849 resultados para Leveduras - Taxonomia
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A taxonomic survey of representatives of the genus Geastrum took place during the rainy season from 2006 to 2009 in four districts in the state of Rio Grande do Norte: Parque Estadual Dunas do Natal (Atlantic Forest), Mata do Jiqui EMPARN (Atlantic Forest) and Estação Ecológica do Seridó (Caatinga). Fourteen species were recorded: G. entomophilum, G. fimbriatum, G. hirsutum, G. javanicum, G. lageniforme, G. lloydianum, G. minimum, G. morganii, G. ovalisporum, G. pectinatum, G. saccatum, G. schweinitzii, G. setiferum and G. triplex. Of these species, eleven occurred in the Atlantic Forest and six in the Caatinga. A new species has been recorded to science, G. entomophilum, other as a first record for Brazil, G. morganii, six new records for the Northeast, and ten new records for Rio Grande do Norte. The material was tumbled in the Herbarium UFRN. Additionally, a survey of the species of the genus deposited in the Herbarium UFRN was accomplished, resulting in 244 herbarium specimens belonging to thirty-three species. Of these ones, twenty-three were collected in Brazil and ten are from Czech Republic, Europe, as donation from the VZ Herbarium
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Candidíase é um problema de importância crescente, devido o aumento do número de indivíduos imunocomprometidos e o surgimento de cepas resistentes aos antifúngicos convencionais. É de fundamental importância a busca por novos agentes antifúngicos mais eficazes, menos tóxicos, sendo os óleos essenciais (OEs) excelentes alternativas para esse propósito. Esse estudo investigou a atividade biológica do OE de Mentha spicata L. sobre Candida guilliermondii de origem anal e vaginal. Para tanto foram determinadas a Concentração Inibitória Mínima (CIM), Concentração Fungicida Mínima (CFM), cinética do crescimento das leveduras (Time-Kill), alterações micromorfológicas (técnica do microcultivo em câmara úmida) e investigação do mecanismo de ação antifúngico, utilizando o bioensaio do sorbitol. O OE de M. spicata foi obtido pelo processo de extração por destilação a vapor. Na análise fitoquímica desse óleo foi observada a presença de carvona com 84,32%, seguida pelo limoneno (13,70%) e traços de iso-dihidrocarvona (0,82%). Os resultados da análise da CIM variou entre 32 e 128 μg/mL. A CFM variou entre 64 e 1024 μg/mL. Na avaliação da ação de OE e da nistatina 100UI/mL, o antifúngico padrão apresentou o efeito fungicida a partir de 4 horas e para OE de M. spicata foi observado efeito fungistático na CIM, CIMX2 e CIMX4 frente às cepas avaliadas. O OE de M. spicata apresentou forte atividade antifúngica contra as cepas de C. guilliermondii, promovendo alterações micromorfológicas visíveis por microscopia óptica, nas concentrações testadas (CIM, CIMx2), resultado semelhante ao que se observou com a nistatina (100UI/mL). Na investigação do mecanismo de ação antifúngico foi constatado que houve alteração da CIM na presença de sorbitol, com elevação dos valores quatro vezes maior que a concentração inicial, o que indica que os componentes desse OE apresentam ação direta sobre a parede celular das leveduras. Conclui-se que o OE de Mentha spicata é um potencial agente terapêutico no tratamento de candidíase
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Dermatomycoses are fungal infections that attack the skin, hair and nails, in addition to the mucosal and cutaneous-mucosal zones. Objective: Observe the frequency of dermatomycoses, identify etiological agents and establish an association between the results and sex. Age, collection site, time and lesion location. Methods: Between February, 2002 and December, 2004, samples were collected from patients at Giselda Trigueiro Hospital in Natal, Brazil, by lesion scraping and hair removal, following 70% alcohol disinfection, and submitted to direct and culture examination. Results: Of the 817 lesions collected, 325 (39.8%) were fungus positive, with the hair collection site yielding the highest number of positive results (65.8%) and the scalp and hair representing the most frequent lesion sites (65.9%). Negative results occurred mainly in the lower limbs (78.6%). Of the species identified, 55.9% were yeasts, 41.6% dermatophytes and 2.5% Fusarium spp. Non-albicans Candida was the most isolated yeast (43.3%), mainly in females (61.7%) over the age of 40 years (56.4%). T. rubrum was the most isolated dermatophyte (67.9%),notably in males (59.2%) in the 0-20 age group (44.7%). With respect to collection site, 73.9% of the dermatophytes were present in the skin and 61.1% of the yeasts in the nails. When assessing the collection site, the inguinocrural regional was 22.6% positive for dermatophytes, and the nails and hands, 41.8% for yeasts. Conclusions: The results obtained verified that: most of the positive lesions were found in the hair, whereas skin and nail lesions yielded more negative results; T. rubrum was the most isolated dermatophyte and non-albicans candida the most commonly found yeast; positivity was greater in males in the 0-20 year age group at the skin site and in the inguinocrural region, while yeasts were more frequent in females in the over-40 age group at the nail sites
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Post-menarche patients with clinical signs of vulvovaginitis were analyzed in this study, whose aims were the following: identify the frequency of C. albicans and non C. albicans species and negative results, correlate the vaginal culture for yeast with risk factors and symptomatology; compare positive and negative results for yeast in the vaginal and anal cultures; compare the positive results for C. albicans with other results found in the vaginal and anal cultures; and compare concomitant positivity for C. albicans and non C. albicans in the vaginal and anal cultures. Sample selection occurred between May, 2003 and May, 2005, and included 99 patients from Natal, Brazil. The laboratory methods used consisted of CHROMagar Candida culture medium, thermotolerance test at 42-45°C and hypertonic NaCL, in addition to the classic methods of carbohydrate assimilation and fermentation. We used absolute numbers, percentages, means of central tendency, chi-squared test (χ2) with Yates correction, Fisher s exact test and odds ratio for statistical analysis. The most frequent species was C. albicans in 69% of the cases. The positivity for Candida spp showed an association with the use of tight-fitting intimate clothing and/or synthetics, allergic diseases and the occurrence of itching, leukorrhea and erythema. Anal colonization increased the likelihood of vaginal contamination by 2.8 and 4.9 times, respectively, for Candida spp and C. albicans. When compared to the other species, C. albicans-positive anal colonization increased by 3.7 times the likelihood of vaginal positivity. These data suggest likely vaginal contamination originating in the anus
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Young and mature larvae of queen and workers of the thief ant, Solenopsis helena, are herein described for the first time. Specimens were treated and described by usual methods of light and scanning electron microscopy. Many of the observed characteristics confirmed traits of the thief ant larva, reinforcing the assumption that they are a distinct group from fire ants. The larva of S. helena can be recognized from other close species by details of the mouthparts, but seem extensively similar to Solenopsis molesta. These findings are useful for taxonomic studies and phylogenetic inferences.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Despite Candida species are often human commensals isolated from various oral sites such as: tongue, cheek and palatal mucosa plus subgingival region, there are some properties linked to the organism commonly known as virulence factors which confer them the ability to produce disease. Oral candidiasis is one of the main oral manifestations reported in literature related to kidney transplant patients. The objectives of the present study were to identify and investigate virulence factors of yeasts isolated from the oral cavity of kidney transplant recipients admitted at the Hospital Universitário Onofre Lopes, in Natal RN. Seventy Candida species isolated from 111 kidney transplant recipients were investigated in this study. Identification of the isolates was performed by using the evidence of germ tube formation, hypertonic broth, tolerance to grow at 42°C, micromorphology and biochemical profiles. We observed a high rate of isolation of yeasts from the oral cavity of kidney transplant recipients (63.1%) being C. albicans was the most prevalent species. Oral candidiasis was diagnosed in 14.4% of transplant recipients. We evaluated virulence properties of the isolates regarding to: biofilm formation on polystyrene microplates as well as XTT reduction, adherence to acrylic resin and human buccal epithelial cells and proteinase activity. Most isolates were able to form biofilm by the method of adhesion to polystyrene. All isolates of Candida spp. remained viable during biofilm formation when analyzed by the method of XTT reduction. The number of CFU attached to the acrylic resin suggested high adherence for C. parapsilosis. C. albicans isolates showed higher median adherence to human buccal epithelial cells than non-C. albicans Candida isolates. Nevertheless, this difference was not statistically significant. C. dubliniensis showed low ability to adhere to plastic and epithelial cells and biofilm formation. Proteolytic activity was observed for all the isolates investigated, including the unique isolate of C. dubliniensis. There was a statistically significant association between proteinase production and the presence of oral candidiasis. Studies related to oral candidiasis in renal transplant recipients are limited to clinical and epidemiological data, but investigations concerning Candida spp. virulence factor for this group of individuals are still scarce. We emphasize the importance of studies related to virulence factors of yeasts isolated from this population to contribute to the knowledge of microbiological aspects of oral candidiasis
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Vulvovaginal candidiasis (VVC) is one of the most common causes of vaginitis and affects about 75% of women of reproductive age. The majority of cases (80 to 90%) are due to C. albicans, the most virulent species of the genus Candida. Virulence attributes are scarcely investigated and the source of infection remains uncertain. Objective: This study aimed to evaluate the virulence factors and genotypes of clinical isolates of C. albicans sequentially obtained from the anus and vagina of patients with sporadic and recurrent VVC. Materials and methods: We analyzed 62 clinical isolates of C. albicans (36 vaginal and 26 anal strains). Direct examination of vaginal and anal samples and colony forming units (CFU) counts were performed. Yeasts were identified using the chromogenic media CHROMagar Candida® and by classical methodology, and phenotypically characterized regarding to virulence factors, including the ability to adhere to epithelial cells, proteinase activity, morphogenesis and biofilm formation. The genotypes of the strains were investigated with ABC genotyping, microsatellite genotyping with primer M13 and RAPD. Results: We found 100% agreement between direct examination and culture of vaginal samples. Filamentous forms were present in most of the samples of vaginal secretion, which presented CFU counts significantly higher than the samples of anal secretion. There was no statistically significant difference between virulence factors of infecting vaginal isolates and those presented by colonizing anal isolates; as well as for the comparison of the vaginal isolates from patients with different clinical conditions (sporadic or recurrent VVC). There was a decrease in the ability to adhere to HBEC, morphogenesis and biofilm formation of the vaginal isolates during the progress of infection. There was an association between the ability to express different virulence factors and the clinical manifestations presented by the patients. Genotype A was the most prevalent (93.6%), followed by genotype C (6.4%). We found maintenance of the same ABC genotype and greater prevalence of microevolution for the vaginal strains of C. albicans sequentially obtained. Vaginal and anal isolates of C. albicans obtained simultaneously from the same patient presented the same ABC genotype and high genetic relatedness. Conclusion: It is noteworthy that the proliferation of yeast and bud-to-hypha transition are important for the establishment of CVV. The expression of virulence factors is important for the pathogenesis of VVC, although it does not seem to be determinant in the transition from colonization to infection or to the installation of recurrent condition. Genotype A seems to be dominant over the others in both vaginal and anal isolates of patients with VVC. The most common scenario was microevolution of the strains of C. albicans in the vaginal environment. It is suggested that the anal reservoir constituted a possible source of vaginal infection, in most cases assessed
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The frequency of disseminated candidiasis caused by yeast has enhancing in intensive care unit. Despite the availability of new antifungal drugs, C. albicans sepsis mortality causes can be as high as 30-40%. So, it has been needed to looking for a new therapeutic medicament that helps in treatment and prevention of this infection. Previous data that demonstrated that particulated β-glucan stimulates the immune system and experiments of this work were conducted to investigating if β-glucan extracted from Saccharomices cerevisiae, could modified the evolution of mouse model C. albicans systemic infection. Balb/c mice with sepsis and β-1,3 glucan treated or not were analyzed the influence of β-1,3 glucan in survival of the animals, in the fungal burdens in kidney, in the production of urea and TNF even in the histopathology of kidney. The experiments shown that the infected animals a nd glucan treated had great survival (p<0,05), less unit form colony in kidney and normal levels of urea. In the kidney histopathology of not glucan treated animals it has seen more lesions when compared with treated animals. So we conclude that β-1,3 glucan could stimulate the immune system against disseminated C. albicans
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Foram recuperadas 58 populações de Rotylenchulus reniformis de amostras de solo e raízes de diferentes culturas e inoculadas em plantas de algodoeiro (Gossypium hirsutum) cv. COODETEC 402 e de mamona (Ricinus communis), mantidas em vasos de argila em casa de vegetação do Departamento de Fitossanidade da UNESP/FCAV, Campus de Jaboticabal - São Paulo. Foi realizado estudo morfométrico comparativo das populações ao microscópio óptico composto, seguido da ordenação das populações segundo análises multivariadas de agrupamento e de componentes principais. Foram avaliadas 11 variáveis morfométricas em dez fêmeas jovens de cada população e sete variáveis derivadas. A amplitude de variação de caracteres morfométricos em populações brasileiras desse nematóide tais como, comprimento do estilete, V e forma da cauda, é maior que em populações da mesma espécie de outras regiões do mundo. Os dados obtidos confirmam que o comprimento do estilete, presença de machos e V são suficientes para identificação de R. reniformis e que esta é a espécie do grupo predominante nos agroecossistemas brasileiros.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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As cigarras são importantes pragas de diversas culturas, entre plantas cultivadas e ornamentais. Estudos de taxonomia e morfologia de insetos são primordiais para pesquisas etológicas e para o emprego de métodos de controle. Ao estudar coleções entomológicas de cigarras, foi constatado o primeiro registro de ocorrência de Fidicinoides picea e Fidicinoides poulaini (Hemiptera: Cicadidae) no Brasil, espécies coletadas nos Estados do Pará e de Manaus, respectivamente. Neste trabalho, são apresentadas as descrições morfológicas da cabeça, do tórax, do abdome e da asa.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)