RESUMO
Amblyomma geayi is a tick of the Ixodidae family found primarily in mammals and wild birds from tropical regions in South America. This case report the occurrence of an ixodid tick species A. geayi found in a brown-throated sloth (Bradypus variegatus) from the botanical zoo Park of the Federal University of Acre, Rio Branco, Acre, Western Amazon.(AU)
O Amblyomma geayi é um carrapato da família Ixodidae, encontrado principalmente em mamíferos e aves silvestres de regiões tropicais da América do Sul. Descreve-se a ocorrência de um carrapato ixodídeo da espécie A. geayi, encontrado em uma preguiça (Bradypus variegatus) proveniente do Parque Zoobotânico da Universidade Federal do Acre, Rio Branco, Acre, Amazônia Ocidental.(AU)
Assuntos
Animais , Feminino , Carrapatos , Bichos-Preguiça/parasitologia , Ecossistema AmazônicoRESUMO
O Amblyomma geayi é um carrapato da família Ixodidae, encontrado principalmente em mamíferos e aves silvestres de regiões tropicais da América do Sul. Descreve-se a ocorrência de um carrapato ixodídeo da espécie A. geayi, encontrado em uma preguiça (Bradypus variegatus) proveniente do Parque Zoobotânico da Universidade Federal do Acre, Rio Branco, Acre, Amazônia Ocidental.(AU)
Amblyomma geayi is a tick of the Ixodidae family found primarily in mammals and wild birds from tropical regions in South America. This case report the occurrence of an ixodid tick species A. geayi found in a brown-throated sloth (Bradypus variegatus) from the botanical zoo Park of the Federal University of Acre, Rio Branco, Acre, Western Amazon.(AU)
Assuntos
Animais , Feminino , Bichos-Preguiça/parasitologia , Carrapatos , Ecossistema AmazônicoRESUMO
The authors confirm the presence of one female and two males of Amblyomma aureolatum and five females and one male of A. ovale parasitizing southern brown howler monkeys in the municipalities of Indaial, Blumenau, Garuva, and Jaraguá do Sul, Santa Catarina State, Brazil.(AU)
Assuntos
Animais , Alouatta/classificação , Carrapatos/classificação , Parasitos/parasitologiaRESUMO
The authors confirm the presence of one female and two males of Amblyomma aureolatum and five females and one male of A. ovale parasitizing southern brown howler monkeys in the municipalities of Indaial, Blumenau, Garuva, and Jaraguá do Sul, Santa Catarina State, Brazil.
Assuntos
Animais , Alouatta/classificação , Carrapatos/classificação , Parasitos/parasitologiaRESUMO
Microcin H47 is a gene-encoded peptide antibiotic produced by a natural Escherichia coli strain isolated in Uruguay. In order to identify cellular components necessary for its antibiotic action, microcin H47-resistant mutants isolated in this work, as well as previously described mutants affected in membrane proteins, were analyzed. These studies indicated that (i) receptor outer membrane proteins for ferric-catechol siderophores would be involved in microcin-specific binding to the cell surface, (ii) the TonB pathway is needed for microcin H47 uptake, and (iii) the presence of the ATP synthase complex is necessary for microcin action. The possibility that this last structure contains the antibiotic target is discussed.
Assuntos
Adenosina Trifosfatases/metabolismo , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Peptídeos , Peptídeos Catiônicos Antimicrobianos , Bacteriófagos/genética , Clonagem Molecular , Colicinas/farmacologia , Meios de Cultura , DNA Bacteriano/química , DNA Bacteriano/genética , Plasmídeos/genéticaRESUMO
Microcin H47, a gene-encoded peptide antibiotic produced by a natural Escherichia coli strain, was shown to be secreted by a three-component ATP-binding cassette exporter which was revealed to be strongly related to that of colicin V. The results of sequence and gene fusion analyses, as well as heterologous complementation assays, are presented.
Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Proteínas de Bactérias/genética , Proteínas de Escherichia coli , Escherichia coli/genética , Transportadores de Cassetes de Ligação de ATP/fisiologia , Sequência de Aminoácidos , Antibacterianos , Proteínas de Bactérias/fisiologia , Colicinas/química , DNA Bacteriano/análise , Escherichia coli/fisiologia , Dados de Sequência Molecular , Família Multigênica , Peptídeos , Mapeamento por Restrição , Homologia de Sequência de AminoácidosRESUMO
Microcin H47 is a bactericidal antibiotic produced by a naturally occurring Escherichia coli strain isolated in Uruguay. The microcin genetic system is located in the chromosome and extends over a 10-kb DNA segment containing the genes required for microcin synthesis, secretion, and immunity. The smallest microcin synthesis gene, mchB, was sequenced and shown to encode a highly hydrophobic peptide. An mchB-phoA gene fusion, which directed the synthesis of a hybrid bifunctional protein with both PhoA and microcin H47-like activities, was isolated. The results presented herein lead us to propose that microcin H47 is indeed a ribosomally synthesized peptide antibiotic and that its peptide precursor already has antibiotic activity of the same specificity as that of mature microcin.
Assuntos
Antibacterianos/biossíntese , Bacteriocinas/genética , Peptídeos , Sequência de Aminoácidos , Bacteriocinas/biossíntese , Sequência de Bases , Células Cultivadas , Genes Bacterianos , Dados de Sequência Molecular , Plasmídeos/genética , Ribossomos/metabolismoRESUMO
Microcin H47 is a bactericidal antibiotic produced by a natural Escherichia coli isolate. The genetic system encoding microcin production and immunity consists of at least seven clustered genes. Four of these are devoted to microcin biosynthesis and two genes are required for its secretion into the extracellular medium. The product of the seventh gene, mchI, determines the cell's self-immunity. This gene was shown to encode a highly hydrophobic 69-residue peptide. Analysis of the MchI amino acid sequence, as well as the characterization of MchI-PhoA hybrid proteins, indicated that the microcin immunity product is probably exported out of the cytoplasm and remains an integral membrane peptide. This localization of the immunity peptide points to the cellular membrane as the site of action of microcin H47.
Assuntos
Antibacterianos/imunologia , Bacteriocinas/imunologia , Genes Bacterianos/genética , Sequência de Aminoácidos , Bacteriocinas/genética , Sequência de Bases , Clonagem Molecular , Escherichia coli/genética , Dados de Sequência Molecular , Mutação , Proteínas Recombinantes de Fusão/análiseRESUMO
The microcin H47 genetic determinants span a DNA region of ca. 10 kb and represent the first description of an enterobacterial antibiotic system located in the chromosome of the producing strain. Transcriptional and translational fusions to lacZ showed a complex transcriptional organization of the microcin H47 system. Complementation tests identified six genes that are necessary for the production of the antibiotic; the products of two of them are involved in the export of microcin to the extracellular medium. The immunity determinant was located in an 0.8-kb DNA fragment. There is a putative "silent region" of ca. 3 kb inside the system that could not be clearly related to any antibiotic function. Protein products were identified and assigned to three production genes and also to a gene from the silent region.
Assuntos
Antibacterianos/biossíntese , Bacteriocinas/genética , Enterobacteriaceae/genética , Bacteriocinas/biossíntese , Bacteriocinas/imunologia , Clonagem Molecular , Eletroforese em Gel de Poliacrilamida , Enterobacteriaceae/imunologia , Teste de Complementação Genética , Mutagênese Insercional , Mapeamento por Restrição , Transcrição GênicaRESUMO
Microcin H47 (MccH47) is a novel microcin antibiotic produced by a natural Escherichia coli isolate. In contrast to all the other colicins and microcins examined to date, which are plasmid encoded, the genes for MccH47 synthesis and immunity are located on the chromosome. These genetic determinants were cloned and shown to extend over a continuous DNA region of ca. 10 kb.