RESUMO
ICU nurses hold an important role in the management of septic patients underlining with their ability to recognize SIRS that is the first step in the proinflammatory and procoagulant cascade following an infection. Early and timely approach to organ dysfunction can indeed modify the damages due to hypoperfusion. The ability to recognize organ dysfunction using different monitoring devices available should be part of the nursing attitudes.
Assuntos
Cuidados Críticos/métodos , Sepse/diagnóstico , Sepse/enfermagem , Sistema Nervoso Central/fisiopatologia , Humanos , Monitorização Fisiológica , Sepse/fisiopatologiaRESUMO
The sequence and genetic organization of the 1,600-bp replication region of the Lactobacillus vector pPSC22, a plasmid derived from a 7-kb cryptic plasmid of L. plantarum used for the cloning of heterologous genes in several lactobacilli, were determined. Sequence analysis revealed the presence of a plus origin of replication containing the two functional elements nic and bind, required for initiation of the leading strands typical of the rolling circle (RC)-replicating plasmids belonging to the pLS1 family. Two open reading frames (copA and repA) were located within the Lactobacillus portion of pPSC22. The repA gene product, a 234-amino acid protein, showed homologies with the Rep protein of the streptococcal plasmid pLS1 and contained the three conserved domains detected in most Rep proteins of RC-replicating plasmids and ss-coliphages. The genetic organization of the replication region of pPSC22 shared relevant homologies with the lactococcal plasmids pWVO1 and pFX2.
Assuntos
Lactobacillus/genética , Plasmídeos/genética , Origem de Replicação/genética , Sequência de Bases , Técnicas In Vitro , Dados de Sequência MolecularRESUMO
To identify the elements involved in Bordetella pertussis fimbriae regulation and to determine whether fimX is an expressed gene, the promoter regions of fimX, fim2 and fim3 from strain BPSA1 were isolated and linked to the promoterless CAT gene in pLAFR2. By following CAT activity in Bordetella bronchiseptica vir+ and vir- strains we established that the fimX promoter, like those for fim2 and fim3, is active, although at a low level, and vir-regulated. This suggests that the fimX protein might be produced in minute quantities which are not detectable by conventional methods. Comparison of the three fim promoter sequences and transcriptional activities identifies two conserved elements necessary for transcription in the -60 to -20 region: the 'fim box' and the 'C-stretch'. Mutations in these two sequences drastically reduce transcription and alter the interaction with vir components, suggesting a role for the two elements in the regulation of fim genes. Finally, we suggest that the apparent constitutive nature of fim3 in BPSA1 is due to a modification in the length of the 'C-stretch'.
Assuntos
Bordetella/genética , Fímbrias Bacterianas/fisiologia , Regulação Bacteriana da Expressão Gênica , Regiões Promotoras Genéticas , Sequência de Bases , Bordetella bronchiseptica/genética , Bordetella pertussis/genética , Cloranfenicol O-Acetiltransferase/genética , Clonagem Molecular , Análise Mutacional de DNA , DNA de Cadeia Simples/genética , Dados de Sequência Molecular , Proteínas Recombinantes de Fusão/genética , Transcrição GênicaAssuntos
Proteínas da Membrana Bacteriana Externa/genética , Bordetella pertussis/genética , Genes Bacterianos , Sequência de Aminoácidos , Sequência de Bases , Proteínas de Fímbrias , Fímbrias Bacterianas , Substâncias Macromoleculares , Dados de Sequência Molecular , Homologia de Sequência do Ácido NucleicoRESUMO
A search for pilin genes in a Bordetella pertussis (Bp) genomic library has led to the identification of several clones which hybridize to synthetic oligonucleotides with sequences derived from amino acid sequences of Bp fimbrial subunits. One of these clones (corresponding to a gene we have named fimX) contains an open reading frame encoding a protein with a molecular weight of about 20 kD and a sequence similar but not identical to the fimbrial subunit fim2 and to other fimbrial protein sequences. In this communication we present the cloning and nucleotide sequence of the fimX gene and its homology to the fim2 gene. A genomic analysis on the positional relationship between the two genes is also presented.
Assuntos
Proteínas da Membrana Bacteriana Externa/genética , Sequência de Bases , Bordetella pertussis/genética , Clonagem Molecular , DNA Bacteriano , Homologia de Sequência do Ácido Nucleico , Sequência de Aminoácidos , Cosmídeos , Proteínas de Fímbrias , Regulação da Expressão Gênica , Dados de Sequência Molecular , Hibridização de Ácido NucleicoRESUMO
Bordetella pertussis fimbriae, which mediate the adherence of the microorganism to the epithelium of the respiratory tract, elicit a protective immunogenic response which could be taken advantage of for the creation of an acellular vaccine against pertussis. A few of the fimbrial proteins have been partially characterized by immunological means which recently the cloning and characterization of pilin and pilin-like genes are allowing us to study their structure, regulation of expression during the infectious cycle of Bordetella pertussis, and the basis for antigenic variation. In this communication we will review recent data on Bordetella pertussis pilin and pilin-like genes and their products, with particular emphasis on data most relevant to the design of an acellular vaccine.
Assuntos
Proteínas da Membrana Bacteriana Externa/genética , Bordetella pertussis/genética , Genes Bacterianos , Sequência de Aminoácidos , Bordetella pertussis/patogenicidade , Proteínas de Fímbrias , Fímbrias Bacterianas , Regulação Bacteriana da Expressão Gênica , Dados de Sequência Molecular , Virulência/genéticaRESUMO
RecA protein was found to catalyze the dissociation of the strands of a DNA substrate consisting of a 20-nucleotide primer annealed to circular single-stranded M13mp DNA. The strand separation reaction requires ATP hydrolysis and the presence of single-stranded DNA flanking the duplex DNA region to be unwound. RecA-catalyzed strand separation is effective only for very short duplexes, not exceeding 30 bp, and is not stimulated by single-stranded DNA-binding protein. These results are consistent with the ability of recA protein to disrupt regions of secondary structure in single-stranded DNA and to incorporate large non-homologies into heteroduplex DNA.