Thesis (MSc (Veterinary Science)--University of Pretoria, 2007. / Includes bibliographical references.

Thesis (MSc (Production Animal Studies)--University of Pretoria, 2007. / Includes bibliographical references.

Thesis (Ph. D.) -- University of Texas Southwestern Medical Center at Dallas, 2005. / Vita. Bibliography: 284-323.

Thesis (Ph. D.)--California Institute of Technology, 1943. / No collective t.p.; titles transcribed from individual title pages. Includes bibliographical references.

Our study was focused on the effect of tick-borne encephalitis virus infection on global gene expression in two human neural cell lines (neuroblastoma and glioblastoma). Changes of gene expression were determined using microarray approach. We identified several genes with up-or down-regulated expression in neural cells following the infection. The changes in expression of some of them were similar in both cell lines,other exhibited different pattern.

Cattle ticks and tick-borne infections (TBIs) undermine cattle health and productivity in the whole of sub-Saharan Africa (SSA) including Nigeria. In this West African country, two thirds of the cattle population are reared in the central-northern regions, kept under the traditional pastoral husbandry of Fulani herders. Under the Fulanis’ management, cattle are grazed extensively, being exposed to infestation by several tick genera (i.e. Amblyomma, Hyalomma, and Rhipicephalus spp., sub-genus Boophilus spp. included), vectors of the causative agents of the most important bovine TBIs in West Africa: anaplasmosis, babesiosis and ehrlichiosis (cowdriosis). Nevertheless, the Fulani pastoralists do not usually employ chemicals to control ticks in their cattle, merely relying on traditional methods (i.e. manual removal of the most conspicuous specimens). This approach, however, does not prevent cattle from being re-infested, leaving the animals challenged by a broad variety of other tick species, most of which are vectors of economically relevant TBIs. Knowledge of tick and TBIs occurrence is an essential pre-requisite to assist field diagnosis and devising effective control strategies for a given area. Existing information on tick infestation of cattle in Nigeria is rather out-dated, mostly derived from studies carried out in the south of the country. Similarly, all studies published to date on cattle TBIs in the country do not include any molecular analysis, being based instead on cytological and/or serological diagnostics. Therefore, the aim of the present thesis was to assess the presence of cattle ticks and TBIs occurring in an area of Central Nigeria (i.e. Plateau State). This is a densely populated area with traditionally managed cattle, where no acarides have historically been employed on livestock. The work undertaken herein firstly reviews the information available to date on ticks and TBIs known to be endemic in Nigerian cattle, identifying gaps present in the existing knowledge, leading to the rationale of this study. An initial survey was conducted documenting the tick species infesting cattle in Central Nigeria, in order to assess the infestation rate of surveyed animals at the time of the year when the tick load on the host is known to be most abundant (i.e. the wet season). The survey provided novel information on tick populations in cattle in Nigeria disclosing the presence of a broad variety of species, most of which are vectors of hazardous TBIs. In order to conduct a molecular diagnosis of the TBIs within the study area, a novel methodology was developed (i.e. reverse line blotting, RLB). The application of this approach was based on a thorough review of its application to the diagnosis of TBIs worldwide as well as in SSA. The optimisation of the RLB at the University of Edinburgh to enable the detection of a broad-spectrum of TBIs in Nigeria, caused by an array of five genera of microorganisms (i.e. Ehrlichia and Anaplasma, Theileria and Babesia, Rickettsia spp.) is presented. The assessment of the analytical sensitivity of this technique for the detection of Anaplasma marginale, a highly endemic tick-borne pathogen in SSA, demonstrated a detection threshold of ≥ 7 infected cells (keeping the limit of a natural infection). The occurrence of TBIs in cattle in the study area was assessed during a large-scale epidemiological survey through the application of the validated RLB. This study disclosed the occurrence of a high prevalence of several bovine TBIs in Central Nigeria, some of which are of great veterinary and zoonotic concern. The RLB enabled the detection of carrier status as well as of numerous multiple infections (69.5%, 95% CI: 65.5–73.6%). Based on the findings presented, endemic stability for highly prevalent haemoparasites (i.e. Theileria mutans, Theileria velifera, Theileria taurotragi, Anaplasma marginale, Ehrlichia species Omatjenne) is postulated, whereas a more instable epidemiological scenario is hypothesized for other microorganisms (i.e. Anaplasma centrale and Babesia bovis), which might be connected with outbreaks of clinically apparent disease, sporadically seen in the study area. The effect of a monthly tsetse-borne trypanosomiasis-focused control programme (based on the application 0.005% deltamethrin spray formulation, applied only to the lower quarters of cattle) on the kinetics of bovine TBIs was assessed at the village level. Longitudinal monitoring of control and treated cattle was conducted over the period of eleven months. Results generated provide input to the improvement of future control strategies to be rolled out across SSA, aiming to achieve an integrated control of both trypanosomiasis and TBIs. The present thesis contributes to a better understanding of the epidemiology of bovine TBIs in Nigeria as well as in the rest of West Africa, using a highly sensitive tool of wide applicability. These findings will be shared with the local pastoralist communities to further promote effective yet sustainable, vector control, in tune with the traditional long-established practices.

Made available in DSpace on 2016-08-15T20:27:58Z (GMT). No. of bitstreams: 1 JosivaniaSP_TESE.pdf: 2216086 bytes, checksum: 4328c3795e67888b55db8e1be380a936 (MD5) Previous issue date: 2015-11-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Small wild mammals, including rodents and marsupials, have ecological and epidemiological importance for being prey and predators in ecological chains, hosts of ecto and endoparasites and pathogens reservoirs. In Northeast Brazil, only a few studies have evaluated the diversity of ectoparasites and their hosts in the Caatinga biome. This study aimed to identify the hosts and their ectoparasites, with morphometric analysis and chaetotaxy and to determine the rates of parasitic Prevalence, Abundance and Medium Intensity of ectoparasites collected from rodents and marsupials, proceeding from the Experimental Station Rafael Fernandes, Rio Grande do Norte, Brazil, at the Universidade Federal Rural do Semi-Árido (UFERSA). The animals were captured between January 2014 and February 2015, in a fragment of 26 hectares, divided into six equally spaced transects (20m). Tomahawk and Sherman traps were distributed in six consecutive nights of each month and in 100 capture stations. The captured animals were identified by morphology and submitted to ectoparasites collection. All the collected ectoparasites were classified based on morphometric characters, chaetotaxy and taxonomic keys, as well as DNA extraction, PCR and sequencing of the amplified products. 78 small mammals were captured, from which 69 were classified as Didelphimorphia order: Gracilinanus agilis (Burmeister, 1854) and Monodelphis domestica (Wagner, 1842); and nine Rodentia: Wiedomys Hershkovitz, 1959, Thrichomys Trouessart, 1880 and Rattus norvegicus Berkenhout, 1769. It was collected ectoparasites identified as: Amblyomma (Koch, 1844), Amblyomma parvum, Aragão 1908, Amblyomma auricularium (Conil, 1878), Ornithodoros mimon Kohls, Clifford e Jones 1969, Ornithodoros Kohls, Clifford e Jones 1837, Quadraseta Brennan, 1970, Eutrombicula Ewing, 1938, Metachiroecius Fain, 1996, Aeromychirus Fain, 1976, Amlistrophorus Fain, 1981, Radfordia Ewing, 1938, Listropsoralges aff. similis, Ornithonyssus pereirai (Fonseca, 1935), Tur lativentralis (Fonseca 1936), Polyplax spinulosa (Burmeister, 1839) and Eogyropus lenti lenti (Werneck 1936). As for the parasitic rates were noted that for the Ixodidae and Argasidae studied, M. domestica presented higher parasitism values for A. auricularium; G. agilis, O. mimon and Thrichomys sp., to A. parvum and A. auricularium. As for mites, the prevalence was the same in M. domestica and to all its studied Listrophoridae. Also for rodents, it was observerd the same prevalence rate for Laelapidae mites and Polyplacidae lice in the Thrichomys sp. All of those records of small mammals and ectoparasites shown are unprecedented to Mossoró, Rio Grande do Norte. This study supports evidences from the literature that ectoparasites use marsupials and wild rodents as hosts for immature stages. Justifies the importance of maintaining a legal reserve area in the Caatinga biome for preservation of these animals. In addition, this research increases knowledge about the occurrence of Acari, Phthiraptera and its ectoparasitic association with the wildlife in Northeast Brazil / Os pequenos mamíferos silvestres, dentre eles os roedores e marsupiais, apresentam importância ecológica e epidemiológica por serem presas e predadores nas cadeias ecológicas, hospedeiros de ecto e endoparasitos e reservatórios de agentes patogênicos. No Nordeste do Brasil, poucos estudos avaliaram a diversidade de ectoparasitos e seus hospedeiros no bioma Caatinga. Objetivou-se identificar os hospedeiros e seus ectoparasitos, realizar morfometria e quetotaxia e determinar os índices parasitários de Prevalência, Abundância e Intensidade Média dos ectoparasitos coletados de roedores e marsupiais, procedentes da Estação Experimental Rafael Fernandes da Universidade Federal Rural do Semi-Árido (UFERSA). Capturou-se animais de janeiro de 2014 a fevereiro de 2015, em um fragmento de 26 hectares da Estação, divididos em seis transectos equidistantes (20m). Foram distribuídas armadilhas Tomahawk e Sherman em seis noites consecutivas de cada mês e em cem estações de captura. Os animais capturados foram identificados pela morfologia e submetidos à coleta dos ectoparasitos. Estes foram classificados com base em caracteres morfométricos, quetotaxia e chaves taxonômicas, além de extração de DNA, PCR e sequenciamento dos produtos amplificados. Foram capturados 78 pequenos mamíferos, dos quais 69 foram classificados na ordem Didelphimorphia: Gracilinanus agilis (Burmeister, 1854) e Monodelphis domestica (Wagner, 1842); e nove Rodentia: Wiedomys Hershkovitz, 1959, Thrichomys Trouessart, 1880 e Rattus norvegicus Berkenhout, 1769. Coletou-se ectoparasitos identificados como: Amblyomma (Koch, 1844), Amblyomma parvum Aragão, 1908, Amblyomma auricularium (Conil, 1878), Ornithodoros mimon Kohls, Clifford e Jones, 1969, Ornithodoros Kohls, Clifford e Jones 1837, Quadraseta Brennan, 1970, Eutrombicula Ewing, 1938, Metachiroecius Fain, 1996, Aeromychirus Fain, 1976, Amlistrophorus Fain, 1981, Radfordia Ewing, 1938, Listropsoralges aff. similis, Ornithonyssus pereirai (Fonseca, 1935), Tur lativentralis (Fonseca 1936), Polyplax spinulosa (Burmeister, 1839) e Eogyropus lenti lenti Werneck 1936. Quanto aos índices parasitários, observou-se que para os Ixodidae e Argasidae estudados, M. domestica apresentou maiores valores de parasitismo para A. auricularium; G. agilis, para O. mimon e Thrichomys sp., para A. parvum e A. auricularium. Quanto aos ácaros, a prevalência foi igual em M. domestica e para todos os seus Listrophoridae estudados. Igualmente, para os roedores, observou-se mesmo valor de prevalência para os ácaros Laelapidae e para os piolhos Polyplacidae em Thrichomys sp. Todos os registros dos pequenos mamíferos e ectoparasitos apresentados são inéditos para Mossoró, Rio Grande do Norte. Este estudo corrobora evidências da literatura dos ectoparasitos utilizarem marsupiais e roedores silvestres como hospedeiros em fases imaturas. Justifica a importância da manutenção de uma área de reserva legal no bioma Caatinga para conservação destes animais. Em adição, a presente pesquisa aumenta o conhecimento sobre ocorrência de Acari, Phthiraptera e sua associação ectoparasitária de vida selvagem, no Nordeste do Brasil

Saliva of Ixodid ticks contains a whole array of pharmacologically active molecules with vasodilatory, antihemostatic, and immunomodulatory activities. This thesis focuses on two types of salivary proteins, serpins and cystatins, and their role in immunomodulation. These protease inhibitors are known to affect many biological functions. To better understand their role in tick saliva we examined their effect on dendritic cells and their ability to modulate the immune response after pathogen infection. As model pathogens, Borrelia spirochetes and tick-borne encephalitis virus were used.

In this study we examined the effect of the tick saliva from I. ricinus and the effect of recombinant protein IRS-2 from the saliva of I. ricinus on dendritic cells derived from the mice bone marrow. We studied their effect on the production of cytokines by dendritic cells after the stimulation by B. burgdorferi, their effect on the expression of genes, that participate in phagocytosis, and the impact of the tick saliva on phagocytosis of B. burgdorferi by dendritic cells.

This study is focused on changes in protein expression in a glioblastoma cell line during infection with tick-borne encephalitis virus. Newly synthesized proteins were distinguished from previously synthesized proteins using bioorthogonal chemistry (BONCAT method) to observe changes in protein synthesis. Labelled proteins were visualized using two-dimensional PAGE and western blotting followed by Click reaction on membrane. Differences in protein pattern between control and infected cells were observed.