Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 52-57).

Thesis (M.S. - Soil, Water and Environmental Science)--University of Arizona. / Includes bibliographical references (leaves 69-78).

Microgemma hepaticus gen.n.sp.n. is described from the liver of juvenile mullet, Chelon labrosus. Development occurs within xenomas, of diameter 500 µm. These have microvillar surfaces, encircling bands of mitochondria and a reticulate nucleus with many nucleoli. Meronts are plasmodial, divide by plasmotomy and are enclosed within host membranes. Sporonts are free in the cytoplasm and divide by multiple exogenous budding. In sporogenesis the polar sac is formed from golgi vesicles, the manubrium form a dense golgi body and the coiled polar filament form a spiral cisterna linked with the perinuclear membrane system and golgi reticulum. This was also implicated in the formation of the endospore. The polaroplast developed from expanded sacs derived from the manubrium. Uninucleate spores (4.2 x 2.4 µm) possessed 7-9 filament coils and lamellar polaroplast. Foci of infection were associated with liver connective tissue, and histopathological effects limited to adjacent cell necrosis due to pressure atrophy in restricted sites. Host responses result in granuloma formation, with gradual resolution of the lesion. In vitro investigations into spore hatching and viability showed exsporulation was stimulated by oxidising agents and following pretreatment with media of low pH or high osmolarity. Inoculation of spores into RTG cell cultures resulted in observations of a freshly injected sporoplasm, and a plasmodial stage after 72 hours. The ultrastructure of extruded filaments, spore cases and cell penetration is described. Attempts at transmission of the parasite to mullet by stomach tube, feeding of crustacean spore carriers or intraperitoneal injection were unsuccessful and suggested that larval fishes may be the targets of infection. The possible transmission of the parasite in the marine environment is discussed. On the basis of structural and developmental features the genus Microgemma is placed in the family Unikaryonidae. The affiliation of the genus with other fish microsporidia is noted, and wider implications of life cycles and nuclear behaviour to taxonomy and evolution are discussed.

Thesis--Copenhagen. / Summary in Danish. Bibliography: p. 84-89.

Thesis (Ph. D.)--Rutgers University, 2009. / "Graduate Program in Biology." Includes bibliographical references (p. 150-164).

Thesis--Copenhagen. / Summary in Danish. Bibliography: p. 84-89.

Orientador: Carlos Fernando Salgueroisa de Andrade / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-07-23T21:48:47Z (GMT). No. of bitstreams: 1 AmbrosGinarte_CarmenMaria_M.pdf: 7008446 bytes, checksum: 956da0bb0b3e71d3411cb770b7c5e815 (MD5) Previous issue date: 1998 / Resumo: Foi realizado um levantamento de larvas de simulídeos em localidades dos estados de São Paulo, Paraná, Mato Grosso, Rio Grande do Sul, Santa Catarina e Minas Gerais, durante o período de fevereiro de 1996 a maio de 1998. Após a análise das larvas de simulídeos coletadas em cada localidade, encontrou-se parasitismo por Polydispyrenia simu/ii (Microspora: Duboscquiidae) nas localidades de Morungabal/SP (24,06% na rampa de cimento à jusante do lago e 1,32% no leito de um riacho) e no leito de riacho em Leme/SP (5,68%). Outras microsporidioses foram observadas nas localidades da Serra do Japi/SP, onde a prevalência foi muito baixa durante o período de estudo; além de Barra do Uma/SP; Paulínia/SP; Sorocaba/SP; Tibají/PR; Rolândia/PR; São Francisco de Paula/RS; Barão/RS; Santo Antônio de Atalanta/SC e em Itapema/SC. Além do parasitismo por microsporídeos, encontrou-se também parasitismo por Isomermis sp. (Nematoda: Mermithidae) em larvas de simulídeos na Serra do Japi/SP, onde a prevalência dessa parasitose variou no mínimo de 1,28% a máximo de 21,30% na rampa de cimento à jusante do lago e no mínimo de 0,86% a máximo de 20% no leito do mesmo riacho; observando-se as maiores ocorrências no mês de maio de 1996 (na rampa) e em setembro de 1997 (no leito do riacho) que correspondem aos meses inicio e fim do inverno, diminuindo grandemente durante os meses de verão, período em que há um aumento nas temperaturas e precipitações. Se mostra também como variou a densidade larval relativa de simulídeos durante este período, nesta localidade e é correlacionada com a ocorrência de parasitismo. Parasitismo por outros mermitídeos foram encontrados também em larvas de diferentes espécies de simulídeos das localidades de MorungabalSP, Leme/SP, Barra do Uma/SP, Sorocaba/SP, Tibají/PR, Rolândía/PR, São Francisco de Paula/RS, Barão/RS, Santo Antônio de Atalanta/SC e Montes Verdes/MG Na localidade de Ilhabela/SP registra-se pela primeira vez parasitismo pelo fungo Coelomycidium sp. em larvas de Simu/ium (Chirostilbia) pertinax, localidade esta submetida durante vários anos ao controle químico e agora recebe controle biológico com Bacillus thuringiensis var. israelensis sorotipo H-14. Nenhuma parasitose foi observada nas localidades: Chapada dos Guimarães/MT, Florianópolis/SC e nas localidades estudadas no município de Campinas/SP. No laboratório, determinou-se para /somermis sp, que após dez dias da emergência do nematódeo da larva hospedeira, os pós-parasitas mudam para adultos em um meio de água destilada à uma temperatura entre 22 e 24°C. Areia úmida, colocada em um recipiente fechado e mantido a uma temperatura de 17 °C é eficaz para a criação das formas de vida livre de /somermis sp. no laboratório; e parece ser a sexta semana após a colocação dos pós-parasitas na cultura de areia úmida, a mais indicada para a inundação da cultura e obtenção da maior quantidade de larvas infectivas ou preparasíticas. As tentativas feitas para avaliar /somermis sp. em hospedeiros alternativos no laboratório foram infrutíferas, indicando que este merrmitídeo parece ser um parasita específico de larvas de simulídeos / Abstract: A survey of parasites in simuliid larvae was carried out in different localities in the states of São Paulo, Paraná, Mato Grosso, Rio Grande do Sul, Santa Catarina and Minas Gerais, from F February 1996 to May 1998 o Exarnination of the larvae collected from the above mentioned localities revealed parasitism by Polydispyrenia simulii (Microspora: Dubosquiidae) in Morungaba/SP (24006% in larvae tromp a cemented ramp in the lake outlet, and 1032% in larvae from the stream bed) and from Leme/SP, collected from the stream bed. Microsporidiosis caused by other species was also found in Serra do Japi/SP, Barra do Una/SP, Paulínia/SP, Sorocaba/SP, Tibaji/PR, São Francisco de Paula/RS, Barão/RS, Santo Antonio de Atalanta/SC and Itapema/SC, the occurrence being very low in Serra do Japi during the survey periodo beside rnicrosporidian, parasitism by /somermis spo (Nematoda: Merrnithidae) was also found in simuliid larvae collected from Serra do Japi/SP. The ocorrence of this parasite ranged from 1.28% to 21.30% in larvae collected from the cemented ramp in the lake outlet, and from O o 86% to 20% in larvae collected from the stream bed. The higher occurrence of /somermis sp. in the above mentioned sites, was probably related to the winter season, during the months of May 1996 and September 1997. It was low during the surnrner months, period of hight temperatures and rain fall. Also relative variation in larval density is shown for the simuliid species found in Serra do Japi/SP and is correlated to the ocorrence of parasitism. Parasitism by other merrnitids species was also found in larvae of different simuliid species in the localities of Morungaba/SP, Leme/SP, Barra do Una/SP, Sorocaba/SP, Tibaji/PR, Rolândia/PR, São Francisco de Paula/RS, Barão/RS, Santo Antonio de Atalanta/SC and Montes Verdes/MG. We also observed rnicoses caused by Coelomycidium sp. in the larvae of Simulium. (Chirostilbia) pertinax in Ilhabela/SP o This is the first record in the literatura about Coelomycidium spo attacking larvae of So (Ch.) pertinax in Ilhabela, the refered locality was subjected to simuliid chernical control for many years but recently a biological control program using Bacil/us thuringiensis varo israelensis H-14 is being undertaken. Parasitism was not found in simuliid larvae collected from the localities in Campinas/SP, Chapada dos GuimarãesIMT and Florianópolis/SC. We observed that Isomermis sp. requires approximately 10 day after the post emergence from the simulid host to transform into adult in distilled water, at 22 to 24°C. The free stage of the nematode Isomermis sp. was successfully breed under laboratory conditions in a closed vial with wet sand and kept at 17°C. It can be suggested that the sixth week after introducing the post-parasites in wet sand is more appropriate in order to inundate the culture to obtain a large number of pre-parasitic infective worms. Attempts to evaluate the infection caused by of Isomermis sp. in altemative hosts under laboratory conditions were unsuccessfull, indicating a possible specificity of the parasite to simuliid host / Mestrado / Mestre em Ciências Biológicas

No description available.

No description available.

Microsporidia infect invertebrate and vertebrate animals. Human pathogenic microsporidia are associated with severe disease in immunocompromised individuals, and mostly asymptomatic infection in the immunocompetent. Treatment options for microsporidiosis are limited, incompletely effective, and associated with toxicity. Furthermore, microsporidia infection of healthy individuals is poorly understood, and the consequences of asymptomatic infection have not been determined. Little is known about the molecular mechanisms of microsporidia infection, but such information is essential for the development of new therapies. Spores adhere to host cell surfaces in vitro. Our laboratory has focused on determining specific host cell and microsporidia spore surface participants in spore adherence. Our previous studies have shown that host cell sulfated glycosaminoglycans and the spore surface protein EnP1 participate in spore adherence to host cells. Additionally, in vitro inhibition or augmentation of spore adherence decreased or increased host cell infection, respectively. These studies demonstrated the importance of spore adherence in host cell infection and began to characterize the host cell and spore determinants of adherence. The goal of this research was to further characterize host cell and spore participants in microsporidia adherence and infection of host cells in vitro. We characterized an intracellular microsporidia protein and related antibodies for analyses of microsporidia spore surface proteins; characterized a spore surface protein, MsADAM, involved in spore adherence to and infection of host cells in vitro; and suggested a role for host cell integrins in microsporidia adherence to and infection of host cells in vitro.