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Influence of temperature, water activity, and oil content on growth and aflatoxin production on oil seeds by Aspergillus flavus and A. parasiticusChih-Hsuan Chang (9865223) 18 December 2020 (has links)
<p>Aflatoxins (AFs) are highly toxic second metabolites produced by <i>Aspergillus flavus </i>and<i> A. parasiticus</i>. They are widely detected in cereals, spices, and drinks worldwide. Aflatoxin contamination of foods and crops poses a high health risk for humans and livestock. It is well known that environmental conditions and substrates could influence fungal growth and aflatoxin production. This study tested the effect of water activity (0.82, 0.86, 0.90, 0.94, and 0.98 a<sub>w</sub>) and incubation temperatures (20°, 27°, and 35°C) on the growth and aflatoxin production of <i>A. flavus </i>and <i>A. parasiticus</i> on ground flax seeds and ground niger seeds. The effect of oil contents of ground niger seeds on fungal growth and aflatoxin production was also investigated in this study.</p><p> These two fungal species could not grow on any of the tested substrates with 0.82 a<sub>w</sub> at 20°, 27°, or 35°C. <i>Aspergillus flavus</i> grew most rapidly on flax seeds with 0.90 a<sub>w</sub> at 27°C and also 0.94 a<sub>w</sub> at 27° or 35°C. However, on niger seeds, <i>A. flavus </i>grew best at 0.90 or 0.94 a<sub>w</sub> incubated at 35°C as well as at 0.94 or 0.98 a<sub>w</sub> incubated at 27°C. <i>Aspergillus parasiticus</i> showed the optimum growth on flax seeds with 0.90 a<sub>w</sub> at 35°C, whereas on niger seeds, the optimum occurred on seeds with 0.90 a<sub>w</sub> at 35°C and also on seeds with 0.94 a<sub>w</sub> at 27° or 35°C. The optimum conditions for <i>A. flavus </i>to produce high levels of aflatoxins (270-299 μg/kg) on flax seeds were 0.90 a<sub>w</sub> at 35°C; whereas, the optimum conditions for <i>A. flavus </i>to produce aflatoxin (203-278 μg/kg) on niger seeds were 0.90 or 0.98 a<sub>w</sub> at 27°C and also 0.90 a<sub>w</sub> at 35°C. <i>Aspergillus parasiticus</i> produced high levels of aflatoxins (284-365 μg/kg) on flax seeds under the following three conditions, 0.86 or 0.98 a<sub>w</sub> at 35°C and 0.94 a<sub>w</sub> at 27°C; <i>A. parasiticus</i> produced 200-384 μg/kg of aflatoxins on niger seeds under nine out of 12 tested incubation conditions.</p><p> Reducing mean oil contents from 35.2 to 10.5% of ground niger seeds had very little effect on the growth of the two fungi but significantly decreased their aflatoxin production under certain incubation conditions. On de-oiled niger seeds inoculated with <i>A. flavus</i>, only 13μg/kg of AFB1 was found on seeds with 0.94 a<sub>w</sub> at 27°C; whereas, on de-oiled niger seeds inoculated with <i>A. parasiticus</i>, high levels of aflatoxins (245-345 μg/kg) were only detected under the three following incubation conditions, 0.90 or 0.94 a<sub>w</sub> at 27°C, and 0.86 a<sub>w</sub> at 35°C.</p> This study showed that the optimum growth and aflatoxin production by <i>A. flavus </i>and<i> A. parasiticus </i>were not identical and influenced by incubation conditions, including temperature, water activity, and growth substrates. The results of this study could help establish guidelines for post-harvest and storage conditions for oil seeds to prevent fungal growth and aflatoxin formation.
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Doryphoribius smokiensis, a New Species of Eutardigrada (Hypsibiidae) from the Great Smoky Mountains National Park, TN, USA (North America)Bartels, Paul J., Nelson, Diane R., Kaczmarek, Łukasz, Michalczyk, Łukasz 26 November 2007 (has links)
A new eutardigrade, Doryphoribius smokiensis sp. nov., is described from soil and leaf litter samples collected in the Great Smoky Mountains National Park in Tennessee, USA. The new species differs from two similar species (with two macroplacoids and a sculptured dorsal cuticle without gibbosities) by the presence of a very wide buccal tube (high buccal tube pt ratio: >20.0), absence of enlarged bases of claws, absence of eyes, and other morphological and morphometric characters.
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The Effects of Media Constituents Upon the Growth and Pigment Production of Micrococcus Flavus, Micrococcus Roseus, Micrococcus Subcitreus, and Sarcina CitreaMartin, Joseph Hearn 08 1900 (has links)
This investigation has for its aim the explanation of growth and pigment production of Micrococcus flavus, Micrococcus roseus, Micrococcus subvitreus, and Sarcina citrea by the addition of various nutrient test materials to a standard culture medium.
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Effects of Storage Conditions of Aspergillus Growth and Aflatoxin Production in Peanuts. A Study in GhanaDarko, Clara Bernice 13 February 2017 (has links)
Peanuts (Arachis-hypogaea) are one of the staples in Ghana, Sub-Saharan Africa, and other developing countries. This leguminous crop is frequently contaminated with aflatoxins, which are secondary metabolites of some Aspergillus fungi, mostly Aspergillus. flavus and Aspergillus parasiticus. Aflatoxins in foods are known to cause liver cancer, stunted growth in children, immune system disorders and economic losses. Aflatoxin contamination of peanuts during storage is worse in the tropics because climatic storage conditions there are almost the same as the optimum conditions for Aspergillus growth: temperature conditions of about 26-43 °C and relative humidity of 62-99%. This study investigated the growth of Aspergillus and the production of aflatoxin in shelled peanuts under varying treatment and packaging conditions. In addition, the appropriate pre-storage treatments and packaging needed to reduce aflatoxin production and to maintain quality of shelled and in-shell peanuts in storage under tropical environments were studied. Another aim was to determine the impact of the switch to hermetic storage on peanut farming and marketing profitability in Ghana.
Different peanut treatments, with and without Aspergillus flavus fungi, were packaged in different systems; specifically, polypropylene woven sacks and hermetic packaging. Peanuts were analyzed for fungi growth, aflatoxin production and lipid oxidation (peroxide value and p-Anisidine value).
Partial roasting and blanching of peanuts eliminated aflatoxigenic fungi and halted aflatoxin production in stored peanuts, increased the effectiveness of peanut sorting and, hence, helped reduce or eliminate aflatoxin levels along the peanut value chain. Additionally, the results of this study demonstrated that hermetic storage, by suppressing aflatoxin production, has the potential for maintaining peanut quality vis a vis polypropylene woven packaging. Profitability analysis conducted as part of this study revealed that the use of the hermetic storage system would not only improve farmer and trader profits, but also reduce the incidence of various ailments attributed to aflatoxins. / Ph. D. / Peanuts are one of the staple crops in Ghana, Sub-Saharan Africa, and other developing countries. This crop is frequently contaminated with a special type of molds which produce a poisonous substance called aflatoxin. In foods, it is known to cause liver cancer, stunted growth in children, immune system disorders and economic losses. Aflatoxin contamination during storage in the tropical regions is worst because peanuts are mostly packaged in polypropylene woven sacks and stored under environmental conditions. Unfortunately, climatic conditions promote mold growth and aflatoxin production. In view of this problem, this study was aimed at finding appropriate, affordable and adoptable storage solutions to control fungi growth and aflatoxin production. A portion of the shelled peanuts was partially roasted to kill the molds and to stop aflatoxin production, and then peeled to facilitate the sorting of discolored peanuts which are believed to contain aflatoxins. The partially roasted peanuts and raw ones were packaged in conventional polypropylene woven sacks and hermetic packaging system and stored. It was demonstrated that partial roasting and peeling of peanuts can kill molds and halt aflatoxin production in stored peanuts. Partial roasting increased the effectiveness of peanut sorting and hence, aided in reducing aflatoxin levels along the peanut value chain. Additionally, the results of this study have shown that, compared to polypropylene woven sacks, hermetic storage suppresses mold growth because it eliminates oxygen from the package and results in lower aflatoxin levels and reduces the rate of quality deterioration. Profitability analysis conducted as part of this study revealed that the use of the hermetic storage system would not only improve farmer and trader profitability, but also help reduce the incidence of various ailments that have been attributed to aflatoxins.
With the high potential of making additional profits when the hermetic packaging system is adopted, I recommend that local production and marketing of a hermetic storage system be encouraged, along with the active creation of awareness of their benefits in reducing the incidence of aflatoxins.
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Diversité génétique et sensibilité aux antifongiques d'isolats d'Aspergillus spp. provenant d'élevages aviaires du Guangxi , ChineWang, Dong ying 13 April 2012 (has links) (PDF)
Les champignons du genre Aspergillus sont des moisissures banales de l'environnement. Elles sont présentes dans le sol et sur des végétaux en décomposition. Les Aspergillus se propagent par l'intermédiaire de spores microscopiques en suspension dans l'air. L'Homme et les animaux sont exposés en permanence aux spores aspergillaires mais les défenses immunes empêchent leur développement dans l'organisme. Lorsque ces défenses sont amoindries, une aspergillose est possible. Dans ce cas, Aspergillus fumigatus et A. flavus sont le plus souvent incriminés. Les oiseaux sont beaucoup plus sensibles que les mammifères et l'environnement représenté par les élevages aviaires est propice à la prolifération des moisissures du genre Aspergillus. L'objectif de ce travail de thèse a été de caractériser la diversité génétique et la sensibilité aux antifongiques d'isolats d'Aspergillus provenant d'élevages aviaires dans la province du Guangxi en Chine. La première partie de la thèse est une analyse bibliographique sur les champignons du genre Aspergillus, les aspergilloses et les caractéristiques de l'élevage aviaire en Chine. Une première enquête a été réalisée dans 3 élevages près de la ville de Nanning et dans un élevage (incluant un éclosoir) à proximité de la ville de Guilin. Des écouvillonnages pharyngés et des prélèvements d'air ont été réalisés pendant plusieurs semaines. Des prélèvements ont également été faits sur des œufs dans l'éclosoir. Cette enquête a montré que le niveau de contamination fongique dépendait du type d'élevage. De nombreux isolats fongiques ont pu être collectés : 188 isolats d'A. fumigatus et 159 isolats d'A. flavus. La seconde partie du travail expérimental a porté sur la caractérisation de la diversité génétique d'A. fumigatus et d'A. flavus. Pour cela, la technique MLVA (multiple locus VNTR analysis) a été utilisée. Pour A. flavus, 8 marqueurs VNTR (variable-number tandem-repeat) ont été sélectionnés et une réaction PCR multiplex a été mise au point. Au total, 91 isolats d'A. flavus, incluant 6 souches de référence, ont été caractérisées avec le panel des 8 marqueurs VNTR. Cette analyse a permis de définir 78 génotypes distincts et un index de discrimination de 0,993. L'analyse de 188 isolats d'A. fumigatus avec 10 marqueurs VNTR a permis de définir 142 génotypes distincts. Certains génotypes d'A. flavus ou d'A. fumigatus sont clairement regroupés dans le nuage de point généré par l'analyse MST (minimum spanning tree). La troisième partie du travail expérimental a porté sur la sensibilité aux antifongiques de 177 isolats d'A. fumigatus. Ces isolats ont été récupérés dans des élevages aviaires en Chine et en France. Les isolats de Chine sont pour la plupart sensibles avec des valeurs minimales inhibitrices (vis-à-vis de l'itraconazole) comprises entre 0,38 et 0,75 µg/mL. Les isolats de France sont pour la plupart sensibles avec des valeurs minimales inhibitrices (vis-à-vis de l'itraconazole) comprises entre 0.19 and 1 µg/mL. Quatre souches ont été considérées comme résistantes : 2 souches provenant de deux élevages en Chine et 2 souches provenant de deux élevages en France. Des mutations sur le gène Cyp51A ont été détectées pour 11 isolats (3 résistants et 8 sensibles). Vingt et une mutations nucléotidiques ont été identifiées. Onze de ces mutations sont silencieuses et 9 sont à l'origine d'un changement de la composition de la protéine. Sept substitutions ont déjà été décrites dans la littérature ; les mutations A116R, E130D et Q131H sont originales.
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Estudo etiológico, clínico, laboratorial e epidemiológico da bola fúngica pulmonar por Aspergillus spp / Etiological, clinical, laboratory and epidemiologic study of fungus ball by Aspergillus sppGuazzelli, Luciana Silva January 2011 (has links)
Descrição: Bola fúngica é definida como uma macrocolônia composta por emaranhado de hifas, células inflamatórias, fibrina, muco e fragmentos de tecidos. Aspergillus fumigatus é o agente etiológico mais frequente, responsável por cerca de 90% dos casos, seguido de A niger e A flavus, respectivamente. O antecedente mais comum para o desenvolvimento da bola fúngica é cavidade secundária à tuberculose e a manifestação clínica mais presente e causadora de óbitos nesses pacientes é a hemoptise. Objetivos: Investigar as espécies de Aspergillus causadoras de bola fúngica pulmonar, determinar as condições predisponentes e/ou associadas e a comprovação laboratorial para o diagnóstico etiológico e observar a resposta as diferentes medidas terapêuticas dos pacientes com bola fúngica pulmonar. Delineamento: Foram analisados retrospectivamente, prontuários de pacientes para a caracterização da bola fúngica pulmonar por Aspergillus. Local do estudo: Laboratório de Micologia da Santa Casa Complexo Hospitalar, no período de 1980 a 2009. Pacientes e métodos: Foram incluídos neste estudo todos os pacientes com diagnóstico de bola fúngica pulmonar aspergilar de uma população de 750 casos de aspergilose, de 1980 a 2009. Os critérios para o diagnóstico foram os seguintes: isolamento da espécie de Aspergillus proveniente do material de cavidade pulmonar associado à imagem radiográfica compatível; isolamento da espécie de Aspergillus em outros materiais do trato respiratório, excluindo material da cavidade, associado ou não ao exame direto positivo; imunodifusão radial dupla positiva para Aspergillus associada ao exame de imagem compatível. Resultados: Foram incluídos 391 pacientes com bola fúngica pulmonar aspergilar, a idade variou de 18-78 anos, sendo 67,3% do gênero masculino. O diagnóstico foi baseado nos achados clínicos, radiológicos e laboratoriais. Em todos os pacientes foram detectados achados característicos de bola fúngica tanto no radiograma quanto na tomografia de tórax e bola fúngica complexa foi detectado em 97,4% da casuística. Tuberculose curada foi a principal condição predisponente (89%). Hemoptise foi manifestação clínica mais frequente (89%). A espécie A. fumigatus foi o agente etiológico mais isolado, 89,3% dos casos, seguido de A niger 7,1% e menos frequente A flavus 3,3%. A positividade no cultivo foi de 84,7% nos espécimes clínicos e a imunodifusão radial dupla de 81,6% dos pacientes. A principal medida terapêutica foi ressecção cirúrgica apresentando desfecho favorável em 88,3%. A eliminação da bola fúngica por lise espontânea ocorreu em 2,3% dos casos. Mortalidade foi atribuída à cirurgia e a hemoptise em 32,3 e 13,8%, respectivamente. Conclusões: Tuberculose curada e hemoptise é a primeira hipótese diagnóstica de bola fúngica pulmonar. O sinal radiológico indicativo de bola fúngica é cavidade contendo produto patológico com densidade de partes moles, espessamento da parede da cavidade e da pleura circunjacente. A detecção de anticorpos séricos por imunodifusão radial dupla, e o cultivo de espécimes do trato respiratório inferior determinaram A. fumigatus como o principal agente etiológico da bola fúngica pulmonar. A medida terapêutica mais utilizada nos pacientes do presente estudo foi ressecção cirúrgica, e a metade da ocorrência de óbito esteve presente nestes casos. / Background: Pulmonary fungus ball is defined as a conglomeration, within a cavity of intertwined Aspergillus hyphae, inflammatory cells, fibrin, mucus and cellular debris. Aspergillus fumigatus is the most frequent etiologic agent, about 90% of cases, followed by A niger and A flavus, respectively. The most common condiction to develop fungus ball is residual cavities of healed tuberculosis, and the most prevalent clinical manifestation and cause of death is hemoptysis in these patients. Objectives: To investigate the species of Aspergillus causing pulmonary fungus ball, we compared underlying conditions, laboratory evidence to the etiological diagnosis, and response of the different therapy, and outcome of patients with pulmonary fungus ball. Design: We analyzed retrospectively the medical records of patients for the characterization of pulmonary Aspergillus fungus ball. Settings: A university-based tertiary care hospital in Porto Alegre, Rio Grande do Sul, Brazil. Patients and methods: The study included patients diagnosed with pulmonary Aspergillus fungus ball in a population of 750 cases of aspergillosis, from 1980 to 2009. The criteria for the diagnosis were: isolation of Aspergillus species from the material of the pulmonary cavity associated with the compatible radiographic image; isolation of Aspergillus species from other materials of the respiratory tract, excluding cavity material, with or without direct examination positive; double immunodiffusion positive for Aspergillus associated with compatible image. Results: We included 391 patients with pulmonary Aspergillus fungus ball, age ranged from 18 to 78 years, 67.3% were male. The diagnosis was based on clinical, radiological, and laboratory findings. In all patients we detected the characteristic findings of fungal ball, on X-ray and tomography; and complex fungal ball, on their radiological appearance, was detected in 97.4% of cases. Healed tuberculosis was the commonest pre-existing disease (89%). Hemoptysis was the major symptoms (89%). The species A. fumigatus was the most common etiologic agent, 89.3% of cases, followed by 7.1% A niger and A flavus less frequent in 3.3%. Culture was positive in 84.7% specimes, and immunodiffusion in 81.6% patients. The main treatment was surgical resection in 88.3% that had a favorable outcome. Spontaneous lysis was obtained in 2.3% of cases. Mortality was attributed to the surgery and hemoptysis in 32.3 and 13.8%, respectively. Conclusions: Patient with healed tuberculosis and hemoptysis is the first hypothesis diagnostic fungus ball. The most frequent radiological signs were rounded dense opacity surrounded with a halo of air in a thick cavity wall and thickening of the pleura over cavity. The detection of serum antibodies by double immunodiffusion, and the cultive of the lower respiratory tract specimens determined A. fumigatus as the main agent of pulmonary fungal ball. The detection of serum antibodies by double immunodiffusion, and the cultivation of the lower respiratory tract specimens determined A. fumigatus as the main agent of pulmonary fungal ball. The measure most commonly used therapy in patients of this study was to surgical resection, and half of the patients who died were in these cases.
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Estudo etiológico, clínico, laboratorial e epidemiológico da bola fúngica pulmonar por Aspergillus spp / Etiological, clinical, laboratory and epidemiologic study of fungus ball by Aspergillus sppGuazzelli, Luciana Silva January 2011 (has links)
Descrição: Bola fúngica é definida como uma macrocolônia composta por emaranhado de hifas, células inflamatórias, fibrina, muco e fragmentos de tecidos. Aspergillus fumigatus é o agente etiológico mais frequente, responsável por cerca de 90% dos casos, seguido de A niger e A flavus, respectivamente. O antecedente mais comum para o desenvolvimento da bola fúngica é cavidade secundária à tuberculose e a manifestação clínica mais presente e causadora de óbitos nesses pacientes é a hemoptise. Objetivos: Investigar as espécies de Aspergillus causadoras de bola fúngica pulmonar, determinar as condições predisponentes e/ou associadas e a comprovação laboratorial para o diagnóstico etiológico e observar a resposta as diferentes medidas terapêuticas dos pacientes com bola fúngica pulmonar. Delineamento: Foram analisados retrospectivamente, prontuários de pacientes para a caracterização da bola fúngica pulmonar por Aspergillus. Local do estudo: Laboratório de Micologia da Santa Casa Complexo Hospitalar, no período de 1980 a 2009. Pacientes e métodos: Foram incluídos neste estudo todos os pacientes com diagnóstico de bola fúngica pulmonar aspergilar de uma população de 750 casos de aspergilose, de 1980 a 2009. Os critérios para o diagnóstico foram os seguintes: isolamento da espécie de Aspergillus proveniente do material de cavidade pulmonar associado à imagem radiográfica compatível; isolamento da espécie de Aspergillus em outros materiais do trato respiratório, excluindo material da cavidade, associado ou não ao exame direto positivo; imunodifusão radial dupla positiva para Aspergillus associada ao exame de imagem compatível. Resultados: Foram incluídos 391 pacientes com bola fúngica pulmonar aspergilar, a idade variou de 18-78 anos, sendo 67,3% do gênero masculino. O diagnóstico foi baseado nos achados clínicos, radiológicos e laboratoriais. Em todos os pacientes foram detectados achados característicos de bola fúngica tanto no radiograma quanto na tomografia de tórax e bola fúngica complexa foi detectado em 97,4% da casuística. Tuberculose curada foi a principal condição predisponente (89%). Hemoptise foi manifestação clínica mais frequente (89%). A espécie A. fumigatus foi o agente etiológico mais isolado, 89,3% dos casos, seguido de A niger 7,1% e menos frequente A flavus 3,3%. A positividade no cultivo foi de 84,7% nos espécimes clínicos e a imunodifusão radial dupla de 81,6% dos pacientes. A principal medida terapêutica foi ressecção cirúrgica apresentando desfecho favorável em 88,3%. A eliminação da bola fúngica por lise espontânea ocorreu em 2,3% dos casos. Mortalidade foi atribuída à cirurgia e a hemoptise em 32,3 e 13,8%, respectivamente. Conclusões: Tuberculose curada e hemoptise é a primeira hipótese diagnóstica de bola fúngica pulmonar. O sinal radiológico indicativo de bola fúngica é cavidade contendo produto patológico com densidade de partes moles, espessamento da parede da cavidade e da pleura circunjacente. A detecção de anticorpos séricos por imunodifusão radial dupla, e o cultivo de espécimes do trato respiratório inferior determinaram A. fumigatus como o principal agente etiológico da bola fúngica pulmonar. A medida terapêutica mais utilizada nos pacientes do presente estudo foi ressecção cirúrgica, e a metade da ocorrência de óbito esteve presente nestes casos. / Background: Pulmonary fungus ball is defined as a conglomeration, within a cavity of intertwined Aspergillus hyphae, inflammatory cells, fibrin, mucus and cellular debris. Aspergillus fumigatus is the most frequent etiologic agent, about 90% of cases, followed by A niger and A flavus, respectively. The most common condiction to develop fungus ball is residual cavities of healed tuberculosis, and the most prevalent clinical manifestation and cause of death is hemoptysis in these patients. Objectives: To investigate the species of Aspergillus causing pulmonary fungus ball, we compared underlying conditions, laboratory evidence to the etiological diagnosis, and response of the different therapy, and outcome of patients with pulmonary fungus ball. Design: We analyzed retrospectively the medical records of patients for the characterization of pulmonary Aspergillus fungus ball. Settings: A university-based tertiary care hospital in Porto Alegre, Rio Grande do Sul, Brazil. Patients and methods: The study included patients diagnosed with pulmonary Aspergillus fungus ball in a population of 750 cases of aspergillosis, from 1980 to 2009. The criteria for the diagnosis were: isolation of Aspergillus species from the material of the pulmonary cavity associated with the compatible radiographic image; isolation of Aspergillus species from other materials of the respiratory tract, excluding cavity material, with or without direct examination positive; double immunodiffusion positive for Aspergillus associated with compatible image. Results: We included 391 patients with pulmonary Aspergillus fungus ball, age ranged from 18 to 78 years, 67.3% were male. The diagnosis was based on clinical, radiological, and laboratory findings. In all patients we detected the characteristic findings of fungal ball, on X-ray and tomography; and complex fungal ball, on their radiological appearance, was detected in 97.4% of cases. Healed tuberculosis was the commonest pre-existing disease (89%). Hemoptysis was the major symptoms (89%). The species A. fumigatus was the most common etiologic agent, 89.3% of cases, followed by 7.1% A niger and A flavus less frequent in 3.3%. Culture was positive in 84.7% specimes, and immunodiffusion in 81.6% patients. The main treatment was surgical resection in 88.3% that had a favorable outcome. Spontaneous lysis was obtained in 2.3% of cases. Mortality was attributed to the surgery and hemoptysis in 32.3 and 13.8%, respectively. Conclusions: Patient with healed tuberculosis and hemoptysis is the first hypothesis diagnostic fungus ball. The most frequent radiological signs were rounded dense opacity surrounded with a halo of air in a thick cavity wall and thickening of the pleura over cavity. The detection of serum antibodies by double immunodiffusion, and the cultive of the lower respiratory tract specimens determined A. fumigatus as the main agent of pulmonary fungal ball. The detection of serum antibodies by double immunodiffusion, and the cultivation of the lower respiratory tract specimens determined A. fumigatus as the main agent of pulmonary fungal ball. The measure most commonly used therapy in patients of this study was to surgical resection, and half of the patients who died were in these cases.
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Estudo etiológico, clínico, laboratorial e epidemiológico da bola fúngica pulmonar por Aspergillus spp / Etiological, clinical, laboratory and epidemiologic study of fungus ball by Aspergillus sppGuazzelli, Luciana Silva January 2011 (has links)
Descrição: Bola fúngica é definida como uma macrocolônia composta por emaranhado de hifas, células inflamatórias, fibrina, muco e fragmentos de tecidos. Aspergillus fumigatus é o agente etiológico mais frequente, responsável por cerca de 90% dos casos, seguido de A niger e A flavus, respectivamente. O antecedente mais comum para o desenvolvimento da bola fúngica é cavidade secundária à tuberculose e a manifestação clínica mais presente e causadora de óbitos nesses pacientes é a hemoptise. Objetivos: Investigar as espécies de Aspergillus causadoras de bola fúngica pulmonar, determinar as condições predisponentes e/ou associadas e a comprovação laboratorial para o diagnóstico etiológico e observar a resposta as diferentes medidas terapêuticas dos pacientes com bola fúngica pulmonar. Delineamento: Foram analisados retrospectivamente, prontuários de pacientes para a caracterização da bola fúngica pulmonar por Aspergillus. Local do estudo: Laboratório de Micologia da Santa Casa Complexo Hospitalar, no período de 1980 a 2009. Pacientes e métodos: Foram incluídos neste estudo todos os pacientes com diagnóstico de bola fúngica pulmonar aspergilar de uma população de 750 casos de aspergilose, de 1980 a 2009. Os critérios para o diagnóstico foram os seguintes: isolamento da espécie de Aspergillus proveniente do material de cavidade pulmonar associado à imagem radiográfica compatível; isolamento da espécie de Aspergillus em outros materiais do trato respiratório, excluindo material da cavidade, associado ou não ao exame direto positivo; imunodifusão radial dupla positiva para Aspergillus associada ao exame de imagem compatível. Resultados: Foram incluídos 391 pacientes com bola fúngica pulmonar aspergilar, a idade variou de 18-78 anos, sendo 67,3% do gênero masculino. O diagnóstico foi baseado nos achados clínicos, radiológicos e laboratoriais. Em todos os pacientes foram detectados achados característicos de bola fúngica tanto no radiograma quanto na tomografia de tórax e bola fúngica complexa foi detectado em 97,4% da casuística. Tuberculose curada foi a principal condição predisponente (89%). Hemoptise foi manifestação clínica mais frequente (89%). A espécie A. fumigatus foi o agente etiológico mais isolado, 89,3% dos casos, seguido de A niger 7,1% e menos frequente A flavus 3,3%. A positividade no cultivo foi de 84,7% nos espécimes clínicos e a imunodifusão radial dupla de 81,6% dos pacientes. A principal medida terapêutica foi ressecção cirúrgica apresentando desfecho favorável em 88,3%. A eliminação da bola fúngica por lise espontânea ocorreu em 2,3% dos casos. Mortalidade foi atribuída à cirurgia e a hemoptise em 32,3 e 13,8%, respectivamente. Conclusões: Tuberculose curada e hemoptise é a primeira hipótese diagnóstica de bola fúngica pulmonar. O sinal radiológico indicativo de bola fúngica é cavidade contendo produto patológico com densidade de partes moles, espessamento da parede da cavidade e da pleura circunjacente. A detecção de anticorpos séricos por imunodifusão radial dupla, e o cultivo de espécimes do trato respiratório inferior determinaram A. fumigatus como o principal agente etiológico da bola fúngica pulmonar. A medida terapêutica mais utilizada nos pacientes do presente estudo foi ressecção cirúrgica, e a metade da ocorrência de óbito esteve presente nestes casos. / Background: Pulmonary fungus ball is defined as a conglomeration, within a cavity of intertwined Aspergillus hyphae, inflammatory cells, fibrin, mucus and cellular debris. Aspergillus fumigatus is the most frequent etiologic agent, about 90% of cases, followed by A niger and A flavus, respectively. The most common condiction to develop fungus ball is residual cavities of healed tuberculosis, and the most prevalent clinical manifestation and cause of death is hemoptysis in these patients. Objectives: To investigate the species of Aspergillus causing pulmonary fungus ball, we compared underlying conditions, laboratory evidence to the etiological diagnosis, and response of the different therapy, and outcome of patients with pulmonary fungus ball. Design: We analyzed retrospectively the medical records of patients for the characterization of pulmonary Aspergillus fungus ball. Settings: A university-based tertiary care hospital in Porto Alegre, Rio Grande do Sul, Brazil. Patients and methods: The study included patients diagnosed with pulmonary Aspergillus fungus ball in a population of 750 cases of aspergillosis, from 1980 to 2009. The criteria for the diagnosis were: isolation of Aspergillus species from the material of the pulmonary cavity associated with the compatible radiographic image; isolation of Aspergillus species from other materials of the respiratory tract, excluding cavity material, with or without direct examination positive; double immunodiffusion positive for Aspergillus associated with compatible image. Results: We included 391 patients with pulmonary Aspergillus fungus ball, age ranged from 18 to 78 years, 67.3% were male. The diagnosis was based on clinical, radiological, and laboratory findings. In all patients we detected the characteristic findings of fungal ball, on X-ray and tomography; and complex fungal ball, on their radiological appearance, was detected in 97.4% of cases. Healed tuberculosis was the commonest pre-existing disease (89%). Hemoptysis was the major symptoms (89%). The species A. fumigatus was the most common etiologic agent, 89.3% of cases, followed by 7.1% A niger and A flavus less frequent in 3.3%. Culture was positive in 84.7% specimes, and immunodiffusion in 81.6% patients. The main treatment was surgical resection in 88.3% that had a favorable outcome. Spontaneous lysis was obtained in 2.3% of cases. Mortality was attributed to the surgery and hemoptysis in 32.3 and 13.8%, respectively. Conclusions: Patient with healed tuberculosis and hemoptysis is the first hypothesis diagnostic fungus ball. The most frequent radiological signs were rounded dense opacity surrounded with a halo of air in a thick cavity wall and thickening of the pleura over cavity. The detection of serum antibodies by double immunodiffusion, and the cultive of the lower respiratory tract specimens determined A. fumigatus as the main agent of pulmonary fungal ball. The detection of serum antibodies by double immunodiffusion, and the cultivation of the lower respiratory tract specimens determined A. fumigatus as the main agent of pulmonary fungal ball. The measure most commonly used therapy in patients of this study was to surgical resection, and half of the patients who died were in these cases.
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Mutantní glykosidasy s vysokou substrátovou specifitou a jejich analýza / Mutant glycosidases with a high substrate specificity and their analysisNekvasilová, Pavlína January 2019 (has links)
β-N-acetylhexosaminidases (EC 3.2.1.52, GH 20) are retaining exo-glycosidases that in vivo cleavage both β-N-acetylglucosamine (GlcNAc) or β-N-acetylgalactosamine (GalNAc) residues fom glycostructures. Under suitable reaction conditions, these enzymes are able to synthesize the glycosidic bond in good yields. Substitution of selected amino acid(s) in the emzyme active site by site-directed mutagenesis may change the enzyme's substrate specificity or suppress the hydrolytic activity of the enzyme in favor of synthesis. The present thesis deals with three mutant β-N-acetylhexosaminidases from Talaromyces flavus, in which the amino acid residues responsible for binding to C-4 hydroxyl of the substrate (Arg218, Glu546) were exchanged for amino acids proposed on the basis of molecular modeling. The effect of introduced single point mutations on substrate specificity of prepared enzymes was studied. Mutant β-N-acetylhexosaminidases were heterologously expressed in Pichia pastoris and characterized. Furthermore, transglycosylation reactions with these enzymes were performed. The prepared carbohydrate products were characterized by NMR.
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Connectivity of Coastal and Oceanic Ecosystems: Pelagic Habitat Use by Juvenile Reef Fishes in the Gulf of MexicoBowen, Katie 09 December 2015 (has links)
The assemblage structure, abundance, biomass, and vertical distribution of juvenile reef fishes in the offshore pelagic habitat of the northern Gulf of Mexico are described as part of the NOAA-supported Offshore Nekton Sampling and Analysis Program. The results presented here are from a 3-month, continuous sampling series in 2011 in which discrete depth strata from 0 to 1500 m were sampled using a 10-m2 MOCNESS midwater trawl. This is the first study to examine pelagic juvenile reef fish distributions across the entire oceanic northern Gulf of Mexico seaward of the continental shelf break after the Deepwater Horizon Oil Spill. During this series, 87,407 specimens were collected, of which 838 were reef fishes, representing seven orders, 30 families and 119 species. The faunal composition of pelagic juvenile reef fishes was diverse and well mixed, with no discernable spatial structure with respect to water masses and solar cycle. Seventy-nine percent of the pelagic juvenile reef fishes were collected in the epipelagic and the dominant families were Congridae, Carangidae, Tetraodontidae, and Acanthuridae. Species richness, biomass, and frequency of occurrence of pelagic juvenile reef fishes was greatest between 0-200 m and decreased with depth. Data from the assemblage structure, abundance, biomass, and vertical distribution of pelagic juvenile reef fishes collected from this cruise series will contribute to the lack of knowledge regarding the dispersal dynamics and coastal-connectivity of these fishes in the northern Gulf of Mexico.
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