997 resultados para Candida spp - Teses


Relevância:

20.00% 20.00%

Publicador:

Resumo:

A population survey of the giant conifer aphid Cinara spp. was carried out in two areas of Pinus elliottii using yellow pan traps, during two years, from July 1997 to June 1999. During the collection period, the predominant species was Cinara pinivora (Wilson, 1919), representing 99% of the collected species. A few specimens of Cinara maritimae (Dufour, 1833) and only one winged female of Cinara fresai Blanchard, 1939 were collected. The population of C. pinivora was statistically higher in the area with 4.5 year-old trees than in the 1.5 year-old ones. The highest population peaks were registered in July 1997 and in August 1998. An unexpected high number of winged parthenogenetic females was collected in December 1998. C. fresai Blanchard, 1939 is recorded for the first time for Brazil.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Field surveys were carried during four soybean seasons in Southern Brazil to evaluate the occurrence of parasitoids in eggs of Anticarsia gemmatalis Hübner, 1818 and their incidence along the crop season. Eggs were collected by visual search on soybean leaves and from plants kept inside cages where A. gemmatalis moths were allowed to lay eggs. Trichogramma acacioi Brun, Moraes & Soares, 1984 was recorded for the first time in eggs of A. gemmatalis and the citations in the literature of Trichogramma lasallei Pinto, 1998 in Brazil where based on the material collected in this survey. Apart from these species, Trichogramma pretiosum Riley, 1879, Trichogramma rojasi Nagaraja & Nagarkatti, 1973 and Trichogramma atopovirilia Oatman & Platner, 1983 were also collected, all of which have been previously recorded in this host. Parasitized eggs were collected all over the period of occurrence of A. gemmatalis, from January to April each year. Total parasitism ranged from 4.8% in 2000 and 2002, 23.3% in 2001 and 28.9% in 2003. T. pretiosum and T. acacioi accounted for more than 80% of the parasitoids emerged each year, followed by T. atopovirilia, T. rojasi and T. lasallei, with less than 20% of incidence. Both the sex ratio and the mean number of parasitoids/egg did not differ among the species. Searching for A. gemmatalis eggs proved to be time consuming in comparison to the collection of eggs laid by moths inside the cages, which showed to be a useful method to provide qualitative estimates of parasitism in eggs of A. gemmatalis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

O objetivo deste trabalho foi avaliar o potencial de utilização de Trichogramma atopovirilia Oatman & Platner, 1983 e T. pretiosum Riley, 1879 como agentes de controle de Ecdytolopha aurantiana (Lima, 1927) (Lepidoptera: Tortricidae), importante praga da citricultura paulista. Foram realizados estudos de biologia em diferentes temperaturas, exigências térmicas e capacidade de parasitismo, visando fornecer subsídios a programas de controle biológico com estes parasitóides. A razão sexual não foi afetada pelas temperaturas estudadas (18, 20, 22, 25, 28, 30 e 32ºC), porém, a longevidade de fêmeas das duas espécies foi maior a 22 e 25ºC. Para a porcentagem de emergência e longevidade de fêmeas, a temperatura que tendeu a ser mais adequada foi a de 25ºC. A duração do período ovo-adulto para as duas espécies foi inversamente relacionada com o aumento da temperatura, sendo as exigências térmicas dessas espécies muito próximas, em torno de 108 GD. O hospedeiro natural, E. aurantiana, ou o alternativo, Anagasta kuehniella (Zeller, 1879) (Lepidoptera, Pyralidae), não afetaram o número de ovos parasitados por fêmea de Trichogramma. Porém, a porcentagem de parasitismo e o número de adultos emergidos por ovo, quando provenientes de ovos de E. aurantiana, foram maiores do que os criados sobre ovos de A. kuehniella. A porcentagem de emergência foi, no entanto, maior quando os parasitóides foram provenientes de ovos de A. kuehniella. As duas espécies de Trichogramma estudadas poderão ser testadas em campo para controle do bicho-furão-dos-citros, havendo uma indicação de que as exigências térmicas também podem servir como um bom parâmetro para seleção de espécies e/ou linhagens de Trichogramma, aliadas ao estudo de capacidade de parasitismo.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The flowering phenologies of Sessea brasiliensis and three species of Cestrum (C. amictum, C. schlechtendalii and C. sendtnerianum), all belonging to the Solanaceae, were monitored in a fragment of the montane Atlantic rain forest within São Paulo city from July 1993 through June 1995. A total of 11,021 flies belonging to five species of the flavopilosa group of Drosophila (D. cestri, D. cordeiroi, D. hollisae, D. incompta and D. mariaehelenae), plus 1,244 flies belonging to four species of Zygothrica (Z. dispar, Z. vittimaculosa, Z. vittinubila and Z. aff. vittipunctata) emerged from 33,955 sampled flowers. Cestrum amictum, C. sendtnerianum and Sessea brasiliensis are recorded for the first time as host plants for the species of the Neotropical flavopilosa group ofDrosophila. Additionally, at least ten less abundant taxa belonging also to the Drosophilidae, plus 1,073 microhymenopteran parasitoids (Braconidae, Eucoilidae, and Pteromalidae), emerged from the sampled flowers of S. brasiliensis e Cestrum spp. The present study raised from nine to eleven the number of species of Cestrum previously recorded as breeding sites for these flies. A comprehensive list of species of Solanaceae known to host six species of Drosophila and four species of Zygothrica in southeastern and southern Brazil is included.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The identification of novel transcription factors associated with antifungal response may allow the discovery of fungus-specific targets for new therapeutic strategies. A collection of 241 Candida albicans transcriptional regulator mutants was screened for altered susceptibility to fluconazole, caspofungin, amphotericin B, and 5-fluorocytosine. Thirteen of these mutants not yet identified in terms of their role in antifungal response were further investigated, and the function of one of them, a mutant of orf19.6102 (RCA1), was characterized by transcriptome analysis. Strand-specific RNA sequencing and phenotypic tests assigned Rca1 as the regulator of hyphal formation through the cyclic AMP/protein kinase A (cAMP/PKA) signaling pathway and the transcription factor Efg1, but also probably through its interaction with a transcriptional repressor, most likely Tup1. The mechanisms responsible for the high level of resistance to caspofungin and fluconazole observed resulting from RCA1 deletion were investigated. From our observations, we propose that caspofungin resistance was the consequence of the deregulation of cell wall gene expression and that fluconazole resistance was linked to the modulation of the cAMP/PKA signaling pathway activity. In conclusion, our large-scale screening of a C. albicans transcription factor mutant collection allowed the identification of new effectors of the response to antifungals. The functional characterization of Rca1 assigned this transcription factor and its downstream targets as promising candidates for the development of new therapeutic strategies, as Rca1 influences host sensing, hyphal development, and antifungal response.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Parasitóides do gênero Neodohrniphora Malloch, 1914 geralmente atacam operárias de Atta sexdens rubropilosa Forel, 1908 em baixa freqüência, mas os ataques alteram o ritmo de forrageamento das colônias, reduzindo o número e tamanho das operárias e aumentando o abandono de fragmentos vegetais ao longo das trilhas. O forrageamento de A. sexdens rubropilosa pode ser diurno ou noturno, mas existem dúvidas se Neodohrniphora spp. atacam as operárias dessa formiga também durante a noite. Os objetivos deste estudo foram verificar a ocorrência de ataques e avaliar o grau de parasitismo de forídeos do gênero Neodohrniphora em operárias de A. sexdens rubropilosa sob três níveis de luminosidade em laboratório, incluindo a ausência de luz. Os níveis de luminosidade foram: alta (0,65 µmol/m³/s); baixa (0,05 µmol/m³/s) e ausência de luz (0,0 µmol/m³/s). Fêmeas de Neodohrniphora tonhascai Brown, 2001 e Neodohrniphora elongata Brown, 2001 coletadas no campo e liberadas em laboratório somente efetuaram ataques e foram obtidas operárias parasitadas sob alta luminosidade, sugerindo que essas espécies não são ativas no campo durante o período noturno (ausência de luz). Os resultados sugerem também que o estímulo visual em Neodohrniphora spp. pode ser um componente essencial para a localização e reconhecimento do hospedeiro.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Biologia do psilídeo-de-concha Glycaspis brimblecombei Moore (Hemiptera, Psyllidae) em Eucalyptus spp.. Glycaspis brimblecombei Moore também conhecido por psilídeo-de-concha, se caracteriza por ser uma espécie específica ao gênero Eucalyptus L'Her. Este trabalho teve por objetivo determinar o ciclo biológico de G. brimblecombei em Eucalyptus spp. O trabalho foi conduzido em câmara climatizada (BOD), sob a temperatura de 26 °C e fotofase de 12 horas. As espécies de Eucalyptus utilizadas para o experimento foram: Eucalyptus camaldulensis, E. tereticornis, E. urophylla, E. grandis, Corymbia citriodora e um híbrido de E. grandis x E. urophylla ('urograndis'). Inicialmente foram utilizados 100 repetições (ninfas) tratamento (espécies de Eucalyptus). As avaliações foram diárias. Os parâmetros biológicos avaliados foram a duração e viabilidade do estágio ninfal, longevidade dos adultos, número de posturas/fêmea, duração do período embrionário, número e viabilidade ovos, longevidade dos adultos e duração do ciclo total. Os resultados obtidos demonstraram que salvo C. citriodora que apresentou ser letal ao desenvolvimento ninfal de G. brimblecombei as demais espécies de Eucalyptus testadas oferecem condições ao desenvolvimento biológico deste psilídeo, sendo que neste trabalho E. camaldulensis mostrou-se a mais adequada.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of our survey was to assess the effect of irrigation water of the microbiological quality on the production chain of lettuce in the Dakar area. Microbiological analysis showed that 35% of irrigation water was contaminated by Salmonella spp. between the two water-types used for irrigation (groundwater and wastewater), no significant difference (p>0.05) in their degree of contamination was found. The incidence of different types of irrigation water on the contamination rate of lettuces from the farm (Pikine and Patte d'Oie) was not different either (p>0.05). However, the contamination rate of lettuce from markets of Dalifort and Grand-Yoff that were supplied by the area of Patte d'Oie was greater than those of Sham and Zinc supplied by Pikine (p<0.05). Comparison of serotypes of Salmonella isolated from irrigation water and lettuce showed that irrigation water may affect the microbiological quality of lettuce. Manures, frequently used as organic amendment in cultivating lettuce are another potential source of contamination. These results showed that lettuce may constitute effective vectors for the transmission of pathogens to consumers. Extensive treatment of the used wastewater and/or composting of manure could considerably reduce these risks.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Feeding and oviposition preferences of Ctenarytaina spatulata Taylor (Hemiptera, Psyllidae) for Eucalyptus spp. and other Myrtaceae in Brazil. The Australian psyllid, Ctenarytaina spatulata Taylor (Hemiptera, Psyllidae), was first detected in Brazil in 1994, where it was found on drought-affected shoots of Eucalyptus grandis in a plantation located in the northern part of Paraná State. The oviposition and feeding preferences of this psyllid were examined on 19 Eucalyptus species, one Eucalyptus hybrid (Cambiju), three Corymbia species and four native Myrtaceae species (Hexaclames edulis, Marlieria edulis, Plinia trunciflora, and Psydium sp.) under greenhouse conditions. The largest populations of C. spatulata were found on E. robusta and E. pellita, while sizeable infestations were also found on E. urophylla, E. grandis, and the Cambiju hybrid. The plants with the greatest symptoms of damage were E. grandis and E. resinifera. Eucalyptus cinerea, E. benthamii, E. pilularis, and E. dunnii were not infested and E. cloeziana was minimally infested. Among the Corymbia species, the number of eggs of C. spatulata was very low on C. citriodora and C. torelliana. No eggs and nymphs of C. spatulata were found on native Brazilian Myrtaceae. The number of eggs on plants was highly correlated with the subsequent levels of nymphs, suggesting that egg counts can be used as a viable monitoring tool to assist with the integrated management of this pest.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

From a collection of yeast isolates isolated from patients in Tunisian hospitals between September 2006 and July 2010, the yeast strain JEY63 (CBS 12513), isolated from a 50-year-old male that suffered from oral thrush, could not be identified to the species level using conventional methods used in clinical laboratories. These methods include matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), germ tube formation, and the use of CHROMagar Candida and metabolic galleries. Sequence analysis of the nuclear rRNA (18S rRNA, 5.8S rRNA, and 26S rRNA) and internal transcribed spacer regions (ITS1 and ITS2) indicated that the ribosomal DNA sequences of this species were not yet reported. Multiple gene phylogenic analyses suggested that this isolate clustered at the base of the Dipodascaceae (Saccharomycetales, Saccharomycetes, and Ascomycota). JEY63 was named Candida tunisiensis sp. nov. according to several phenotypic criteria and its geographical origin. C. tunisiensis was able to grow at 42°C and does not form chlamydospores and hyphae but could grow as yeast and pseudohyphal forms. C. tunisiensis exhibited most probably a haploid genome with an estimated size of 10 Mb on at least three chromosomes. Using European Committee for Antimicrobial Susceptibility Testing (EUCAST) and Clinical and Laboratory Standards Institute (CLSI) Candida albicans susceptibility breakpoints as a reference, C. tunisiensis was resistant to fluconazole (MIC = 8 μg/ml), voriconazole (MIC = 0.5 μg/ml), itraconazole (MIC = 16 μg/ml), and amphotericin B (MIC = 4 μg/ml) but still susceptible to posaconazole (MIC = 0.008 μg/ml) and caspofungin (MIC = 0.5 μg/ml). In conclusion, MALDI-TOF MS permitted the early selection of an unusual isolate, which was still unreported in molecular databases but could not be unambiguously classified based on phylogenetic approaches.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ants are among the most common arthropods that colonize termite nests. The aim of this study was to identify the ant fauna associated to termite nests found in a cacao plantation in the county of Ilhéus, Bahia, Brazil, with emphasis on the fauna that uses the nests as foraging and/or nesting environment. For this purpose, 34 active, decadent and abandoned nests of Nasutitermes corniger, N. ephratae and Nasutitermes sp., with different volumes and degrees of activity, were dissected. A total of 54 ant species, belonging to 23 genera and five subfamilies, was found in the constructions. The active, decadent and abandoned termite nests presented, respectively, six, eight and 48 ant species. Crematogaster acuta and Ectatomma tuberculatum were the most frequent species in the active and decadent nests, respectively, while the most frequent species in the abandoned nests were Solenopsis pollux, Thaumatomyrmex contumax and Thaumatomyrmex sp. Twenty-six ant species had true colonies within the termitaria. The Formicidae species richness in the nests was inversely related to the degree of termite activity in the nests. The occurrence of living, decadent or abandoned termitaria of Nasutitermes spp. in cacao plantations foments the heterogeneity of habitats available in the plantations and favors the maintenance of high diversity of organisms that use obligatory or opportunistically this substrate.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A base de datos obtenidos en los años 1976,1981,1983,1984,1985 aproximadamente entre 3° 30’ y 12° 30’ S en la plataforma continental peruana, se analizaron diámetros de células, presencia de tricomas en vainas, distribuciones y biomasas húmedas y secas sin ceniza de Thioploca spp.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Interaction betweeen Telenomus remus and Trichogramma pretiosum in the management of Spodoptera spp. The use of egg parasitoids is a promising strategy for Integrated Pest Management (IPM), but different species of parasitoids have greater or lesser control efficiency, depending on the pest species. Recently, not only Anticarsia gemmatalis and Pseudoplusia includens but also Spodoptera cosmioides and S. eridania have been among the key Lepidoptera larvae attacking soybeans. This study evaluated the combination of Telenomus remus and Trichogramma pretiosum for parasitism of eggs of the Spodoptera complex, for better control efficiency and broader spectrum of action among the key pests of soybeans. The experiment was carried out under controlled environmental conditions (25 ± 2ºC; 70 ± 10% RH; and 14 h photophase) in a completely randomized experimental design with seven treatments and 10 replicates with S. frugiperda, S. cosmioides and S. eridania eggs. Each replicate consisted of one egg mass of each Spodoptera species, with approximately 100 eggs offered to the parasitoids. The treatments were: 1) 10 females of T. pretiosum; 2) nine females of T. pretiosum and one female of T. remus; 3) eight females of T. pretiosum and two females of T. remus; 4) seven females of T. pretiosum and three females of T. remus; 5) six females of T. pretiosum and four females of T. remus; 6) five females of T. pretiosum and five females of T. remus, and 7) 10 females of T. remus. The parameter evaluated was the percentage of parasitized eggs. Results showed that treatments combining both parasitoid species with only 1 T. remus for each 9 T. pretiosum (10%) and only 2 T. remus for each 8 T. pretiosum (20%) were enough to significantly increase the parasitism observed on eggs of S. cosmioides and S. frugiperda, respectively. This association of T. pretiosum and T. remus in different proportions is very promising for biological control in IPM programs because it provides wide spectrum of control.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

As the mortality associated with invasive Candida infections remains high, it is important to make optimal use of available diagnostic tools to initiate antifungal therapy as early as possible and to select the most appropriate antifungal drug. A panel of experts of the European Fungal Infection Study Group (EFISG) of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) undertook a data review and compiled guidelines for the clinical utility and accuracy of different diagnostic tests and procedures for detection of Candida infections. Recommendations about the microbiological investigation and detection of candidaemia, invasive candidiasis, chronic disseminated candidiasis, and oropharyngeal, oesophageal, and vaginal candidiasis were included. In addition, remarks about antifungal susceptibility testing and therapeutic drug monitoring were made.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Partial DNA sequences from two mitochondrial (mt) and one nuclear gene (cytochrome b, 12S rRNA, and C-mos) were used to estimate the phylogenetic relationships among the six extant species of skinks endemic to the Cape Verde Archipelago. The species form a monophyletic unit, indicating a single colonization of the islands, probably from West Africa. Mabuya vaillanti and M. delalandii are sister taxa, as indicated by morphological characters. Mabuya fogoensis and M. stangeri are closely related, but the former is probably paraphyletic. Mabuya spinalis and M. salensis are also probably paraphyletic. Within species, samples from separate islands always form monophyletic groups. Some colonization events can be hypothesized, which are in line with the age of the islands. C-mos variation is concordant with the topology derived from mtDNA.