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Braz. j. microbiol ; 49(1): 138-143, Jan.-Mar. 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-889188


ABSTRACT Q fever is a worldwide zoonosis caused by Coxiella burnetii—a small obligate intracellular Gram-negative bacterium found in a variety of animals. It is transmitted to humans by inhalation of contaminated aerosols from urine, feces, milk, amniotic fluid, placenta, abortion products, wool, and rarely by ingestion of raw milk from infected animals. Nested PCR can improve the sensitivity and specificity of testing while offering a suitable amplicon size for sequencing. Serial dilutions were performed tenfold to test the limit of detection, and the result was 10× detection of C. burnetti DNA with internal nested PCR primers relative to trans-PCR. Different biological samples were tested and identified only in nested PCR. This demonstrates the efficiency and effectiveness of the primers. Of the 19 samples, which amplify the partial sequence of C. burnetii, 12 were positive by conventional PCR and nested PCR. Seven samples—five spleen tissue samples from rodents and two tick samples—were only positive in nested PCR. With these new internal primers for trans-PCR, we demonstrate that our nested PCR assay for C. burnetii can achieve better results than conventional PCR.

Humanos , Proteínas de Bactérias/genética , Elementos de DNA Transponíveis , Reação em Cadeia da Polimerase/métodos , Coxiella burnetii/isolamento & purificação , Transposases/genética , Febre/microbiologia , Proteínas de Bactérias/metabolismo , Coxiella burnetii/classificação , Coxiella burnetii/genética , Transposases/metabolismo
Braz. j. microbiol ; 47(4): 785-792, Oct.-Dec. 2016. tab
Artigo em Inglês | LILACS | ID: biblio-828193


Abstract Acinetobacter baumannii is widely recognized as an important pathogen associated with nosocomial infections. The treatment of these infections is often difficult due to the acquisition of resistance genes. A. baumannii presents a high genetic plasticity which allows the accumulation of these resistance determinants leading to multidrug resistance. It is highlighted the importance of the horizontal transfer of resistance genes, through mobile genetic elements and its relationship with increased incidence of multidrug resistant A. baumannii in hospitals. Considering that resistance to carbapenems is very important from the clinical and epidemiological point of view, the aim of this article is to present an overview of the current knowledge about genetic elements related to carbapenem resistance in A. baumannii such as integrons, transposons, resistance islands and insertion sequences.

DNA Bacteriano , Elementos de DNA Transponíveis , Carbapenêmicos/farmacologia , Resistência beta-Lactâmica , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/genética , Antibacterianos/farmacologia , Mutagênese Insercional , Integrons , Ilhas Genômicas
Braz. j. microbiol ; 46(3): 929-936, July-Sept. 2015. tab, ilus
Artigo em Inglês | LILACS | ID: lil-755799


Pseudomonas syringae pv. maculicola is a natural pathogen of members of the Brassicaceae plant family. Using a transposon-based mutagenesis strategy in Pseudomonas syringaepv. maculicola M2 (PsmM2), we conducted a genetic screen to identify mutants that were capable of growing in M9 medium supplemented with a crude extract from the leaves of Arabidopsis thaliana. A mutant containing a transposon insertion in the hrpZ gene (PsmMut8) was unable to infect adult plants from Arabidopsis thaliana or Brassica oleracea, suggesting a loss of pathogenicity. The promotorless cat reporter present in the gene trap was expressed if PsmMut8 was grown in minimal medium (M9) supplemented with the leaf extract but not if grown in normal rich medium (KB). We conducted phylogenetic analysis using hrpAZB genes, showing the classical 5-clade distribution, and nucleotide diversity analysis, showing the putative position for selective pressure in this operon. Our results indicate that the hrpAZB operon from Pseudomonas syringaepv. maculicola M2 is necessary for its pathogenicity and that its diversity would be under host-mediated diversifying selection.


Arabidopsis/microbiologia , Proteínas da Membrana Bacteriana Externa/genética , Brassica/microbiologia , Doenças das Plantas/microbiologia , Pseudomonas syringae/genética , Pseudomonas syringae/patogenicidade , Sequência de Bases , Meios de Cultura , Elementos de DNA Transponíveis/genética , Genes Bacterianos , Mutação/genética , Folhas de Planta/microbiologia , Regiões Promotoras Genéticas/genética
Rio de Janeiro; Editora Fiocruz; 2015. 196 p. ilus, tab, graf.
Monografia em Português | LILACS | ID: lil-782422


Este livro representa um projeto desafiador: o estudo de sequências genéticas repetidas que são capazes de se mover, tornando os genomas dinâmicos e flexíveis. Os elementos de transposição (TEs) têm a capacidade de se multiplicar e mudar de lugar no genoma, levar consigo genes, promover rearranjos cromossômicos e alterar a expressão de genes vizinhos. Trata-se de um dos tópicos mais instigantes na área da genética, que durante décadas não recebeu o devido reconhecimento. O livro surgiu de uma reunião de integrantes do grupo de pesquisa Elementos de Transposição como Agentes de Diversidade, do CNPq, que consideram indispensável disponibilizar a pesquisadores e estudantes informações que permitam compreender a dinâmica e a plasticidade dos genomas em decorrência da presença dos TEs. O livro não esgota as inúmeras informações e implicações decorrentes da interação genoma-TE mas propicia aos leitores o contato atualizado e a compreensão dos principais temas relacionados à estrutura e funcionamento dessas sequências genéticas móveis e sua relação com a evolução dos organismos, afirmam as organizadoras...

Humanos , Cromossomos , Elementos de DNA Transponíveis , Doença/genética , Genoma Humano , Biotecnologia , Epigênese Genética , Transferência Genética Horizontal
Braz. j. microbiol ; 45(3): 785-789, July-Sept. 2014. tab
Artigo em Inglês | LILACS | ID: lil-727003


Streptococcus agalactiae (GBS) is a major source of human perinatal diseases and bovine mastitis. Erythromycin (Ery) and tetracycline (Tet) are usually employed for preventing human and bovine infections although resistance to such agents has become common among GBS strains. Ery and Tet resistance genes are usually carried by conjugative transposons (CTns) belonging to the Tn916 family, but their presence and transferability among GBS strains have not been totally explored. Here we evaluated the presence of Tet resistance genes (tetM and tetO) and CTns among Ery-resistant (Ery-R) and Ery-susceptible (Ery-S) GBS strains isolated from human and bovine sources; and analyzed the ability for transferring resistance determinants between strains from both origins. Tet resistance and int-Tn genes were more common among Ery-R when compared to Ery-S isolates. Conjugative transfer of all resistance genes detected among the GBS strains included in this study (ermA, ermB, mef, tetM and tetO), in frequencies between 1.10-7 and 9.10-7, was possible from bovine donor strains to human recipient strain, but not the other way around. This is, to our knowledge, the first report of in vitro conjugation of Ery and Tet resistance genes among GBS strains recovered from different hosts.

Animais , Bovinos , Humanos , Conjugação Genética , Técnicas de Transferência de Genes , Streptococcus agalactiae/genética , Antibacterianos/farmacologia , Elementos de DNA Transponíveis , Farmacorresistência Bacteriana , Eritromicina/farmacologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/veterinária , Streptococcus agalactiae/efeitos dos fármacos , Streptococcus agalactiae/isolamento & purificação , Tetraciclina/farmacologia
Braz. j. microbiol ; 45(3): 841-843, July-Sept. 2014. ilus
Artigo em Inglês | LILACS | ID: lil-727011


We evaluated a multiplex-PCR to differentiate Mycobacterium bovis from M. tuberculosis Complex (MTC) by one step amplification based on simultaneous detection of pncA 169C > G change in M. bovis and the IS6110 present in MTC species. Our findings showed the proposed multiplex-PCR is a very useful tool for complementation in differentiating M. bovis from other cultured MTC species.

Técnicas Bacteriológicas/métodos , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase Multiplex/métodos , Mycobacterium bovis/isolamento & purificação , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/microbiologia , Amidoidrolases/genética , Elementos de DNA Transponíveis , DNA Bacteriano/genética , Mycobacterium bovis/classificação , Mycobacterium bovis/genética , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/genética , Tuberculose/diagnóstico
Braz. j. microbiol ; 45(2): 533-538, Apr.-June 2014. ilus, tab
Artigo em Inglês | LILACS | ID: lil-723114


Brucella is an intracellular pathogen capable of infecting animals and humans. The aim of this study was to identify Brucella spp in sera of high risk individuals by a polymerase chain reaction (PCR)-based method. A total of 180 patients suspected to have Brucellosis were examined by serological tests. To establish a PCR protocol for diagnosis of active brucellosis, DNA was extracted from the serum samples by using a commercial kit. PCR amplification was done for detection of Brocella DNA using BCSP31 target gene and IS711 locus. The PCR assay showed that an amplicon of 223 bp was obtained in 73.8% (133/180) of the tested sera using primers (B4/B5) derived from a gene encoding the 31-kDa Brucella abortus antigen. In another PCR, an amplicon of 498 bp was obtained in 63.8% (115/180) of the samples using Brucella abortus-specific primers derived from a locus adjacent to the 3'-end of IS711, and also an amplicon of 731 bp was produced in 4.4% (8/180) of the tested samples using Brucella melitensis-specific primers. When the Wright method was used as a gold standard, the sensitivity and specificity of the PCR technique for genus identification were found to be 96 and 80.7%, respectively. However, the sensitivity value obtained with the species-specific PCR method was 82%, and specificity was similar to that previous reported. This is the first report of a high frequency of Brucella abortus in patients suspicious of Brucellosis from the Zanjan province.

Adolescente , Adulto , Idoso , Animais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Brucella abortus/isolamento & purificação , Brucella melitensis/isolamento & purificação , Brucelose/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase/métodos , Soro/microbiologia , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Brucella abortus/genética , Brucella melitensis/genética , Elementos de DNA Transponíveis , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Irã (Geográfico) , Sensibilidade e Especificidade
Rio de Janeiro; s.n; 2014. xviii,107 p. ilus, tab, graf.
Tese em Português | LILACS | ID: lil-736964


A produção de carbapenemases do tipo KPC tem se tornado um importante mecanismo de resistência aos carbapenemas na família Enterobacteriaceae. Embora seja descrita predominantemente em Klebsiella pneumoniae, a enzima KPC também tem sido encontrada em diferentes espécies de Enterobacteriaceae. Contudo, pouco se sabe sobre a epidemiologia da disseminação do gene blaKPC-2 nestas outras espécies. No Brasil, a enzima KPC foi relatada inicialmente em K. pneumoniae no Recife, em 2006, mas atualmente já se encontra disseminada pelo país, onde sua incidência tem aumentado significativamente. Portanto, o objetivo desse trabalho foi realizar a caracterização molecular de amostras brasileiras produtoras de KPC pertencentes a diferentes espécies de Enterobacteriaceae (excluindo K. pneumoniae), isoladas de diferentes estados brasileiros no período de 2009 a 2011. O perfil de resistência foi avaliado por difusão em ágar e E-test. A variante alélica de blaKPC, assim como a participação do transposon Tn4401 e a análise da presença de outros genes de beta-lactamases (TEM, SHV e CTX-M) foram realizadas por PCR e sequenciamento. Análise plasmidial e hibridação foram realizadas para determinar o ambiente genético do gene blaKPC. Para a tipagem molecular foi realizado PFGE e MLST (somente para Escherichia coli)Foram encaminhadas ao Laboratório de Pesquisa em Infecção Hospitalar da Fundação Oswaldo Cruz, 83 amostras produtoras de KPC-2 (correspondendo as espécies: Enterobacter aerogenes, Enterobacter cloacae, Escherichia coli, Pantoea agglomerans, Providencia stuartii, Citrobacter freundii, Klebsiella oxytoca, Morganella morganii e Serratia marcescens) provenientes de 9 estados das regiões sudeste, nordeste e centro-oeste do país. Em amostras KPC positivas, foram encontrados altos percentuais de resistência à maioria dos antimicrobianos testados, inclusive tigeciclina (36,1 porcento não sensíveis) e polimixina B (16,5 porcento)...

The production of Klebsiella pneumoniae carbapenemase (KPC)-type enzymes has become an important mechanism of carbapenem resistance in the Family Enterobacteriaceae.Although it is predominantly described in Klebsiella pneumoniae, the KPC enzyme has also been found in different species of Enterobacteriaceae. Moreover, little is known about theepidemiology of the dissemination of blaKPC gene in other Enterobacteriaceae species. InBrazil, KPC was initially described in K. pneumoniae in Recife, state of Pernambuco, in 2006, but currently this enzyme is already disseminated throughout the country, where itsincidence has increased significantly. Thus, this study aimed to perform the molecular characterization of KPC-producing brazilian isolates belonging to different species of Enterobacteriaceae (non-K. pneumoniae) originated from different Brazilian states between2009 and 2011. The resistance profile was evaluated by disc-diffusion method and E-test. The allelic variant of the blaKPC gene, as well as the participation of Tn4401 and the presence of other beta-lactamase genes (TEM, SHV and CTX-M) were analyzed by PCR and genome sequencing. Plasmid analysis and hibridization were used to determine the genetic environment of the blaKPC gene. Molecular typing was done by PFGE and MLST (only forEscherichia coli). Eighty three unique clinical isolates of Enterobacteriaceae KPC-2-producers were referred to the Laboratório de Pesquisa em Infecção Hospitalar from Fundação Oswaldo Cruz, corresponding to 9 different species (Enterobacter aerogenes, Enterobacter cloacae, Escherichia coli, Pantoea agglomerans, Providencia stuartii, Citrobacter freundii, Klebsiella oxytoca, Morganella morganii and Serratia marcescens) isolated from 9 states located in northeast, southeast and central regions of Brazil. Highresistance rates towards most of the antimicrobial agents tested, including tigecycline (36.1 percent nonsusceptible) and polymyxin B (16.5 percent) were detected...

Humanos , Elementos de DNA Transponíveis , Enterobacteriaceae , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/genética , Epidemiologia Molecular
São Paulo; s.n; 2014. 158 p. ilus, tab.
Tese em Português | LILACS | ID: lil-774124


A resistência bacteriana a antibióticos é aceita como um dos maiores problemas de saúde pública. As tetraciclinas são antibióticos de amplo espectro, e após seu uso indiscriminado observou-se o surgimento de bactérias resistentes, levando médicos e veterinários a diminuírem seu uso. Objetivos. Verificar o perfil de sensibilidade a tetraciclinas em isolados clínicos e ambientais de Escherichia coli, Klebsiella pneumoniae e Aeromonas spp., bem como pesquisar os principais genes tet associados à resistência a esta classe de antibióticos e determinar a potencial forma de disseminação destes genes através da caracterização de seu ambiente genético. Material e Métodos. Os perfis de sensibilidade à tetraciclina (TET), doxiciclina (DOX), minociclina (MIN) e tigeciclina (TGC) de 572 isolados foram obtidos através das técnicas de Disco-Difusão e Concentração Inibitória Mínima. Os isolados não-sensíveis à tetraciclina foram submetidos a reações de PCR para pesquisa de grupos Inc, genes tet e para a caracterização de seu ambiente genético pela pesquisa das integrases de classes 1, 2, 3 e 4, e dos elementos genéticos móveis Tn1721, IS26, Tn10 e ISAS5. Perfis de similaridade genética dos isolados foram obtidos através das técnicas de ERIC-PCR e PFGE. Após análise destes resultados 33 cepas foram selecionadas para as técnicas de S1-PFGE e transformação. Resultados. A partir dos 572 isolados 18,5 por cento foram resistentes à TET, 13,5 por cento à DOX, 8 por cento à MIN...

The antibiotic resistance is accepted as one of the major problems for public health. Tetracyclines are broad spectrum antibiotics, and its indiscriminate use promoted the emergence of resistant bacteria, leading physicians and veterinarians to decrease its use. Objectives. Verify the susceptibility of clinical and environmental isolates of Escherichia coli, Klebsiella pneumoniae and Aeromonas spp. to tetracyclines, and also search for the main tet genes associated with resistance to these antibiotics and determine the potential mechanism of tet genes dissemination by characterizing their genetic context. Material and Methods. Disk-Diffusion and Minimum Inhibitory Concentration tests were carried out in 572 isolates using tetracycline (TET), doxycycline (DOX), minocycline (MIN) and tigecycline (TGC). PCR was carried out in TET non-susceptible isolates for the detection of Inc groups, tet genes and its genetic context determination through the search of classes 1, 2, 3, and 4 integrases, and Tn1721, Tn10, IS26 and ISAS5 mobile genetic elements. Genetic similarities patterns were determined by ERIC-PCR and PFGE techniques. After analyzing the results 33 strains were selected for the S1-PFGE and transformation experiments. Results. From 572 isolates, 18.5 per cent were TET-resistant, 13.5 per cent DOX-resistant, 8 per cent MIN-resistant and none resistant to TGC. Twenty-two per cent and 16.3 per cent of clinical and environmental isolates were TET-resistant...

Resistência Microbiana a Medicamentos , Escherichia coli/genética , Tetraciclinas , Elementos de DNA Transponíveis/genética , Integrons/genética , Saúde Pública
Braz. j. microbiol ; 44(3): 897-899, July-Sept. 2013. ilus, tab
Artigo em Inglês | LILACS | ID: lil-699784


We here identified for the first time the presence of Mycobacterium avium paratuberculosis (MAP) sheep (S) strain in Argentina. IS900 polymerase chain reaction (PCR) was positive. The S strain was compared with MAP cattle (C) strains by using IS1311 PCR-restriction endonuclease analysis (PCR-REA), multiplex PCR and restriction fragment length polymorphism (RFLP) analysis.

Animais , Mycobacterium avium subsp. paratuberculosis/classificação , Mycobacterium avium subsp. paratuberculosis/isolamento & purificação , Paratuberculose/microbiologia , Doenças dos Ovinos/microbiologia , Argentina , Elementos de DNA Transponíveis , DNA Bacteriano/genética , Reação em Cadeia da Polimerase Multiplex , Mycobacterium avium subsp. paratuberculosis/genética , Polimorfismo de Fragmento de Restrição , Paratuberculose/diagnóstico , Ovinos , Doenças dos Ovinos/diagnóstico
Biomédica (Bogotá) ; 33(1): 36-41, ene.-mar. 2013. ilus
Artigo em Espanhol | LILACS | ID: lil-675130


Se informa un caso de mastitis granulomatosa causada por Mycobacterium tuberculosis en una paciente inmunocompetente con lesiones inflamatorias crónicas de la mama, diagnosticada por la detección de ADN de la micobacteria mediante la técnica de reacción en cadena de la polimerasa de la secuencia de inserción IS6110 presente en el complejo M. tuberculosis , en una biopsia de mama embebida en parafina. La tuberculosis primaria de la mama es rara, incluso en países con alta prevalencia de tuberculosis, y debe sospecharse en pacientes con mastitis granulomatosa crónica de causa no clara. El pilar del tratamiento es la quimioterapia antituberculosa y, ocasionalmente, la cirugía.

We report a case of granulomatous mastitis caused by Mycobacterium tuberculosis in an immunocompetent woman with chronic inflammatory lesions of the breast. It was diagnosed by detection of mycobacteria DNA using polymerase chain reaction technique targeting IS6110 insertion element of M. tuberculosis complex in a paraffin-embedded histological specimen. The primary breast tuberculosis is rare, even in countries where the incidence and prevalence of pulmonary and extra pulmonary tuberculosis are high. It should be suspected in female patients with chronic granulomatous mastitis with no apparent cause. The cornerstone of treatment is antituberculous chemotherapy, and surgery is rarely required.

Adulto , Feminino , Humanos , Mastite/diagnóstico , Tuberculoma/diagnóstico , Tuberculose Cutânea/diagnóstico , Antibacterianos/uso terapêutico , Antituberculosos/uso terapêutico , Biópsia , Neoplasias da Mama/diagnóstico , Diagnóstico Diferencial , Elementos de DNA Transponíveis/genética , DNA Bacteriano/análise , Dermatomicoses/diagnóstico , Etambutol/uso terapêutico , Reações Falso-Negativas , Febre/etiologia , Isoniazida/uso terapêutico , Mastite/patologia , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Pirazinamida/uso terapêutico , Rifampina/uso terapêutico , Dermatopatias Bacterianas/diagnóstico , Tuberculoma/patologia , Tuberculose Cutânea/patologia , Perda de Peso
Electron. j. biotechnol ; 15(4): 9-9, July 2012. ilus, tab
Artigo em Inglês | LILACS | ID: lil-646959


In the present study, a novel plant transformation system for Doritaenopsis and Phalaenopsis has been developed. The pollen-mediated activation tagging system was established by artificial pollination. The pollens, co-cultured with Agrobacterium tumefaciens strain EHA105 harbouring an activation tagging vector (pTAG-8), were used for pollination. In order to optimize the transformation efficiency, several factors (concentration of A. tumefaciens, concentration of acetosyringone during co-cultivation and the duration of co-cultivation) known to influence Agrobacterium-mediated DNA transfer were examined. A concentration of 0.5-1 x 10(8) CFU/ml for A. tumefaciens, 0.1 mM acetosyringone, and 6 hrs of co-culture period were found to be the optimal condition for high transformation efficiency. Integration of T-DNA into the genome of putative transgenic plants was confirmed by PCR and DNA blot analyses. Single copy of the transgene was observed in all transgenic plants analyzed. Most of the transgenic plants had a morphologically normal phenotype and the overall capsule formation efficiency was similar to control plant. Our results showed a new approach of genetic transformation in orchids and this method can be employed for genetic improvement of the orchids.

Agrobacterium tumefaciens , Orchidaceae/genética , Polinização , Elementos de DNA Transponíveis/genética , Reação em Cadeia da Polimerase , Transformação Genética
Mem. Inst. Oswaldo Cruz ; 106(7): 785-793, Nov. 2011. ilus
Artigo em Inglês | LILACS | ID: lil-606640


Genome sequences for Schistosoma japonicum and Schistosoma mansoni are now available. The schistosome genome encodes ~13,000 protein encoding genes for which the function of only a minority is understood. There is a valuable role for transgenesis in functional genomic investigations of these new schistosome gene sequences. In gain-of-function approaches, transgenesis can lead to integration of transgenes into the schistosome genome which can facilitate insertional mutagenesis screens. By contrast, transgene driven, vector-based RNA interference (RNAi) offers powerful loss-of-function manipulations. Our laboratory has focused on development of tools to facilitate schistosome transgenesis. We have investigated the utility of retroviruses and transposons to transduce schistosomes. Vesicular stomatitis virus glycoprotein (VSVG) pseudotyped murine leukemia virus (MLV) can transduce developmental stages of S. mansoni including eggs. We have also observed that the piggyBac transposon is transpositionally active in schistosomes. Approaches with both VSVG-MLV and piggyBac have resulted in somatic transgenesis and have lead to integration of active reporter transgenes into schistosome chromosomes. These findings provided the first reports of integration of reporter transgenes into schistosome chromosomes. Experience with these systems is reviewed herewith, along with findings with transgene mediated RNAi and germ line transgenesis, in addition to pioneering and earlier reports of gene manipulation for schistosomes.

Animais , Humanos , Camundongos , Técnicas de Transferência de Genes , Genoma Helmíntico/genética , Schistosoma japonicum/genética , Schistosoma mansoni/genética , Animais Geneticamente Modificados , Cromossomos/genética , Cromossomos/virologia , Elementos de DNA Transponíveis , DNA de Helmintos/genética , DNA Viral/genética , DNA Viral/isolamento & purificação , Vetores Genéticos , Vírus da Leucemia Murina/genética , Vírus da Leucemia Murina/isolamento & purificação , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/isolamento & purificação , Interferência de RNA , Schistosoma japonicum/virologia , Schistosoma mansoni/virologia , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/isolamento & purificação
Genet. mol. biol ; 34(4): 707-710, 2011. ilus
Artigo em Inglês | LILACS | ID: lil-605928


Transposable elements (TEs) are mobile nucleotide sequences which, through changing position in host genomes, partake in important evolutionary processes. The expression patterns of two TEs, P element transposon and 412 retrotransposon, were investigated during Drosophila melanogaster and D. willistoni embryogenesis, by means of embryo hybridization using riboprobes. Spatiotemporal transcription patterns for both TEs were similar to those of developmental genes. Although the two species shared the same P element transcription pattern, this was not so with 412 retrotransposon. These findings suggest that the regulatory sequences involved in the initial development of Drosophila spp are located in the transposable element sequences, and differences, such as in this case of the 412 retrotransposon, lead to losses or changes in their transcription patterns.

Animais , Elementos de DNA Transponíveis , Drosophila/embriologia , Retroelementos , Sequência de Bases , Drosophila/genética , Transcrição Genética
An. acad. bras. ciênc ; 81(4): 679-689, Dec. 2009. ilus, tab
Artigo em Inglês | LILACS | ID: lil-529929


The P element is one of the most thoroughly studied transposable elements (TE). Its mobilization causes the hybrid dysgenesis that was first described in Drosophila melanogaster. While studies of the P element have mainly been done in D. melanogaster, it is believed that Drosophila willistoni was the original host species of this TE and that P was transposed to the D. melanogaster genome by horizontal transfer. Our study sought to compare the transcriptional behavior of the P element in embryos of D. melanogaster, which is a recent host, with embryos of two strains of D. willistoni, a species that has contained the P element for a longer time. In both species, potential transcripts of transposase, the enzyme responsible for the TE mobilization, were detected, as were transcripts of the 66-kDa repressor, truncated and antisense sequences, which can have the ability to prevent TEs mobilization. The truncated transcripts reveal the truncated P elements present in the genome strains and whose number seems to be related to the invasion time of the genome by the TE. No qualitative differences in antisense transcripts were observed among the strains, even in the D. willistoni strain with the highest frequency of heterochromatic P elements.

O elemento P é um dos elementos transponíveis (TE) mais amplamente estudado. Sua mobilização causa a disgenesia do híbrido que foi primeiramente descrita em D. melanogaster. Apesar dos estudos sobre o elemento P terem sido realizados principalmente com D. melanogaster, acredita-se que D. willistoni foi a espécie hospedeira original deste TE e que ele se transpôs para o genoma de D. melanogaster por transferência horizontal. Nosso estudo visou a comparação do comportamento transcripcional do elemento P em embriões de D. melanogaster, que é a hospedeira recente, com o de embriões de duas linhagens de D. willistoni, uma espécie que é, a longo tempo, hospedeira do elemento P. Em ambas as espécies foram detectados transcritos potenciais da transposase, enzima responsável pela mobilização do TE, bem como transcritos do repressor de 66-kDa e de seqüências truncadas e antisenso, os quais podem ter a habilidade de prevenir a mobilização de TEs. Os transcritos truncados refletem os elementos P truncados presentes no genoma das linhagens e cujo número parece relacionado com o tempo de invasão do genoma pelo TE. Nenhuma diferença qualitativa de transcritos antisenso foi observada entre as espécies, mesmo na linhagem de D. willistoni com alta freqüência de elemento P heterocromático.

Animais , Humanos , Masculino , Elementos de DNA Transponíveis/genética , Drosophila/embriologia , Transcrição Genética/genética , Drosophila melanogaster/genética , Drosophila/classificação , Drosophila/genética , Eletroforese em Gel de Ágar , Transferência Genética Horizontal , Reação em Cadeia da Polimerase Via Transcriptase Reversa
Neotrop. ichthyol ; 7(4): 601-605, 2009. ilus
Artigo em Inglês | LILACS, VETINDEX | ID: lil-536334


The genus Astyanax is prominent among Characiformes, due to the large number of species found and its wide geographic distribution. In this work, Astyanax laticeps specimens from the laguna dos Patos system were cytogenetically analyzed. A diploid number of 2n = 50 chromosomes distributed into 6m+16sm+16st+12a (FN = 88) was found, without differences between males and females. A few small heterochromatin blocks were observed, besides three more conspicuous C-bands, corresponding to NORs, as confirmed by silver nitrate and CMA3 staining, FISH, and DAPI negative staining. These regions were located in a medium-sized subtelocentric and in a large subtelocentric chromosomal pair, probably because of a deletion of this region in one homologous chromosome, or due to a transposition event between them.(AU)

O gênero Astyanax é destacado entre os Characiformes, pelo grande número de espécies encontradas e a ampla distribuição geográfica. Neste trabalho, foram analisados citogeneticamente espécimes de Astyanax laticeps do sistema da laguna do Patos. O número diplóide observado foi de 2n = 50 cromossomos distribuídos em 6m+16sm+16st+12a (NF= 88), sem diferenças entre machos e fêmeas. Foram observados poucos blocos de heterocromatina, além de três bandas-C mais conspícuas, correspondentes às NORs, confirmado pela coloração com nitrado de prata,CMA3, FISH, e coloração negativa ao DAPI. Estas regiões foram localizadas em um cromossomo subtelocêntrico de tamanho médio e em um par subtelocêntrico grande, provavelmente devido a deleção desta região em um dos cromossomos homólogos, ou por eventos de transposição entre eles.(AU)

Animais , DNA Ribossômico/genética , Elementos de DNA Transponíveis/genética , Citogenética/métodos , Characidae/genética
Genet. mol. res. (Online) ; 7(1): 107-116, Jan. 2008. ilus, tab
Artigo em Inglês | LILACS | ID: lil-553777


Despite the wide distribution of transposable elements (TEs) in mammalian genomes, part of their evolutionary significance remains to be discovered. Today there is a substantial amount of evidence showing that TEs are involved in the generation of new exons in different species. In the present study, we searched 22,805 genes and reported the occurrence of TE-cassettes in coding sequences of 542 cow genes using the RepeatMasker program. Despite the significant number (542) of genes with TE insertions in exons only 14 (2.6%) of them were translated into protein, which we characterized as chimeric genes. From these chimeric genes, only the FAST kinase domains 3 (FASTKD3) gene, present on chromosome BTA 20, is a functional gene and showed evidence of the exaptation event. The genome sequence analysis showed that the last exon coding sequence of bovine FASTKD3 is ~85% similar to the ART2A retrotransposon sequence. In addition, comparison among FASTKD3 proteins shows that the last exon is very divergent from those of Homo sapiens, Pan troglodytes and Canis familiares. We suggest that the gene structure of bovine FASTKD3 gene could have originated by several ectopic recombinations between TE copies. Additionally, the absence of TE sequences in all other species analyzed suggests that the TE insertion is clade-specific, mainly in the ruminant lineage.

Animais , Feminino , Bovinos/genética , Elementos de DNA Transponíveis , Genoma , Quimera/genética , Sequência de Aminoácidos , Evolução Molecular , Éxons , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Homologia de Sequência de Aminoácidos
Rev. argent. microbiol ; 39(3): 145-150, jul.-sep. 2007. ilus, tab
Artigo em Inglês | LILACS | ID: lil-634551


In 2003, the incidence of tuberculosis in Argentina showed an increase compared to 2002. The severe national crisis at the end of the 90s has probably strongly contributed to this situation. The goal of this work was to estimate the extent of the spread of the most predominant Mycobacterium tuberculosis strains and to assess the spread of predominant M. tuberculosis clusters as determined by spoligotyping and IS6110 RFLP. The study involved 590 pulmonary, smear-positive TB cases receiving medical attention at health centers and hospitals in Northern Buenos Aires (NBA) suburbs, from October 2001 to December 2002. From a total of 208 clinical isolates belonging to 6 major clusters, 63 (30.2%) isolates had identical spoligotyping and IS6110 RFLP pattern. Only 22.2% were shown to have epidemiological connections with another member of their respective cluster. In these major clusters, 30.2% of the 208 TB cases studied by both molecular techniques and contact tracing could be convincingly attributable to a recently acquired infection. This knowledge may be useful to assess the clonal distribution of predominant M. tuberculosis clusters in Argentina, which may make an impact on TB control strategies.

La incidencia de la tuberculosis en Argentina mostró en 2003 un incremento en comparación con 2002. La grave crisis nacional a fines de los 90 ha probablemente contribuido en gran medida a esta situación. El objetivo del presente trabajo fue determinar la diversidad genética de aislamientos de Mycobacterium tuberculosis y el grado de dispersión de algunas cepas mayoritarias genéticamente relacionadas. El estudio involucró 590 aislamientos clínicos provenientes de muestras respiratorias con examen directo positivo, de pacientes atendidos en los hospitales y centros de salud que conforman la región Gran Buenos Aires Norte (NBA), de octubre de 2001 a diciembre de 2002. De 208 aislamientos que se encontraron en los 6 mayores clusters, 63 (30,2%) tenían patrones idénticos de spoligotyping y de IS6110 RFLP. En el 22,2% de los casos fue posible verificar la conexión epidemiológica con otro miembro del respectivo cluster. Concluimos que el 30,2% de estos agrupamientos principales pueden ser atribuidos a una infección reciente. Estos resultados pueden ser útiles para determinar la distribución clonal de los grupos predominantes de M. tuberculosis en Argentina, lo que puede impactar en las estrategias de control de la tuberculosis.

Adulto , Criança , Feminino , Humanos , Masculino , Transmissão de Doença Infecciosa , Mycobacterium tuberculosis/genética , Tuberculose/microbiologia , Argentina/epidemiologia , Técnicas de Tipagem Bacteriana/métodos , Análise por Conglomerados , Elementos de DNA Transponíveis/genética , DNA Bacteriano/genética , Genótipo , Pessoal de Saúde , Infecções por HIV/epidemiologia , Incidência , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Sequências Repetitivas de Ácido Nucleico , População Suburbana , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/transmissão , Tuberculose/epidemiologia , Tuberculose/transmissão
Mem. Inst. Oswaldo Cruz ; 101(supl.2): 25-27, Dec. 2006. tab, ilus
Artigo em Inglês | LILACS | ID: lil-441339


Vertebral lesions have been the main evidence for infection by the Mycobacterium tuberculosis complex (MTC) in paleopathology. Skeletal involvement is expected in a small percentage of infected individuals. Recently, several authors report a correlation between rib lesions and tuberculosis (TB) complex infection. This study tests the hypothesis that rib lesions can serve as a useful marker for MTC infection within the Mississippian Schild skeletal collection from West-Central Illinois. Ribs from 221 adults and juveniles were examined, and affected individuals were tested for TB complex infection. DNA from rib samples of affected individuals was amplified with primers targeting the IS6110 insertion element, which is common to all members of the TB complex. Although it cannot allow discrimination between different species of TB, IS6110 is present in many copies within their genomes, and its presence is thus an indication of MTC infection. The results support the use of rib lesions as a marker for TB infection. Additionally, we demonstrate that MTC DNA can be recovered from ribs that lack lesions in individuals who have lesions of other bones. We recommend that an examination of ribs be incorporated into investigations for TB.

Adulto , Feminino , História Antiga , Humanos , Masculino , Pessoa de Meia-Idade , DNA Bacteriano/genética , Mycobacterium tuberculosis/genética , Costelas/lesões , Tuberculose Pulmonar/história , Elementos de DNA Transponíveis/genética , DNA Bacteriano/química , Illinois , Paleopatologia , Reação em Cadeia da Polimerase , Costelas/patologia , Tuberculose Pulmonar/patologia
Mem. Inst. Oswaldo Cruz ; 101(7): 755-757, Nov. 2006. ilus, tab
Artigo em Inglês | LILACS | ID: lil-439459


The technique to generate transgenic mosquitoes requires adaptation for each target species because of aspects related to species biology, sensitivity to manipulation and rearing conditions. Here we tested different parameters on the microinjection procedure in order to obtain a transgenic Neotropical mosquito species. By using a transposon-based strategy we were able to successfully transform Aedes fluviatilis (Lutz), which can be used as an avian malaria model. These results demonstrate the usefulness of the piggyBac transposable element as a transformation vector for Neotropical mosquito species and opens up new research frontiers for South American mosquito vectors.

Animais , Masculino , Feminino , Aedes/genética , Elementos de DNA Transponíveis/genética , Técnicas de Transferência de Genes , Insetos Vetores/genética , Transformação Genética/genética , Genes de Insetos , Células Germinativas , Microinjeções