Naturally Occurring Scrapie in Southdown Sheep     

Jeff W. Tyler  Dusty M. Weaver  James R. Turk  Katherine I. O''Rourke  Michael G. Harrington  William Taylor  Allen Jenny 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1999,13(3):213-216

The purpose of this study was to characterize naturally occurring scrapie in the Southdown breed of sheep. Experimental subjects included 4 Southdown ewes admitted to the University of Missouri, College of Veterinary Medicine Large Animal Clinic. All 4 sheep had signs compatible with clinical scrapie. Cerebrospinal fluid (CSF) cell counts ranged from a low of 1 nucleated cell/microL to high of 4 cells/microL with a median of 3 cells/microL. Cerebrospinal protein concentrations ranged from 26 to 78 mg/dL with a median of 53 mg/dL. Immunoassay of the CSF for the 14-3-3 protein yielded positive results in 3 of the 4 sheep. Sequencing of the prion protein (PrP) gene revealed that all 4 sheep were homozygous for glutamine at codon 171 and, hence, were of the QQ genotype. Histopathologic examination of brain stem tissue sections revealed intracytoplasmic neuronal vacuolation and mild spongiform changes in the gray matter neuropil in all 4 ewes. The diagnosis of scrapie was confirmed by immunohistochemical staining for the abnormal PrP Our results suggest that the genetics of scrapie susceptibility are probably similar in Suffolk and Southdown sheep. Positive immunoassay results for the 14-3-3 protein were observed in 3 of the 4 sheep.  相似文献   

Polymerase chain reaction identification of Mycobacterium avium in formalin-fixed, paraffin-embedded animal tissues.     

J M Miller  A L Jenny  J L Ellingson 《Journal of veterinary diagnostic investigation》1999,11(5):436-440

A PCR procedure previously developed for identification of Mycobacterium bovis in formalin-fixed tissues was used to identify mycobacteria of the M. avium complex. Tissues were examined from 100 culture-positive cases of M. avium complex infection, including 86 in which the subspecies was not identified and 14 that had been identified as M. avium subsp. paratuberculosis. Each sample was tested with 5 primer sets, 16S ribosomal RNA (rRNA), IS900, IS901, IS1245, and a heat shock protein (hspX), that detect 1 or both M. avium subspecies. The success rate of PCR detection varied with the primers used and the animal species tested. Among the 86 cases with no M. avium subspecies designation, primers for the 16S rRNA gene were clearly the most efficient because they produced amplicons from all samples that reacted with any other primer set. The overall detection rate in this group of samples was 71%: highest in avian tissues (89%) followed by swine (72%) and ruminants (57%) None of the avian or swine tissues reacted with primers for IS900 or hspX, which identify M. a. paratuberculosis. In contrast, 7 of the 12 ruminant samples that were 16S rRNA positive reacted with 1 or both of these primers. All of the 14 cases shown by culture to be M. a. paratuberculosis infections were positive with IS900 primers, whereas only 11 were positive for 16S rRNA. These results indicate that 16S rRNA primers are the most useful for PCR identification of M. avium in formalin-fixed tissues of nonruminant species. However, IS900 primers should also be used when ruminant tissues are examined because these primers provide the greatest sensitivity for detection of M. a. paratuberculosis infections.  相似文献   

Abstracts of presentations on selected topics at the XIVth international plant protection congress (IPPC) July 25–30, 1999     

R. Hull  H. A. Kuiper  Maryvon Y. Noordam  Marjorie A. Hoy  Jenny S. Cory  A. C. Fereres  P. Gonzalez  F. Meins  Y. Elkind  Benedicte Charrier 《Phytoparasitica》1999,27(4):299-332

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Updated abundance estimates for common bottlenose dolphins (Tursiops truncatus) inhabiting West Bay,Texas     

Jenny A. Litz  Errol I. Ronje  Heidi R. Whitehead  Lance P. Garrison 《水产资源保护:海洋与淡水生态系统》2019,29(11):1959-1970