Dissertations / Theses on the topic 'Mosquitoes as carriers of disease'
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Fenoff, Roy S. "A survey of Wyoming mosquitoes for vectors of dog heartworm." Laramie, Wyo. : University of Wyoming, 2007. http://proquest.umi.com/pqdweb?did=1317326331&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Leung, Lai-king. "Are health-education programmes effective in improving knowledge of and compliance with non-pharmacological measures against mosquito-borne disease?" Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40721073.
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Hugo, Riel Leon Eklund. "Evaluation of methodologies for determining the age structure and survivorship of Ochlerotatus vigilax and other medically important mosquito vector species in Australia /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18159.pdf.
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Hurst, Timothy Parker. "Evaluation of Australian native fish and lavicides for the integrated control of freshwater mosquito vectors /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18164.pdf.
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Modelski, Kimberly A. "Comparison of climatic conditions and mosquito abundances in New Castle County, Delaware." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 3.25 Mb., 229 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:1435830.
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Schmeisser, Glen A. "Location of the insect binding specificity domain of the bacillus thuringiensis subsp. israelensis 128 kDa toxin." Virtual Press, 1994. http://liblink.bsu.edu/uhtbin/catkey/897503.
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The ultimate goal of this research was to perform a domain exchange between a computer identified insect specificity region of the mosquito larvicidal protein Cry IVB and a previously identified domain in a related protein toxin which targets lepidopteran insect larvae. If the insect specificity domain has been correctly identified, an exchange of DNA in this manner transfers the toxicity of one peptide to another by an exchange of the insect specificity domains. New, chimeric peptides may be designed which will target a larger spectrum of insect larvae.In previous research a domain exchange was performed between the two genes carried on plasmid vectors in E. coli and low levels of toxicity to mosquito larvae were observed. Initial efforts of this research attempted to identify these recombinants. However, stability was not achieved by sequential colony screens. Furthermore, a recently published three-dimensional structural model for all the B. thuringiensis crystalline toxins became available and it was quickly determined that the first exchanges excluded most of the f3-sheet domain that is responsible for insect cell receptor binding, the feature that gives the toxins their specificity. Therefore, it was decided that a larger, more inclusive region of Cry IVB DNA must be exchanged between the two toxins.Extensive computer analyses of the Cry IVB sequence and retroactive comparison of these sequences to the three-dimensional model yielded a fragment of DNA that encoded more than 60% of the putative insect specificity domain. Oligonucleotide primers were subsequently designed to flank this region so that the polymerase chain reaction could be employed to amplify the region. Additionally, the primers were engineered to contain terminal restriction endonuclease sites to ease in the exchange of the domain encoding region into Cry IA(c). The region of Cry IVB DNA flanked by the oligonucleotide primers was successfully amplified by the PCR and cloned into the plasmid vector pUC 19 as a reservoir for a future domain exchange.Department of Biology
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Robinson, Mary J. "Cloning a mosquitocidal fragment of Bacillus thuringiensis subsp. israelensis and location of the insect binding specificity domain of the 130 kDa toxin gene." Virtual Press, 1991. http://liblink.bsu.edu/uhtbin/catkey/774740.
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Various strains of Bacillus thuringiensis Mt.) produce crystalline endotoxins specific for larvae of different insect classes. Two strains, B.t. subspp. israelensis and kurstaki produce similar 130 kDa toxins encoded by the CryIVB gene (toxic to Diptera) and the CryIA gene (toxic to Lepidoptera), respectively. The N-terminal region of the CryIVB gene was cloned into the Escherichia coli expression vector pKX223-3. A mosquitocidal transformant was obtained as determined by mosquito bioassays. The gene fragment, if stable, can be cloned into cyanobacteria to achieve biological control of mosquito-borne diseases. A second goal was to identify the binding specificity domain of the CryIVB gene which encodes the portion of the protein toxin that binds the insect midgut causing cell lysis and death. Two potential insect binding specificity domains identified by computer analyses were switched with a known binding specificity region of the CryIA gene. The polymerase chain reaction was utilized to obtain gene fragments of the CryIVB gene which replaced the CryIA gene binding specificity domain. The resulting recombinant clones carrying the CryIA gene containing the .000nd proposed insect binding specificity domain of the CryIVB gene were fotsd to be mosquitocidal.Department of Biology
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Russell, Brenda Lurline. "Factors preventing the metabolism of carbohydrates by Bacillus sphaericus 2362." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/45179.
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Bacillus sphaericus 2362 is a mosquito pathogenic bacterium. Its greatest industrial potential may be in developing countries where mosquitos are often vectors for diseases. This strain is typical of the species in that it is unable to grow using carbohydrates as a sole source of carbon. The goal of this research was to determine the metabolic deficiency(s) responsible for the inability of this organism to grow on carbohydrates. Compounds that supported light growth of this organism on an agar-solidified, defined medium included acetate, glycerol, and gluconate. Growth in a defined liquid medium with acetate as the source of carbon was much slower than growth in a complex, protein-based broth. B. sphaericus grew poorly in a defined, liquid medium with glycerol or gluconate as the carbon source. Activity of enzymes responsible for the initiation of metabolism of some substrates was not detected in cell extracts. These enzymes were: glucokinase, hexokinase, beta-galactosidase, and amylase. Growth of this bacterium on glycerol as a sole source of carbon implies the presence of the enzymes from the lower half of the Embden-Meyerhof-Parnas (EMP) pathway. Two enzymes of the upper half of the EMF pathway, phosphofructokinase and fructose diphosphate aldolase, were undetected in cell extracts. In addition, glucose dehydrogenase activity was not detected. The inability to form glucose-6-phosphate from glucose prevents the catabolism of this and related substrates via the Entner-Doudoroff (ED), hexose monophosphate (HMP), and EMF pathways. Oxygen uptake studies indicated that B. sphaericus oxidized gluconate slightly but only when the cells were grown in a complex, protein-based medium supplemented with gluconate. Although gluconokinase activity was detected in cell extracts, no activity was detected for the key enzymes of the ED (phosphogluconate dehydratase/KDPG aldolase), or HMP (6-phosphogluconate dehydrogenase) pathway. It is unclear how B. sphaericus grows on a defined medium with gluconate as the sole source of carbon. In addition to enzymatic deficiencies, whole cells were unable to accumulate [¹⁴C]glucose or [¹⁴C]sucrose.Master of Science
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梁麗琼 and Lai-king Leung. "Are health-education programmes effective in improving knowledge of and compliance with non-pharmacological measures against mosquito-borne disease?" Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40721073.
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Silva, Gilcia Aparecida de Carvalho. "Estudos sobre a competencia vetorial de populações de mosquitos (Diptera, Culiciade) da região metropolitana do Recife, Pernambuco e de Campinas, São Paulo, Brasil, para Dirofilaria immitis (Nematoda, Onchocercidae)." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314470.
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Orientador: Carlos Fernando Salgueirosa de AndradeTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-05T12:43:31Z (GMT). No. of bitstreams: 1 Silva_GilciaAparecidadeCarvalho_D.pdf: 2420692 bytes, checksum: 389c3c5a059387fa98ae9be752bd8f0e (MD5) Previous issue date: 2006
Resumo: Mosquitos pertencentes aos gêneros Culex, Aedes, Anopheles, Mansonia, Psorophora e Coquillettidia são susceptíveis à infecção por Dirofilaria immitis (Leidy, 1856), podendo transmitir o filarídeo aos cães e gatos. Os vetores de D. immitis no Brasil são conhecidos apenas nos Estados do Rio de Janeiro e do Maranhão, fazendo-se necessária a investigação da susceptibilidade e da competência vetorial de espécies existentes nos demais Estados brasileiros. O presente trabalho teve por finalidade verificar a freqüência de infecção por D. immitis em cães domiciliados na Região Metropolitana do Recife, bem como avaliar a susceptibilidade e a competência vetorial de Culex quinquefasciatus Say, 1823, Aedes aegypti Linnaeus, 1762 e Ae. albopictus Skuse, 1894 provenientes de área endêmica e não endêmica para a transmissão desse filarídeo, em condições experimentais. A resposta imune humoral (melanização) apresentada pelos mosquitos expostos à infecção também foi avaliada. Para a realização do inquérito epidemiológico, 816 amostras de sangue canino foram coletadas nas áreas costeiras da Região Metropolitana do Recife e no município de Bezerros, agreste do Estado de Pernambuco. As amostras sangüíneas foram analisadas por meio de teste parasitológico para a pesquisa de microfilárias de D. immitis, utilizando-se o método modificado de Knott. Para a avaliação da competência vetorial Cx. Quinquefasciatus população RECIFE, Ae. aegypti populações RECIFE, UNICAMP e linhagem ROCKFELLER e Ae. albopictus população RECIFE foram criados em insetário sob condições controladas (28 '+ ou ¿' '1 GRAU C¿ e 80 ' + ou ¿' 5% de umidade relativa do ar). As fêmeas das espécies estudadas foram alimentadas com sangue canino contendo diferentes densidades de microfilárias de D. immitis, por meio de membrana artificial confeccionada com pele fresca de animal. Para Cx. quinquefasciatus, que é uma espécie ornitofílica, foi utilizada pele de codorna, e para Ae. aegypti e Ae. albopictus a membrana artificial foi confeccionada com pele de rato. Os resultados obtidos no estudo mostraram freqüência de 3,61%, 7,89% e 7,69% de cães infectados na Ilha de Itamaracá, Igarassu e Recife, respectivamente. Após as infecções experimentais, observou-se que a mortalidade de Cx. quinquefasciatus não foi influenciada pela exposição a diferentes densidades de microfilárias de D. immitis (F = 0,0615, p>0,05) e os índices encontrados variaram de 8,9% a 36,25%. Os índices de eficiência vetorial (IEV) apresentados por Cx. quinquefasciatus população RECIFE variaram de 7,8% a 56,5%. Em relação à razão de infecção, o maior índice foi encontrado no grupo de fêmeas expostas a densidade de 1913 microfilárias/ml, entretanto, não foi influenciado pela taxa de ingurgitamento das fêmeas (F=3,2937, p>0,05). Por meio de melanização, Cx. quinquefasciatus população RECIFE, limitou a intensidade do parasitismo, promovendo o equilíbrio da relação parasito-hospedeiro e deste modo passando a ser um excelente vetor de D. immitis na Região Metropolitana do Recife. Dentre as espécies de Aedes estudadas, verificou-se que a população RECIFE de Ae. aegypti apresentou maior mortalidade (70,7%) ao final dos experimentos, apresentando diferença estatisticamente significante (p<0,01) em relação à linhagem ROCKFELLER, população UNICAMP e Ae. albopictus população RECIFE, que não diferiram entre si (p>0,05). Em relação ao índice de eficiência vetorial (IEV) foi detectado um índice de 7,4% para a linhagem ROCKFELLER e uma variação de 20,0% a 53,8% para as populações de Ae. aegypti e 25,2% para Ae. albopictus população RECIFE. O maior número de larvas de D. immitis infectantes na probóscide foi apresentado por Ae. albopictus população RECIFE, além de uma baixa mortalidade. Desta forma, esta população mostrou-se susceptível ao filarídeo e por apresentar baixa mortalidade, foi considerada como a melhor vetora. Ae. aegypti população RECIFE não apresentou reação de melanização e apresentou mortalidade acentuada, enquanto que Ae. aegypti população UNICAMP e linhagem ROCKFELLER mostraram-se refratárias à infecção por D. immitis
Abstract: Mosquitoes belong to the genus Culex, Aedes, Anopheles, Mansonia, Psorophora and Coquillettidia are susceptible to infection of Dirofilaria immitis (Leidy, 1856) and some of them serve as vectors heartworm disease in dogs and cats. Although the potential vectors of canine heartworm in Brazil have been recorded only in Rio de Janeiro and Maranhão State and no more date are available. The objective of this study was to verify the frequency of heartworm infection in dogs in metropolitan region of Recife and also identify under experimental conditions their ability of Culex quinquefasciatus Say, 1823, Aedes aegypti Linnaeus, 1762 and Ae. albopictus Skuse,1894 from enzootic and non enzootic areas to become infected with and transmit D. immitis. After the experimental infection of mosquitoes, the melanization response to larvae of D. immitis also was evaluated. The survey study were performed on a total of 816 dogs from costal areas of Metropolitan Region of Recife and Bezerros County, located in agreste area of Pernambuco State. Whole blood samples were collected from all animals and were examined for the presence of microfilariae of D. immitis by the modified Knott test. To verify the vector competence of Cx. quinquefasciatus RECIFE population, Ae. aegypti RECIFE, UNICAMP populations and also ROCKFELLER strain and Ae. albopictus RECIFE population, the mosquitoes were reared under constant insectary conditions (28 '+ or ¿' '1 DEGREE C¿ and 80 '+ or ¿' 5% relative humidity). Females mosquitoes, were exposed to blood¿s dog with diferents density of D. immitis microfilariae by artificial feeding apparatus made by fresh animal skin. For this puporse, ornithophilic Cx. quinquefasciatus was feeding by skin quail menbrane, and for the Ae. aegypti and Ae. albopictus the artificial membrane was made by rat skin. The results of the survey study showed 3.61%, 7.89%, and 7.69% of heartworm infection frequency in dog from Itamaracá Island, Igarassu and the city of Recife respectively. The mortality of Cx. Quinquefasciatus RECIFE population observed in the vector competence study did not show influence of different density of microfilariae of D. immitis (F = 0.0615, p>0.05) and the mortality rate was 8.9% to 36.25%. The vector efficiency (VE) rates of Cx. quinquefasciatus RECIFE population were 7.8% to 56.5%. The higher infection rate was showed in females feeding with blood containing 1913 mf/ml, but no influence was observed in engorged females. The melanization response observed in Cx. quinquefasciatus was important for vector survival by limiting the number of larvae, acting as an important mechanism of parasitic-host interactions. The data indicate that the Cx. quinquefasciatus RECIFE population should is an excelent vector of D. immitis at metropolitan region of Recife. Significant difference (p<0.01) was observed in the mortality rates between the RECIFE population of Ae. aegypti, UNICAMP population, ROCKFELLER strain, and Ae. albopictus RECIFE population. Although no difference were observed between Ae. aegypti ROCKFELLER, UNICAMP and Ae. albopictus RECIFE population. The vector efficiency (VE) rates of Ae. aegypti and Ae. albopictus RECIFE population were 7.4% to 53.8% and 25.2% respectively. Not only the high number of infective third stage larvae of D. immitis in mouth of mosquitoes but also low mortality was observed in Ae. albopictus RECIFE population. This data showed that this specie is the best vector of heartworm infection in the study area. No melanization response was observed in Ae. Aegypti RECIFE population but high mortality was reported. The UNICAMP population and ROCKFELLER strain of Ae. aegypti were refractory to infection to D. immitis
Doutorado
Doutor em Parasitologia
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Lewis, Lynn Owens. "Surface proteins of the mosquito-pathogenic strains of Bacillus sphaericus." Diss., Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/77819.
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Weinstein, Philip. "Changing representations of mosquito borne disease risk in Reunion." University of Western Australia. European Languages and Studies Discipline Group. French Studies, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0174.
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[Truncated abstract] In March 2005, the Indian Ocean island of Reunion, a former colony and now overseas department of France, saw the first cases of what was to become a massive epidemic of the mosquito borne viral infection Chikungunya. More than 250,000 people, one third of the Island's population, were subject to high fevers, rash, and joint and muscle pains over the next 18 months, yet the public health authorities in metropolitan France were arguably slow to take the epidemic seriously. The research presented here explores attitudes underlying the management of the epidemic by examining both metropolitan and local representations of mosquito borne disease from historical, epidemiological and media perspectives. The research seeks to answer the general question Does colonial history continue to influence the representation and management of mosquito borne disease in Reunion? Three parallel approaches are taken to answering this question, using a common framework of tropicality (a Western discourse that exalts the temperate world over its tropical counterpart, and overlaps with colonialism and orientalism). ... Several factors are likely to have contributed to the persistence of tropicality in public health practice in Reunion: Othering as a universal phenomenon; the cost of administering interventions to combat tropical diseases in the remote environments of French overseas departments and territories; the denial of a serious public health risk as a cultural trait in Reunion; and the significant role of the colonies in forming and maintaining the French national identity. It has to be acknowledged that historically, tropicalism does appear to have played one positive role in the management of mosquito borne disease:
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Francis, Stephen Starko. "West Nile virus in Nevada : mosquito infection rates and weather /." abstract and full text PDF (free order & download UNR users only), 2006. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1440921.
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Thesis (M.S.)--University of Nevada, Reno, 2006."December, 2006." Includes bibliographical references (leaves 29-33). Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2006]. 1 microfilm reel ; 35 mm.
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Hambrick, Bethany Lynn. "Population Dynamics and Community Structure of Mosquitoes (Diptera: Culicidae) Recorded in Denton, Texas from 2005 to 2015." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1157552/.
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A population survey was conducted on the mosquito species recorded in Denton, Texas for the years of 2005 to 2015. Data used in this project were obtained from an ongoing, long-term surveillance program led by the City of Denton and conducted through the University of North Texas. Research focused on the population dynamics and community structure of mosquitoes collected within urban areas of Denton, Texas in relation to certain environmental variables. A total of 80,837 female mosquitoes were captured and represented 38 species found under the following genera: Aedes, Anopheles, Coquillettidia, Culex, Culiseta, Mansonia, Orthopodomyia, Psorophora, Toxorhynchites, and Uranotaenia. Culex quinquefasciatus was the most abundant species followed by Aedes vexans. Seasonal patterns of the most abundant species revealed high variability throughout the study. Container breeders were most abundant in August and those that breed in floodwaters were most abundant in the months of May and September. Samples were tested for arbovirus presence through the Texas Department of State Health Services in Austin, Texas and multiple pools tested positive for West Nile virus throughout the study. Stepwise multiple regression and Spearman's rank correlation analyses were performed to examine the relationship between the mosquito community and environmental variables. Data revealed that temperature, precipitation, and dew point were the most important variables influencing the mosquito population in the City of Denton.
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Neira, Oviedo Marco. "Arboviral infection in mosquito vectors : survey and pathogenesis studies /." View abstract, 2005. http://wwwlib.umi.com/dissertations/fullcit/3203335.
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Goodfellow, Angela Mary. "Malaria vectors in an irrigated and in a rain-fed division of southern Sri Lanka." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82243.
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Anopheles species composition and relative seasonal abundance were measured in an irrigated division (low historical malaria incidence) and in a rain-fed division (high historical malaria incidence) of southern Sri Lanka. Twelve species of anophelines were represented in adult and larval collections with Anopheles vagus Donitz being the most abundant. In cattle-baited net trap collections, Anopheles adults were significantly more abundant in the irrigated division than in the rain-fed division. In pyrethrum-spray sheet collections, cattle-baited but trap collections and larval collections, Anopheles abundance was significantly greater in the rain-fed division. Houses were of poorer construction in the rain-fed division, where pyrethrum-spray sheet collections consisted mainly of Anopheles subpictus Grassi (98%) and Anopheles culicifacies Giles (2%). Hut trap collections also consisted mainly of An. subpictus (88%) and An. culicifacies (7%). Net trap collections consisted mainly of An. vagus (43%) and Anopheles peditaeniatus Leicester (31%). Larval collections also consisted of An. peditaeniatus (24%) and An. vagus (21%). Weak associations were found between species abundance and environmental factors explored in this study (e.g., vegetation, water quality, sunlight exposure). The greater malaria risk in the rain-fed division is due in part to the occurrence of potential vectors in relatively higher numbers.
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Boyd, Ann Marie. "Interactions between common vertebrate hosts and the mosquito vectors of Ross River and Barmah Forest viruses in urban Brisbane, South East Queensland, Australia /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18059.pdf.
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Cruz, Danilo Esdras Rocha. "Fauna de mosquiteiros (Diptera: Culicidae) em fragmento de caatinga no Alto Sertão Sergipano." Pós-Graduação em Ecologia e Conservação, 2013. https://ri.ufs.br/handle/riufs/4415.
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The family Culicidae has great public health importance for being composed by haematophagous insects in majority, which can be vector of diseases for the human being and other vertebrates. The knowledge about culicideos fauna, besides of data about various species that compose the Caatinga biome, can also bring information about species that are vector of pathogens, providing important tools in case of eventual epidemic outbreak at the region. The Caatinga biome occupies around 55% of all northeast region, representing 11% of Brazil s surface, and holds the position of the less preserved biome of the country, relative to its total area. This work aimed to realize a mosquitoes fauna survey, as well as ecologic aspects analysis for adult species in two areas of Caatinga and immature in three semi permanent breeding grounds. The study was realized in the city of Poço Redondo, semi-arid of Sergipe, where the Unidade de Conservação Monumento Natural Grota do Angico is located under exclusive domain of Caatinga. Collects were made monthly in two areas of Caatinga, between 5 p.m. and 8 p.m. using the Shannon trap for adults, and in three breeding grounds with plastic dipper method for mosquito larvae collects. On ecologic aspects analysis were used the Shannon diversity index, Pielou s equitability, Berger-Parker dominance, Nonmetric multidimensional scaling (NMDS) for species composition. A number of 1788 specimens were collected on total among adults and immature, distributed on ten genus, Aedes, Aedomyia, Anopheles, Coquilettidia, Culex, Haemagogus, Mansonia, Ochlerotatus, Psorophora and Uranotaenia and 21 species. The adults resulted in 583 specimens, 268 from shrubby Caatinga and 315 from arboreal Caatinga, dominant species were Mansonia (Man) indubitans and Ochlerotatus (Och) scapularis,there was no difference between these areas on species composition or abundance, however, the arboreal Caatinga was richer in species. In relation to the immature, breeding sede captured the larger number of specimens (N=590), followed by breeding cancela (N=436) and the smaller value on breeding trilha (N=179). Species composition did not show difference between breedings, dominant species were Anopheles (Nys) albitarsis and Culex (Cx) chidesteri. The presence of mosquitoes species with vector importance, some of that capable to adapt on anthropic ambient, associated with lack of knowledge about Caatinga s mosquitoes suggests future studies to avoid epidemiologic outbreaks in the Unidade de conservação Monumento Natural Grota do Angico .A família Culicidae apresenta grande importância em saúde pública por ser composta de insetos em sua maioria hematófagos, os quais podem veicular diversas doenças para o homem e demais vertebrados. O conhecimento sobre a fauna de culicídeos, além de gerar informações sobre as espécies que compõem o bioma Caatinga, permite conhecer espécies vetoras de patógenos fornecendo importantes ferramentas em caso de eventuais surtos epidêmicos na região. O bioma Caatinga ocupa cerca 55% de toda a região Nordeste, representando 11% da superfície do Brasil, e detém a posição de bioma menos conservado em relação à área total. O presente trabalho objetivou realizar levantamento da fauna de mosquitos, bem como análise de aspectos ecológicos para as espécies de adultos em duas áreas de Caatinga e espécies de imaturos em três criadouros semipermanentes de solo. O estudo foi realizado no município de Poço Redondo, situado no alto sertão sergipano, na unidade de conservação Monumento Natural Grota do Angico, sob o domínio exclusivo de Caatinga. As coletas foram realizadas mensalmente em dois ambientes de Caatinga das 17 às 20 horas através de armadilha de Shannon para adultos, e em três criadouros de solo utilizando metodologia de concha para coleta de larvas. Para análise de aspectos ecológicos foram utilizados os índices de diversidade de Shannon, equitabilidade de Pielou, dominância de Berger-Parker e escalonamento multidimensional não métrico (NMDS) para composição de espécies. No total foram coletados 1788 espécimes entre adultos e imaturos, distribuídos em dez gêneros, Aedes, Aedomyia, Anopheles, Coquilettidia, Culex, Haemagogus, Mansonia, Ochlerotatus, Psorophora e Uranotaenia e 21 espécies. Os adultos somaram 583 exemplares, sendo 268 na Caatinga arbustiva e 315 na Caatinga arbórea, as espécies dominantes foram Mansonia (Man) indubitans e Ochlerotatus (Och) scapularis, a composição de espécies e a abundância não diferiram entre as áreas, no entanto a Caatinga arbórea apresentou maior riqueza de espécies. Em relação aos imaturos, no criadouro sede foi capturado maior número de espécimes (N=590), seguido do criadouro cancela (N= 436) e os menores valores no criadouro trilha (N= 179). A composição das espécies não variou entre as áreas, as espécies dominantes para imaturos foram Anopheles (Nys) albitarsis e Culex (Cx) chidesteri. A presença de espécies com importância vetorial, dentre elas algumas com capacidade de adaptação ao ambiente antropizado, aliada ao déficit de conhecimento sobre os mosquitos da Caatinga sugerem continuidade de estudos para evitar que quadros epidemiológicos possam se instalar na unidade de conservação Monumento Natural Grota do Angico.
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Jardine, Andrew. "The impact of dryland salinity on Ross River virus in south-western Australia : an ecosystem health perspective." University of Western Australia. School of Population Health, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0182.
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[Truncated abstract] A functional ecosystem is increasingly being recognised as a requirement for health and well being of resident human populations. Clearing of native vegetation for agriculture has left 1.047 million hectares of south-west Western Australia affected by a severe form of environmental degradation, dryland salinity, characterised by secondary soil salinisation and waterlogging. This area may expand by a further 1.7-3.4 million hectares if current trends continue. Ecosystems in saline affected regions display many of the classic characteristics of Ecosystem Distress Syndrome (EDS). One outcome of EDS that has not yet been investigated in relation to dryland salinity is adverse human health implications. This thesis focuses on one such potential adverse health outcome: increased incidence of Ross River virus (RRV), the most common mosquito-borne disease in Australia. Spatial analysis of RRV notifications did not reveal a significant association with dryland salinity. To overcome inherent limitations with notification data, serological RRV antibody prevalence was also investigated, and again no significant association with dryland salinity was detected. However, the spatial scale imposed limited the sensitivity of both studies. ... This thesis represents the first attempt to prospectively investigate the influence of secondary soil salinity on mosquito-borne disease by combining entomological, environmental and epidemiological data. The evidence collected indicates that RRV disease incidence is not currently a significant population health priority in areas affected by dryland salinity despite the dominant presence of Ae. camptorhynchus. Potential limiting factors include; local climatic impact on the seasonal mosquito population dynamics; vertebrate host distribution and feeding behaviour of Ae. camptorhynchus; and the scarce and uneven human population distribution across the region. However, the potential for increased disease risk in dryland salinity affected areas to become apparent in the future cannot be discounted, particularly in light of the increasing extent predicted to develop over coming decades before any benefits of amelioration strategies are observed. Finally, it is important to note that both dryland salinity and salinity induced by irrigation are important forms of environmental degradation in arid and semi-arid worldwide, with a total population of over 400 million people. Potential health risks will of course vary widely across different regions depending on a range of factors specific to the local region and the complex interactions between them. It is therefore not possible to make broad generalisations. The need is highlighted for similar research in other regions and it is contended that an ecosystem health framework provides the necessary basis for such investigations.
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Gouge, Dawn H., James R. Hagler, Shaku Nair, Kathleen Walker, Shujuan Li, Christopher S. Bibbs, Chris Sumner, and Kirk A. Smith. "Human Disease Causing Viruses Vectored by Mosquitoes." College of Agriculture, University of Arizona (Tucson, AZ), 2017. http://hdl.handle.net/10150/625572.
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7 p.There are a number of disease-causing viruses transmitted to people primarily through the bite of infected mosquitoes. Female mosquitoes take blood meals to produce eggs. A mosquito that bites an infected animal may pick up a virus within the blood meal. If the mosquito is the appropriate species, and conditions inside the insect and the surrounding environment are supportive, the virus reproduces within the mosquito. Later, the mosquito may pass the virus on to other animals (including humans) as they feed again.
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Nascimento, Ana Mércia Dias. "Atividade repelente e larvicida de Xylopia laevigata, X. frutescens (Annonaceae) e Lippia pedunculosa (Verbenaceae) sobre mosquitos Aedes aegypti (Diptera-Culicidae)." Pós-Graduação em Biologia Parasitária, 2014. https://ri.ufs.br/handle/riufs/3257.
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Dengue is an important arboviral disease transmitted to humans through the bite of female mosquito Aedes aegypti. As there is no vaccine available, the control of disease occurs, mainly, by the reduction of mosquito population and personal protection to prevent contact between hosts and vectors. Given the increasing process of chemical resistance to insecticides, natural products emerge as safer alternatives for integrated control of endemic diseases. The aim of this work was to evaluate the larvicidal and repellent activities of essentials oils extracted from Xylopia laevigata, Xylopia frutescens and Lippia pedunculosa and of their majority compounds, piperitenone oxide and r-limonene. The
larvicidal activity was investigated by exposure of third instar larvae to different concentrations of essentials oils. After 24 hours of exposition, larvae showing lack of mobility or inability to move to water s surface were considered as dead. The repellency effect was based on the suppression of mosquitoes landing on human skin. Essentials oils were diluted in ethanol and applied directly over the volunteer s skin. For each essential oil were performed 12 tests, in which oils concentrations ranged from 0.1 to 10%. The essential oil of L. pedunculosa and its major volatile compounds were shown to be toxic
for Ae. aegypti larvae, with CL50 lower than 60 ppm. In the other hand, plants of Xylopia genus just proved to be toxic to Ae. aegypti when in concentrations higher than 1000 ppm. This fact make their use in large-scale unfeasible. All plants tested provided some degree of protection against mosquitoes landing. However only the essential oil of L. pedunculosa and piperitenone oxide provided 100 % of protection against mosquito landings when tested in concentrations lower than 1%. Although its performamnce against dengue mosquitoes, the essential oil of L. pedunculosa shows toxicity the human skin. Therefore, further studies are required to get formulations which are able to provide longer time
protection.A dengue é uma importante arbovirose transmitida ao homem por meio da picada do mosquito fêmea Aedes aegypti. Como não há vacinas, o controle da transmissão da doença se dá, principalmente, com a redução da população de mosquitos e a adoção de medidas de proteção individual que impeçam o contato entre hospedeiros e vetores. Diante do agravamento do processo de resistência aos inseticidas químicos, os produtos de origem vegetal se apresentam como alternativas mais seguras para o controle integrado de doenças vetoriais endêmicas. O objetivo deste trabalho foi avaliar a atividade repelente e larvicida dos óleos essenciais extraídos das plantas Xylopia laevigta, Xylopia frutescens e Lippia pedunculosa, bem como seus constituintes voláteis, óxido de piperitenona e r-limoneno sobre mosquitos Ae. aegypti. A atividade larvicida foi investigada a partir da exposição de larvas de terceiro estádio às diferentes concentrações dos óleos essenciais e componentes voláteis. Após 24 horas de exposição foram contabilizadas as larvas mortas, considerando mortalidade a ausência de mobilidade ou incapacidade da larva em se mover até a superfície da água. A ação repelente foi observada a partir da supressão de pousos dos mosquitos sobre a pele humana. Os óleos essenciais e compostos químicos foram diluídos em etanol e aplicados diretamente sobre a pele dos voluntários. Para cada produto foram realizados doze testes, nos quais as concentrações variavam de 0,1 à 10%. Tanto o óleo essencial obtido a partir da L. pedunculosa quanto os seus principais compostos voláteis mostraram-se tóxicos para larvas de Ae. aegypti, apresentando CL50 inferior à 60 ppm. Em contrapartida, as plantas do gênero Xylopia apenas mostraram-se tóxicas para as larvas quando em concentrações superiores à 1000 ppm, fato que inviabiliza a sua utilização em larga escala. No que diz respeito à ação repelente, todos os produtos avaliados forneceram algum grau de proteção contra pouso de mosquitos adultos sobre a pele humana. Entretanto, apenas o óleo essencial da L. pedunculosa e o óxido de piperitenona foram capazes de fornecer 100% de proteção, quando testados em concentrações inferiores a 1%. Apesar de eficaz na repelência contra o mosquito transmissor da dengue, o óleo essencial da L. pedunculosa apresentou toxidade sobre a pele humana. Portanto, mais estudos fazem-se necessários a fim de que sejam elaboradas formulações de uso tópico capazes de veicular adequadamente os constituintes químicos dos óleos por um prolongado período de tempo.
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Rasgon, Jason Laurence. "Wolbachia infection dynamics and applied vector-borne disease control in mosquitoes /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
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STRAZZELLA, ARIANNA. "MOLECULAR MECHANISMS OF RENAL DISEASE IN CARRIERS OF LCAT GENE MUTATIONS." Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/884566.
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BACKGROUND: Familial LCAT deficiency (FLD) is a rare genetic disease characterized by the complete inactivity of LCAT, the only human enzyme able to esterify cholesterol in plasma; as a consequence, carriers’ lipid and lipoprotein profile presents low HDL-C concentration, the accumulation of small and discoidal preβ-HDL particles and LpX. Renal disease is the major cause of morbidity and mortality in FLD carriers but the molecular mechanisms of kidney failure are poorly understood. Currently, there are no effective therapies available for these patients and the use of synthetic HDL is under investigation. Furthermore, a condition of acquired LCAT deficiency can characterize common pathologies, such as chronic kidney disease.
AIM: Aim of this project was to analyze the unknown aspects of renal disease in LCAT deficiency, including the molecular mechanisms behind the onset of renal damage and the characterization of the lipid alterations responsible for this condition, the study of potential effective therapeutic strategies and the evaluation of the impact of non-genetic LCAT reduction on renal disease development in general population,
RESULTS: The characterization of LCAT deficient carriers’ HDL by lipidomics analyses identified alterations in phospholipids and sphingolipids classes, including an accumulation of phosphatidylethanolamine, dihydroceramides and ceramides, as well as a depletion in phosphatidylethanolamine plasmalogen. Moreover, carriers’ HDL were enriched in short and saturated fatty acids and depleted in long chain polyunsaturated fatty acids. These alterations could potentially trigger some nephrotoxic mechanisms identified through the in vitro studies in podocytes and tubular cells, such as the increased oxidative stress and apoptosis induced by FLD carriers’ lipoprotein alterations.
The metabolism and effect of a synthetic HDL, CER-001, was evaluated in murine model of LCAT deficiency; results collected in this part showed an amelioration of lipid profile after CER-001 treatment, with an increase of HDL-C and a reduction of triglycerides. Even more important, the molecule ameliorated renal function, reducing the albuminuria and restoring nestin and nephrin expression, by removing cholesterol accumulated in the kidney. The results set the basis to test the molecule in one FLD carrier, in which an analogous mechanism was identified by in vitro studies.
The results collected in the last part of the work highlighted the predictive values of non-genetic reduction in LCAT concentration on the renal disease progression in general population. The development of renal damage could be partially explained by the pro-oxidant effect mediated by the sera from subjects with low LCAT in renal cells; the involvement of the enzyme was demonstrated through the restoration of the antioxidant propriety induced by in vitro incubation of serum with rhLCAT.
CONCLUSION: Results collected within this project provided a deeper knowledge of the alterations in HDL lipid composition and the consequent nephrotoxic mechanisms in LCAT deficiency. Moreover, treatment with CER-001 demonstrated a beneficial effect on the kidney disease in LCAT deficient mice, supporting the testing of the formulation in FLD carriers. Finally, the evaluation of the relationship between low LCAT levels and progression of renal disease revealed that LCAT concentration can predict renal kidney injury in general population.
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Alves, R. O. N. "Avian malaria associations with British mosquitoes." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:dea2e4b0-f4d8-4fae-9209-fa02d083192c.
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Avian malaria (Plasmodium spp.) is a popular model system to study the ecology and evolution of parasite-host-vector interactions in the wild. These studies have historically focused mostly on the avian hosts and the malaria parasites. Knowledge regarding the role of vectors is essential to our understanding of these wild systems, but has only very recently started to accumulate. This thesis aimed to contribute to this field by assessing mosquito-malaria-host associations for British mosquitoes and the role of mosquito ecology in shaping these parasite systems in a British woodland study site, using molecular, field ecology and statistical modelling methodologies. From the 12 mosquito species or species groups found, I showed that the Cx.pipiens/torrentium mosquito group is likely to have a major role in avian malaria transmission in Great Britain, while Cs. annulata may be transmitting P. circumflexum. I also demonstrated a positive spatial association between mosquito density per host and avian malaria prevalence, in accordance with theoretical expectations for malaria transmission. Findings here provide evidence that avian malaria transmission in British woodlands is limited mainly to June-August, being preceded by relapse of previous infections or, alternatively, by maintenance of chronic blood parasitaemia through the colder months; this agrees with theoretical expectations and findings elsewhere for temperate climates. This thesis also described local-scale spatial heterogeneity and seasonal variation in adult mosquito abundance within a British woodland where avian malaria is endemic, with differing patterns found between species or species groups. Spatially, variation in adult mosquito abundance was associated with microclimatic and landscape variables such as distances to mosquito breeding sites, microclimate and canopy height; seasonally, variation in mosquito abundance was associated with temperature and rainfall, alongside calendar date. The heterogeneity in mosquito parameters and associations with environmental variables found at a site where avian malaria is endemic highlights the need to anticipate such complexity when trying to understand Plasmodium transmission. By doing so, we further extend the potential of these parasite systems to improve our knowledge regarding the ecology and evolution of parasite-host-vector associations.
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Peery, Ashley Nicole. "Chromosomal Evolution of Malaria Vectors." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/71698.
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International malaria control initiatives such as the Roll Back Malaria Initiative (RBM) and the Medicines for Malaria Venture (MMV) mobilize resources and spur research aimed at vector control as well as the treatment and eventual eradication of the disease. These efforts have managed to reduce incidence of malaria by an estimated 37% worldwide since 2000. However, despite the promising success of control efforts such as these, the World Health Organization reports a staggering 438,000 deaths from malaria in 2015. The continuing high death toll of malaria as well as emerging insecticide and antimalarial drug resistance suggests that while encouraging, success in reducing malaria incidence may be tenuous. Current vector control strategies are often complicated by ecological and behavioral heterogeneity of vector mosquito populations. As an additional obstruction, mosquito genomes are highly plastic as evidenced by the wealth or chromosomal inversions that have occurred in this genus. Chromosomal inversions have been correlated with differences in adaptation to aridity, insecticide resistance, and differences in resting behavior. However, a good understanding of the molecular mechanisms for inversion generation is still lacking. One possible contributor to inversion formation in Anopheles mosquitoes includes repetitive DNA such as transposable elements (TEs), tandem repeats (TRs) and inverted repeats (IRs). This dissertation provides physical maps for two important malaria vectors, An. stephensi and An. albimanus (Ch.2 and Ch. 3) and then applies those maps to the identification of inversion breakpoints in malaria mosquitoes. Repeat content of each chromosomal arm and the molecular characterization of lineage specific breakpoints is also investigated (Ch. 2 and Ch.4). Our study reveals differences in patterns of chromosomal evolution of Anopheles mosquitoes vs. Drosophila. First, mosquito chromosomes tend to shuffle as intact elements via whole arm translocations and do not under fissions or fusions as seen in fruitflies. Second, the mosquito sex chromosome is changing at a much higher rate relative to the autosomes in malaria mosquitoes than in fruit flies. Third, our molecular characterization of inversion breakpoints indicates that TEs and TRs may participate in inversion genesis in an arm specific manner.Ph. D.
Malaria is a complex and devastating disease vectored by the bite of a female Anopheles mosquito. This disease claimed an estimated 438,000 lives in 2015. The mobilization of funding and resources as part of global malaria eradication initiatives have reduced the global incidence of malaria by 37% in the last 15 years. Deaths from malaria are also 60% lower vs. the year 2000. These promising gains are threatened by the ability of Anopheles mosquitoes to adapt in the face of malaria control efforts. Anopheles mosquito chromosomes are known to be highly plastic, as evidenced by numerous chromosomal inversions. Recent years have seen increases in insecticide resistance, and behavioral change in mosquito populations that allow them to avoid insecticides and remain prolific vectors of disease. This ability of mosquito vectors to adapt threatens to unravel recent progress towards a malaria free world. The projects presented in this dissertation explore mechanisms of chromosomal evolution, specifically the potential role of repetitive DNA in the generation of chromosomal inversions. The exploration of chromosomal inversions was facilitated by the creation of physical maps for Anopheles species. Prominent malaria vectors An. stephensi andAn. albimanus were physically mapped in Chapter 2 and Chapter 3 respectively. In chapter 1 and chapter 3 physical maps are utilized for the identification of chromosomal inversion breakpoints using 2 species (Ch. 2) and many species (Ch. 4). Repeat content was quantified along each chromosomal arm (Ch 2,4) and in inversion breakpoint regions (Ch 3). This dissertation presents physical maps for two important malaria species that have been applied to the study of chromosomal evolution and will also serve as community tools for further study of malaria mosquitoes. Our work on chromosomal evolution has revealed the Anopheles chromosomes tend to undergo translocations as intact elements and do not under fissions and fusions as seen in fruitflies. We also find that the malaria mosquito sex chromosome changes much more rapidly relative to the autosomes than in fruitflies. Additionally, repetitive DNA including transposable elements (TEs) and tandem repeats (TRs) may be encouraging chromosomal inversions but with differing roles on different chromosomal arms.
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Li, Pui-lin Jennifer. "Aspects of bacteriology/virology of shellfish in relation to public health /." Hong Kong : University of Hong Kong, 1997. http://sunzi.lib.hku.hk/hkuto/record.jsp?B18734261.
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Pardanani, Neeta N. "Ecological determinants of lyme disease in an endemic community /." View online ; access limited to URI, 2004. http://wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3160034.
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Salgueiro, Sancha P. "Molecular studies on pea enation mosaic virus." Thesis, University of East Anglia, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317586.
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Manoharan, Malini. "Genomic, structural and functional characterization of odorant binding proteins in olfaction of mosquitoes involved in infectious disease transmission." Phd thesis, Université de la Réunion, 2011. http://tel.archives-ouvertes.fr/tel-00979587.
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The role of odorant binding proteins in the olfaction of mosquitoes, the primary mechanism of human host recognition, has been an important focus of biological research in the field of infectious disease transmission by these insects. This thesis provides an in depth knowledge of these proteins in three mosquito species Anopheles gambiae, Aedes aegypti and Culex quinquefasciatus. A large scale analysis on these genomes has been carried out towards the identification of the odorant binding proteins in the mosquito genomes. Identification of many new OBP members, in particular in the Aedes aegypti and Culex quinquefasciatus species, and an extensive phylogenetic analysis presenting a novel classification of the OBP subfamilies of these mosquito species has been proposed. This results further demonstrates the extraordinary multiplicity and diversity of the OBP gene repertoire in these three mosquito genomes and highlights the striking sequence features that are nevertheless highly conserved across all mosquito OBPs. Owing to the availability of homologous structures from mosquitoes or related species, the 3D structure modelling of all the Classic OBPs from the three genomes (representing in total 137 structures) has been performed. This was completed by large scale docking studies on these structures by screening a large set of compounds that are known to be mosquito attractants or repellents. These provide many exciting new insights into the structural and functional aspects towards understanding the efficacy of some repellents and of some attractants from human emanations. Through molecular dynamics simulation, the structural changes observed in an OBP bounded to an odorant when pH conditions are modified were characterized and the probable mechanism of ligand binding and release is presented. This work provides the first insights to many of the long awaited questions on the genomic, structural and functional characterization of mosquito OBPs and can be viewed as a reliable starting point for further experimental research focussed on these aspects.
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Engdahl, Cecilia. "Selective inhibition of acetylcholinesterase 1 from disease-transmitting mosquitoes : design and development of new insecticides for vector control." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-134625.
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Acetylcholinesterase (AChE) is an essential enzyme with an evolutionary conserved function: to terminate nerve signaling by rapid hydrolysis of the neurotransmitter acetylcholine. AChE is an important target for insecticides. Vector control by the use of insecticide-based interventions is today the main strategy for controlling mosquito-borne diseases that affect millions of people each year. However, the efficiency of many insecticides is challenged by resistant mosquito populations, lack of selectivity and off-target toxicity of currently used compounds. New selective and resistance-breaking insecticides are needed for an efficient vector control also in the future. In the work presented in this thesis, we have combined structural biology, biochemistry and medicinal chemistry to characterize mosquito AChEs and to develop selective and resistance-breaking inhibitors of this essential enzyme from two disease-transmitting mosquitoes.We have identified small but important structural and functional differences between AChE from mosquitoes and AChE from vertebrates. The significance of these differences was emphasized by a high throughput screening campaign, which made it evident that the evolutionary distant AChEs display significant differences in their molecular recognition. These findings were exploited in the design of new inhibitors. Rationally designed and developed thiourea- and phenoxyacetamide-based non-covalent inhibitors displayed high potency on both wild type and insecticide insensitive AChE from mosquitoes. The best inhibitors showed over 100-fold stronger inhibition of mosquito than human AChE, and proved insecticide potential as they killed both adult and larvae mosquitoes.We show that mosquito and human AChE have different molecular recognition and that non-covalent selective inhibition of AChE from mosquitoes is possible. We also demonstrate that inhibitors can combine selectivity with sub-micromolar potency for insecticide resistant AChE.
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Chu, Ka-wing, and 朱嘉永. "Diversity and evolution of coronaviruses and astroviruses in bat, wildbirds and rodents." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47849733.
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Bats and birds are known to be the reservoirs of a number of zoonotic diseases. The
capacity of flight and the diversity of these animals may make them special in maintaining
and disseminating diverse viruses leading to instances of emerging zoonoses. In particular
bats are increasingly recognized to be reservoirs of a wide range of viruses, including Nipah,
Ebola and severe acute respiratory syndrome (SARS) coronaviruses. In most instances these
viruses appear to establish long-term persistence in bats.
In this thesis I report the identification of novel astroviruses from different
insectivorous species of apparently healthy bats sampled in Hong Kong and in 11 provinces
of Mainland China with high positive rates. Astroviruses are important causes of diarrhea in
many animal species, including humans. This study revealed a remarkably high genetic
diversity of bat astroviruses, which form novel distinct phylogenetic groups in the genus
Mamastrovirus. Evidence for varying degrees of host restriction for bats astroviruses has
been found. The finding of diverse astroviruses in Miniopterus bats captured within a single
cave habitat in Hong Kong illustrates a very unusual virus host relationship between
astroviruses and these bats.
Surveillance of astroviruses in rodents, the only mammal with species numbers
surpassing that of bats, has revealed a novel astrovirus in only 1.6 % of the faecal samples of
urban brown rat (Rattus norvegicus) in Hong Kong in marked contrast with the prevalence
and diversity of astroviruses in bats. Rat astrovirus was phylogenetically related to human
astroviruses MLB1 which was detected from clinical samples from diarrhoeal patients in
Hong Kong in this study. The unusually high positive rates of astroviruses in bats have been
again highlighted.
Avastroviruses were detected in 7.1% of the aquatic wild bird samples. Avastrovirus
have also been detected in doves in Hong Kong, pond herons and a less whistling duck in
Cambodia. A phylogenetic analysis of these novel astroviruses together with other previously
known astroviruses revealed that avastrovirus can be divided into 3 monophyletic groups. On
the other hand, avian coronaviruses was detected in 12.5% of the aquatic wild bird samples.
Phylogenetic analysis of these avian coronaviruses has led us to suggest taxonomic separation
of these viruses into two groups as gammacoronaviruses and deltacoronaviruses. Frequent
interspecies transmissions of gammacoronaviruses between duck species were demonstrated.
Analysis of the avian viral sequences and host mitochondrial DNA sequences suggested that
some coronaviruses may have coevolved with birds from the same order.
With the discoveries of coronaviruses and astroviruses in mammalian and birds, we
now have a better understanding on the diversity and ecology of these two virus families in
wildlife. These findings provide new insights into the ecology and evolution of these viruses
in nature and have revealed possible inter-species transmissions of these viruses. The role of
bats as a reservoir of viruses with potential to pose zoonotic threats to human health was also
reinforced. Studies of the virus ecology in wildlife as demonstrated in this thesis will help
formulating better strategies for controlling emerging diseases in the future.published_or_final_version
Microbiology
Doctoral
Doctor of Philosophy
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Dark, Michael James. "Comparative genomics of Anaplasma marginale : a preliminary examination of factors involved in tick transmission." Pullman, Wash. : Washington State University, 2008. http://www.dissertations.wsu.edu/Dissertations/Fall2008/m_dark_110708.pdf.
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Chu, Ka-wing. "Novel coronaviruses in bats of the genus Miniopterus." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B38523450.
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Nurton, Jane Patricia. "An investigation of Borrelia burgdorferi in South Africa." Thesis, Rhodes University, 1993. http://hdl.handle.net/10962/d1005408.
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Four commonly occurring genera of ticks in South Africa were tested for their capacity to acquire and transmit Borrelia burgdoiferi, the causative agent of Lyme disease. Attempts were made to infect rabbits with a culture of B. burgdoiferi, and tick transmission experiments were carried out using the rabbits as the host of infection. Only one rabbit was successfully infected. Histological changes associated with a B. burgdoiferi infection were noted in this rabbit, but no spirochaetes were isolated. All other host animals failed to become infected with the B. burgdoiferi. As a consequence transmission experiments with the local ticks failed. Serological surveys conducted on rodents, horses and cattle using immunofluorescent and haemagglutination tests indicated that there is evidence that Borrelia species occur widely and that there is a possibility of B. burgdoiferi occurring in South Africa. Studies conducted on ticks from suspected endemic areas revealed the presence, in Ixodes bakeri only, of a spirochaete-like organism that reacted with monoclonal antibody H5332. Shortcomings of the study are highlighted and proposals are presented to address the problem of identifying specific B. burgdoiferi infections.
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Davis, Rex. "An economic analysis of the common cattle tick (Boophilus microplus) in Queensland /." St. Lucia, Qld, 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16443.pdf.
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Li, Sze-ming Kenneth. "Bat as the animal origin of SARS-CoV and reservoir of diverse coronaviruses." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B42182463.
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Damian, Maxwell Simon, Andreas Hertel, Peter Seibel, Heinz Reichmann, Georg Bachmann, Walter Schachenmayr, Gustav Hoer, and Wolfgang Dorndorf. "Follow-Up in Carriers of the ‘MELAS’ Mutation without Strokes." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-133386.
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Eight carriers of the A3243G mutation of mitochondrial DNA without stroke-like episodes were monitored for up to 7 years in clinical and metabolic studies, by magnetic resonance imaging (MRI) and positron emission tomography (PET). None developed mitochondrial encephalopathy (MELAS), but 2 developed diabetes mellitus, 1 terminal kidney failure and 2 cardiomyopathy. One patient improved markedly under ubiquinone. Electroencephalography showed progressive slowing in 2 cases, but electrophysiological tests and MRI were otherwise noncontributary. PET showed widespread cortical and basal ganglion metabolic deficits in 6 cases. We conclude that internal medical complications are more common than MELAS in adult carriers of the mutation. PET findings, firstly reported in such patients, suggest that chronic subclinical encephalopathy is very frequent, and PET may play a role in monitoring in the futureDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
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Battersby, Alexandra. "The physical and psychological health of x-linked carriers of chronic granulomatous disease in the United Kingdom." Thesis, University of Newcastle upon Tyne, 2015. http://hdl.handle.net/10443/2942.
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Chronic Granulomatous Disease (CGD) is a rare primary immunodeficiency in which there is a defect in one of the subunits of NADPH oxidase resulting in recurrent, severe infection, inflammation and autoimmunity. In the UK, 70% of cases are inherited in an X-linked (XL) manner, with the remainder being autosomal recessive (AR). Patients with CGD have an absent, or significantly reduced, neutrophil oxidative burst (NOB). XL-CGD carriers have a dual population of cells, those that function normally and produce an oxidative burst, and those that do not. XL-CGD carriers have been reported to have higher rates of discoid lupus, but there is little literature about other significant medical problems. Anecdotally, XL-CGD carriers suffer from more significant medical problems akin to that seen in CGD patients. Methods XL-CGD carriers were identified from the UK CGD Registry and through consultants caring for patients at the main centres in the UK; Great North Children’s Hospital, Newcastle upon Tyne, Great Ormond Street Hospital and the Royal Free Hospital, London. A control group of carriers of Muscular Dystrophy (MD) were recruited from the Great North Children’s Hospital. XL-CGD carriers completed questionnaires about their medical and psychological health. Blood samples were taken for neutrophil oxidative burst, autoantibody panel and cytokine measurement. MD carriers completed psychological health questionnaires. Questionnaires were compared with population data, where available, and published works about comparable groups. Psychological health questionnaires were compared to the recruited MD carrier control group. Results 81 XL-CGD carriers were recruited from 62 families, 2 were deceased. iii The mean NOB at enrolment was 47% with the majority of XL-CGD carriers falling in the range of 21-60%. Photosensitivity was reported in 74% of the recruited XL-CGD carriers and 40% reported a DLE-type malar rash. 26% of XL-CGD carriers met 4 or more of the ARA SLE criteria, whilst a further 30% met 3 or more criteria. 23% suffered recurrent or significant infection. 53% suffered from gastrointestinal symptoms and 59% suffered joint symptoms. Other autoimmune phenomena including Raynaud’s phenomenon were reported. 66% XL-CGD carriers suffered greater than normal levels of anxiety and 27% suffered depression. The XL-CGD carriers had significantly higher anxiety scores than parents of children with Cystic Fibrosis and had similar anxiety scores to published data about patients with SLE. 50% XL-CGD carriers suffered excessive fatigue. IL-8 levels were significantly higher in XL-CGD carriers compared to healthy controls. IL-8 levels were significantly higher in XL-CGD carriers reporting excessive fatigue than XL-CGD carriers who did not report significant fatigue. Quality of Life (QoL) Scores were reduced in all domains and significantly worse than UK population data. The XL-CGD carriers had poorer QoL than CGD patients in the social function, vitality and bodily pain domains. Conclusions This is the first study to have evaluated the health of XL-CGD carriers, and has demonstrated that XL-CGD carriers experience similar problems to CGD patients, with infection, inflammation and autoimmunity all demonstrated in this study. Excessive fatigue was reported in approximately half of the XL-CGD carriers and was associated with higher levels of IL-8. The aetiology for the symptoms seen in the XL-CGD carriers in this study is unclear. There was a lack of consistent correlation with degree of residual NOB function, with only recurrent skin abscesses, diarrhoea and abdominal pain being significantly associated with lower values. The raised IL-8 in the fatigued XL-CGD carriers supports the hypothesis of an inflammatory process but further work is required to investigate this. The lack of association with degree of iv residual NOB function means identifying XL-CGD carriers at risk of medical symptoms is not possible simply by assessing their NOB function. Psychological health has also been affected with the high rates of anxiety in the XL-CGD carrier population and significantly reduced QoL scores in comparison to UK population data. This has not been previously demonstrated. The psychological health problems are likely to be multifactorial in aetiology. This study has clearly demonstrated that XL-CGD carriers must now be considered as potential patients and should be pro-actively assessed and managed. It is not yet clear what the optimal medical management is, and this now needs to be investigated.
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Witjes-Ané, Marie-Noëlle Wilhelmina. "The evolution of cognitive, motor and behavioural characteristics in 'presymptomatic' carriers for huntington's disease : a prospective study /." [S.l.] : [s.n.], 2003. http://catalogue.bnf.fr/ark:/12148/cb40022359v.
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Wardrop, Elizabeth Ann. "Transmission of potato virus S by aphids." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63934.
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Guénette, Suzanne. "Characterization of Brugia pahangi b-tubulin genes and gene products." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=70165.
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The $ beta$-tubulin gene family of the parasitic nematode, Brugia pahangi consists of three to five $ beta$-tubulin sequences. Two genomic clones containing $ beta$-tubulin sequences were isolated and characterized. The $ beta$1-tubulin gene spans 3.8 kb, is organized into 9 exons and expresses an mRNA of 1.7 kb which codes for a protein of 448 amino acids. A partial nucleotide sequence of the second clone confirmed the isolation of a distinct $ beta$-tubulin sequence, $ beta$2-tubulin. The $ beta$1-tubulin transcript is found in microfilariae and adult worms, whereas the $ beta$2-tubulin transcript is predominant in male adult worms but absent from microfilariae. Results of this study also indicate that the maturation of the $ beta$1-tubulin message involves the acquisition of the conserved nematode 22-nucleotide splice leader sequence. Antipeptide IgGs raised against the divergent carboxy-terminal region of $ beta$1-tubulin recognize the same $ beta$-tubulin isoform pattern as a phylum cross-reactive monoclonal antibody. This result suggests that the $ beta$1-tubulin is highly represented in B. pahangi adults and microfilariae.
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Damian, Maxwell Simon, Andreas Hertel, Peter Seibel, Heinz Reichmann, Georg Bachmann, Walter Schachenmayr, Gustav Hoer, and Wolfgang Dorndorf. "Follow-Up in Carriers of the ‘MELAS’ Mutation without Strokes." Karger, 1998. https://tud.qucosa.de/id/qucosa%3A26458.
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Eight carriers of the A3243G mutation of mitochondrial DNA without stroke-like episodes were monitored for up to 7 years in clinical and metabolic studies, by magnetic resonance imaging (MRI) and positron emission tomography (PET). None developed mitochondrial encephalopathy (MELAS), but 2 developed diabetes mellitus, 1 terminal kidney failure and 2 cardiomyopathy. One patient improved markedly under ubiquinone. Electroencephalography showed progressive slowing in 2 cases, but electrophysiological tests and MRI were otherwise noncontributary. PET showed widespread cortical and basal ganglion metabolic deficits in 6 cases. We conclude that internal medical complications are more common than MELAS in adult carriers of the mutation. PET findings, firstly reported in such patients, suggest that chronic subclinical encephalopathy is very frequent, and PET may play a role in monitoring in the future.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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Smith, Cassandra Lauren. "Comparative phylogenetic exploration of the human mitochondrial proteome : insights into disease and metabolism." Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/284285.
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Mitochondria are a key organelle within human cells, with functions ranging from ATP synthesis to apoptosis. Changes in mitochondrial function are associated with many diseases, as well as 'natural' processes like ageing. Mitochondria have a unique evolutionary origin, as the result of an endosymbiotic relationship between a bacterium and an archaeal cell. Therefore, the phylogenetic history of the mitochondrial proteome is also unique within the total human proteome. A new description of the genes encoding the human mitochondrial proteome - IMPI (Integrated Mitochondrial Protein Index) 2017 - provided an opportunity for exploration of mitochondrial proteome history and the application of this knowledge to the understanding of gene function, disease and ageing. To facilitate the exploration of the mitochondrial proteome, I created a manually curated dataset of 190,097 predicted orthologues of the 1,550 IMPI 2017 human genes across 359 species, using reciprocal best hit analysis as the basis for orthologue prediction. I used this to explore gene history and the potential for phylogenetic profiling to predict the function of uncharacterised genes. This inspired the use of phylogenetic profiling within two phyla of animals, to link presence and absence of metabolic genes to the function of mitochondrial transporters. Potential transport substrates were predicted for two groups of uncharacterised mitochondrial carriers. I also used the dataset to identify features of genes associated with monogenetic disease, as well as differences between recessive and dominant disease genes. A similar orthologue identification method was used to explore the total sequenced viral proteome for potential orthologues of mitochondrial proteins. This showed that a range of mitochondrial proteins are shared with viruses, potentially facilitating the co-opting of mitochondrial function during viral infection of eukaryotic cells. I then used orthology to explore the conservation of residues linked to protein acetylation and identify a link with lifespan in warm-blooded vertebrates. In conclusion, I have used orthology to further the understanding of human mitochondrial proteome history and developed applications of this information. For example, phylogenetic features of disease genes are being used as part of a wider pipeline to predict mitochondrial disease genes. Furthermore, predicted substrates of the SLC25A14/30 mitochondrial carriers are being tested. My dataset provides further opportunities to explore the evolution and function of the mitochondrion.
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Hart, Francis Charles. "The Effect of Environmental Variables on Local West Nile Virus Infection Rates in Culex Mosquitoes Using an 'Ecological Niche' Model." Ohio University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1271699445.
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Golding, Nicholas. "Mapping and understanding the distributions of potential vector mosquitoes in the UK : new methods and applications." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:6ae52a0a-2aaa-42d6-a57a-e3879ad559d8.
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A number of emerging vector-borne diseases have the potential to be transmitted in the UK by native mosquitoes. Human infection by some of these diseases requires the presence of communities of multiple vector mosquito species. Mitigating the risk posed by these diseases requires an understanding of the spatial distributions of the UK mosquito fauna. Little empirical data is available from which to determine the distributions of mosquito species in the UK. Identifying areas at risk from mosquito-borne disease therefore requires statistical modelling to investigate and predict mosquito distributions. This thesis investigates the distributions of potential vector mosquitoes in the UK at landscape to national scales. A number of new methodological approaches for species distri- bution modelling are developed. These methods are then used to map and understand the distributions of mosquito communities with the potential to transmit diseases to humans. Chapter 2 reports the establishment of substantial populations of the West Nile virus (WNV) vector mosquito Culex modestus in wetlands in southern England. This represents a drastic shift in the species’ known range and an increase in the risk of WNV transmission where Cx. modestus is present. Chapter 3 develops and applies a new species interaction distribution model which identifies fish and ditch shrimp of the genus Palaemonetes as predators which may restrict the distribution of the potential WNV vector community in these wetlands. Chapter 4 develops a number of methods to make robust predictions of the probability of presence of a species from presence-only data, by eliciting and applying estimates of the species’ prevalence. Chapter 5 introduces a new Bayesian species distribution modelling approach which outperforms existing methods and has number of useful features for dealing with poor- quality data. Chapter 6 applies methods developed in the previous two chapters to produce the first high-resolution distribution maps of potential vector mosquitoes in the UK. These maps identify several wetland areas where vector communities exist which could maintain WNV transmission in birds and transmit it to humans. This thesis makes significant contributions to our understanding of the distributions of UK mosquito species. It also provides methods for species distribution modelling which could be widely applied in ecology and epidemiology.
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Lau, Hok-nang, and 劉學能. "Identification of novel coronaviruses in dead birds in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44660108.
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Liu, Hei-man, and 廖羲文. "The detection of picornaviruses in bat in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44660224.
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Lee, Chiu-fai, and 李照輝. "Molecular epidemiology of lineage C betacoronaviruses in bats in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/196542.
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Nine years after the Severe Acute Respiratory Syndrome (SARS) pandemic in 2003, a novel human coronavirus, Middle East Respiratory Syndrome coronavirus (MERS-CoV), emerged in the Middle East in 2012 and was believed to be of animal origin. Molecular study on the genome of MERS-CoV showed that it belongs to lineage C betacoronavirus and is closely related to the previously described Tylonycteris bat coronavirus HKU4 (Ty-BatCoV HKU4) and Pipistrellus bat coronavirus HKU5 (Pi-BatCoV HKU5) identified in Tylonycteris pachypus and Pipistrellus abramus respectively. In this study, 597 respiratory and 934 alimentary specimens from 1174 bats of 12 different species were collected in 20 sampling sites of Hong Kong over seven years from November 2005 to November 2012. Degenerate primers designed from alignment of RdRp genes of lineage C betacoronaviruses were able to amplify partial RdRp sequences in two bat species only in this study, including 8 lesser bamboo bats and 34 Japanese pipistrelle, with 200-bp sequences shared 99-100% and 96-100% nucleotide identities to Ty-BatCoV HKU4 and Pi-BatCoV HKU5 respectively. Phylogenetic analysis showed that Ty-BatCoV HKU4 and Pi-BatCoV HKU5 were closely related to but still distinct from MERS-CoV, implying that the two bat coronaviruses are probably not the direct ancestor virus of MERS-CoV. The infection of Pi-BatCoV HKU5 is independent of sex (P = 0.494) but juvenile Japanese pipistrelles were more susceptible to the infection (P = 0.000101) while the infection of Ty-BatCoV HKU4 is independent of both sex (P = 0.464) and age (P = 0.193). Additionally, the mean body weight of the adult lesser bamboo bats positive for Ty-BatCoV HKU4 was significantly lower than that of the negative ones (P = 0.03). On the other hand, there was no significant difference in the mean body weights between the positive and negative bats for Pi-BatCoV HKU5 among the juvenile Japanese pipistrelles (P = 0.06). Continuous surveillance study of coronaviruses on different bat species as well as other potential intermediate animal hosts should be carried on the evolution study of the lineage C betacoronaviruses.published_or_final_version
Microbiology
Master
Master of Medical Sciences
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Khechara, Martin Peter. "The nematode Caenorhabditis elegans as an alternative model for bacterial infection." Thesis, n.p, 2004. http://ethos.bl.uk/.
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Poon, Wing-shan Rosana. "Discovery and characterization of two novel subgroups of coronaviruses." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43278450.
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