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Dermatófitos: interação patógeno-hospedeiro e resistência a antifúngicos; Dermatophytes: host-pathogen interaction and antifungal resistance

PERES, Nalu Teixera de Aguiar; MARANHÃO, Fernanda Cristina Albuquerque; ROSSI, Antonio; MARTINEZ-ROSSI, Nilce Maria
Fonte: Sociedade Brasileira de Dermatologia Publicador: Sociedade Brasileira de Dermatologia
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
36.32%
As micoses cutâneas estão entre as infecções mais comuns em humanos e se tornaram um importante problema de saúde pública, principalmente por causarem infecções invasivas em pacientes imunodeprimidos. Durante a infecção, a interação dermatófito-hospedeiro desencadeia adaptações metabólicas específicas que permitem aos patógenos aderirem e penetrarem no tecido, remodelando seu metabolismo para captar nutrientes e superar os mecanismos de defesa do hospedeiro. Esse remodelamento metabólico e a inter-relação entre metabolismo, morfogênese e resposta ao estresse são importantes fatores que estão sendo intensamente avaliados em diversos patógenos. As células do hospedeiro também respondem aos estímulos do patógeno, ativando vias de sinalização intracelular que culminam no desencadeamento de uma resposta imune contra o agente infeccioso. O entendimento molecular dessas respostas metabólicas pode ajudar no estabelecimento de novas estratégias terapêuticas. Nesta revisão, são abordados diferentes aspectos da biologia dos dermatófitos, com ênfase na interação dermatófito-hospedeiro e nos mecanismos de resistência a antifúngicos.; Cutaneous mycoses are among the most common infections in humans and have become an important public health issue because they cause invasive infections in immunocompromised patients. During the infectious process...

Enzymatic differences between the endophyte Guignardia mangiferae (Botryosphaeriaceae) and the citrus pathogen G. citricarpa

ROMAO, A. S.; SPOSITO, M. B.; ANDREOTE, F. D.; AZEVEDO, J. L.; ARAUJO, W. L.
Fonte: FUNPEC-EDITORA Publicador: FUNPEC-EDITORA
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.38%
The endophyte Guignardia mangiferae is closely related to G. citricarpa, the causal agent of citrus black spot; for many years these species had been confused with each other. The development of molecular analytical methods has allowed differentiation of the pathogen G. citricarpa from the endophyte G. mangiferae, but the physiological traits associated with pathogenicity were not described. We examined genetic and enzymatic characteristics of Guignardia spp strains; G. citricarpa produces significantly greater amounts of amylases, endoglucanases and pectinases, compared to G. mangiferae, suggesting that these enzymes could be key in the development of citrus black spot. Principal component analysis revealed pectinase production as the main enzymatic characteristic that distinguishes these Guignardia species. We quantified the activities of pectin lyase, pectin methylesterase and endopolygalacturonase; G. citricarpa and G. mangiferae were found to have significantly different pectin lyase and endopolygalacturonase activities. The pathogen G. citricarpa is more effective in pectin degradation. We concluded that there are significant physiological differences between the species G. citricarpa and G. mangiferae that could be associated with differences in pathogenicity for citrus plants.; CNPq/RHAE (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico/Programa de Capacitacao de Recursos Humanos para Atividades Estrategicas); Fundo de Defesa da Citricultura (FUNDECITRUS)

A new set of microsatellite markers for the genetic characterization of Ceratocystis fimbriata, an economically important plant pathogen

RIZATTO, Simone; BATISTA, Carlos Eduardo de Araujo; BAJAY, Miklos Maximiliano; SIGRIST, Mario Sergio; ITO, Margarida Fumiko; MONTEIRO, Mariza; CAVALLARI, Marcelo Mattos; PINHEIRO, Jose Baldin; ZUCCHI, Maria Imaculada
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.32%
Ceratocystis fimbriata is a fungal pathogen which attacks several economically important plants, but occurs in host-associated, morphologically indistinguishable forms. In Brazil, this fungus seriously attacks mango trees (Mangifera indica), causing severe loss of yield. This work aimed to develop and characterize a novel set of microsatellite markers for this important pathogen, providing researchers with new molecular tools for the characterization of isolates. Twenty polymorphic primer pairs were designed from a microsatellite-enriched library. We tested the usefulness of these markers through genotyping thirteen isolates of the fungus. On average, 6.65 alleles per locus were detected, revealing the ability of this set of markers to characterize C. fimbriata isolates associated to mango and to other plant species.; FAPESP foundation, Brazil[Proc. FAPESP 2008/02335-1]

Patossistema caupi X Macrophomina phaseolina: método de detecção em sementes, esporulação e controle do patógeno.; The pathosystem cowpea x Macrophomina phaseolina: detection in seeds, esporulation and pathogen control.

Athayde Sobrinho, Candido
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 14/01/2005 PT
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36.38%
Apesar da espécie Vigna unguiculata (L.) Walp. ser bastante rústica e estar adaptada às condições adversas de clima e solo brasileiros, seu rendimento é muito baixo. Diversas causas têm sido levantadas para explicar esse comportamento; entre elas destacam-se as doenças fúngicas, sobretudo aquelas cujos patógenos são transmitidos por sementes, em especial a podridão cinzenta do caule, causada por Macrophomina phaseolina (Tassi) Goid. A abordagem analítica desse patossistema revelou alguns problemas emergentes. Entre eles, destacam-se: a) desconhecimento da qualidade sanitária das sementes de caupi, utilizadas para semeadura; b) desunifomidade na metodologia usada para detectar os patógenos presentes nas semente; c) dificuldade na esporulação do patógeno, máxime de alguns isolados reticentes em esporular em meios artificiais de cultivo, cujo comportamento dificulta os trabalhos de seleção de genótipos resistentes; d) carência de medidas de controle do patógeno, que empreguem práticas naturais, como uso de sementes sadias, de indutores de resistência e de cultivares resistentes, de fácil uso e passível de adoção por parte dos produtores. Na estruturação da matriz lógica do presente estudo...

Estabelecimento de um patossistema modelo e análise da interação molecular planta-patógeno entre Eucalyptus grandis e Puccinia psidii Winter por meio da técnica de RNA-Seq.; Establishment of a model pathosystem and analysis of the molecular plant-pathogen interaction between Eucalyptus grandis and Puccinia psidii Winter

Leite, Thiago Falda
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 17/05/2012 PT
Relevância na Pesquisa
36.38%
Mais de 20 milhões de hectares em todo o mundo são atualmente destinados a plantações de Eucalyptus, sendo que o Brasil possui a segunda maior área. No ano de 2007 a rede internacional EUCAGEN, liderada pelo Brasil, África do Sul e Estados Unidos, surgiu com o objetivo de colaboração para a pesquisa genômica do eucalipto. A árvore escolhida para o sequenciamento (Brasuz) foi fornecida pelo Brasil e em 2011 as primeiras sequências foram disponibilizadas. Em todas as fases de seu desenvolvimento, o eucalipto está sob o constante ataque de patógenos, destacando-se a ferrugem, causada pelo Basideomiceto Puccinia psidii Winter como a mais importante doença em regiões tropicais. A doença vem se espalhando rapidamente pelo mundo e recentemente foi relatada na Austrália, centro de origem do eucalipto. Com o objetivo de estudar o mecanismo molecular da interação plantapatógeno entre Eucalyptus grandis e Puccinia psidii, estabeleceu-se um patossistema modelo composto por um isolado monopustular do fungo e plantas resistente e susceptível provenientes de uma progênie de meios irmãos da planta Brasuz. O desenvolvimento do patógeno nos genótipos selecionados foi analisado por meio de microscopia de luz e de epifluorescência...

Salmonella enterica Serovar Typhimurium Response Involved in Attenuation of Pathogen Intracellular Proliferation

Cano, David A.; Martínez-Moya, Marina; Pucciarelli, M. Graciela; Groisman, Eduardo A.; Casadesús, Josep; García-Del Portillo, Francisco
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /10/2001 EN
Relevância na Pesquisa
36.32%
Salmonella enterica serovar Typhimurium proliferates within cultured epithelial and macrophage cells. Intracellular bacterial proliferation is, however, restricted within normal fibroblast cells. To characterize this phenomenon in detail, we investigated the possibility that the pathogen itself might contribute to attenuating the intracellular growth rate. S. enterica serovar Typhimurium mutants were selected in normal rat kidney fibroblasts displaying an increased intracellular proliferation rate. These mutants harbored loss-of-function mutations in the virulence-related regulatory genes phoQ, rpoS, slyA, and spvR. Lack of a functional PhoP-PhoQ system caused the most dramatic change in the intracellular growth rate. phoP- and phoQ-null mutants exhibited an intracellular growth rate 20- to 30-fold higher than that of the wild-type strain. This result showed that the PhoP-PhoQ system exerts a master regulatory function for preventing bacterial overgrowth within fibroblasts. In addition, an overgrowing clone was isolated harboring a mutation in a previously unknown serovar Typhimurium open reading frame, named igaA for intracellular growth attenuator. Mutations in other serovar Typhimurium virulence genes, such as ompR, dam, crp, cya...

The Animal Pathogen-Like Type III Secretion System Is Required for the Intracellular Survival of Burkholderia mallei within J774.2 Macrophages

Ribot, Wilson J.; Ulrich, Ricky L.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /07/2006 EN
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36.32%
Burkholderia mallei is a highly infectious gram-negative pathogen and is the causative agent of human and animal glanders. By generating polar mutations (disruption of bsaQ and bsaZ) in the B. mallei ATCC 23344 animal pathogen-like type III secretion system (TTS), we demonstrate that this bacterial protein delivery system is required for intracellular growth of B. mallei in J774.2 cells, formation of macrophage membrane protrusions, actin polymerization, and phagosomal escape. These findings suggest that TTS plays a role in the intracellular trafficking of B. mallei and may facilitate cell-to-cell spread via actin-based motility.

Chlamydia trachomatis Species-Specific Induction of Ezrin Tyrosine Phosphorylation Functions in Pathogen Entry▿

Swanson, Kena A.; Crane, Deborah D.; Caldwell, Harlan D.
Fonte: American Society for Microbiology (ASM) Publicador: American Society for Microbiology (ASM)
Tipo: Artigo de Revista Científica
EN
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36.32%
Chlamydia trachomatis is an obligate intracellular pathogen of humans that exhibits species-specific biological characteristics in its early interactions with host cells that are likely important to pathogenesis. One such characteristic is the tyrosine phosphorylation (Tyr-P) of an ∼70-kDa polypeptide that occurs only after infection of mammalian cells by human strains. We sought to identify this protein because of its potential significance to the pathogenesis of human chlamydial infections. Using an immunoproteomic approach we identified the host protein ezrin, a member of the ezrin-radixin-moesin (ERM) protein family that serves as a physical link between host cell receptors and the actin cytoskeleton. Confocal microscopy studies showed colocalization of ezrin and actin at the tips and crypts of microvilli, the site of chlamydial attachment and entry, respectively. To demonstrate a functional role for ezrin we infected cells with a dominant-negative (DN) ezrin phenotype or treated cells with ezrin-specific small interfering RNA (siRNA). We found that both DN and siRNA-treated cells were significantly less susceptible to infection by human chlamydial strains. Moreover, we demonstrated that inhibition of infection in ezrin DN cells occurred at the stage of chlamydial entry. We hypothesize that the C. trachomatis-specific Tyr-P of ezrin might relate to an undefined species-specific mechanism of pathogen entry that involves chlamydial specific ligand(s) and host cell coreceptor usage.

Host-Pathogen Interactions of Actinobacillus pleuropneumoniae with Porcine Lung and Tracheal Epithelial Cells▿ †

Auger, Eliane; Deslandes, Vincent; Ramjeet, Mahendrasingh; Contreras, Irazù; Nash, John H. E.; Harel, Josée; Gottschalk, Marcelo; Olivier, Martin; Jacques, Mario
Fonte: American Society for Microbiology (ASM) Publicador: American Society for Microbiology (ASM)
Tipo: Artigo de Revista Científica
EN
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36.43%
Host-pathogen interactions are of great importance in understanding the pathogenesis of infectious microorganisms. We developed in vitro models to study the host-pathogen interactions of porcine respiratory tract pathogens using two immortalized epithelial cell lines, namely, the newborn pig trachea (NPTr) and St. Jude porcine lung (SJPL) cell lines. We first studied the interactions of Actinobacillus pleuropneumoniae, an important swine pathogen, using these models. Under conditions where cytotoxicity was absent or low, we showed that A. pleuropneumoniae adheres to both cell lines, stimulating the induction of NF-κB. The NPTr cells consequently secrete interleukin 8, while the SJPL cells do not, since they are deprived of the NF-κB p65 subunit. Cell death ultimately occurs by necrosis, not apoptosis. The transcriptomic profile of A. pleuropneumoniae was determined after contact with the porcine lung epithelial cells by using DNA microarrays. Genes such as tadB and rcpA, members of a putative adhesin locus, and a gene whose product has high homology to the Hsf autotransporter adhesin of Haemophilus influenzae were upregulated, as were the genes pgaBC, involved in biofilm biosynthesis, while capsular polysaccharide-associated genes were downregulated. The in vitro models also proved to be efficient with other swine pathogens...

Internalization of flax rust avirulence proteins into flax and tobacco cells can occur in the absence of the pathogen

Rafiqi, Maryam; Gan, Pamela H P; Ravensdale, Michael; Lawrence, Gregory J; Ellis, Jeffrey G; Jones, David A; Hardham, Adrienne R; Dodds, Peter N
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica Formato: 16 pages
Relevância na Pesquisa
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Translocation of pathogen effector proteins into the host cell cytoplasm is a key determinant for the pathogenicity of many bacterial and oomycete plant pathogens. A number of secreted fungal avirulence (Avr) proteins are also inferred to be delivered into host cells, based on their intracellular recognition by host resistance proteins, including those of flax rust (Melampsora lini). Here, we show by immunolocalization that the flax rust AvrM protein is secreted from haustoria during infection and accumulates in the haustorial wall. Five days after inoculation, the AvrM protein was also detected within the cytoplasm of a proportion of plant cells containing haustoria, confirming its delivery into host cells during infection. Transient expression of secreted AvrL567 and AvrM proteins fused to cerulean fluorescent protein in tobacco (Nicotiana tabacum) and flax cells resulted in intracellular accumulation of the fusion proteins. The rust Avr protein signal peptides were functional in plants and efficiently directed fused cerulean into the secretory pathway. Thus, these secreted effectors are internalized into the plant cell cytosol in the absence of the pathogen, suggesting that they do not require a pathogen- encoded transport mechanism. Uptake of these proteins is dependent on signals in their N-terminal regions...

The role of oomycete effectors in plant–pathogen interactions

Hardham, Adrienne R; Cahill, David M
Fonte: CSIRO Publishing Publicador: CSIRO Publishing
Tipo: Artigo de Revista Científica Formato: 7 pages
Relevância na Pesquisa
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Plants constantly come into contact with a diverse range of microorganisms that are potential pathogens, and they have evolved multi-faceted physical and chemical strategies to inhibit pathogen ingress and establishment of disease. Microbes, however, have developed their own strategies to counteract plant defence responses. Recent research on plant microbe interactions has revealed that an important part of the infection strategies of a diverse range of plant pathogens,including bacteria, fungi and oomycetes, is the production of effector proteins that are secreted by the pathogen and that promote successful infection by manipulating plant structure and metabolism, including interference in plant defence mechanisms. Pathogen effector proteins may function either in the extracellular spaces within plant tissues or within the plant cell cytoplasm. Extracellular effectors include cell wall degrading enzymes and inhibitors of plant enzymes that attack invading pathogens. Intracellular effectors move into the plant cell cytoplasm by as yet unknown mechanisms where, in incompatible interactions, they may be recognised by plant resistance proteins but where, incompatible interactions, they may suppress the plant’s immune response. This article presents a brief overview of our current understanding of the nature and function of effectors produced by oomycete plant pathogens.; Support from the Australian Research Council during the preparation of this review is acknowledged by both authors.

Re-organization of the cytoskeleton and endoplasmic reticulum in the Arabidopsis pen1-1 mutant inoculated with the non-adapted powdery mildew pathogen, Blumeria graminis f. sp. hordei

Takemoto, Daigo; Jones, David A; Hardham, Adrienne R
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica Formato: 11 pages
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Plant cells attacked by microorganisms rapidly translocate cytoplasm to the site of pathogen penetration, a response that usually involves rearrangement of actin microfilaments. In this study, we monitored re-organization of green fluorescent protein (GFP)-labelled actin microfilaments, microtubules and endoplasmic reticulum (ER) during infection by the powdery mildew pathogen Blumeria graminis f. sp. hordei in non-host Arabidopsis and in the rabidopsis penetration 1-1 (pen1-1) mutant, which shows increased penetration susceptibility to non-adapted pathogens. Comparison of pen1-1 with wild-type Arabidopsis showed that the actin, microtubule and ER networks all responded in the pen1-1 mutant as they do in wild-type plants. Actin microfilaments became focused on the penetration site and ER accumulated at the penetration site while the overall arrangement of micro-tubule arrays was largely unaffected. These results indicate that the block in vesicle secretion conferred by the pen1-1 mutation does not interfere with cytoplasmic aggregation or recruitment of actin or ER to the infection site. In the pen1-1 mutant, the higher rate of successful penetration by the non-adapted pathogen results in an increased incidence of hypersensitive cell death. In dying cells...

Pathogen eradication using the pistachio dieback bacterium as a model.

Vu Thanh, Tu Anh
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2012
Relevância na Pesquisa
36.46%
Pistachio dieback is a bacterial disease involving internal staining, trunk and limb lesions, decline, dieback and, in some instances, death of trees. The causal agent is Xanthomonas translucens pv. pistaciae (Xtp), a vascular pathogen that provides a local model to assess the effectiveness of existing eradication strategies for systemic bacterial pathogens of woody perennials which are likely to be introduced into Australia. Burning and burial are two accepted means of disposal of diseased plant material for eradication purposes. However, there is little or no information on the survival of bacterial pathogens following burning or burial of infected wood. The aim of the project was to evaluate the efficacy of burning and burial as means of safe disposal of diseased wood. Burning of pistachio wood, naturally infected with Xtp, was conducted twice in field conditions. Controlled laboratory experiments with pure cultures of Xtp and with naturally and artificially infected pistachio wood were performed to support the results of the burns. Viable Xtp was detected in some non-burned wood, but not in charcoal, ash or partially burned wood. In liquid culture, 65°C was lethal to Xtp whereas survival at 60°C or less varied with culture medium and duration of exposure. In infected wood Xtp survived exposure to 40 - 55°C for at least 60 min in vitro but was killed by exposure to 60°C for 15 min or more. These data corroborated the burning experiment. Survival of Xtp in infected pistachio wood placed on the soil surface or buried 10 cm deep was evaluated in an open environment at the University of Adelaide...

Molekulare Charakterisierung ausgewählter pathogenresponsiver Rezeptorkinasen aus Arabidopsis thaliana; Molecular characterization of selected pathogen-responsive receptor kinases from Arabidopsis thaliana

Schwedt, Anne
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
Relevância na Pesquisa
36.38%
Pflanzen verfügen über verschiedene Arten von Rezeptoren um die Gegenwart potentieller Pathogene zu perzipieren. Eine der größten Genfamilien unter ihnen stellt, nach Arabidopsis-Genomanalyse, die Gruppe der leuzinreichen Rezeptorkinasen (LRR-RLKs) dar. Neben der Funktion von LRR-RLKs in pflanzlichen Entwicklungsprozessen konnte bisher nur für die PAMP-Rezeptoren FLS2 und EFR eine Aufgabe in der Pathogenabwehr nachgewiesen werden. Unter Zuhilfenahme der reversen Genetik war es in dieser Arbeit möglich für drei Kandidaten die Bedeutung in Prozessen der angeborenen Immunität nachzuweisen. Die DRK5 ist scheinbar an der Vermittlung der Basisresistenz nach Pto DC3000-Infektion beteiligt. Die Überprüfung des bakteriellen Wachstums in drk5-Mutanten zeigt eine erhöhte Suszeptibilität der Pflanzen gegenüber diesem Pathogen verglichen mit dem Wildtyp. Nichtvirulente und avirulente Bakterien weisen jedoch kein verändertes Wachstum auf. Für die DRK6 war es möglich, eine Beteiligung in der kultivarspezifischen Immunantwort nachzuweisen. Ein DRK6-Gendefekt hat dabei spezifisch Einfluss auf die vollständige Etablierung der RPM1-vermittelten Resistenz. Er erhöht die Suszeptibilität der Pflanze gegenüber Pto AvrRpm1 und Pto avrB...

Molekulare und funktionelle Analyse der pathogenresponsiven Rezeptorkinase DRK3 aus Arabidopsis thaliana; Molecular and functional analysis of the pathogen induced receptor-like kinase DRK3 from Arabidopsis thaliana

Postel, Sandra
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
Relevância na Pesquisa
36.46%
Pflanzen besitzen ein Immunsystem und sind dem Angriff von Pathogenen nicht wehrlos ausgesetzt, sondern zeigen Resistenz gegen eine Vielzahl möglicher Pathogene. Es wurde gezeigt, dass einige rezeptorähnliche Kinasen (RLKs) eine wichtige Rolle bei der Erkennung von pathogenspezifischen Strukturen und bei der Aktivierung von Abwehrreaktionen spielen. Ein gut untersuchtes Beispiel ist der Flagellinrezeptor FLS2. Dieser Rezeptor weist strukturelle Ähnlichkeiten zu TOLL-ähnlichen Rezeptoren aus Säugern auf, die in immunabwehr- und entwicklungspezifische Reaktionen involviert sind. In Microarray-Experimenten wurde gezeigt, dass die Expression von 49 RLKs durch bakterielle Pathogene oder Elizitoren induziert wird. Da hierzu auch FLS2 zählt, wurde angenommen, dass möglicherweise auch andere RLKs eine Funktion in Reaktionen der Immunabwehr besitzen. Eine dieser RLKs wurde in dieser Arbeit eingehend untersucht und als defence-related receptor kinase 3 (DRK3) bezeichnet. Ein knockout dieses Genes führt in Arabidopsis Pflanzen zu einer erhöhten Resistenz gegenüber dem virulenten Bakterium Pto DC3000. Dies geht mit einer verstärkten Produktion an reaktiven Sauerstoffspezies und einem vermehrten Auftreten von Zelltod einher. Unter Verwendung des Hefe-Dihybrid-Systems wurde nach mit dem DRK3-Protein interagierenden Proteinen gesucht. Hierbei konnte als potentieller Interaktionspartner ein Resistenzprotein...

Determinants of the Sympatric Host-Pathogen Relationship in Tuberculosis

David, Susana; Mateus, A. R. A.; Duarte, Elsa L.; Albuquerque, José; Portugal, Clara; Sancho, Luísa; Lavinha, João; Gonçalves, Guilherme
Fonte: PLOS Publicador: PLOS
Tipo: Artigo de Revista Científica
Publicado em 03/11/2015 ENG
Relevância na Pesquisa
36.46%
Major contributions from pathogen genome analysis and host genetics have equated the possibility of Mycobacterium tuberculosis co-evolution with its human host leading to more stable sympatric host-pathogen relationships. However, the attribution to either sympatric or allopatric categories depends on the resolution or grain of genotypic characterization. We explored the influence on the sympatric host-pathogen relationship of clinical (HIV infection and multidrug-resistant tuberculosis [MDRTB]) and demographic (gender and age) factors in regards to the genotypic grain by using spacer oligonucleotide typing (spoligotyping) for classification of M. tuberculosis strains within the Euro-American lineage. We analyzed a total of 547 tuberculosis (TB) cases, from six year consecutive sampling in a setting with high TB-HIV coinfection (32.0%). Of these, 62.0% were caused by major circulating pathogen genotypes. The sympatric relationship was defined according to spoligotype in comparison to the international spoligotype database SpolDB4. While no significant association with Euro-American lineage was observed with any of the factors analyzed, increasing the resolution with spoligotyping evidenced a significant association of MDRTB with sympatric strains...

Development of a process-based model to predict pathogen budgets for the Sydney drinking water catchment

Ferguson, Christobel M; Croke, Barry; Beatson, Peter J.; Ashbolt, Nicholas J; Deere, D A
Fonte: I W A Publishing Publicador: I W A Publishing
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.38%
In drinking water catchments, reduction of pathogen loads delivered to reservoirs is an important priority for the management of raw source water quality. To assist with the evaluation of management options, a process-based mathematical model (pathogen ca

Pathogen Pollutant Loading Responses to Precipitation Dynamics and Land Cover

O'Banion, Ryan
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project Formato: 8504803 bytes; application/pdf
EN
Relevância na Pesquisa
36.38%
The Newport River Estuary in Carteret County, North Carolina has been placed on the state’s 303D list for its inability to meet federally mandated surface water quality criteria. A pathogen pollutant Total Maximum Daily Load (TMDL) study with fecal coliform as an indicator species has therefore been undertaken by Kenneth H. Reckhow of Duke University. Integral to the completion of this TMDL is an understanding of the terrestrial pathogen pollutant loading responses to precipitation dynamics and land use within the Newport River Estuary. This masters project investigates pathogen pollutant loading by completing three primary objectives. Through visual analysis of sampled fecal coliform and flow data, the best available data are chosen for model fitting and creation. Geospatial analysis tools are then developed in Python and ArcGIS to accurately delineate coastal watersheds with Light Detection and Ranging (LIDAR) data. The data are then used to calibrate a model to predict fecal coliform loading responses to precipitation dynamics within the Newport River Estuary. The results of the three primary objectives illustrate the complicated relationship between fecal coliform loading and precipitation events. The geospatial analysis tools allow for the accurate delineation of coastal watersheds at scales previously unavailable to managers. Additionally...

A deterministic model to quantify pathogen loads in drinking water catchments: pathogen budget for the Wingecarribee

Ferguson, C M; Croke, Barry; Ashbolt, Nicholas J; Deere, D A
Fonte: IWA Publishing Publicador: IWA Publishing
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.49%
This paper describes the development and testing of a mathematical model as a tool to quantify pathogen loads in Sydney's drinking water catchments. It has been used to identify, quantify and prioritise sources of Cryptosporidium, Giardia and E. coli in the Wingecarribee catchment. The pathogen model promotes understanding of the relative significance of different sources of pathogen risks as well as their fate and transport as they move through the subcatchments. This pathogen model not only enables water utility managers to identify those catchment segments that may contribute the highest load of pathogens, but also where management options will be most effective.

Development and field application of a molecular probe for the primary pathogen of the coral disease white plague type II

Richardson,Laurie L; Mills,DeEtta K; Remily,Elizabeth R; Voss,Joshua D
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2005 EN
Relevância na Pesquisa
36.56%
One of the current problems in the field of coral disease research is that of tracking coral pathogens in the natural environment.A promising method to do this is by use of pathogen-specific molecular probes. However,this approach has been little used to date.We constructed,and validated in the laboratory,a fluoro-chrome-labeled molecular probe specific to Aurantimonas coralicida ,the bacterial pathogen of the Caribbean coral disease white plague type II (WPII).We then used the probe to test field samples of diseased coral tissue for the presence of this pathogen.Probe design was based on a unique subset (25 nucleotides)of the complete16S rRNA gene sequence derived from a pure culture of the pathogen.The pathogen-specific probe was labeled with the fluorochrome GreenStar*™FITC (fluorescein isothiocyanate,GeneDetect Ltd,New Zealand).As a control, we used the universal eubacterial probe EUB 338,labeled with a different fluorochrome (TRITC,tetra-methyl-rhodamine isothiocyanate).Both probes were applied to laboratory samples of pure cultures of bacteria, and field samples collected from the surface of the disease line of corals exhibiting signs of white plague (types I and II),healthy controls,and corals with an uncharacterized disease ("patchy necrosis ").All samples were analyzed using fluorescence in situ hybridization (FISH).We have determined that the probe is specific to our laboratory culture of the coral pathogen...