scholarly journals First identification of Sarcocystis tenella (Railliet, 1886) Moulé, 1886 (Protozoa: Apicomplexa) by PCR in naturally infected sheep from Brazil

2009 ◽  
Vol 165 (3-4) ◽  
pp. 332-336 ◽  
Author(s):  
Rodrigo Costa da Silva ◽  
Chunlei Su ◽  
Helio Langoni
Keyword(s):  
Infected Sheep ◽  
Sarcocystis Tenella

Transplacental transmission of Neospora caninum to lambs in successive pregnancies of naturally infected sheep in Southern Brazil

2021 ◽  
Vol 23 ◽  
pp. 100537
Author(s):  
Kamila Alcalá Gonçalves Pereira ◽  
Renato Silva de Sousa ◽  
Mary Suzan Varaschin ◽  
Ana Paula Brenner Busch Becker ◽  
Alda Lúcia Gomes Monteiro ◽  
...  
Keyword(s):  
Neospora Caninum ◽  
Infected Sheep ◽  
Transplacental Transmission ◽  
Southern Brazil

scholarly journals Evaluation of a Preclinical Blood Test for Scrapie in Sheep Using Immunocapillary Electrophoresis

2006 ◽  
Vol 89 (3) ◽  
pp. 720-727 ◽  
Author(s):  
Roy Jackman ◽  
David J Everest ◽  
Mary Jo Schmerr ◽  
Mohammed Khawaja ◽  
Pat Keep ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Prion Protein ◽  
Clinical Signs ◽  
Test System ◽  
Buffy Coat ◽  
Infected Sheep ◽  
Test Method ◽  
Peptide Sequence ◽  
Transmissible Spongiform Encephalopathies ◽  
Blood Samples

Abstract An analytical method is described for detection of endogenous disease-associated prion protein in the buffy coat fraction from the blood of sheep infected with scrapie. The method has been improved and evaluated for its performance in the preclinical diagnosis of ovine transmissible spongiform encephalopathies. The test system uses a protocol for sample preparation that includes extraction and concentration and a test method that uses a liquid-phase competitive immunoassay for prion protein. Antibodies directed to a peptide sequence at the C-terminus of the prion protein (PrP) and a fluorescein-labeled peptide conjugate are used in the assay. Free zone capillary electrophoresis with laser-induced fluorescence for detection is used to separate the antibody-bound fluorescently labeled peptide and free labeled peptide. In this assay, the PrP competes with the fluorescently labeled peptide for limited antibody binding sites, which results in a reduction of the peak representing the immunocomplex of the antibody bound to the fluorescently labeled peptide. When blood samples from scrapie-infected sheep aged 712 months and of the scrapie-susceptible PrP genotypes VRQ/VRQ and VRQ/ARQ were analyzed, the abnormal PrP was found in blood samples. These results correlated with the post-mortem diagnosis of scrapie. The sheep were preclinical and appeared normal at the time of testing but later died with clinical disease approximately 12 months after testing. In older animals, and those with clinical signs, a smaller percentage of animals tested positive. This study has demonstrated that this technology can be used as a sensitive, rapid preclinical test to detect the disease-associated PrP in the blood of scrapie-infected sheep. Improvements in the extraction protocol and capillary electrophoresis conditions will enhance the robustness of this test.

Ultrastructure and Frequency of Mastitis Caused by Ovine Progressive Pneumonia Virus Infection in Sheep

1986 ◽  
Vol 23 (2) ◽  
pp. 184-189 ◽  
Author(s):  
P. Deng ◽  
R. C. Cutlip ◽  
H. D. Lehmkuhl ◽  
K. A. Brogden
Keyword(s):  
Virus Infection ◽  
Mammary Glands ◽  
Infected Sheep ◽  
Mammary Tissue ◽  
Target Organs ◽  
Cellular Debris ◽  
Ovine Progressive Pneumonia

Twenty-five sheep, experimentally ( n = 15) or naturally ( n = 6) infected with ovine progressive pneumonia virus and noninfected controls ( n = 4), were evaluated for histological and ultrastructural lesions of mastitis. Histologically, nine of 15 experimentally infected sheep and all six naturally infected sheep had lympho-plasmacytic mastitis. Severity of the lesion increased with length of time after infection. Periductal lymphatic nodules were seen in five sheep experimentally infected for 2.8 years or longer and in five naturally infected sheep that wore 3.7 years old or older. Ultrastructurally, responses to ovine progressive pneumonia virus were diffuse lympho-plasmacytic infiltrates in glandular interstitium, lymphocytic and occasional plasmacytic infiltrates in ductal walls and lumens, lymphoblasts surrounded by small lymphocytes in glandular interstitium, and degeneration of epithelium releasing cells and cellular debris into the lumen. Based on the prevalence of lesions, the mammary tissue was more susceptible to ovine progressive pneumonia virus than other target organs: lung, brain, and synovium. Lesions did not differ between breeds of sheep. Ovine progressive pneumonia virus was not seen in the mammary tissue but was isolated from 15 of 17 mammary glands.

scholarly journals Brucella abortus RB51 and Hot Saline Extract from Brucella ovis as Antigens in a Complement Fixation Test Used To Detect Sheep Vaccinated with Brucella abortus RB51

2001 ◽  
Vol 8 (1) ◽  
pp. 119-122 ◽  
Author(s):  
Rosanna Adone ◽  
Franco Ciuchini
Keyword(s):  
Immune Responses ◽  
Brucella Abortus ◽  
Complement Fixation Test ◽  
Complement Fixation ◽  
Infected Sheep ◽  
Fixation Test ◽  
Anticomplementary Activity ◽  
Serum Samples ◽  
Saline Extract ◽  
Brucella Ovis

ABSTRACT The efficacy of Brucella abortus RB51 and hot saline extract (HSE) from Brucella ovis as antigens in complement fixation (CF) tests was comparatively evaluated in detecting immune responses of sheep vaccinated with B. abortus strain RB51. For this study, four 5-month-old sheep were vaccinated subcutaneously with 5 × 109 CFU of RB51, and two sheep received saline. Serum samples collected at different times after vaccination were tested for the presence of antibodies to RB51 by a CF test with RB51 as antigen, previously deprived of anticomplementary activity, and with HSE antigen, which already used as the official antigen to detectB. ovis-infected sheep. The results showed that vaccinated sheep developed antibodies which reacted weakly against HSE antigen and these antibodies were detectable for 30 days after vaccination. However, antibodies to RB51 could be detected for a longer period after vaccination by using homologous RB51 antigen in CF tests. In fact, high titers were still present at 110 days postvaccination with RB51 antigen. Sera from sheep naturally infected with B. ovisalso reacted to RB51 but gave lower titers than those detected by HSE antigen. As expected, all sera from RB51-vaccinated sheep remained negative when tested with standard S-type Brucella standard antigens.

scholarly journals Sheep scab spatial distribution: the roles of transmission pathways

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Emily Joanne Nixon ◽  
Ellen Brooks-Pollock ◽  
Richard Wall
Keyword(s):  
Disease Transmission ◽  
Movement Control ◽  
Cost Effective ◽  
Infected Sheep ◽  
Disease Spread ◽  
Psoroptes Ovis ◽  
Long Distance ◽  
Sheep Scab ◽  
The Uk ◽  
The Impact

Abstract Background Ovine psoroptic mange (sheep scab) is a highly pathogenic contagious infection caused by the mite Psoroptes ovis. Following 21 years in which scab was eradicated in the UK, it was inadvertently reintroduced in 1972 and, despite the implementation of a range of control methods, its prevalence increased steadily thereafter. Recent reports of resistance to macrocyclic lactone treatments may further exacerbate control problems. A better understanding of the factors that facilitate its transmission are required to allow improved management of this disease. Transmission of infection occurs within and between contiguous sheep farms via infected sheep-to-sheep or sheep–environment contact and through long-distance movements of infected sheep, such as through markets. Methods A stochastic metapopulation model was used to investigate the impact of different transmission routes on the spatial pattern of outbreaks. A range of model scenarios were considered following the initial infection of a cluster of highly connected contiguous farms. Results Scab spreads between clusters of neighbouring contiguous farms after introduction but when long-distance movements are excluded, infection then self-limits spatially at boundaries where farm connectivity is low. Inclusion of long-distance movements is required to generate the national patterns of disease spread observed. Conclusions Preventing the movement of scab infested sheep through sales and markets is essential for any national management programme. If effective movement control can be implemented, regional control in geographic areas where farm densities are high would allow more focussed cost-effective scab management. Graphical Abstract

scholarly journals PrPSc Is Not Detected in Peripheral Blood Leukocytes of Scrapie-Infected Sheep: Determining the Limit of Sensitivity by Immunohistochemistry

2002 ◽  
Vol 9 (2) ◽  
pp. 499-502 ◽  
Author(s):  
Lynn M. Herrmann ◽  
Timothy V. Baszler ◽  
Donald P. Knowles ◽  
William P. Cheevers
Keyword(s):  
Lymph Node ◽  
Peripheral Blood ◽  
Infected Sheep ◽  
Peripheral Blood Leukocytes ◽  
Retropharyngeal Lymph Node ◽  
Blood Leukocytes

ABSTRACT Peripheral blood leukocytes (PBLs) from scrapie-infected sheep were evaluated for the presence of PrPSc by using dissociated retropharyngeal lymph node (DRLN) cells and immunohistochemistry (IHC). PrPSc-positive cells were detected in 2.05% ± 0.28% of 3 × 106 DRLN cells, but were not detected in 3 × 106 PBLs from scrapie-infected sheep. Titration of DRLN cells mixed with PBLs showed that IHC detects a minimum of 0.00205% or 60 PrPSc-positive cells in 3 × 106 PBLs.

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