| production of cell-cell signalling molecules by bacteria isolated from human chronic wounds. | to (i) identify chronic wound bacteria and to test their ability to produce acyl-homoserine-lactones (ahls) and autoinducer-2 (ai-2) cell-cell signalling molecules and (ii) determine whether chronic wound debridement samples might contain these molecules. | 2010 | 19840177 |
| production of cell-cell signalling molecules by bacteria isolated from human chronic wounds. | to (i) identify chronic wound bacteria and to test their ability to produce acyl-homoserine-lactones (ahls) and autoinducer-2 (ai-2) cell-cell signalling molecules and (ii) determine whether chronic wound debridement samples might contain these molecules. | 2010 | 19840177 |
| are algal genes in nonphotosynthetic protists evidence of historical plastid endosymbioses? | how photosynthetic organelles, or plastids, were acquired by diverse eukaryotes is among the most hotly debated topics in broad scale eukaryotic evolution. the history of plastid endosymbioses commonly is interpreted under the "chromalveolate" hypothesis, which requires numerous plastid losses from certain heterotrophic groups that now are entirely aplastidic. in this context, discoveries of putatively algal genes in plastid-lacking protists have been cited as evidence of gene transfer from a ph ... | 2009 | 19843329 |
| the siderophore pyoverdine of pseudomonas syringae pv. tabaci 6605 is an intrinsic virulence factor in host tobacco infection. | to investigate the role of iron uptake mediated by the siderophore pyoverdine in the virulence of the plant pathogen pseudomonas syringae pv. tabaci 6605, three predicted pyoverdine synthesis-related genes, pvdj, pvdl, and fpva, were mutated. the pvdj, pvdl, and fpva genes encode the pyoverdine side chain peptide synthetase iii l-thr-l-ser component, the pyoverdine chromophore synthetase, and the tonb-dependent ferripyoverdine receptor, respectively. the delta pvdj and delta pvdl mutants were un ... | 2010 | 19854904 |
| the siderophore pyoverdine of pseudomonas syringae pv. tabaci 6605 is an intrinsic virulence factor in host tobacco infection. | to investigate the role of iron uptake mediated by the siderophore pyoverdine in the virulence of the plant pathogen pseudomonas syringae pv. tabaci 6605, three predicted pyoverdine synthesis-related genes, pvdj, pvdl, and fpva, were mutated. the pvdj, pvdl, and fpva genes encode the pyoverdine side chain peptide synthetase iii l-thr-l-ser component, the pyoverdine chromophore synthetase, and the tonb-dependent ferripyoverdine receptor, respectively. the delta pvdj and delta pvdl mutants were un ... | 2010 | 19854904 |
| identification of catechin as one of the flavonoids from combretum albiflorum bark extract that reduces the production of quorum-sensing-controlled virulence factors in pseudomonas aeruginosa pao1. | quorum-sensing (qs) regulates the production of key virulence factors in pseudomonas aeruginosa and other important pathogenic bacteria. in this report, extracts of leaves and bark of combretum albiflorum (tul.) jongkind (combretaceae) were found to quench the production of qs-dependent factors in p. aeruginosa pao1. chromatographic fractionation of the crude active extract generated several active fractions containing flavonoids, as shown by their typical spectral features. purification and str ... | 2010 | 19854927 |
| identification of catechin as one of the flavonoids from combretum albiflorum bark extract that reduces the production of quorum-sensing-controlled virulence factors in pseudomonas aeruginosa pao1. | quorum-sensing (qs) regulates the production of key virulence factors in pseudomonas aeruginosa and other important pathogenic bacteria. in this report, extracts of leaves and bark of combretum albiflorum (tul.) jongkind (combretaceae) were found to quench the production of qs-dependent factors in p. aeruginosa pao1. chromatographic fractionation of the crude active extract generated several active fractions containing flavonoids, as shown by their typical spectral features. purification and str ... | 2010 | 19854927 |
| classification of myoviridae bacteriophages using protein sequence similarity. | we advocate unifying classical and genomic classification of bacteriophages by integration of proteomic data and physicochemical parameters. our previous application of this approach to the entirely sequenced members of the podoviridae fully supported the current phage classification of the international committee on taxonomy of viruses (ictv). it appears that horizontal gene transfer generally does not totally obliterate evolutionary relationships between phages. | 2009 | 19857251 |
| measurement of intrinsic rate constants in the tyrosine hydroxylase reaction. | tyrosine hydroxylase (tyrh) is a pterin-dependent mononuclear non-heme aromatic amino acid hydroxylase that catalyzes the conversion of tyrosine to dihydroxyphenylalanine (dopa). chemical quench analyses of the enzymatic reaction show a burst of dopa formation, followed by a linear rate equal to the k(cat) value at both 5 and 30 degrees c. the effects of increasing solvent viscosity confirm that k(cat) is approximately 84% limited by diffusion, most probably due to slow product release, and that ... | 2010 | 20025246 |
| complete genome sequence of the fire blight pathogen erwinia pyrifoliae dsm 12163t and comparative genomic insights into plant pathogenicity. | erwinia pyrifoliae is a newly described necrotrophic pathogen, which causes fire blight on asian (nashi) pear and is geographically restricted to eastern asia. relatively little is known about its genetics compared to the closely related main fire blight pathogen e. amylovora. | 2010 | 20047678 |
| nanocytotoxicity: violacein and violacein-loaded poly (d, l-lactide-co-glycolide) nanoparticles acting on human leukemic cells. | violacein is a compound obtained from chromobacterium violaceum, a bacterium found in the amazonian region. violacein-loaded poly (d, l-lactide-co-glycolide) nanoparticles has a similar inhibitory effect evaluated by trypan blue assay on leukemic hl60 cells than the free form. however, the cytotoxic effects evaluated by phosphatase activity and mtt reduction assays were lower for the encapsulated form than for free violacein. based on morphological changes, violacein and violacein entrapped in n ... | 2009 | 20055097 |
| an automated system for rapid non-destructive enumeration of growing microbes. | the power and simplicity of visual colony counting have made it the mainstay of microbiological analysis for more than 130 years. a disadvantage of the method is the long time required to generate visible colonies from cells in a sample. new rapid testing technologies generally have failed to maintain one or more of the major advantages of culture-based methods. | 2010 | 20062794 |
| chromobacterium violaceum infection in a free-ranging howler monkey in costa rica. | chromobacterium violaceum is a gram-negative saprobe bacterium that is a rare opportunistic pathogen in mammals. there are numerous reports in humans including fatalities, but no record exists in free-ranging nonhuman primates. here we report an infection by c. violaceum in a wild adult male howler monkey (alouatta palliata) captured at ballena marine national park, in southwestern costa rica. the individual had severe skin lesions over its extremities; gross findings included multiple skin ulce ... | 2010 | 20090050 |
| violacein-producing collimonas sp. from the sea surface microlayer of costal waters in trøndelag, norway. | a new strain belonging to the genus collimonas was isolated from the sea surface microlayer off the coast of trøndelag, norway. the bacterium, designated collimonas ct, produced an antibacterial compound active against micrococcus luteus. subsequent studies using lc-ms identified this antibacterial compound as violacein, known to be produced by several marine-derived bacteria. fragments of the violacein biosynthesis genes vioa and viob were amplified by pcr from the collimonas ct genome and sequ ... | 2009 | 20098599 |
| blocking of pseudomonas aeruginosa and chromobacterium violaceum lectins by diverse mammalian milks. | pseudomonas aeruginosa and chromobacterium violaceum morbid and mortal infections are initiated by bacterial adherence to host-cell receptors via their adhesins, including lectins (which also contribute to bacterial biofilm formation). pseudomonas aeruginosa produces a galactophilic lectin, pa-il (leca), and a fucophilic (lewis-specific) lectin, pa-iil (lecb), and c. violaceum produces a fucophilic (h-specific) lectin, cv-iil. the antibiotic resistance of these bacteria prompted the search for g ... | 2010 | 20105519 |
| distribution of virulence factors and molecular fingerprinting of aeromonas species isolates from water and clinical samples: suggestive evidence of water-to-human transmission. | a total of 227 isolates of aeromonas obtained from different geographical locations in the united states and different parts of the world, including 28 reference strains, were analyzed to determine the presence of various virulence factors. these isolates were also fingerprinted using biochemical identification and pulse-field gel electrophoresis (pfge). of these 227 isolates, 199 that were collected from water and clinical samples belonged to three major groups or complexes, namely, the a. hydr ... | 2010 | 20154106 |
| aiim, a novel class of n-acylhomoserine lactonase from the leaf-associated bacterium microbacterium testaceum. | n-acylhomoserine lactones (ahls) are used as quorum-sensing signal molecules by many gram-negative bacteria. we have reported that microbacterium testaceum stlb037, which was isolated from the leaf surface of potato, has ahl-degrading activity. in this study, we cloned the aiim gene from the genomic library of stlb037, which has ahl-degrading activity and shows high homology with the alpha/beta hydrolase fold family from actinobacteria. purified aiim as a maltose binding fusion protein showed hi ... | 2010 | 20173075 |
| carbon-dependent control of electron transfer and central carbon pathway genes for methane biosynthesis in the archaean, methanosarcina acetivorans strain c2a. | the archaeon, methanosarcina acetivorans strain c2a forms methane, a potent greenhouse gas, from a variety of one-carbon substrates and acetate. whereas the biochemical pathways leading to methane formation are well understood, little is known about the expression of the many of the genes that encode proteins needed for carbon flow, electron transfer and/or energy conservation. quantitative transcript analysis was performed on twenty gene clusters encompassing over one hundred genes in m. acetiv ... | 2010 | 20178638 |
| space microbiology. | the responses of microorganisms (viruses, bacterial cells, bacterial and fungal spores, and lichens) to selected factors of space (microgravity, galactic cosmic radiation, solar uv radiation, and space vacuum) were determined in space and laboratory simulation experiments. in general, microorganisms tend to thrive in the space flight environment in terms of enhanced growth parameters and a demonstrated ability to proliferate in the presence of normally inhibitory levels of antibiotics. the mecha ... | 2010 | 20197502 |
| rapid differentiation of francisella species and subspecies by fluorescent in situ hybridization targeting the 23s rrna. | francisella (f.) tularensis is the causative agent of tularemia. due to its low infectious dose, ease of dissemination and high case fatality rate, f. tularensis was the subject in diverse biological weapons programs and is among the top six agents with high potential if misused in bioterrorism. microbiological diagnosis is cumbersome and time-consuming. methods for the direct detection of the pathogen (immunofluorescence, pcr) have been developed but are restricted to reference laboratories. | 2010 | 20205957 |
| secondary colonies of bacteria induced by salts of alkali metals, with special reference to chromobacterium violaceum and other bacteria on lithium chloride agar. | | 1947 | 20295177 |
| measurement of the intramolecular isotope effect on aliphatic hydroxylation by chromobacterium violaceum phenylalanine hydroxylase. | the non-heme iron enzyme phenylalanine hydroxylase from chromobacterium violaceum has previously been shown to catalyze the hydroxylation of benzylic and aliphatic carbons in addition to the normal aromatic hydroxylation reaction. the intrinsic isotope effect for hydroxylation of 3-cyclochexylalanine by the enzyme was determined in order to gain insight into the reactivity of the iron center. with 3-[(2)h(11)-cyclohexyl]alanine as the substrate, the isotope effect on the k(cat) value was 1, cons ... | 2010 | 20355730 |
| bacillus pumilus of palk bay origin inhibits quorum-sensing-mediated virulence factors in gram-negative bacteria. | the aim of the current study was to inhibit quoring-sensing(qs)-mediated virulence factors of representative gram-negative bacteria by marine bacterial isolates. bacteria isolated from palk bay sediments were screened for anti-qs activity. eleven strains inhibited qs signals in chromobacterium violaceum (atcc 12472) and c. violaceum cv026. the marine bacterial strain s8-07 reduced the accumulation of n-acyl homoserine lactone (ahls) and showed significant inhibition of lasa protease(76%), lasb e ... | 2010 | 20381609 |
| novel anti-infective compounds from marine bacteria. | as a result of the continuous evolution of microbial pathogens towards antibiotic-resistance, there have been demands for the development of new and effective antimicrobial compounds. since the 1960s, the scientific literature has accumulated many publications about novel pharmaceutical compounds produced by a diverse range of marine bacteria. indeed, marine micro-organisms continue to be a productive and successful focus for natural products research, with many newly isolated compounds possessi ... | 2010 | 20411112 |
| finding new enzymes from bacterial physiology: a successful approach illustrated by the detection of novel oxidases in marinomonas mediterranea. | the identification and study of marine microorganisms with unique physiological traits can be a very powerful tool discovering novel enzymes of possible biotechnological interest. this approach can complement the enormous amount of data concerning gene diversity in marine environments offered by metagenomic analysis, and can help to place the activities associated with those sequences in the context of microbial cellular metabolism and physiology. accordingly, the detection and isolation of micr ... | 2010 | 20411113 |
| production of metabolites as bacterial responses to the marine environment. | bacteria in marine environments are often under extreme conditions of e.g., pressure, temperature, salinity, and depletion of micronutrients, with survival and proliferation often depending on the ability to produce biologically active compounds. some marine bacteria produce biosurfactants, which help to transport hydrophobic low water soluble substrates by increasing their bioavailability. however, other functions related to heavy metal binding, quorum sensing and biofilm formation have been de ... | 2010 | 20411122 |
| growth inhibition and pro-apoptotic activity of violacein in ehrlich ascites tumor. | the continuing threat to biodiversity lends urgency to the need of identification of sustainable source of natural products. this is not so much trouble if there is a microbial source of the compound. herein, violacein, a natural indolic pigment extracted from chromobacterium violaceum, was evaluated for its antitumoral potential against the ehrlich ascites tumor (eat) in vivo and in vitro. evaluation of violacein cytotoxicity using different endpoints indicated that eat cells were twofold (ic(5 ... | 2010 | 20416285 |
| pentaplexed quantitative real-time pcr assay for the simultaneous detection and quantification of botulinum neurotoxin-producing clostridia in food and clinical samples. | botulinum neurotoxins are produced by the anaerobic bacterium clostridium botulinum and are divided into seven distinct serotypes (a to g) known to cause botulism in animals and humans. in this study, a multiplexed quantitative real-time pcr assay for the simultaneous detection of the human pathogenic c. botulinum serotypes a, b, e, and f was developed. based on the taqman chemistry, we used five individual primer-probe sets within one pcr, combining both minor groove binder- and locked nucleic ... | 2010 | 20435756 |
| novel tryptophan metabolites, chromoazepinone a, b and c, produced by a blocked mutant of chromobacterium violaceum, the biosynthetic implications and the biological activity of chromoazepinone a and b. | chromobacterium violaceum produces tryptophan metabolites, purple pigments of violacein and deoxyviolacein. a blocked mutant was prepared with n-methyl-n'-nitrosoguanidine to gain insights into the biosynthetic mechanisms of the pigments. five tryptophan metabolites were isolated: three novel compounds, named chromoazepinone a, b and c and two known compounds, chromopyrrolic acid and arcyriarubin a. the structure determinations of the three novel compounds are described. the biosynthetic pathway ... | 2010 | 20490411 |
| chromobacterium pathogenicity island 1 type iii secretion system is a major virulence determinant for chromobacterium violaceum-induced cell death in hepatocytes. | summary chromobacterium violaceum is a gram-negative bacterium that causes fatal septicaemia in humans and animals. c. violaceum atcc 12472 possesses genes associated with two distinct type iii secretion systems (t3sss). one of these systems is encoded by chromobacterium pathogenicity islands 1 and 1a (cpi-1/-1a), another is encoded by chromobacterium pathogenicity island 2 (cpi-2). here we show that c. violaceum causes fulminant hepatitis in a mouse infection model, and cpi-1/-1a-encoded t3ss i ... | 2010 | 20545857 |
| antimycobacterial activity in vitro of pigments isolated from antarctic bacteria. | in this study, we describe the antimycobacterial activity of two pigments, violacein, a purple violet pigment from janthinobacterium sp. ant5-2 (j-pvp), and flexirubin, a yellow-orange pigment from flavobacterium sp. ant342 (f-yop). these pigments were isolated from bacterial strains found in the land-locked freshwater lakes of schirmacher oasis, east antarctica. the minimum inhibitory concentrations (mics) of these pigments for avirulent and virulent mycobacteria were determined by the micropla ... | 2010 | 20556653 |
| identification and characterization of a novel bacterial atp-sensitive k+ channel. | five bacterial species that are most likely to have putative prokaryotic inward rectifier k(+) (kir) channels were selected by in silico sequence homology and membrane topology analyses with respect to the number of transmembrane domains (tms) and the presence of k(+) selectivity filter and/or atp binding sites in reference to rabbit heart inward rectifier k(+) channel (kir6.2). a dot blot assay with genomic dnas when probed with whole rabbit kir6.2 cdna further supported the in silico analysis ... | 2010 | 20571950 |
| the novel two-component regulatory system bfisr regulates biofilm development by controlling the small rna rsmz through cafa. | the formation of biofilms by the opportunistic pathogen pseudomonas aeruginosa is a developmental process governed by a novel signal transduction system composed of three two-component regulatory systems (tcss), bfisr, bfmsr, and mifsr. here, we show that bfisr-dependent arrest of biofilm formation coincided with reduced expression of genes involved in virulence, posttranslational/transcriptional modification, and rhl quorum sensing but increased expression of rhlab and the small regulatory rnas ... | 2010 | 20656909 |
| characterization and pcr-based replicon typing of resistance plasmids in acinetobacter baumannii. | acinetobacter baumannii is an opportunistic pathogen, especially in intensive care units, and multidrug-resistant isolates have increasingly been reported during the last decade. despite recent progress in knowledge of antibiotic resistance mechanisms in a. baumannii, little is known about the genetic factors driving isolates toward multidrug resistance. in the present study, the a. baumannii plasmids were investigated through the analysis and classification of plasmid replication systems and th ... | 2010 | 20660691 |
| genetic and phenotypic diversity in burkholderia: contributions by prophage and phage-like elements. | burkholderia species exhibit enormous phenotypic diversity, ranging from the nonpathogenic, soil- and water-inhabiting burkholderia thailandensis to the virulent, host-adapted mammalian pathogen b. mallei. genomic diversity is evident within burkholderia species as well. individual isolates of burkholderia pseudomallei and b. thailandensis, for example, carry a variety of strain-specific genomic islands (gis), including putative pathogenicity and metabolic islands, prophage-like islands, and pro ... | 2010 | 20667135 |
| interkingdom signaling between pathogenic bacteria and caenorhabditis elegans. | investigators have recently turned to the soil nematode caenorhabditis elegans as a small animal infection model to study infectious disease. to extrapolate findings concerning bacterial pathogenesis from non-mammals to mammals, virulence factors should be conserved in function, independent of the infection model. emerging from these studies is the observation that bacterial virulence regulatory networks function in a conserved manner across multiple hosts, including nematodes, mice and plants. ... | 2010 | 20667738 |
| the chitinolytic activity of listeria monocytogenes egd is regulated by carbohydrates but also by the virulence regulator prfa. | chitin, an insoluble polymer of n-acetyl-d-glucosamine (glcnac), is one of the most abundant carbohydrate polymers in marine and terrestrial environments. chitin hydrolysis by listeria monocytogenes depends on two chitinase-encoding genes, chia and chib, and the aim of this study was to investigate their regulation. chitin induces the expression of both chitinases in late exponential growth phase, and chia but not chib is furthermore induced by the monomer glcnac. furthermore, their expression i ... | 2010 | 20675445 |
| construction of self-transmissible green fluorescent protein-based biosensor plasmids and their use for identification of n-acyl homoserine-producing bacteria in lake sediments. | many bacteria utilize quorum sensing (qs) systems to communicate with each other by means of the production, release, and response to signal molecules. n-acyl homoserine lactone (ahl)-based qs systems are particularly widespread among the proteobacteria, in which they regulate various functions. it has become evident that ahls can also serve as signals for interspecies communication. however, knowledge on the impact of ahls for the ecology of bacteria in their natural habitat is scarce, due main ... | 2010 | 20675456 |
| genome sequencing reveals widespread virulence gene exchange among human neisseria species. | commensal bacteria comprise a large part of the microbial world, playing important roles in human development, health and disease. however, little is known about the genomic content of commensals or how related they are to their pathogenic counterparts. the genus neisseria, containing both commensal and pathogenic species, provides an excellent opportunity to study these issues. we undertook a comprehensive sequencing and analysis of human commensal and pathogenic neisseria genomes. commensals h ... | 2010 | 20676376 |
| phenotypic and physiological alterations by heterologous acylhomoserine lactone synthase expression in pseudomonas putida. | many bacteria harbour an incomplete quorum-sensing (qs) system, whereby they possess luxr homologues without the qs acylhomoserine lactone (ahl) synthase, which is encoded by a luxi homologue. an artificial ahl-producing plasmid was constructed using a cvii gene encoding the c6-ahl [n-hexanoyl homoserine lactone (hhl)] synthase from chromobacterium violaceum, and was introduced successfully into both the wild-type and a ppor (luxr homologue) mutant of pseudomonas putida. our data provide evidenc ... | 2010 | 20705668 |
| evaluation of anti-quorum-sensing activity of edible plants and fruits through inhibition of the n-acyl-homoserine lactone system in chromobacterium violaceum and pseudomonas aeruginosa. | to find out an alternative strategy to antibiotic usage against bacterial infection. | 2010 | 20720417 |
| comparative biogeography of chromobacterium from the neotropics. | the genus chromobacterium encompasses free-living gram-negative bacteria. until 2007, the genus consisted of only one species but six species are now recognized. chromobacterium violaceum is the type species of the genus and is commonly found in soil and water in tropical and sub-tropical regions. we have investigated a collection of 111 isolates displaying violet pigmentation from undisturbed aquatic and soil environments from brazilian cerrado ecosystem. the 16s rrna gene phylogeny revealed th ... | 2011 | 20803105 |
| enzymatic processing of fumiquinazoline f: a tandem oxidative-acylation strategy for the generation of multicyclic scaffolds in fungal indole alkaloid biosynthesis. | aspergillus fumigatus af293 is a known producer of quinazoline natural products, including the antitumor fumiquinazolines, of which the simplest member is fumiquinazoline f (fqf) with a 6-6-6 tricyclic core derived from anthranilic acid, tryptophan, and alanine. fqf is the proposed biological precursor to fumiquinazoline a (fqa) in which the pendant indole side chain has been modified via oxidative coupling of an additional molecule of alanine, yielding a fused 6-5-5 imidazoindolone. we recently ... | 2010 | 20804163 |
| sepl resembles an aberrant effector in binding to a class 1 type iii secretion chaperone and carrying an n-terminal secretion signal. | here we show that the type iii secretion gatekeeper protein sepl resembles an aberrant effector protein in binding to a class 1 type iii secretion chaperone (orf12, here renamed cesl). we also show that short n-terminal fragments (≤70 amino acids) from sepl are capable of targeting fusion proteins for secretion and translocation. | 2010 | 20833800 |
| regulation of the violacein biosynthetic gene cluster by acylhomoserine lactone-mediated quorum sensing in chromobacterium violaceum atcc 12472. | chromobacterium violaceum produces the purple pigment violacein by quorum-sensing regulation. 20-bp of the lux box-like sequence was found upstream of vioa in c. violaceum atcc 12472. cvir received c10-hsl and c6-hsl and activated the transcription of vioa in escherichia coli. however, in strain atcc 12472, c6-hsl inhibited both c10-hsl-mediated violacein production and the transcription of vioa. | 2010 | 20944413 |
| isolation and characterization of new potential probiotic bacteria based on quorum-sensing system. | this work was aimed at identifying strains which can degrade quorum-sensing (qs) molecules from fish gut, with properties suitable for use as probiotic in aquaculture. | 2010 | 20955192 |
| nonflowering plants possess a unique folate-dependent phenylalanine hydroxylase that is localized in chloroplasts. | tetrahydropterin-dependent aromatic amino acid hydroxylases (aahs) are known from animals and microbes but not plants. a survey of genomes and ests revealed aah-like sequences in gymnosperms, mosses, and algae. analysis of full-length aah cdnas from pinus taeda, physcomitrella patens, and chlamydomonas reinhardtii indicated that the encoded proteins form a distinct clade within the aah family. these proteins were shown to have phe hydroxylase activity by functional complementation of an escheric ... | 2010 | 20959559 |
| what is type vi secretion doing in all those bugs? | the identification of bacterial secretion systems capable of translocating substrates into eukaryotic cells via needle-like appendages has opened fruitful and exciting areas of microbial pathogenesis research. the recent discovery of the type vi secretion system (t6ss) was met with early speculation that it too acts as a 'needle' that pathogens aim at host cells. new reports demonstrate that certain t6sss are potent mediators of interbacterial interactions. in light of these findings, we examine ... | 2010 | 20961764 |
| rationale for possible targeting of histone deacetylase signaling in cancer diseases with a special reference to pancreatic cancer. | there is ongoing interest to identify signaling pathways and genes that play a key role in carcinogenesis and the development of resistance to antitumoral drugs. given that histone deacetylases (hdacs) interact with various partners through complex molecular mechanims leading to the control of gene expression, they have captured the attention of a large number of researchers. as a family of transcriptional corepressors, they have emerged as important regulators of cell differentiation, cell cycl ... | 2010 | 20981265 |
| rationale for possible targeting of histone deacetylase signaling in cancer diseases with a special reference to pancreatic cancer. | there is ongoing interest to identify signaling pathways and genes that play a key role in carcinogenesis and the development of resistance to antitumoral drugs. given that histone deacetylases (hdacs) interact with various partners through complex molecular mechanims leading to the control of gene expression, they have captured the attention of a large number of researchers. as a family of transcriptional corepressors, they have emerged as important regulators of cell differentiation, cell cycl ... | 2010 | 20981265 |
| bioassays of quorum sensing compounds using agrobacterium tumefaciens and chromobacterium violaceum. | in most bacteria, a global level of regulation exists involving intercellular communication via the production and response to cell density-dependent signal molecules. this cell density-dependent regulation has been termed quorum sensing (qs). qs is a global regulator, which has been associated with a number of important features in bacteria including virulence regulation and biofilm formation. consequently, there is considerable interest in understanding, detecting, and inhibiting qs. acyl homo ... | 2011 | 21031300 |
| the crystal structures of the salmonella type iii secretion system tip protein sipd in complex with deoxycholate and chenodeoxycholate. | the type iii secretion system (t3ss) is a protein injection nanomachinery required for virulence by many human pathogenic bacteria including salmonella and shigella. an essential component of the t3ss is the tip protein and the salmonella sipd and the shigella ipad tip proteins interact with bile salts, which serve as environmental sensors for these enteric pathogens. sipd and ipad have long central coiled coils and their n-terminal regions form α-helical hairpins and a short helix α3 that pack ... | 2011 | 21031487 |
| the crystal structures of the salmonella type iii secretion system tip protein sipd in complex with deoxycholate and chenodeoxycholate. | the type iii secretion system (t3ss) is a protein injection nanomachinery required for virulence by many human pathogenic bacteria including salmonella and shigella. an essential component of the t3ss is the tip protein and the salmonella sipd and the shigella ipad tip proteins interact with bile salts, which serve as environmental sensors for these enteric pathogens. sipd and ipad have long central coiled coils and their n-terminal regions form α-helical hairpins and a short helix α3 that pack ... | 2011 | 21031487 |
| distribution analysis of hydrogenases in surface waters of marine and freshwater environments. | surface waters of aquatic environments have been shown to both evolve and consume hydrogen and the ocean is estimated to be the principal natural source. in some marine habitats, h(2) evolution and uptake are clearly due to biological activity, while contributions of abiotic sources must be considered in others. until now the only known biological process involved in h(2) metabolism in marine environments is nitrogen fixation. | 2010 | 21079771 |
| cross-species induction of antimicrobial compounds, biosurfactants and quorum-sensing inhibitors in tropical marine epibiotic bacteria by pathogens and biofouling microorganisms. | enhancement or induction of antimicrobial, biosurfactant, and quorum-sensing inhibition property in marine bacteria due to cross-species and cross-genera interactions was investigated. four marine epibiotic bacteria (bacillus sp. s3, b. pumilus s8, b. licheniformis d1, and serratia marcescens v1) displaying antimicrobial activity against pathogenic or biofouling fungi (candida albicans ca and yarrowia lipolytica yl), and bacteria (pseudomonas aeruginosa pa and bacillus pumilus bp) were chosen fo ... | 2010 | 21086131 |
| volatile-mediated killing of arabidopsis thaliana by bacteria is mainly due to hydrogen cyanide. | the volatile-mediated impact of bacteria on plant growth is well documented, and contrasting effects have been reported ranging from 6-fold plant promotion to plant killing. however, very little is known about the identity of the compounds responsible for these effects or the mechanisms involved in plant growth alteration. we hypothesized that hydrogen cyanide (hcn) is a major factor accounting for the observed volatile-mediated toxicity of some strains. using a collection of environmental and c ... | 2010 | 21115704 |
| volatile-mediated killing of arabidopsis thaliana by bacteria is mainly due to hydrogen cyanide. | the volatile-mediated impact of bacteria on plant growth is well documented, and contrasting effects have been reported ranging from 6-fold plant promotion to plant killing. however, very little is known about the identity of the compounds responsible for these effects or the mechanisms involved in plant growth alteration. we hypothesized that hydrogen cyanide (hcn) is a major factor accounting for the observed volatile-mediated toxicity of some strains. using a collection of environmental and c ... | 2010 | 21115704 |
| immense essence of excellence: marine microbial bioactive compounds. | oceans have borne most of the biological activities on our planet. a number of biologically active compounds with varying degrees of action, such as anti-tumor, anti-cancer, anti-microtubule, anti-proliferative, cytotoxic, photo protective, as well as antibiotic and antifouling properties, have been isolated to date from marine sources. the marine environment also represents a largely unexplored source for isolation of new microbes (bacteria, fungi, actinomycetes, microalgae-cyanobacteria and di ... | 2010 | 21116414 |
| the dimeric sos mutagenesis protein umud is active as a monomer. | the homodimeric umud gene products play key roles in regulating the cellular response to dna damage in escherichia coli. umud(2) is composed of 139-amino acid subunits and is up-regulated as part of the sos response. subsequently, damage-induced reca·ssdna nucleoprotein filaments mediate the slow self-cleavage of the n-terminal 24-amino acid arms yielding umud'(2). umud(2) and umud'(2) make a number of distinct protein-protein contacts that both prevent and facilitate mutagenic translesion synth ... | 2010 | 21118802 |
| the dimeric sos mutagenesis protein umud is active as a monomer. | the homodimeric umud gene products play key roles in regulating the cellular response to dna damage in escherichia coli. umud(2) is composed of 139-amino acid subunits and is up-regulated as part of the sos response. subsequently, damage-induced reca·ssdna nucleoprotein filaments mediate the slow self-cleavage of the n-terminal 24-amino acid arms yielding umud'(2). umud(2) and umud'(2) make a number of distinct protein-protein contacts that both prevent and facilitate mutagenic translesion synth ... | 2010 | 21118802 |
| three motab stator gene products in bdellovibrio bacteriovorus contribute to motility of a single flagellum during predatory and prey-independent growth. | the predatory bacterium bdellovibrio bacteriovorus uses flagellar motility to locate regions rich in gram-negative prey bacteria, colliding and attaching to prey and then ceasing flagellar motility. prey are then invaded to form a "bdelloplast" in a type iv pilus-dependent process, and prey contents are digested, allowing bdellovibrio growth and septation. after septation, bdellovibrio flagellar motility resumes inside the prey bdelloplast prior to its lysis and escape of bdellovibrio progeny. b ... | 2010 | 21148728 |
| three motab stator gene products in bdellovibrio bacteriovorus contribute to motility of a single flagellum during predatory and prey-independent growth. | the predatory bacterium bdellovibrio bacteriovorus uses flagellar motility to locate regions rich in gram-negative prey bacteria, colliding and attaching to prey and then ceasing flagellar motility. prey are then invaded to form a "bdelloplast" in a type iv pilus-dependent process, and prey contents are digested, allowing bdellovibrio growth and septation. after septation, bdellovibrio flagellar motility resumes inside the prey bdelloplast prior to its lysis and escape of bdellovibrio progeny. b ... | 2010 | 21148728 |
| gram-positive marine bacteria as a potential resource for the discovery of quorum sensing inhibitors. | inhibitors of bacterial quorum sensing have been proposed as potentially novel therapeutics for the treatment of certain bacterial diseases. we recently reported a marine halobacillus salinus isolate that secretes secondary metabolites capable of quenching quorum sensing phenotypes in several gram-negative reporter strains. to investigate how widespread the production of such compounds may be in the marine bacterial environment, 332 gram-positive isolates from diverse habitats were tested for th ... | 2010 | 21152942 |
| quorum sensing in bacterial species that use degenerate autoinducers can be tuned by using structurally identical non-native ligands. | many bacteria use quorum sensing (qs) to regulate cell-density dependent phenotypes that play critical roles in the maintenance of their associations with eukaryotic hosts. in gram-negative bacteria, qs is primarily controlled by n-acylated l-homoserine lactone (ahl) signals and their cognate luxr-type receptors. ahl-luxr-type receptor binding regulates the expression of target genes necessary for qs phenotypes. we recently identified a series of non-native ahls capable of intercepting ahl-luxr ... | 2011 | 21154995 |
| quorum quenching in cultivable bacteria from dense marine coastal microbial communities. | acylhomoserine lactone (ahls)-mediated quorum-sensing (qs) processes seem to be common in the marine environment and among marine pathogenic bacteria, but no data are available on the prevalence of bacteria capable of interfering with qs in the sea, a process that has been generally termed 'quorum quenching' (qq). one hundred and sixty-six strains isolated from different marine dense microbial communities were screened for their ability to interfere with ahl activity. twenty-four strains (14.4%) ... | 2010 | 21155853 |
| metagenomic analyses: past and future trends. | metagenomics has revolutionized microbiology by paving the way for a cultivation-independent assessment and exploitation of microbial communities present in complex ecosystems. metagenomics comprising construction and screening of metagenomic dna libraries has proven to be a powerful tool to isolate new enzymes and drugs of industrial importance. so far, the majority of the metagenomically exploited habitats comprised temperate environments, such as soil and marine environments. recently, metage ... | 2010 | 21169428 |
| metagenomic analyses: past and future trends. | metagenomics has revolutionized microbiology by paving the way for a cultivation-independent assessment and exploitation of microbial communities present in complex ecosystems. metagenomics comprising construction and screening of metagenomic dna libraries has proven to be a powerful tool to isolate new enzymes and drugs of industrial importance. so far, the majority of the metagenomically exploited habitats comprised temperate environments, such as soil and marine environments. recently, metage ... | 2010 | 21169428 |
| a novel cdsab operon is involved in the uptake of l-cysteine and participates in the pathogenesis of yersinia ruckeri. | application of in vivo expression technology (ivet) to yersinia ruckeri, an important fish pathogen, allowed the identification of two adjacent genes that represent a novel bacterial system involved in the uptake and degradation of l-cysteine. analysis of the translational products of both genes showed permease domains (open reading frame 1 [orf1]) and amino acid position identities (orf2) with the l-cysteine desulfidase from methanocaldococcus jannaschii, a new type of enzyme involved in the br ... | 2010 | 21169490 |
| a novel cdsab operon is involved in the uptake of l-cysteine and participates in the pathogenesis of yersinia ruckeri. | application of in vivo expression technology (ivet) to yersinia ruckeri, an important fish pathogen, allowed the identification of two adjacent genes that represent a novel bacterial system involved in the uptake and degradation of l-cysteine. analysis of the translational products of both genes showed permease domains (open reading frame 1 [orf1]) and amino acid position identities (orf2) with the l-cysteine desulfidase from methanocaldococcus jannaschii, a new type of enzyme involved in the br ... | 2010 | 21169490 |
| novel pan-genomic analysis approach in target selection for multiplex pcr identification and detection of burkholderia pseudomallei, burkholderia thailandensis, and burkholderia cepacia complex species: a proof-of-concept study. | burkholderia pseudomallei, burkholderia thailandensis, and the burkholderia cepacia complex differ greatly in pathogenicity and epidemiology. yet, they are occasionally misidentified by biochemical profiling, and even 16s rrna gene sequencing may not offer adequate discrimination between certain species groups. using the 23 b. pseudomallei, four b. thailandensis, and 16 b. cepacia complex genome sequences available, we identified gene targets specific to each of them (a tat domain protein, a 70- ... | 2010 | 21177905 |
| new insights into the genetic organization of the fk228 biosynthetic gene cluster in chromobacterium violaceum no. 968. | the biosynthetic gene cluster of fk228, an fda-approved anticancer natural product, was identified and sequenced previously. the genetic organization of this gene cluster has now been delineated through systematic gene deletion and transcriptional analysis. as a result, the gene cluster is redefined to contain 12 genes: depa through depj, depm, and a newly identified pathway regulatory gene, depr. | 2010 | 21183645 |
| reconstitution of the fk228 biosynthetic pathway reveals cross talk between modular polyketide synthases and fatty acid synthase. | functional cross talk between fatty acid biosynthesis and secondary metabolism has been discovered in several cases in microorganisms; none of them, however, involves a modular biosynthetic enzyme. previously, we reported a hybrid modular nonribosomal peptide synthetase (nrps)-polyketide synthase (pks) pathway for the biosynthesis of fk228 anticancer depsipeptide in chromobacterium violaceum strain 968. this pathway contains two pks modules on the depbc enzymes that lack a functional acyltransfe ... | 2010 | 21183648 |
| histone deacetylase inhibitors in the treatment of hematological malignancies and solid tumors. | the human genome is epigenetically organized through a series of modifications to the histone proteins that interact with the dna. in cancer, many of the proteins that regulate these modifications can be altered in both function and expression. one example of this is the family of histone deacetylases (hdacs), which as their name implies remove acetyl groups from the histone proteins, allowing for more condensed nucleosomal structure. hdacs have increased expression in cancer and are also believ ... | 2010 | 21188171 |
| histone deacetylase inhibitors in the treatment of hematological malignancies and solid tumors. | the human genome is epigenetically organized through a series of modifications to the histone proteins that interact with the dna. in cancer, many of the proteins that regulate these modifications can be altered in both function and expression. one example of this is the family of histone deacetylases (hdacs), which as their name implies remove acetyl groups from the histone proteins, allowing for more condensed nucleosomal structure. hdacs have increased expression in cancer and are also believ ... | 2010 | 21188171 |
| inhibition of quorum sensing in chromobacterium violaceum by pigments extracted from auricularia auricular. | this study aimed to search for a novel quorum-sensing inhibitor from some fungi and analyse its inhibitory activity. | 2011 | 21204879 |
| chromoblastomycosis after a leech bite complicated by myiasis: a case report. | chromoblastomycosis is a chronic mycotic infection, most common in the tropics and subtropics, following traumatic fungal implantation. | 2011 | 21226934 |
| biochemical and structural characterization of wlba from bordetella pertussis and chromobacterium violaceum: enzymes required for the biosynthesis of 2,3-diacetamido-2,3-dideoxy-d-mannuronic acid. | the unusual sugar 2,3-diacetamido-2,3-dideoxy-d-mannuronic acid, or mannac3naca, has been observed in the lipopolysaccharides of both pathogenic and nonpathogenic gram-negative bacteria. it is added to the lipopolysaccharides of these organisms by glycosyltransferases that use as substrates udp-mannac3naca. five enzymes are ultimately required for the biosynthesis of udp-mannac3naca starting from udp-n-acetylglucosamine. the second enzyme in the pathway, encoded by the wlba gene and referred to ... | 2011 | 21241053 |
| screening of certain medicinal plants from india for their anti-quorum sensing activity. | discovery of quorum sensing (qs) system to coordinate virulence and biofilm formation in bacterial pathogens has triggered search for safe, stable and non-toxic anti-qs compounds from natural products. ethanolic extracts of 24 indian medicinal plants were tested by agar well and disc diffusion assay for anti-qs activity using chromobacterium violaceum (cv12472 and cvo26) reporter strains. ahl from c. violaceum cv31532 was isolated and partially purified for its use in cvo26 based bioassay. effec ... | 2010 | 21250604 |
| chromobacterium violaceum and its important metabolites--review. | c. violaceum appeared as important bacterium in different applications and mainly these aspects are related to the production of violacein. this review discusses the last reports on biosynthetic pathways, production, genetic aspects, biological activities, pathological effects, antipathogenic screening through quorum sensing, environmental effects and the products of c. violaceum with industrial interest. an important discussion is on biological applications in medicine and as industrial product ... | 2010 | 21253897 |
| evidence for a high-spin fe(iv) species in the catalytic cycle of a bacterial phenylalanine hydroxylase. | phenylalanine hydroxylase is a mononuclear non-heme iron protein that uses tetrahydropterin as the source of the two electrons needed to activate dioxygen for the hydroxylation of phenylalanine to tyrosine. rapid-quench methods have been used to analyze the mechanism of a bacterial phenylalanine hydroxylase from chromobacterium violaceum. mo¨ssbauer spectra of samples prepared by freeze-quenching the reaction of the enzyme-(57)fe(ii)-phenylalanine-6-methyltetrahydropterin complex with o(2) revea ... | 2011 | 21261288 |
| hypersensitive response and acyl-homoserine lactone production of the fire blight antagonists erwinia tasmaniensis and erwinia billingiae. | fire blight caused by the gram-negative bacterium erwinia amylovora can be controlled by antagonistic microorganisms. we characterized epiphytic bacteria isolated from healthy apple and pear trees in australia, named erwinia tasmaniensis, and the epiphytic bacterium erwinia billingiae from england for physiological properties, interaction with plants and interference with growth of e. amylovora. they reduced symptom formation by the fire blight pathogen on immature pears and the colonization of ... | 2008 | 21261861 |
| characterisation of two quorum sensing systems in the endophytic serratia plymuthica strain g3: differential control of motility and biofilm formation according to life-style. | n-acylhomoserine lactone (ahl)-based quorum sensing (qs) systems have been described in many plant-associated gram-negative bacteria to control certain beneficial phenotypic traits, such as production of biocontrol factors and plant growth promotion. however, the role of ahl-mediated signalling in the endophytic strains of plant-associated serratia is still poorly understood. an endophytic serratia sp. g3 with biocontrol potential and high levels of ahl signal production was isolated from the st ... | 2011 | 21284858 |
| tannin-rich fraction from terminalia catappa inhibits quorum sensing (qs) in chromobacterium violaceum and the qs-controlled biofilm maturation and lasa staphylolytic activity in pseudomonas aeruginosa. | the study aimed to test the activity of terminalia catappa l. against bacterial quorum sensing (qs) in order to provide a potential scientific basis for the traditional use of leaf extracts of this plant as an antiseptic. | 2011 | 21291979 |
| structural basis for c-di-gmp-mediated inside-out signaling controlling periplasmic proteolysis. | the bacterial second messenger bis-(3'-5') cyclic dimeric guanosine monophosphate (c-di-gmp) has emerged as a central regulator for biofilm formation. increased cellular c-di-gmp levels lead to stable cell attachment, which in pseudomonas fluorescens requires the transmembrane receptor lapd. lapd exhibits a conserved and widely used modular architecture containing a hamp domain and degenerate diguanylate cyclase and phosphodiesterase domains. c-di-gmp binding to the lapd degenerate phosphodieste ... | 2011 | 21304926 |
| first report of performance of the versant ct/gc dna 1.0 assay (kpcr) for detection of chlamydia trachomatis and neisseria gonorrhoeae. | we evaluated the analytical, work flow, and clinical performance of the versant ct/gc dna 1.0 assay (versant ct/gc assay, where "ct" represents chlamydia trachomatis and "gc" represents neisseria gonorrhoeae). the assay simultaneously detects chlamydia trachomatis and neisseria gonorrhoeae in swab and first-catch urine (fcu) specimens. the limit of detection (lod) was determined to be 342 copies/ml for c. trachomatis and 137 copies/ml for gc. the versant ct/gc assay detected 15 c. trachomatis se ... | 2011 | 21307209 |
| acyldepsipeptide hdac inhibitor production induced in burkholderia thailandensis. | natural product gene clusters are often tightly regulated, resulting in gene cluster silencing in laboratory fermentation studies. the systematic overexpression of transcription factors (tfs) associated with biosynthetic gene clusters found in the genome of burkholderia thailandensis e264 identified a set of tfs that, when overexpressed, alter the secondary metabolome of this bacterium. the isolation and characterization of burkholdacs a and b, two new acyldepsitripeptide histone deacetylase inh ... | 2011 | 21348454 |
| long-chain acylhomoserine lactones increase the anoxic ammonium oxidation rate in an oland biofilm. | the oxygen-limited autotrophic nitrification/denitrification (oland) process comprises one-stage partial nitritation and anammox, catalyzed by aerobic and anoxic ammonium-oxidizing bacteria (aeraob and anaob), respectively. the goal of this study was to investigate whether quorum sensing influences anoxic ammonium oxidation in an oland biofilm, with anaob colonizing 13% of the biofilm, as determined with fluorescent in situ hybridization (fish). at high biomass concentrations, the specific anoxi ... | 2011 | 21360147 |
| enterobacteriaceae associated with eggs of podocnemis expansa and podocnemis unifilis (testudines:chelonia) in nonpolluted sites of national park of araguaia plains, brazil. | fertile eggs of podocnemis expansa and podocnemis unifilis were investigated for the presence of enterobacteria, as these two endangered species have the potential for conservation measures that include egg transfer. knowledge of normal microflora associated with turtles and turtle eggs would help effectively manage the transfer of these eggs among institutions. thirty eggs of each species were collected, aseptically transferred, cracked inside plastic bags containing tetrathionate broth, and sp ... | 2010 | 21370647 |
| automated identification of medically important bacteria by 16s rrna gene sequencing using a novel comprehensive database, 16spathdb. | despite the increasing use of 16s rrna gene sequencing, interpretation of 16s rrna gene sequence results is one of the most difficult problems faced by clinical microbiologists and technicians. to overcome the problems we encountered in the existing databases during 16s rrna gene sequence interpretation, we built a comprehensive database, 16spathdb (http://147.8.74.24/16spathdb) based on the 16s rrna gene sequences of all medically important bacteria listed in the manual of clinical microbiology ... | 2011 | 21389154 |
| the chromobacterium violaceum type iii effector cope, a guanine nucleotide exchange factor for rac1 and cdc42, is involved in bacterial invasion of epithelial cells and pathogenesis. | the type iii secretion system (t3ss) encoded by chromobacterium pathogenicity islands 1 and 1a (cpi-1/-1a) is critical for chromobacterium violaceum pathogenesis. t3ss-dependent virulence is commonly characterized by type iii effector virulence function, but the full repertoire of the effector proteins of cpi-1/-1a t3ss is unknown. in this study, we showed that expression of cpi-1/-1a t3ss is controlled by the master regulator cila. we used transcriptional profiling with dna microarrays to defin ... | 2011 | 21435035 |
| phylogenetic distribution and evolutionary history of bacterial dead-box proteins. | dead-box proteins are found in all domains of life and participate in almost all cellular processes that involve rna. the presence of dead and helicase_c conserved domains distinguish these proteins. dead-box proteins exhibit rna-dependent atpase activity in vitro, and several also show rna helicase activity. in this study, we analyzed the distribution and architecture of dead-box proteins among bacterial genomes to gain insight into the evolutionary pathways that have shaped their history. we i ... | 2011 | 21437710 |
| screening of traditional chinese medicinal plants for quorum-sensing inhibitors activity. | the misuse of antibiotics has contributed to widespread development of antimicrobial resistance among clinically significant bacterial species. alternative approaches other than those using antibiotics are needed in the fight against infectious diseases. quorum sensing (qs) is an intercellular signaling and gene regulatory mechanism, which is used by a number of opportunistic pathogenic bacteria in determining virulence gene expression. the study of qs may yield another strategy for disease cont ... | 2011 | 21439518 |
| antipathogenic potential of marine bacillus sp. ss4 on n-acyl-homoserine-lactone-mediated virulence factors production in pseudomonas aeruginosa (pao1). | antipathogenic therapy is an outcome of the quorum-sensing inhibition (qsi) mechanism, which targets autoinducer-dependent virulent gene expression in bacterial pathogens. n-acyl homoserine lactone (ahl) acts as a key regulator in the production of virulence factors and biofilm formation in pseudomonas aeruginosa pao1 and violacein pigment production in chromobacterium violaceum. in the present study, the marine bacterial strain ss4 showed potential qsi activity in a concentration-dependent mann ... | 2011 | 21451248 |
| characterization of a gene cluster and its putative promoter region for violacein biosynthesis in pseudoalteromonas sp. 520p1. | violacein, a purple pigment produced by some gram-negative bacteria, has various physiological properties, such as antitrypanosomal and antitumoral activities. a gene cluster that encodes five enzymes, vioa-vioe, is responsible for synthesizing violacein. the expression of these enzymes is known to be regulated by a quorum sensing mechanism in chromobacterium violaceum and pseudoalteromonas sp. 520p1. to clarify the molecular mechanism of regulation of violacein synthesis, we cloned and characte ... | 2011 | 21472536 |
| phenolic composition and antimicrobial and antiquorum sensing activity of an ethanolic extract of peels from the apple cultivar annurca. | abstract this study investigated the phenolic composition and antioxidant capacity of an ethanolic extract from the peel of the annurca (malus domestica var. annurca), which is widespread in the campania region of southern italy. the antimicrobial effect of the extract on different pathogens was also examined. the potential antiquorum sensing activity of the extract was tested by using the microorganism chromobacterium violaceum. ultra-performance liquid chromatography revealed that rutin, epica ... | 2011 | 21476926 |
| degradation of n-acylhomoserine lactone quorum sensing signaling molecules by potato root surface-associated chryseobacterium strains. | n-acylhomoserine lactones (ahls) are used as quorum-sensing signaling molecules by many gram-negative bacteria. here, 413 bacterial strains were obtained from the roots of potato plants and screened for ahl-degrading bacteria using chromobacterium violaceum reporter strains. sixty one isolates degraded n-hexanoyl-l-homoserine lactone (c6-hsl) within 24 h. based on their 16s rrna gene sequences, most of these isolates were assigned to the genus chryseobacterium and divided into eight groups. most ... | 2011 | 21502740 |
| a strategy for antagonizing quorum sensing. | quorum-sensing bacteria communicate via small molecules called autoinducers to coordinate collective behaviors. because quorum sensing controls virulence factor expression in many clinically relevant pathogens, membrane-permeable quorum sensing antagonists that prevent population-wide expression of virulence genes offer a potential route to novel antibacterial therapeutics. here, we report a strategy for inhibiting quorum-sensing receptors of the widespread luxr family. structure-function studie ... | 2011 | 21504831 |
| c. elegans: model host and tool for antimicrobial drug discovery. | for almost four decades, the nematode caenorhabditis elegans has been of great value in many fields of biological research. it is now used extensively in studies of microbial pathogenesis and innate immunity. the worm lacks an adaptive immune system and relies solely on its innate immune defences to cope with pathogen attack. infectious microbes, many of which are of clinical interest, trigger specific mechanisms of innate immunity, and provoke the expression of antifungal or antibacterial polyp ... | 2011 | 21504910 |
| signaling-mediated cross-talk modulates swarming and biofilm formation in a coral pathogen serratia marcescens. | interactions within microbial communities associated with marine holobionts contribute importantly to the health of these symbiotic organisms formed by invertebrates, dinoflagellates and bacteria. however, mechanisms that control invertebrate-associated microbiota are not yet fully understood. hydrophobic compounds that were isolated from surfaces of asymptomatic corals inhibited biofilm formation by the white pox pathogen serratia marcescens pdl100, indicating that signals capable of affecting ... | 2011 | 21509042 |
| bioinformatic characterization of the trimeric intracellular cation-specific channel protein family. | trimeric intracellular cation-specific (tric) channels are integral to muscle excitation-contraction coupling. tric channels provide counter-ionic flux when calcium is rapidly transported from intracellular stores to the cell cytoplasm. until recently, knowledge of the presence of these proteins was limited to animals. we analyzed the tric family and identified a profusion of prokaryotic family members with topologies and motifs similar to those of their eukaryotic counterparts. prokaryotic memb ... | 2011 | 21519847 |