| chromobacterium haemolyticum-induced bacteremia in a healthy young man. | the genus chromobacterium consists of 7 recognized species. among those, only c. violaceum, commonly found in the soil and water of tropical and subtropical regions, has been shown to cause human infection. although human infection is rare, c. violaceum can cause life-threatening sepsis, with metastatic abscesses, most frequently infecting those who are young and healthy. | 2013 | 24004824 |
| histone deacetylase inhibitors as potential treatment for spinal muscular atrophy. | histone acetylation plays an important role in regulation of transcription in eukaryotic cells by promoting a more relaxed chromatin structure necessary for transcriptional activation. histone deacetylases (hdacs) remove acetyl groups and suppress gene expression. hdac inhibitors (hdacis) are a group of small molecules that promote gene transcription by chromatin remodeling and have been extensively studied as potential drugs for treating of spinal muscular atrophy. various drugs in this class h ... | 2013 | 24130434 |
| efficacy of aiim, an n-acylhomoserine lactonase, against pseudomonas aeruginosa in a mouse model of acute pneumonia. | quorum sensing (qs) in pseudomonas aeruginosa regulates the production of many virulence factors and plays an important role in the pathogenesis of p. aeruginosa infection. n-acyl homoserine lactones (ahl) are major qs signal molecules. recently, a novel ahl-lactonase enzyme, aiim, has been identified. the aim of this study was to evaluate the effect of aiim on the virulence of p. aeruginosa in a mouse model of acute pneumonia. we developed a p. aeruginosa pao1 strain harboring an aiim-expressin ... | 2013 | 23689715 |
| identification in marinomonas mediterranea of a novel quinoprotein with glycine oxidase activity. | a novel enzyme with lysine-epsilon oxidase activity was previously described in the marine bacterium marinomonas mediterranea. this enzyme differs from other l-amino acid oxidases in not being a flavoprotein but containing a quinone cofactor. it is encoded by an operon with two genes loda and lodb. the first one codes for the oxidase, while the second one encodes a protein required for the expression of the former. genome sequencing of m. mediterranea has revealed that it contains two additional ... | 2013 | 23873697 |
| enhancing gold recovery from electronic waste via lixiviant metabolic engineering in chromobacterium violaceum. | conventional leaching (extraction) methods for gold recovery from electronic waste involve the use of strong acids and pose considerable threat to the environment. the alternative use of bioleaching microbes for gold recovery is non-pollutive and relies on the secretion of a lixiviant or (bio)chemical such as cyanide for extraction of gold from electronic waste. however, widespread industrial use of bioleaching microbes has been constrained by the limited cyanogenic capabilities of lixiviant-pro ... | 2013 | 23868689 |
| an additional substrate binding site in a bacterial phenylalanine hydroxylase. | phenylalanine hydroxylase (pah) is a non-heme iron enzyme that catalyzes oxidation of phenylalanine to tyrosine, a reaction that must be kept under tight regulatory control. mammalian pah has a regulatory domain in which binding of the substrate leads to allosteric activation of the enzyme. however, the existence of pah regulation in evolutionarily distant organisms, for example some bacteria in which it occurs, has so far been underappreciated. in an attempt to crystallographically characterize ... | 2013 | 23860686 |
| characterization and complete sequence of lactonase enzyme from bacillus weihenstephanensis isolate p65 with potential activity against acyl homoserine lactone signal molecules. | acyl homoserine lactones (ahls) are the most common class of quorum sensing signal molecules (autoinducers) that have been reported to be essential for virulence of many relevant pathogenic bacteria such as pseudomonas aeruginosa. new approach for controlling infections of such bacteria is through quorum quenching. in this study, the acyl homoserine lactone inhibitory activity of the crude enzyme from a bacillus weihenstephanensis-isolate p65 was characterized. the crude enzyme was found to have ... | 2013 | 23936779 |
| presence of acyl-homoserine lactones in 57 members of the vibrionaceae family. | the aim of this study was to use a sensitive method to screen and quantify 57 vibrionaceae strains for the production of acyl-homoserine lactones (ahls) and map the resulting ahl profiles onto a host phylogeny. | 2013 | 23725044 |
| spatial disaggregation of tick occurrence and ecology at a local scale as a preliminary step for spatial surveillance of tick-borne diseases: general framework and health implications in belgium. | the incidence of tick-borne diseases is increasing in europe. sub national information on tick distribution, ecology and vector status is often lacking. however, precise location of infection risk can lead to better targeted prevention measures, surveillance and control. | 2013 | 23800283 |
| structural and functional characterization of mppr, an enduracididine biosynthetic enzyme from streptomyces hygroscopicus: functional diversity in the acetoacetate decarboxylase-like superfamily. | the nonproteinogenic amino acid enduracididine is a critical component of the mannopeptimycins, cyclic glycopeptide antibiotics with activity against drug-resistant pathogens, including methicillin-resistant staphylococcus aureus. enduracididine is produced in streptomyces hygroscopicus by three enzymes, mppp, mppq, and mppr. on the basis of primary sequence analysis, mppp and mppq are pyridoxal 5'-phosphate-dependent aminotransferases; mppr shares a low, but significant, level of sequence ident ... | 2013 | 23758195 |
| cal poly pomona nue project: implementing microscale and nanoscale investigations throughout the undergraduate curriculum. | nue funded work at california state polytechnic university involved development and implementation of nanotechnology modules for physics courses spanning all levels of the undergraduate curriculum, from freshman service courses to senior level laboratories and independent research projects. these modules demonstrate the application of fundamental physics at the nanoscale that complement macroscopic investigations. the introductory level and some of the advanced level modules have been described ... | 2013 | 24163716 |
| human melioidosis, malawi, 2011. | a case of human melioidosis caused by a novel sequence type of burkholderia pseudomallei occurred in a child in malawi, southern africa. a literature review showed that human cases reported from the continent have been increasing. | 2013 | 23735189 |
| expression and efficient secretion of a functional chitinase from chromobacterium violaceum in escherichia coli. | chromobacterium violaceum is a free-living β-proteobacterium found in tropical and subtropical regions. the genomic sequencing of c. violaceum atcc 12472 has revealed many genes that underpin its adaptability to diverse ecosystems. moreover, c. violaceum genes with potential applications in industry, medicine and agriculture have also been identified, such as those encoding chitinases. however, none of the chitinase genes of the atcc 12472 strain have been subjected to experimental validation. c ... | 2013 | 23725035 |
| esce and escg are cochaperones for the type iii needle protein escf of enteropathogenic escherichia coli. | type iii secretion systems (t3sss) are central virulence mechanisms used by a variety of gram-negative bacteria to inject effector proteins into host cells. the needle polymer is an essential part of the t3ss that provides the effector proteins a continuous channel into the host cytoplasm. it has been shown for a few t3sss that two chaperones stabilize the needle protein within the bacterial cytosol to prevent its premature polymerization. in this study, we characterized the chaperones of the en ... | 2013 | 23524615 |
| macrocyclic drugs and synthetic methodologies toward macrocycles. | macrocyclic scaffolds are commonly found in bioactive natural products and pharmaceutical molecules. so far, a large number of macrocyclic natural products have been isolated and synthesized. the construction of macrocycles is generally considered as a crucial and challenging step in the synthesis of macrocyclic natural products. over the last several decades, numerous efforts have been undertaken toward the synthesis of complex naturally occurring macrocycles and great progresses have been made ... | 2013 | 23708234 |
| mapk pathway activation leads to bim loss and histone deacetylase inhibitor resistance: rationale to combine romidepsin with an mek inhibitor. | to identify molecular determinants of histone deacetylase inhibitor (hdi) resistance, we selected hut78 cutaneous t-cell lymphoma (ctcl) cells with romidepsin in the presence of p-glycoprotein inhibitors to prevent transporter upregulation. resistant sublines were 250- to 385-fold resistant to romidepsin and were resistant to apoptosis induced by apicidin, entinostat, panobinostat, belinostat, and vorinostat. a custom taqman array identified increased insulin receptor (insr) gene expression; imm ... | 2013 | 23532732 |
| the epigenome as a potential mediator of cancer and disease prevention in prenatal development. | epigenetic events establish a particular gene expression signature for each cell type during differentiation and fertilization. disruption of these epigenetic programs in response to environmental stimuli during prenatal exposure dysregulates the fetal epigenome, potentially impacting susceptibility to disease later in life (the fetal basis of adult disease). maternal dietary modifications during gestation and lactation play a pivotal role in the period of fetal (re)programming. recently, many s ... | 2013 | 23815143 |
| plant-derived natural products as sources of anti-quorum sensing compounds. | quorum sensing is a system of stimuli and responses in relation to bacterial cell population density that regulates gene expression, including virulence determinants. consequently, quorum sensing has been an attractive target for the development of novel anti-infective measures that do not rely on the use of antibiotics. anti-quorum sensing has been a promising strategy to combat bacterial infections as it is unlikely to develop multidrug resistant pathogens since it does not impose any selectio ... | 2013 | 23669710 |
| antifeedant, larvicidal and growth inhibitory bioactivities of novel polyketide metabolite isolated from streptomyces sp. ap-123 against helicoverpa armigera and spodoptera litura. | considerable attention has been paid to actinomycetes, especially the secondary metabolites obtained from streptomyces species, as the best alternatives to chemicals as biological control agents for polyphagous pests such as helicoverpa armigera and spodoptera litura. on the basis of their novel biocontrol attributes, novel polyketide metabolite isolated from marine streptomyces sp. ap-123 exhibited significant antifeedant, larvicidal and growth inhibitory activities against polyphagous pests. | 2013 | 23668716 |
| state of the art for the biosorption process--a review. | in recent years, biosorption process has become an economic and eco-friendly alternative treatment technology in the water and wastewater industry. in this light, a number of biosorbents were developed and are successfully employed for treating various pollutants including metals, dyes, phenols, fluoride, and pharmaceuticals in solutions (aqueous/oil). however, still there are few technical barriers in the biosorption process that impede its commercialization and thus to overcome these problems ... | 2013 | 23666641 |
| integrated nonlinear optical imaging microscope for on-axis crystal detection and centering at a synchrotron beamline. | nonlinear optical (nlo) instrumentation has been integrated with synchrotron x-ray diffraction (xrd) for combined single-platform analysis, initially targeting applications for automated crystal centering. second-harmonic-generation microscopy and two-photon-excited ultraviolet fluorescence microscopy were evaluated for crystal detection and assessed by x-ray raster scanning. two optical designs were constructed and characterized; one positioned downstream of the sample and one integrated into t ... | 2013 | 23765294 |
| isolation of extended spectrum β-lactamase (esbl) producing bacteria from urban surface waters in malaysia. | this was a preliminary study to test for the presence of multiple antibiotic-resistant extended spectrum β-lactamase (esbl) producing bacteria in malaysian urban surface waters. although the literature review revealed several published papers on clinical esbl isolates in malaysia, none were found on esbl isolates obtained from local surface waters. | 2013 | 23966820 |
| role of the phenylalanine-hydroxylating system in aromatic substance degradation and lipid metabolism in the oleaginous fungus mortierella alpina. | mortierella alpina is a filamentous fungus commonly found in soil that is able to produce lipids in the form of triacylglycerols that account for up to 50% of its dry weight. analysis of the m. alpina genome suggests that there is a phenylalanine-hydroxylating system for the catabolism of phenylalanine, which has never been found in fungi before. we characterized the phenylalanine-hydroxylating system in m. alpina to explore its role in phenylalanine metabolism and its relationship to lipid bios ... | 2013 | 23503309 |
| evaluation of romidepsin for clinical activity and radioactive iodine reuptake in radioactive iodine-refractory thyroid carcinoma. | historically, systemic therapy for radioactive iodine (rai)-refractory thyroid cancer has been understudied. available drugs have modest efficacy. romidepsin is a histone deacetylase inhibitor with potent antitumor effects both in vitro and in vivo. in thyroid cancer cell lines, romidepsin increases expression of both thyroglobulin and the sodium iodide symporter messenger rnas, suggesting the possibility of improved iodine concentrating ability of rai-resistant tumors. | 2013 | 23186033 |
| characterization of aeromonas hydrophila wound pathotypes by comparative genomic and functional analyses of virulence genes. | aeromonas hydrophila has increasingly been implicated as a virulent and antibiotic-resistant etiologic agent in various human diseases. in a previously published case report, we described a subject with a polymicrobial wound infection that included a persistent and aggressive strain of a. hydrophila (e1), as well as a more antibiotic-resistant strain of a. hydrophila (e2). to better understand the differences between pathogenic and environmental strains of a. hydrophila, we conducted comparative ... | 2013 | 23611906 |
| caffeine as a potential quorum sensing inhibitor. | quorum sensing enables bacteria to control the gene expression in response to the cell density. it regulates a variety of bacterial physiological functions such as biofilm formation, bioluminescence, virulence factors and swarming which has been shown contribute to bacterial pathogenesis. the use of quorum sensing inhibitor would be of particular interest in treating bacterial pathogenicity and infections. in this work, we have tested caffeine as quorum sensing inhibitor by using chromobacterium ... | 2013 | 23598500 |
| hypoxia inducible factor pathway inhibitors as anticancer therapeutics. | hypoxia is a significant feature of solid tumor cancers. hypoxia leads to a more malignant phenotype that is resistant to chemotherapy and radiation, is more invasive and has greater metastatic potential. hypoxia activates the hypoxia inducible factor (hif) pathway, which mediates the biological effects of hypoxia in tissues. the hif complex acts as a transcription factor for many genes that increase tumor survival and proliferation. to date, many hif pathway inhibitors indirectly affect hif but ... | 2013 | 23573973 |
| tracking change: a look at the ecological footprint of antibiotics and antimicrobial resistance. | among the class of pollutants considered as 'emerging contaminants', antibiotic compounds including drugs used in medical therapy, biocides and disinfectants merit special consideration because their bioactivity in the environment is the result of their functional design. antibiotics can alter the structure and function of microbial communities in the receiving environment and facilitate the development and spread of resistance in critical species of bacteria including pathogens. methanogenesis, ... | 2013 | 27029298 |
| piper nigrum, piper betle and gnetum gnemon--natural food sources with anti-quorum sensing properties. | various parts of piper nigrum, piper betle and gnetum gnemon are used as food sources by malaysians. the purpose of this study is to examine the anti-quorum sensing (anti-qs) properties of p. nigrum, p. betle and g. gnemon extracts. the hexane, chloroform and methanol extracts of these plants were assessed in bioassays involving pseudomonas aeruginosa pa01, escherichia coli [psb401], e. coli [psb1075] and chromobacterium violaceum cv026. it was found that the extracts of these three plants have ... | 2013 | 23519352 |
| reactivation of latent hiv by histone deacetylase inhibitors. | latent hiv persists in cd4(+) t cells in infected patients under antiretroviral therapy (art). latency is associated with transcriptional silencing of the integrated provirus and driven, at least in part, by histone deacetylases (hdacs), a family of chromatin-associated proteins that regulate histone acetylation and the accessibility of dna to transcription factors. remarkably, inhibition of hdacs is sufficient to reactivate a fraction of latent hiv in a variety of experimental systems. this bas ... | 2013 | 23517573 |
| tetra- and penta-acylated lipid a structures of porphyromonas gingivalis lps differentially activate tlr4-mediated nf-κb signal transduction cascade and immuno-inflammatory response in human gingival fibroblasts. | porphyromonas gingivalis is a major pathogen of periodontal disease that affects a majority of adults worldwide. increasing evidence shows that periodontal disease is linked to various systemic diseases like diabetes and cardiovascular disease, by contributing to increased systemic levels of inflammation. lipopolysaccharides (lps), as a key virulent attribute of p. gingivalis, possesses significant amount of lipid a heterogeneity containing tetra- (lps1435/1449) and penta-acylated (lps1690) stru ... | 2013 | 23554896 |
| production of n-acyl homoserine lactones and virulence factors of waterborne aeromonas hydrophila. | aeromonads are inhabitants of aquatic ecosystems and are described as being involved in intestinal disturbances and other infections. the purpose of this study was to investigate the production of n-acyl-homoserine lactone (ahl) signal molecules and some virulence factors, including hemolysins, proteases, extracellular nucleases production and cytotoxicity by waterborne aeromonas hydrophila. a total of 24 strains isolated from fresh-water or diseased fish were used in the study. the majority a.h ... | 2013 | 24426120 |
| histone deacetylase inhibitors and pancreatic cancer: are there any promising clinical trials? | pancreatic cancer, although not very frequent, has an exceptionally high mortality rate, making it one of the most common causes of cancer mortality in developed countries. pancreatic cancer is difficult to diagnose, allowing few patients to have the necessary treatment at a relatively early stage. despite a marginal benefit in survival, the overall response of pancreatic cancer to current systemic therapy continues to be poor, and new therapies are desperately needed. histone deacetylase (hdac) ... | 2013 | 23482354 |
| anti-quorum sensing potential of crude kigelia africana fruit extracts. | the increasing incidence of multidrug-resistant pathogens has stimulated the search for novel anti-virulence compounds. although many phytochemicals show promising antimicrobial activity, their power lies in their anti-virulence properties. thus the quorum sensing (qs) inhibitory activity of four crude kigelia africana fruit extracts was assessed qualitatively and quantitatively using the chromobacterium violaceum and agrobacterium tumefaciens biosensor systems. inhibition of qs-controlled viola ... | 2013 | 23447012 |
| relative contributions of vibrio polysaccharide and quorum sensing to the resistance of vibrio cholerae to predation by heterotrophic protists. | protozoan grazing is a major mortality factor faced by bacteria in the environment. vibrio cholerae, the causative agent of the disease cholera, is a natural inhabitant of aquatic ecosystems, and its survival depends on its ability to respond to stresses, such as predation by heterotrophic protists. previous results show that grazing pressure induces biofilm formation and enhances a smooth to rugose morphotypic shift, due to increased expression of vibrio polysaccharide (vps). in addition to neg ... | 2013 | 23441178 |
| antibiotic resistance profiles and quorum sensing-dependent virulence factors in clinical isolates of pseudomonas aeruginosa. | pseudomonas aeruginosa produces multiple virulence factors that have been associated with quorum sensing. the aim of this study was to evaluate the prevalence of drug resistant profiles and quorum sensing related virulence factors. pseudomonas aeruginosa were collected from different patients hospitalized in china, the isolates were tested for their susceptibility to different common antimicrobial drugs and detected qs-related virulence factors. we identified 170 isolates displaying impaired phe ... | 2013 | 24426103 |
| identification of a pseudomonas sp. that inhibits rhl system of quorum sensing. | the production of many pseudomonas aeruginosa virulence factors and secondary metabolites is regulated in concert with cell density by quorum sensing (qs). therefore, strategies designed to inhibit qs are promising for the control of diseases. here, we succeeded in isolating soil bacteria (56 out of 7,000 isolates) capable of inhibiting violacein production by chromobacterium violaceum cv026. we focused on an isolate identified as a pseudomonas sp. based on its 16s rrna nucleotide sequence. a pa ... | 2013 | 24426075 |
| quorum sensing inhibition by asparagopsis taxiformis, a marine macro alga: separation of the compound that interrupts bacterial communication. | the majority of the marine algal species, though completing their life cycle in seawater, are rarely susceptible to fouling, making them an important source of quorum sensing (qs) inhibitory substances. the separation and characterization of qs inhibitors are crucial for any potential application. thirty marine macroalgae were tested for qs inhibition activity by using chromobacterium violaceum cv026 as the reporter strain, and among them, asparagopsis taxiformis showed antibacterial, as well as ... | 2013 | 23344114 |
| ellagic acid derivatives from terminalia chebula retz. downregulate the expression of quorum sensing genes to attenuate pseudomonas aeruginosa pao1 virulence. | burgeoning antibiotic resistance in pseudomonas aeruginosa has necessitated the development of anti pathogenic agents that can quench acylhomoserine lactone (ahl) mediated qs with least risk of resistance. this study explores the anti quorum sensing potential of t. chebula retz. and identification of probable compounds(s) showing anti qs activity and the mechanism of attenuation of p. aeruginosa pao1 virulence factors. | 2013 | 23320085 |
| a successful antimicrobial regime for chromobacterium violaceum induced bacteremia. | chromobacterium violaceum is a proteobacterium found in soil and water in tropical regions. the organism rarely causes infection in humans, yet can cause a severe systemic infection by entering the bloodstream via an open wound. | 2013 | 23286235 |
| the hydrocarbon-degrading marine bacterium cobetia sp. strain mm1ida2h-1 produces a biosurfactant that interferes with quorum sensing of fish pathogens by signal hijacking. | biosurfactants are produced by hydrocarbon-degrading marine bacteria in response to the presence of water-insoluble hydrocarbons. this is believed to facilitate the uptake of hydrocarbons by bacteria. however, these diffusible amphiphilic surface-active molecules are involved in several other biological functions such as microbial competition and intra- or inter-species communication. we report the isolation and characterization of a marine bacterial strain identified as cobetia sp. mm1ida2h-1, ... | 2013 | 23279885 |
| novel approaches for the accumulation of oxygenated intermediates to multi-millimolar concentrations. | metalloenzymes that utilize molecular oxygen as a co-substrate catalyze a wide variety of chemically difficult oxidation reactions. significant insight into the reaction mechanisms of these enzymes can be obtained by the application of a combination of rapid kinetic and spectroscopic methods to the direct structural characterization of intermediate states. a key limitation of this approach is the low aqueous solubility (< 2 mm) of the co-substrate, o2, which undergoes further dilution (typically ... | 2013 | 24368870 |
| predation response of vibrio fischeri biofilms to bacterivorus protists. | vibrio fischeri proliferates in a sessile, stable community known as a biofilm, which is one alternative survival strategy of its life cycle. although this survival strategy provides adequate protection from abiotic factors, marine biofilms are still susceptible to grazing by bacteria-consuming protozoa. subsequently, grazing pressure can be controlled by certain defense mechanisms that confer higher biofilm antipredator fitness. in the present work, we hypothesized that v. fischeri exhibits an ... | 2013 | 23144127 |
| inactivation of the transcriptional regulator-encoding gene sdia enhances rice root colonization and biofilm formation in enterobacter cloacae gs1. | enterobacter cloacae gs1 is a plant growth-promoting bacterium which colonizes rice roots. in the rhizosphere environment, n-acyl homoserine lactone (nahl)-like quorum-sensing signals are known to be produced by host plants and other microbial inhabitants. e. cloacae gs1 was unable to synthesize nahl quorum-sensing signals but had the nahl-dependent transcriptional regulator-encoding gene sdia. this study was aimed at understanding the effects of sdia and nahl-dependent cross talk in rice root c ... | 2013 | 23086212 |
| whole genome sequencing and analysis reveal insights into the genetic structure, diversity and evolutionary relatedness of luxi and luxr homologs in bacteria belonging to the sphingomonadaceae family. | here we report the draft genomes and annotation of four n-acyl homoserine lactone (ahl)-producing members from the family sphingomonadaceae. comparative genomic analyses of 62 sphingomonadaceae genomes were performed to gain insights into the distribution of the canonical luxi/r-type quorum sensing (qs) network within this family. forty genomes contained at least one luxr homolog while the genome of sphingobium yanoikuyae b1 contained seven open reading frames (orfs) that have significant homolo ... | 2014 | 25621282 |
| whole genome sequencing and analysis reveal insights into the genetic structure, diversity and evolutionary relatedness of luxi and luxr homologs in bacteria belonging to the sphingomonadaceae family. | here we report the draft genomes and annotation of four n-acyl homoserine lactone (ahl)-producing members from the family sphingomonadaceae. comparative genomic analyses of 62 sphingomonadaceae genomes were performed to gain insights into the distribution of the canonical luxi/r-type quorum sensing (qs) network within this family. forty genomes contained at least one luxr homolog while the genome of sphingobium yanoikuyae b1 contained seven open reading frames (orfs) that have significant homolo ... | 2014 | 25621282 |
| cultivation of a human-associated tm7 phylotype reveals a reduced genome and epibiotic parasitic lifestyle. | the candidate phylum tm7 is globally distributed and often associated with human inflammatory mucosal diseases. despite its prevalence, the tm7 phylum remains recalcitrant to cultivation, making it one of the most enigmatic phyla known. in this study, we cultivated a tm7 phylotype (tm7x) from the human oral cavity. this extremely small coccus (200-300 nm) has a distinctive lifestyle not previously observed in human-associated microbes. it is an obligate epibiont of an actinomyces odontolyticus s ... | 2014 | 25535390 |
| cultivation of a human-associated tm7 phylotype reveals a reduced genome and epibiotic parasitic lifestyle. | the candidate phylum tm7 is globally distributed and often associated with human inflammatory mucosal diseases. despite its prevalence, the tm7 phylum remains recalcitrant to cultivation, making it one of the most enigmatic phyla known. in this study, we cultivated a tm7 phylotype (tm7x) from the human oral cavity. this extremely small coccus (200-300 nm) has a distinctive lifestyle not previously observed in human-associated microbes. it is an obligate epibiont of an actinomyces odontolyticus s ... | 2014 | 25535390 |
| engineered production of tryprostatins in e. coli through reconstitution of a partial ftm biosynthetic gene cluster from aspergillus sp. | tryprostatin a and b are indole alkaloid-based fungal products that inhibit mammalian cell cycle at the g2/m phase. they are biosynthetic intermediates of fumitremorgins produced by a complex pathway involving a nonribosomal peptide synthetase (ftma), a prenyltransferase (ftmb), a cytochrome p450 hydroxylase (ftmc), an o-methyltransferase (ftmd), and several additional enzymes. a partial fumitremorgin biosynthetic gene cluster (ftmabcd) from aspergillus sp. was reconstituted in escherichia coli ... | 2014 | 26640821 |
| engineered production of tryprostatins in e. coli through reconstitution of a partial ftm biosynthetic gene cluster from aspergillus sp. | tryprostatin a and b are indole alkaloid-based fungal products that inhibit mammalian cell cycle at the g2/m phase. they are biosynthetic intermediates of fumitremorgins produced by a complex pathway involving a nonribosomal peptide synthetase (ftma), a prenyltransferase (ftmb), a cytochrome p450 hydroxylase (ftmc), an o-methyltransferase (ftmd), and several additional enzymes. a partial fumitremorgin biosynthetic gene cluster (ftmabcd) from aspergillus sp. was reconstituted in escherichia coli ... | 2014 | 26640821 |
| violacein inhibits matrix metalloproteinase mediated cxcr4 expression: potential anti-tumor effect in cancer invasion and metastasis. | matrix metalloproteinases (mmp-2 and -9) play an important role in the tumor metastasis through cleavage of proinflammatory cytokines. violacein a small molecule produced by chromobacterium violaceum and has been implicated with anti-cancer effects. in this study we investigated the molecular basis of violacein mediated downregulation of cxcl12/cxcr4, chemokine-receptor ligand interaction. zymography analysis demonstrated that violacein significantly inhibited the cytokine (tnfα and tgfβ) mediat ... | 2014 | 25450700 |
| sodium houttuyfonate affects production of n-acyl homoserine lactone and quorum sensing-regulated genes expression in pseudomonas aeruginosa. | quorum sensing (qs) is a means of cell-to-cell communication that uses diffusible signaling molecules that are sensed by the population to determine population density, thus allowing co-ordinate gene regulation in response to population density. in pseudomonas aeruginosa, production of the qs signaling molecule, n-acyl homoserine lactone (ahl), co-ordinates expression of key factors of pathogenesis, including biofilm formation and toxin secretion. it is predicted that the inhibition of ahl sensi ... | 2014 | 25505457 |
| global and phylogenetic distribution of quorum sensing signals, acyl homoserine lactones, in the family of vibrionaceae. | bacterial quorum sensing (qs) and the corresponding signals, acyl homoserine lactones (ahls), were first described for a luminescent vibrio species. since then, detailed knowledge has been gained on the functional level of qs; however, the abundance of ahls in the family of vibrionaceae in the environment has remained unclear. three hundred and one vibrionaceae strains were collected on a global research cruise and the prevalence and profile of ahl signals in this global collection were determin ... | 2014 | 25419995 |
| inhibition of bacterial quorum sensing by extracts from aquatic fungi: first report from marine endophytes. | in our search for quorum-sensing (qs) disrupting molecules, 75 fungal isolates were recovered from reef organisms (endophytes), saline lakes and mangrove rhizosphere. their qs inhibitory activity was evaluated in chromobacterium violaceum cvo26. four strains of endophytic fungi stood out for their potent activity at concentrations from 500 to 50 μg ml-1. the molecular characterization, based on the internal transcribed spacer (its) region sequences (its1, 5.8s and its2) between the rrna of 18s a ... | 2014 | 25415350 |
| fatal chromobacterium violaceum bacteraemia in rural bandundu, democratic republic of the congo. | we describe the first case of bacteraemia caused by chromobacterium violaceum in the democratic republic of the congo. this diagnosis was made in an apparently healthy adult who was admitted to a rural hospital of the province of bandundu with severe community-acquired sepsis. the patient developed multi-organ failure and died; to our knowledge, this is the first reported fatal case in an adult in africa. | 2014 | 25755887 |
| fatal chromobacterium violaceum bacteraemia in rural bandundu, democratic republic of the congo. | we describe the first case of bacteraemia caused by chromobacterium violaceum in the democratic republic of the congo. this diagnosis was made in an apparently healthy adult who was admitted to a rural hospital of the province of bandundu with severe community-acquired sepsis. the patient developed multi-organ failure and died; to our knowledge, this is the first reported fatal case in an adult in africa. | 2014 | 25755887 |
| the insect microbiome modulates vector competence for arboviruses. | diseases caused by arthropod-borne viruses (arboviruses), such as dengue, west nile, and chikungunya, constitute a major global health burden and are increasing in incidence and geographic range. the natural microbiota of insect vectors influences various aspects of host biology, such as nutrition, reproduction, metabolism, and immunity, and recent studies have highlighted the ability of insect-associated bacteria to reduce vector competence for arboviruses and other pathogens. this reduction ca ... | 2014 | 25393895 |
| amie, a novel n-acylhomoserine lactone acylase belonging to the amidase family, from the activated-sludge isolate acinetobacter sp. strain ooi24. | many gram-negative bacteria use n-acyl-l-homoserine lactones (ahls) as quorum-sensing signal molecules. we have reported that acinetobacter strains isolated from activated sludge have ahl-degrading activity. in this study, we cloned the amie gene as an ahl-degradative gene from the genomic library of acinetobacter sp. strain ooi24. high-performance liquid chromatography analysis revealed that amie functions as an ahl acylase, which hydrolyzes the amide bond of ahl. amie showed a high level of de ... | 2014 | 25172868 |
| the influence of iron on the proteomic profile of chromobacterium violaceum. | chromobacterium violaceum is a bacterium commonly found in tropical and subtropical regions and is associated with important pharmacological and industrial attributes such as producing substances with therapeutic properties and synthesizing biodegradable polymers. its genome was sequenced, however, approximately 40% of its genes still remain with unknown functions. although c. violaceum is known by its versatile capacity of living in a wide range of environments, little is known on how it achiev ... | 2014 | 25361869 |
| the role of dietary histone deacetylases (hdacs) inhibitors in health and disease. | modification of the histone proteins associated with dna is an important process in the epigenetic regulation of dna structure and function. there are several known modifications to histones, including methylation, acetylation, and phosphorylation, and a range of factors influence each of these. histone deacetylases (hdacs) remove the acetyl group from lysine residues within a range of proteins, including transcription factors and histones. whilst this means that their influence on cellular proc ... | 2014 | 25322459 |
| plasma-mediated inactivation of pseudomonas aeruginosa biofilms grown on borosilicate surfaces under continuous culture system. | biofilms are microbial communities attached to a surface and embedded in a matrix composed of exopolysaccharides and excreted nucleic acids. bacterial biofilms are responsible for undesirable effects such as disease, prostheses colonization, biofouling, equipment damage, and pipe plugging. biofilms are also more resilient than free-living cells to regular sterilization methods and therefore it is indispensable to develop better ways to control and remove them. the use of gas discharge plasmas is ... | 2014 | 25302815 |
| a conserved acidic residue in phenylalanine hydroxylase contributes to cofactor affinity and catalysis. | the catalytic domains of aromatic amino acid hydroxylases (aaahs) contain a non-heme iron coordinated to a 2-his-1-carboxylate facial triad and two water molecules. asp139 from chromobacterium violaceum pah (cpah) resides within the second coordination sphere and contributes key hydrogen bonds with three active site waters that mediate its interaction with an oxidized form of the cofactor, 7,8-dihydro-l-biopterin, in crystal structures. to determine the catalytic role of this residue, various po ... | 2014 | 25295853 |
| antinematode activity of violacein and the role of the insulin/igf-1 pathway in controlling violacein sensitivity in caenorhabditis elegans. | the purple pigment violacein is well known for its numerous biological activities including antibacterial, antiviral, antiprotozoan, and antitumor effects. in the current study we identify violacein as the antinematode agent produced by the marine bacterium microbulbifer sp. d250, thereby extending the target range of this small molecule. heterologous expression of the violacein biosynthetic pathway in e. coli and experiments using pure violacein demonstrated that this secondary metabolite facil ... | 2014 | 25295516 |
| solution structure of a c-terminal fragment (175-257) of cv_0373 protein from chromobacterium violaceum adopts a winged helix-turn-helix (whth) fold. | | 2014 | 25270885 |
| punicalagin inhibits salmonella virulence factors and has anti-quorum-sensing potential. | punicalagin, an essential component of pomegranate rind, has been demonstrated to possess antimicrobial activity against several food-borne pathogens, but its activity on the virulence of pathogens and its anti-quorum-sensing (anti-qs) potential have been rarely reported. this study investigated the efficacy of subinhibitory concentrations of punicalagin on salmonella virulence factors and qs systems. a broth microdilution method was used to determine the mics of punicalagin for 10 salmonella st ... | 2014 | 25085489 |
| quorum sensing signal production and microbial interactions in a polymicrobial disease of corals and the coral surface mucopolysaccharide layer. | black band disease (bbd) of corals is a complex polymicrobial disease considered to be a threat to coral reef health, as it can lead to mortality of massive reef-building corals. the bbd community is dominated by gliding, filamentous cyanobacteria with a highly diverse population of heterotrophic bacteria. microbial interactions such as quorum sensing (qs) and antimicrobial production may be involved in bbd disease pathogenesis. in this study, bbd (whole community) samples, as well as 199 bacter ... | 2014 | 25268348 |
| mutational analysis of the quorum-sensing receptor lasr reveals interactions that govern activation and inhibition by nonlactone ligands. | gram-negative bacteria use n-acyl l-homoserine lactone (ahl) quorum-sensing (qs) signals to regulate the expression of myriad phenotypes. non-native ahl analogs can strongly attenuate qs receptor activity and thereby qs signaling; however, we currently lack a molecular understanding of the mechanisms by which most of these compounds elicit their agonistic or antagonistic profiles. in this study, we investigated the origins of striking activity profile switches (i.e., receptor activator to inhibi ... | 2014 | 25242287 |
| guava leaf extract inhibits quorum-sensing and chromobacterium violaceum induced lysis of human hepatoma cells: whole transcriptome analysis reveals differential gene expression. | quorum sensing (qs) is a process mediated via small molecules termed autoinducers (ai) that allow bacteria to respond and adjust according to the cell population density by altering the expression of multitudinous genes. since qs governs numerous bioprocesses in bacteria, including virulence, its inhibition promises to be an ideal target for the development of novel therapeutics. we found that the aqueous leaf extract of psidium guajava (gle) exhibited anti-qs properties as evidenced by inhibiti ... | 2014 | 25229331 |
| targeting the histone orthography of cancer: drugs for writers, erasers and readers. | gene expression is dynamically controlled by epigenetics through post-translational modifications of histones, chromatin-associated proteins and dna itself. all these elements are required for the maintenance of chromatin structure and cell identity in the context of a normal cellular phenotype. disruption of epigenetic regulation is a common event in human cancer. here, we review the key protein families that control epigenetic signalling through writing, erasing or reading specific post-transl ... | 2014 | 25039449 |
| targeting the histone orthography of cancer: drugs for writers, erasers and readers. | gene expression is dynamically controlled by epigenetics through post-translational modifications of histones, chromatin-associated proteins and dna itself. all these elements are required for the maintenance of chromatin structure and cell identity in the context of a normal cellular phenotype. disruption of epigenetic regulation is a common event in human cancer. here, we review the key protein families that control epigenetic signalling through writing, erasing or reading specific post-transl ... | 2014 | 25039449 |
| inhibition of biofilm formation by t7 bacteriophages producing quorum-quenching enzymes. | bacterial growth in biofilms is the major cause of recalcitrant biofouling in industrial processes and of persistent infections in clinical settings. the use of bacteriophage treatment to lyse bacteria in biofilms has attracted growing interest. in particular, many natural or engineered phages produce depolymerases to degrade polysaccharides in the biofilm matrix and allow access to host bacteria. however, the phage-produced depolymerases are highly specific for only the host-derived polysacchar ... | 2014 | 24951790 |
| urinary tract infection by chromobacterium violaceum. | chromobacterium violaceum, a facultative anaerobic proteobacterium, is particularly isolated from water and soil in tropical areas and has been implicated in few infections like septicemia, visceral abscesses, skin and soft tissue infections, meningitis and diarrhea. but urinary tract infection caused by it is very rare. limited awareness about this pathogen and inappropriate antibiotic therapy contribute to a high mortality rate. here, we describe an unusual case of urinary tract infection by c ... | 2014 | 25302195 |
| pantoea sp. isolated from tropical fresh water exhibiting n-acyl homoserine lactone production. | n-acyl homoserine lactone (ahl) serves as signaling molecule for quorum sensing (qs) in gram-negative bacteria to regulate various physiological activities including pathogenicity. with the aim of isolating freshwater-borne bacteria that can cause outbreak of disease in plants and portrayed qs properties, environmental water sampling was conducted. here we report the preliminary screening of ahl production using chromobacterium violaceum cv026 and escherichia coli [psb401] as ahl biosensors. the ... | 2014 | 25197715 |
| atomic force microscopy reveals a morphological differentiation of chromobacterium violaceum cells associated with biofilm development and directed by n-hexanoyl-l-homoserine lactone. | chromobacterium violaceum abounds in soil and water ecosystems in tropical and subtropical regions and occasionally causes severe and often fatal human and animal infections. the quorum sensing (qs) system and biofilm formation are essential for c. violaceum's adaptability and pathogenicity, however, their interrelation is still unknown. c. violaceum's cell and biofilm morphology were examined by atomic force microscopy (afm) in comparison with growth rates, qs-dependent violacein biosynthesis a ... | 2014 | 25111599 |
| competition studies confirm two major barriers that can preclude the spread of resistance to quorum-sensing inhibitors in bacteria. | the growing threat of antibiotic resistance necessitates the development of novel antimicrobial therapies. antivirulence agents that target group-beneficial traits in microorganisms (i.e., phenotypes that help the cells surrounding the producer cell instead of selfishly benefiting only the producer cell) represent a new antimicrobial approach that may be robust against the spread of resistant mutants. one prominent group-beneficial antivirulence target in bacteria is quorum sensing (qs). while s ... | 2014 | 25105594 |
| gastroprotective activity of violacein isolated from chromobacterium violaceum on indomethacin-induced gastric lesions in rats: investigation of potential mechanisms of action. | chromobacterium violaceum, gram-negative bacteria species found in tropical regions of the world, produces a distinct deep violet-colored pigment called violacein. in the present study, we investigated whether violacein can promote a gastroprotective effect and verified the possible mechanisms involved in this action. for this study, an indomethacin-induced gastric ulcer rat model was used. the roles of biomolecules such as mpo, pge2, pro- and anti-inflammatory cytokines, growth factors, caspase ... | 2014 | 25162059 |
| news feature: next-generation antibiotics. | | 2014 | 25097257 |
| short chain n-acyl homoserine lactone production in tropical marine vibrio sinaloensis strain t47. | quorum sensing (qs), acts as one of the gene regulatory systems that allow bacteria to regulate their physiological activities by sensing the population density with synchronization of the signaling molecules that they produce. here, we report a marine isolate, namely strain t47, and its unique ahl profile. strain t47 was identified using 16s rrna sequence analysis confirming that it is a member of vibrio closely clustered to vibrio sinaloensis. the isolated v. sinaloensis strain t47 was confirm ... | 2014 | 25046018 |
| functionalized formazans: a review on recent progress in their pharmacological activities. | this review provides an up to date information about the diverse pharmaceutical activities of formazans. the bibliography includes 97 references which have been published during the period from 1980 to 2013. the covered biological activities of the title compounds include antioxidant, anticonvulsant, therapeutic, anthelmintic, anti-tubercular, antiviral, anti-inflammatory, anticancer, anti-hiv, antimicrobial, antiparkinsonian, cardiovascular and antiproliferative activities. | 2014 | 26257923 |
| functionalized formazans: a review on recent progress in their pharmacological activities. | this review provides an up to date information about the diverse pharmaceutical activities of formazans. the bibliography includes 97 references which have been published during the period from 1980 to 2013. the covered biological activities of the title compounds include antioxidant, anticonvulsant, therapeutic, anthelmintic, anti-tubercular, antiviral, anti-inflammatory, anticancer, anti-hiv, antimicrobial, antiparkinsonian, cardiovascular and antiproliferative activities. | 2014 | 26257923 |
| detection of quorum sensing activity in the multidrug-resistant clinical isolate pseudomonas aeruginosa strain gb11. | a multidrug-resistant clinical bacteria strain gb11 was isolated from a wound swab on the leg of a patient. identity of stain gb11 as pseudomonas aeruginosa was validated by using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (maldi-tof ms). detection of the production of signaling molecules, n-acylhomoserine lactones (ahls), was conducted using three different bacterial biosensors. a total of four different ahls were found to be produced by strain gb11, namely n-b ... | 2014 | 25019635 |
| characterisation of a marine bacterium vibrio brasiliensis t33 producing n-acyl homoserine lactone quorum sensing molecules. | n-acylhomoserine lactones (ahl) plays roles as signal molecules in quorum sensing (qs) in most gram-negative bacteria. qs regulates various physiological activities in relation with population density and concentration of signal molecules. with the aim of isolating marine water-borne bacteria that possess qs properties, we report here the preliminary screening of marine bacteria for ahl production using chromobacterium violaceum cv026 as the ahl biosensor. strain t33 was isolated based on prelim ... | 2014 | 25006994 |
| labrenzia sp. bm1: a quorum quenching bacterium that degrades n-acyl homoserine lactones via lactonase activity. | we report the degradation of quorum sensing n-acylhomoserine lactone molecules by a bacterium isolated from a malaysian marine water sample. maldi-tof and phylogenetic analysis indicated this isolate bm1 clustered closely to labrenzia sp. the quorum quenching activity of this isolate was confirmed by using a series of bioassays and rapid resolution liquid chromatography analysis. labrenzia sp. degraded a wide range of n-acylhomoserine lactones namely n-(3-hexanoyl)-l-homoserine lactone (c6-hsl), ... | 2014 | 24995373 |
| tandem mass spectrometry detection of quorum sensing activity in multidrug resistant clinical isolate acinetobacter baumannii. | many proteobacteria communicate via production followed by response of quorum sensing molecules, namely, n-acyl homoserine lactones (ahls). these molecules consist of a lactone moiety with n-acyl side chain with various chain lengths and degrees of saturation at c-3 position. ahl-dependent qs is often associated with regulation of diverse bacterial phenotypes including the expression of virulence factors. with the use of biosensor and high resolution liquid chromatography tandem mass spectrometr ... | 2014 | 25101326 |
| punica granatum: a review on its potential role in treating periodontal disease. | a wide variety of plants possess enormous treasure of medicinal value. majority of these medicinal plants have been used to treat various systemic conditions successfully. over the recent years, use of these medicinal plants has resurfaced to treat oral conditions. among the oral conditions, periodontal disease remains one of the most common. alternative and preventive options has become the need of the hour in order to overcome the adverse effects of the antimicrobial agents used in large as an ... | 2014 | 25210254 |
| functional genomic characterization of virulence factors from necrotizing fasciitis-causing strains of aeromonas hydrophila. | the genomes of 10 aeromonas isolates identified and designated aeromonas hydrophila wi, riv3, and nf1 to nf4; a. dhakensis ssu; a. jandaei riv2; and a. caviae nm22 and nm33 were sequenced and annotated. isolates nf1 to nf4 were from a patient with necrotizing fasciitis (nf). two environmental isolates (riv2 and -3) were from the river water from which the nf patient acquired the infection. while isolates nf2 to nf4 were clonal, nf1 was genetically distinct. outside the conserved core genomes of ... | 2014 | 24795370 |
| quorum quenching bacteria bacillus sp. qsi-1 protect zebrafish (danio rerio) from aeromonas hydrophila infection. | quorum sensing (qs) is a bacterial regulatory mechanism, which is responsible for controlling the expression of various biological macromolecules such as the virulence factors in a cell density-dependent manner. disruption of the qs system of pathogens has been proposed as a new anti-infective strategy. biodegradation of ahls proves to be an efficient way to interrupt qs, since ahls are the main family of qs autoinducers used in gram negative bacteria. in this study, the effect of bacillus sp. q ... | 2014 | 24962441 |
| freshwater-borne bacteria isolated from a malaysian rainforest waterfall exhibiting quorum sensing properties. | one obvious requirement for concerted action by a bacterial population is for an individual to be aware of and respond to the other individuals of the same species in order to form a response in unison. the term "quorum sensing" (qs) was coined to describe bacterial communication that is able to stimulate expression of a series of genes when the concentration of the signaling molecules has reached a threshold level. here we report the isolation from aquatic environment of a bacterium that was la ... | 2014 | 24932870 |
| quorum sensing activity in pandoraea pnomenusa rb38. | strain rb38 was recovered from a former dumping area in malaysia. maldi-tof mass spectrometry and genomic analysis identified strain rb-38 as pandoraea pnomenusa. various biosensors confirmed its quorum sensing properties. high resolution triple quadrupole liquid chromatography-mass spectrometry analysis was subsequently used to characterize the n-acyl homoserine lactone production profile of p. pnomenusa strain rb38, which validated that this isolate produced n-octanoyl homoserine lactone as a ... | 2014 | 24919016 |
| cancer chemoprevention: current state of the art. | the aim of cancer chemoprevention is disruption or delay of the molecular pathways that lead to carcinogenesis. chemopreventive blocking and/or suppressing agents disrupt the molecular mechanisms that drive carcinogenesis such as dna damage by reactive oxygen species, increased signal transduction to nf-κb, epigenomic deregulation, and the epithelial mesenchymal transition that leads to metastatic progression. numerous dietary phytochemicals have been observed to inhibit the initiation phase of ... | 2014 | 24987270 |
| discovery of pantoea rodasii strain nd03 that produces n-(3-oxo-hexanoyl)-l-homoserine lactone. | proteobacteria use quorum sensing to regulate target gene expression in response to population density. quorum sensing (qs) is achieved via so-called signalling molecules and the best-studied qs signalling system uses n-acyl homoserine lactones (ahls). this study aimed to identify and characterize the production of ahls by a bacterium nd03 isolated from a malaysian tropical rainforest waterfall. molecular identification showed that nd03 is a pantoea sp. closely related to pantoea rodasii. we use ... | 2014 | 24859023 |
| the therapeutic potential of class i selective histone deacetylase inhibitors in ovarian cancer. | epithelial ovarian cancer remains the deadliest gynecologic malignancy. despite advances in treatment, new approaches are needed. histone deacetylases (hdacs) are a family of enzymes that regulate gene expression by removing acetyl groups from lysine residues on histones and non-histone proteins. inhibition of hdacs with small molecules has led to the development of histone deacetylase inhibitors (hdaci) that are in clinical use, primarily for hematologic malignancies. although clinical trials w ... | 2014 | 24904826 |
| quorum sensing activity of a kluyvera sp. isolated from a malaysian waterfall. | in many species of bacteria, the quorum sensing mechanism is used as a unique communication system which allows them to regulate gene expression and behavior in accordance with their population density. n-acylhomoserine lactones (ahls) are known as diffusible autoinducer molecules involved in this communication network. this finding aimed to characterize the production of ahl of a bacterial strain nd04 isolated from a malaysian waterfall. strain nd04 was identified as kluyvera sp. as confirmed b ... | 2014 | 24815680 |
| synergistic effect and antiquorum sensing activity of nymphaea tetragona (water lily) extract. | salmonellosis is a common and widely distributed food borne disease where salmonella typhimurium is one of the most important etiologic agents. the purpose of this study was to investigate the antimicrobial activity of nymphaea tetragona alone and in combination with antibiotics against s. typhimurium. it also aimed to assess the plant for quorum sensing inhibition (qsi) activity and to identify the bioactive compounds. the antibacterial activities of the extract were assessed using broth microd ... | 2014 | 24895589 |
| quorum sensing activity of aeromonas caviae strain yl12, a bacterium isolated from compost. | quorum sensing is a well-studied cell-to-cell communication method that involves a cell-density dependent regulation of genes expression mediated by signalling molecules. in this study, a bacterium isolated from a plant material compost pile was found to possess quorum sensing activity based on bioassay screening. isolate yl12 was identified using matrix-assisted laser desorption ionization time-of-flight (maldi-tof) mass spectrometry and molecular typing using rpod gene which identified the iso ... | 2014 | 24759107 |
| chitinase expression in listeria monocytogenes is positively regulated by the agr system. | the food-borne pathogen listeria monocytogenes encodes two chitinases, chia and chib, which allow the bacterium to hydrolyze chitin, the second most abundant polysaccharide in nature. intriguingly, despite the absence of chitin in human and mammalian hosts, both of the chitinases have been deemed important for infection, through a mechanism that, at least in the case of chia, involves modulation of host immune responses. in this study, we show that the expression of the two chitinases is subject ... | 2014 | 24752234 |
| quorum sensing activity of hafnia alvei isolated from packed food. | quorum sensing (qs) is a mechanism adopted by bacteria to regulate expression of genes according to population density. n-acylhomoserine lactones (ahls) are a type of qs signalling molecules commonly found in gram-negative bacteria which have been reported to play a role in microbial spoilage of foods and pathogenesis. in this study, we isolated an ahl-producing hafnia alvei strain (fb1) from spherical fish pastes. analysis via high resolution triple quadrupole liquid chromatography/mass spectro ... | 2014 | 24736131 |
| isolation of the autoinducer-quenching strain that inhibits lasr in pseudomonas aeruginosa. | quorum sensing (qs) has been recognized as a general phenomenon in microorganisms and plays an important role in many pathogenic bacteria. in this report, we used the agrobacterium tumefaciens biosensor strain nt1 to rapidly screen for autoinducer-quenching inhibitors from bacteria. after initial screening 5389 isolates obtained from land and beach soil, 53 putative positive strains were identified. a confirmatory bioassay was carried out after concentrating the putative positive culture superna ... | 2014 | 24736783 |
| histone deacetylase inhibitor romidepsin induces hiv expression in cd4 t cells from patients on suppressive antiretroviral therapy at concentrations achieved by clinical dosing. | persistent latent reservoir of replication-competent proviruses in memory cd4 t cells is a major obstacle to curing hiv infection. pharmacological activation of hiv expression in latently infected cells is being explored as one of the strategies to deplete the latent hiv reservoir. in this study, we characterized the ability of romidepsin (rmd), a histone deacetylase inhibitor approved for the treatment of t-cell lymphomas, to activate the expression of latent hiv. in an in vitro t-cell model of ... | 2014 | 24722454 |
| rhodotorula mucilaginosa, a quorum quenching yeast exhibiting lactonase activity isolated from a tropical shoreline. | two microbial isolates from a malaysian shoreline were found to be capable of degrading n-acylhomoserine lactones. both matrix assisted laser desorption ionization-time of flight-mass spectrometry and 18s rdna phylogenetic analyses confirmed that these isolates are rhodotorula mucilaginosa. quorum quenching activities were detected by a series of bioassays and rapid resolution liquid chromatography analysis. the isolates were able to degrade various quorum sensing molecules namely n-hexanoyl-l-h ... | 2014 | 24721765 |