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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Expression analysis and antibody neutralization of P44 major surface proteins of anaplasma phagocytophilum during mammalian infection

Wang, Xueqi. January 2006 (has links)
Thesis (Ph. D.)--Ohio State University, 2006. / Available online via OhioLINK's ETD Center; full text release delayed at author's request until 2007 Jun 2

A comparison of antigenic proteins in different anaplasma isolates

Fehrsen, Jeanni January 1994 (has links)
A Thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for a Masters degree. Onderstepoort, 1994 / Anaplasmosis is a tick transmitted haemoparasitic disease of bovines, caused by A. marginale and A. centrale, which occurs worldwide and results in losses of significant economic importance. Bovines that survive infection are immune to reinfection with a homologous isolate and partially protected against heterologous isolates. South African isolates of A.marginale and A. centrale are compared. [Abbreviated Abstract. Open document to view full version] / MT2017

The role of cellular autophagy and type IV secretion system in Anaplasma phagocytophilum infection

Niu, Hua. January 2008 (has links)
Thesis (Ph. D.)--Ohio State University, 2008.

In vivo endothelial cell infection by Anaplasma marginale

Carreño, Abigail D., January 2007 (has links) (PDF)
Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 37-44)

Inhibitory mechanism of human neutrophil apoptosis by Anaplasma phagocytophilum and identification of novel surface proteins of A. phagocytophilum and Ehrlichia chaffeensis

Ge, Yan. January 2007 (has links)
Thesis (Ph. D.)--Ohio State University, 2007. / Full text release at OhioLINK's ETD Center delayed at author's request

Observations on the blood alterations associated with eperythrozoonosis and anaplasmosis in sheep following splenectomy

Becker, Arthur Harlan January 2011 (has links)
Digitized by Kansas State University Libraries

Granulocytic anaplasmosis and Lyme borreliosis exposure of horses in Canada

2013 December 1900 (has links)
A set of studies was designed in order to better understand the exposure of horses in Canada to Ixodes-borne diseases, namely equine granulocytic anaplasmosis (EGA, caused by Anaplasma phagocytophilum) and Lyme borreliosis (LB, caused by Borrelia burgdorferi). In the first study, equine serum samples submitted to veterinary diagnostic laboratories in SK, MB and ON were tested for antibodies against A. phagocytophilum and B. burgdorferi, using the point-of-care SNAP® 4Dx® ELISA. Horses seropositive to EGA were found in SK and MB and horses seropositive to LB were found in SK, MB and ON. Overall seroprevalence according to the SNAP® 4Dx® ELISA was 0.53% for EGA and 1.6% for LB. Samples that tested positive for antibodies against A. phagocytophilum (n=2) and B. burgdorferi (n=6) by SNAP® 4Dx® ELISA and 2 randomly selected subsets of samples that tested negative (n=92 each) were then re-tested using currently recommended serologic methods, and test results were compared. A lack of agreement was found between the SNAP® 4Dx® ELISA and indirect immunofluorescent assay (IFA) for EGA (McNemar test p = 0.000001). Agreement of the SNAP® 4Dx® ELISA and ELISA confirmed with Western Blot (WB) for LB was only fair (Kappa 0.23). Due to the lack of agreement between serologic tests for EGA and LB in the first study, another study to further evaluate the agreement among available serologic tests was conducted. A set of 50 convenience serum samples submitted to the veterinary diagnostic laboratory in SK was tested by SNAP® 4Dx® Plus ELISA for antibodies against A. phagocytophilum and B. burgdorferi. Samples were also tested by IFA for antibodies against A. phagocytophilum in two referral laboratories, and by IFA, ELISA confirmed with WB and Equine Lyme multiplex assay for antibodies against B. burgdorferi in three referral laboratories. Again, test results varied between the different tests. For EGA, all 3 pair-wise test comparisons lacked agreement. For LB, agreement between tests ranged from poor to fair. Differences in test methodology and antigens used, cut-off settings between the laboratories and false positive or false negative results are likely the cause for the different assessment of the same sample as seropositive or seronegative. In the third study, the goal was to describe potential risk factors for exposure of horses in Canada to EGA and LB. Management factors in horses that tested seropositive or seronegative for EGA or LB, respectively, in the previous studies were evaluated. Horse owners were surveyed with regard to their horses’ signalment, timing of pasture housing, and province of residence, travel history, tick infestation history, history of Lyme vaccination and history of previously diagnosed tick-borne disease. Response rate (11.5%) and the number of seropositive horses available for evaluation were low, which precluded statistical analysis. The majority of seropositive horses resided in SK, was pastured in the fall, did not have a recent travel history and had not had visible tick infestation. These observations supported exposure of horses to tick-borne diseases within Canada. Potential risk factors require further investigation. As information about tick infestation in horses is scarce in general, a passive surveillance study of horse ticks in SK was conducted in 2012 and 2013. A total of 833 ticks from over 86 horses were received. All ticks were Dermacentor species, i.e. D. albipictus, D. andersoni and D. variabilis. D. albipictus ticks were mostly received in February and March, D. andersoni mainly in April and June and D. variabilis mostly in May and June. Geographic distribution of the species in SK was similar to that previously reported based on active and passive surveillance. No Ixodes species were received.

Studies on the vector ecology of the American dog tick, Dermacentor variabilis, (Say) (Acari: Ixodidae) in Manitoba, Canada

Yunik, Matthew 02 September 2014 (has links)
The American dog tick, Dermacentor variabilis, is an obligate blood feeding ectoparasite. This tick is a known vector of pathogens that affect the health of wildlife, humans, and livestock and is abundant in Manitoba. The etiological agent of bovine anaplasmosis, Anaplasma marginale, along with members of the spotted fever group rickettsiae are bacteria that are transmitted by this tick. I examined the distribution of these bacteria in Manitoba’s tick population using molecular techniques. During the eradication of an outbreak of bovine anaplasmosis in Manitoba, there was no evidence the bacterium had spilled over into the tick population. Rickettsia montanensis was detected with a mean prevalence of infection of 9.8% (range, 0.00 - 21.74% among localities) in 8 of 10 localities within the province. It was also determined that 19.9% (SE ±1.14) of adult questing ticks collected in one vector season overwintered through to the next spring.

Application of real-time quantitative RT-PCR for improving the diagnosis, treatment, and control of bovine Anaplasmosis

Reinbold, James Brandon January 1900 (has links)
Doctor of Philosophy / Department of Diagnostic Medicine/Pathobiology / Johann F. Coetzee / The Office International des Epizooties (OIE) Animal Health Code categorizes bovine anaplasmosis as a notifiable disease. Many species of the genus Anaplasma cause anaplasmosis. Co-infections with two or more Anaplasma spp. occur in cattle. A competitive ELISA is regarded as a reliable test for identifying A. marginale-infected cattle. However, cross-reactivity among related Anaplasma spp. has been reported when using cELISA. In the absence of effective treatment strategies and vaccine availability, anaplasmosis control strategies are primarily focused on disease identification and prevention and development of chemosterilization strategies. Four studies were completed to improve the diagnosis, treatment, and control of bovine anaplasmosis. In the first study, a real-time qRT-PCR was developed to detect as few as 100 copies of 16S rRNA of both A. marginale and A. phagocytophilum in the same reaction. This detection limit was equitable to the minimum infective unit of one A. marginale bacterium. In the second study, qRT-PCR results determined needle-free injection was superior to needle injection for controlling iatrogenic transmission of A. marginale in cattle. The qRT-PCR demonstrated 100% sensitivity by 21 days post-infection and 21 days prior to 100% sensitivity with cELISA. The third study determined the pharmacokinetic parameters of chlortetracycline in group fed, ruminating Holstein steers: volume of distribution (40.9 L⁄kg); rate constant (0.0478 h-1); dose-normalized area under the curve (0.29 h•µg⁄L); clearance (1.8 L⁄kg⁄h); elimination half-life (16.2 h); maximum concentration/dose (4.5 ng⁄mL); and time of maximum concentration (23.3 h). Dose linearity was confirmed for oral chlortetracycline dosages of 4.4, 11, and 22 mg/kg/day. The final study established an in vivo pharmacokinetic-pharmacodynamic relationship between chlortetracycline and anaplasmosis carrier clearance in bovine plasma (85.3 ng/mL). The qRT-PCR confirmed chemosterilization of all oral chlortetracycline-treated cattle within 49 days of treatment. Furthermore, qRT-PCR was an effective alternative to the subinoculation of splenectomized cattle for accurate and precise disease classification. The diagnosis, treatment, and control of anaplasmosis were enhanced through the application of qRT-PCR. Further studies are necessary for determining the mechanism of action between chlortetracycline binding to the 30S ribosome of A. marginale and carrier clearance.

Diversidade genética de Anaplasma marginale em bovinos amostrados em Itú, estado de São Paulo /

Garcia, Amanda Barbosa. January 2020 (has links)
Orientador: Rosangela Zacarias Machado / Resumo: Anaplasma marginale é uma bactéria, Gram negativa, intracelular obrigatória parasita de eritrócitos e o principal agente da Anaplasmose bovina. Esta doença causa anemia severa, provocando a redução do ganho de peso e da produção de leite e gerando grandes perdas econômicas na pecuária mundial. A diversidade genética desta bactéria vem sendo caracterizada com base na sequência das proteínas de superfície (MSPs), principalmente, na proteína MSP1α, sendo possível identificar as diferentes estirpes geográficas de acordo com as diferenças nas sequências de aminoácidos. O presente estudo teve como objetivo investigar a diversidade genética de A. marginale em bovinos de corte da raça Angus naturalmente infectados durante um surto da enfermidade. Vinte bovinos, com idades entre 6 e 9 meses, oriundos de uma fazenda no município de Itú, estado de São Paulo foram acompanhados por quatro meses e quatro colheitas de sangue foram realizadas. Amostras de soro foram submetidas à Ensaio Imunoenzimático Indireto (iELISA) para detecção de anticorpos IgG anti-A. marginale. As oitenta amostras de sangue total obtidas, foram submetidas à extração de DNA, PCR em tempo real quantitativa (qPCR) para o gene msp1β, semi-nested PCR (snPCR) para o gene msp1α, clonagem do fragmento alvo e sequenciamento pelo método de Sanger. As sequências obtidas foram submetidas à analises de diversidade genética pelo software RepeatAnalyzer. O ensaio Imunoenzimático Indireto (iELISA), utilizando Ag total, revelou baixa... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Anaplasma marginale is a Gram-negative, obligatory intracellular erythrocyte parasite and the main agent of bovine Anaplasmosis. This disease causes severe anemia, causing a reduction in weight gain and milk production and generating major economic losses in livestock worldwide. The genetic diversity of this bacterium has been characterized based on the sequence of surface proteins (MSPs), mainly in the protein MSP1α, making it possible to identify the different geographical strains according to the differences in the amino acid sequences. The present study aimed to investigate the genetic diversity of A. marginale in Angus beef cattle naturally infected during an outbreak of the disease. Twenty cattle, aged 6 to 9 months, from a farm in the city of Itú, state of São Paulo, were followed for four months and four blood samples were taken. Serum samples were subjected to the Indirect Immunoenzymatic Assay (iELISA) to detect antibodies IgG anti-A. marginale. The eighty whole blood samples obtained were subjected to DNA extraction, quantitative real-time PCR (qPCR) for the msp1β gene, semi-nested PCR (snPCR) for the msp1α gene, cloning of the target fragment and sequencing by the Sanger method. The obtained sequences were subjected to genetic diversity analysis using the RepeatAnalyzer software. The Indirect Immunoenzymatic assay (iELISA) revealed low seroprevalence in the sampled animals despite 100% positivity in the qPCR, with quantification between 103 and 107 number of DNA c... (Complete abstract click electronic access below) / Mestre

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