Luxs
Mostrando 1-12 de 45 artigos, teses e dissertações.
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1. Quorum sensing LuxS/autoinducer-2 inhibits Enterococcus faecalis biofilm formation ability
Abstract Objective: To investigate the relation between biofilm formation ability and quorum sensing gene LuxS/AI-2. Materials and Methods: Enterococcus faecalis (E. faecalis) standard strain ATCC 29212 was used in the study. Long flanking homology polymerase chain reaction method was used to build the LuxS gene knockout strain. Sequential culture turbidit
J. Appl. Oral Sci.. Publicado em: 04/10/2018
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2. Quorum sensing em cepas de Enterococcus faecium, Enterococcus faecalis e Bacillus cereus isoladas do processamento de ricota
RESUMO: O fenômeno quorum sensing corresponde a um processo de comunicação intra e interespécies microbianas e é mediado por sinais químicos extracelulares, denominados moléculas sinalizadoras ou auto indutoras (AI). A molécula AI2 está envolvida na comunicação interespécies, denominada sistema “universal” de comunicação. Este estudo teve c
Cienc. Rural. Publicado em: 08/02/2018
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3. Signaling System in Porphyromonas gingivalis Based on a LuxS Protein
The luxS gene of quorum-sensing Vibrio harveyi is required for type 2 autoinducer production. We identified a Porphyromonas gingivalis open reading frame encoding a predicted peptide of 161 aa that shares 29% identity with the amino acid sequence of the LuxS protein of V. harveyi. Conditioned medium from a late-log-phase P. gingivalis culture induced the luc
American Society for Microbiology.
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4. Mutation of luxS of Streptococcus pneumoniae Affects Virulence in a Mouse Model
The LuxS protein is required for the biosynthesis of the type 2 autoinducer (AI-2), which is involved in quorum sensing in a wide range of bacterial species. We have determined the effects of a defined luxS mutation on the virulence of Streptococcus pneumoniae. Although the luxS mutant displayed reduced virulence relative to its wild-type parent, the type 2
American Society for Microbiology.
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5. Growth Phase Regulation of flaA Expression in Helicobacter pylori Is luxS Dependent
LuxS plays a role in the synthesis of an extracellular signaling molecule, autoinducer 2 (AI-2). To analyze a possible role of AI-2 in regulating Helicobacter pylori gene expression, we constructed a panel of transcriptional reporter strains. We show that the expression of H. pylori flaA is growth phase dependent and that flaA transcription increases in asso
American Society for Microbiology.
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6. Role of Neisseria meningitidis luxS in Cell-to-Cell Signaling and Bacteremic Infection
Numerous pathogenic bacteria contain luxS, which is required for autoinducer-2 production. Here, we demonstrate that Neisseria meningitidis contains a functional copy of luxS that is necessary for full meningococcal virulence; strains with a luxS deletion are defective for bacteremia, a prerequisite of meningococcal pathogenesis.
American Society for Microbiology.
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7. Expression of a luxS Gene Is Not Required for Borrelia burgdorferi Infection of Mice via Needle Inoculation
The luxS gene product is an integral component of LuxS/autoinducer-2 (AI-2) quorum-sensing systems in bacteria. A putative luxS gene was expressed at comparable levels by Borrelia burgdorferi strain 297 cultivated either in vitro or in dialysis membrane chambers implanted in rat peritoneal cavities. Although the borrelial luxS gene functionally complemented
American Society for Microbiology.
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8. Colonization of Gnotobiotic Piglets by a luxS Mutant Strain of Escherichia coli O157:H7
Gnotobiotic piglets inoculated with Escherichia coli O157:H7, its luxS mutant derivative, or nonpathogenic E. coli were evaluated for attaching and effacing lesions. Although no differences in clinical symptoms were seen between pigs inoculated with the parent and those inoculated with the luxS mutant, the luxS mutant-inoculated pigs had a lower frequency of
American Society for Microbiology.
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9. Vibrio fischeri LuxS and AinS: Comparative Study of Two Signal Synthases
Vibrio fischeri possesses two acyl-homoserine lactone quorum-sensing systems, ain and lux, both of which are involved in the regulation of luminescence gene expression and are required for persistent colonization of the squid host, Euprymna scolopes. We have previously demonstrated that the ain system induces luminescence at cell densities that precede lux s
American Society for Microbiology.
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10. The luxS Gene of Streptococcus pyogenes Regulates Expression of Genes That Affect Internalization by Epithelial Cells
The gram-positive pathogen Streptococcus pyogenes was recently reported to possess a homologue of the luxS gene that is responsible for the production of autoinducer 2, which participates in quorum sensing of both gram-positive and gram-negative bacteria. To test the effect of LuxS on streptococcal internalization, a LuxS mutant was constructed in strain SP2
American Society for Microbiology.
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11. Crystal structure of the quorum-sensing protein LuxS reveals a catalytic metal site
The ability of bacteria to regulate gene expression in response to changes in cell density is termed quorum sensing. This behavior involves the synthesis and recognition of extracellular, hormone-like compounds known as autoinducers. Here we report the structure of an autoinducer synthase, LuxS from Bacillus subtilis, at 1.6-Å resolution (Rfree = 0.20
The National Academy of Sciences.
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12. Autoinducer 2 Production by Streptococcus gordonii DL1 and the Biofilm Phenotype of a luxS Mutant Are Influenced by Nutritional Conditions
The luxS gene, present in many bacterial genera, encodes the autoinducer 2 (AI-2) synthase. AI-2 has been implicated in bacterial signaling, and this study investigated its role in biofilm formation by Streptococcus gordonii, an organism that colonizes human tooth enamel within the first few hours after professional cleaning. Northern blotting and primer ext
American Society for Microbiology.