV-CU98 may contribute directly to PEMS by affecting the intestine, bursa, and liver and may contribute indirectly by increasing susceptibility to oppor...

Renal tumours are a common neoplastic disease of budgerigars. Although a retro-virus has been implicated as the aetiological agent, there is no definitive proof for this hypothesis. Sixteen birds suspected to have renal tumours were examined in an attempt to elucidate the possible role of retroviruses. Thirteen birds had renal tumours and the majority of these birds showed abdominal enlargement and paresis. Renal masses were detected by radiography in nine birds. Post-mortem examination confirmed the presence of abdominal tumours which were mostly confined to the kidneys. All of the renal tumours were carcinomas. ELISA tests to detect the presence of p27 of avian leukosis virus and virus isolation attempts were negative. DNA from eight tumours was examined by dot-blot hybridization for the presence of sequences hybridizing with a full length clone of the RAV-2 strain of the avian leukosis virus. A positive reaction was detected with DNA from 6/8 tumours. Southern blot hybridization demonstrated the presence of a 7.2 kb fragment following restriction with BamHI and a 4.6 kb fragment in an additional tumour following digestion with EcoRI that were recognized by the RAV-2 probe. These results suggest the presence of a retrovirus in tumours of budgerigars.