Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| chlamydia pneumoniae encodes a functional aromatic amino acid hydroxylase. | chlamydia pneumoniae is a community-acquired respiratory pathogen that has been associated with the development of atherosclerosis. analysis of the c. pneumoniae genome identified a gene (cpn1046) homologous to eukaryotic aromatic amino acid hydroxylases (aroaa-hs). aroaa-hs hydroxylate phenylalanine, tyrosine, and tryptophan into tyrosine, dihydroxyphenylalanine, and 5-hydroxytryptophan, respectively. sequence analysis of cpn1046 demonstrated that residues essential for aroaa-h enzymatic functi ... | 2009 | 19141112 |
| histone deacetylase inhibitor romidepsin enhances anti-tumor effect of erlotinib in non-small cell lung cancer (nsclc) cell lines. | most epidermal growth factor receptor (egfr) mutant non-small cell lung cancers (nsclcs) are sensitive to egfr tyrosine kinase inhibitors (tkis) such as erlotinib or gefitinib, but many egfr wild type nsclcs are resistant to tkis. in this study, we examined the effects of the histone deacetylase inhibitor, romidepsin, in combination with erlotinib, in nsclc cell lines and xenografts. | 2009 | 19179890 |
| chromobacterium violaceum infection in a provincial hospital in sri lanka. | 2008 | 19189802 | |
| synthesis and conformation-activity relationships of the peptide isosteres of fk228 and largazole. | the peptide isosteres (10 and 11) of the naturally occurring and potent histone deacetylase (hdac) inhibitors fk228 and largazole have been synthesized and evaluated side-by-side with fk228, largazole, and saha for inhibition of the class i hdacs 1, 2, 3, and 6. | 2009 | 19193120 |
| minimum contradiction matrices in whole genome phylogenies. | minimum contradiction matrices are a useful complement to distance-based phylogenies. a minimum contradiction matrix represents phylogenetic information under the form of an ordered distance matrix y(i) (,) (j) (n). a matrix element corresponds to the distance from a reference vertex n to the path (i, j). for an x-tree or a split network, the minimum contradiction matrix is a robinson matrix. it therefore fulfills all the inequalities defining perfect order: y(i) (,) (j) (n) >or= y(i) (,) (k) (n ... | 2008 | 19204821 |
| species distribution and antimicrobial susceptibility of gram-negative aerobic bacteria in hospitalized cancer patients. | nosocomial infections pose significant threats to hospitalized patients, especially the immunocompromised ones, such as cancer patients. | 2009 | 19228413 |
| population pharmacokinetics of romidepsin in patients with cutaneous t-cell lymphoma and relapsed peripheral t-cell lymphoma. | romidepsin is a potent histone deacetylase inhibitor under clinical development. the objective of this study was to evaluate the effect of demographic, clinical, and pharmacogenetic covariates on the pharmacokinetics of romidepsin in patients with t-cell lymphoma. | 2009 | 19228751 |
| is gas-discharge plasma a new solution to the old problem of biofilm inactivation? | conventional disinfection and sterilization methods are often ineffective with biofilms, which are ubiquitous, hard-to-destroy microbial communities embedded in a matrix mostly composed of exopolysaccharides. the use of gas-discharge plasmas represents an alternative method, since plasmas contain a mixture of charged particles, chemically reactive species and uv radiation, whose decontamination potential for free-living, planktonic micro-organisms is well established. in this study, biofilms wer ... | 2009 | 19246743 |
| the cin and rai quorum-sensing regulatory systems in rhizobium leguminosarum are coordinated by expr and cins, a small regulatory protein coexpressed with cini. | to understand how the rhizobium leguminosarum raii-rair quorum-sensing system is regulated, we identified mutants with decreased levels of raii-made n-acyl homoserine lactones (ahls). a luxr-type regulator, expr, is required for rair expression, and rair is required to induce raii. since rair (and raii) expression is also reduced in cini and cinr quorum-sensing mutants, we thought cini-made ahls may activate expr to induce rair. however, added cini-made ahls did not induce rair expression in a c ... | 2009 | 19270098 |
| eukaryotic nirk genes encoding copper-containing nitrite reductase: originating from the protomitochondrion? | although denitrification or nitrate respiration has been found among a few eukaryotes, its phylogenetic relationship with the bacterial system remains unclear because orthologous genes involved in the bacterial denitrification system were not identified in these eukaryotes. in this study, we isolated a gene from the denitrifying fungus fusarium oxysporum that is homologous to the bacterial nirk gene responsible for encoding copper-containing nitrite reductase (nirk). characterization of the gene ... | 2009 | 19270125 |
| violacein extracted from chromobacterium violaceum inhibits plasmodium growth in vitro and in vivo. | violacein is a violet pigment extracted from the gram-negative bacterium chromobacterium violaceum. it presents bactericidal, tumoricidal, trypanocidal, and antileishmanial activities. we show that micromolar concentrations efficiently killed chloroquine-sensitive and -resistant plasmodium falciparum strains in vitro; inhibited parasitemia in vivo, even after parasite establishment; and protected plasmodium chabaudi chabaudi-infected mice from a lethal challenge. | 2009 | 19273690 |
| comparison of routine bench and molecular diagnostic methods in identification of burkholderia pseudomallei. | this study compared the identification of burkholderia pseudomallei with that of related organisms. bench tests and latex agglutination were compared with molecular identification. using bench tests and latex agglutination alone, 100% (30/30) of b. pseudomallei isolates were correctly identified. amoxicillin-clavulanate susceptibility testing was also a good and simple discriminatory test. | 2009 | 19279182 |
| the complete genome and proteome of laribacter hongkongensis reveal potential mechanisms for adaptations to different temperatures and habitats. | laribacter hongkongensis is a newly discovered gram-negative bacillus of the neisseriaceae family associated with freshwater fish-borne gastroenteritis and traveler's diarrhea. the complete genome sequence of l. hongkongensis hlhk9, recovered from an immunocompetent patient with severe gastroenteritis, consists of a 3,169-kb chromosome with g+c content of 62.35%. genome analysis reveals different mechanisms potentially important for its adaptation to diverse habitats of human and freshwater fish ... | 2009 | 19283063 |
| globins synthesize the second messenger bis-(3'-5')-cyclic diguanosine monophosphate in bacteria. | globin-coupled sensors are heme-binding signal transducers in bacteria and archaea in which an n-terminal globin controls the activity of a variable c-terminal domain. here, we report that bpegreg, a globin-coupled diguanylate cyclase from the whooping cough pathogen bordetella pertussis, synthesizes the second messenger bis-(3'-5')-cyclic diguanosine monophosphate (c-di-gmp) upon oxygen binding. expression of bpegreg in salmonella typhimurium enhances biofilm formation, while knockout of the bp ... | 2009 | 19285985 |
| characterization of a new plasmid-like prophage in a pandemic vibrio parahaemolyticus o3:k6 strain. | vibrio parahaemolyticus is a common food-borne pathogen that is normally associated with seafood. in 1996, a pandemic o3:k6 strain abruptly appeared and caused the first pandemic of this pathogen to spread throughout many asian countries, america, europe, and africa. the role of temperate bacteriophages in the evolution of this pathogen is of great interest. in this work, a new temperate phage, vp882, from a pandemic o3:k6 strain of v. parahaemolyticus was purified and characterized after mitomy ... | 2009 | 19286788 |
| inter-kingdom signaling: chemical language between bacteria and host. | chemical communication between cells ensures coordination of behavior. in prokaryotes, this chemical communication is usually referred to as quorum sensing, while eukaryotic cells signal through hormones. in the past years, a growing number of reports have shown that bacterial quorum sensing signals, called autoinducers, signal to eukaryotic cells, mimicking hormones. conversely, host hormones can signal to bacterial cells through converging pathways to autoinducer signaling. this inter-kingdom ... | 2009 | 19318290 |
| chromobacterium violaceum endocarditis and hepatic abscesses treated successfully with meropenem and ciprofloxacin. | chromobacterium violaceum infection is uncommon but potentially fatal, with a clinical picture similar to melioidosis but with different antibiotic sensitivities and treatment. this infection can involve any organ, but we believe this is the first reported case of c. violaceum endocarditis. | 2009 | 19351314 |
| type i polyketide synthases that require discrete acyltransferases. | the diverse structures of polyketide natural products are reflected by the equally diverse polyketide biosynthetic enzymes, namely polyketide synthases (pkss). three major classes of pkss are known-noniterative type i pkss, iterative type ii pkss and acyl carrier protein-independent type iii pkss, each of which consists of additional variants. one such variant is the noniterative type i pks in which each pks module lacks the cognate acyltransferase (at) domain. the essential at activity is inste ... | 2009 | 19362640 |
| recurrent chromobacterium violaceum infection in a patient with chronic granulomatous disease. | we report a rare case of recurrent infection of chromobacterium violaceum in an immunocompromised patient. despite the high mortality rate associated with this infection as reported in the literature, this patient survived three episodes of recurrent infection. we believe that with high clinical suspicion, prompt treatment and appropriate antimicrobial agents, it is possible for clinicians to treat this infection effectively and reduce the mortality rate. | 2008 | 19385503 |
| divergent pathways in the biosynthesis of bisindole natural products. | two molecules of the amino acid l-tryptophan are the biosynthetic precursors to a class of natural products named the "bisindoles." hundreds of these bisindole molecules have been isolated from natural sources, and many of these molecules have potent medicinal properties. recent studies have clarified the biosynthetic construction of six bisindole molecules, revealing novel enzymatic mechanisms and leading to combinatorial synthesis of new bisindole compounds. collectively, these results provide ... | 2009 | 19389622 |
| recurrent burkholderia infection in patients with chronic granulomatous disease: 11-year experience at a large referral center. | the epidemiology of burkholderia infection in persons with chronic granulomatous disease is poorly understood. we used species-specific polymerase chain reaction-based assays and genotyping analyses to identify 32 strains representing 9 burkholderia species among 50 isolates recovered from 18 patients with chronic granulomatous disease. we found that recurrent pulmonary infection with distinct burkholderia strains is common in chronic granulomatous disease. | 2009 | 19400745 |
| oxidative dna damage protective activity, antioxidant and anti-quorum sensing potentials of moringa oleifera. | the aqueous extract of leaf (le), fruit (fe) and seed (se) of moringa oleifera was assessed to examine the ability to inhibit the oxidative dna damage, antioxidant and anti-quorum sensing (qs) potentials. it was found that these extracts could significantly inhibit the oh-dependent damage of puc18 plasmid dna and also inhibit synergistically with trolox, with an activity sequence of le > fe > se. hplc and ms/ms analysis was carried out, which showed the presence of gallic acid, chlorogenic acid, ... | 2009 | 19425184 |
| a probable aculeacin a acylase from the ralstonia solanacearum gmi1000 is n-acyl-homoserine lactone acylase with quorum-quenching activity. | the infection and virulence functions of diverse plant and animal pathogens that possess quorum sensing systems are regulated by n-acylhomoserine lactones (ahls) acting as signal molecules. ahl-acylase is a quorum quenching enzyme and degrades ahls by removing the fatty acid side chain from the homoserine lactone ring of ahls. this blocks ahl accumulation and pathogenic phenotypes in quorum sensing bacteria. | 2009 | 19426552 |
| a rationally designed histone deacetylase inhibitor with distinct antitumor activity against ovarian cancer. | histone deacetylase inhibitors (hdacis) are a class of antineoplastic agents previously demonstrating preclinical chemosensitizing activity against drug-resistant cancer cells and mouse xenografts. however, whereas clinical studies have shown efficacy against human hematologic malignancies, solid tumor trials have proved disappointing. we previously developed a novel hdaci, "osu-hdac42," and herein examine its activity against ovarian cancer cell lines and xenografts. osu-hdac42, (i) unlike most ... | 2009 | 19484144 |
| new clinical developments in histone deacetylase inhibitors for epigenetic therapy of cancer. | dna methylation and histone acetylation are two well known epigenetic chromatin modifications. epigenetic agents leading to dna hypomethylation and histone hyperacetylation have been approved for treatment of hematological disorders. the first histone deacetylase inhibitor, vorinostat, has been licensed for cutaneous t cell lymphoma treatment. more than 11 new epigenetic agents are in various stages of clinical development for therapy of multiple cancer types. in this review we summarize novel h ... | 2009 | 19486511 |
| structural basis for the erythro-stereospecificity of the l-arginine oxygenase vioc in viomycin biosynthesis. | the nonheme iron oxygenase vioc from streptomyces vinaceus catalyzes fe(ii)-dependent and alpha-ketoglutarate-dependent cbeta-hydroxylation of l-arginine during the biosynthesis of the tuberactinomycin antibiotic viomycin. crystal structures of vioc were determined in complexes with the cofactor fe(ii), the substrate l-arginine, the product (2s,3s)-hydroxyarginine and the coproduct succinate at 1.1-1.3 a resolution. the overall structure reveals a beta-helix core fold with two additional helical ... | 2009 | 19490124 |
| the long-chain fatty acid sensor, psra, modulates the expression of rpos and the type iii secretion exsceba operon in pseudomonas aeruginosa. | the pseudomonas aeruginosa psra autorepressor has dual roles as a repressor of the fadba5beta-oxidation operon and an activator of the stationary-phase sigma factor rpos and exsceba operon of the type iii secretion system (ttss). previously, we demonstrated that the repression of the fadba5 operon by psra is relieved by long-chain fatty acids (lcfas). however, the signal affecting the activation of rpos and exsc via psra is unknown. in this study, microarray and gene fusion data suggested that l ... | 2009 | 19508282 |
| a novel two-component system bqss-bqsr modulates quorum sensing-dependent biofilm decay in pseudomonas aeruginosa. | pseudomonas aeruginosa can grow either as planktonic- or biofilm-form in response to environmental changes. recent studies show that switching from biofilm to planktonic lifestyle requires rhamnolipids. here we report the identification of a novel twocomponent system bqss-bqsr that regulates biofilm decay in p. aeruginosa. bqss is a multidomain sensor kinase and bqsr is an ompr-like response regulator. deletion of either bqss or bqsr in p. aeruginosa mpao1 resulted in a significant increase in b ... | 2008 | 19513205 |
| lasi/r and rhli/r quorum sensing in a strain of pseudomonas aeruginosa beneficial to plants. | pseudomonas aeruginosa possesses three quorum-sensing (qs) systems which are key in the expression of a large number of genes, including many virulence factors. most studies of qs in p. aeruginosa have been performed in clinical isolates and have therefore focused on its role in pathogenicity. p. aeruginosa, however, is regarded as a ubiquitous organism capable of colonizing many different environments and also of establishing beneficial associations with plants. in this study we examined the ro ... | 2009 | 19525275 |
| homologs of the small rna sgrs are broadly distributed in enteric bacteria but have diverged in size and sequence. | sugar phosphate stress in escherichia coli is sensed and managed by the transcriptional regulator sgrr and the small rna (srna) sgrs. sgrs is a dual function rna that performs base pairing-dependent regulation of mrna targets and encodes a small protein, sgrt. homologs of sgrr were analyzed for gene synteny and inter-homolog identity to identify those that are likely to be functionally analogous. these 22 sgrr homologs were used to manually locate adjacent srnas functionally analogous to sgrs. s ... | 2009 | 19531735 |
| non mycobacterial virulence genes in the genome of the emerging pathogen mycobacterium abscessus. | mycobacterium abscessus is an emerging rapidly growing mycobacterium (rgm) causing a pseudotuberculous lung disease to which patients with cystic fibrosis (cf) are particularly susceptible. we report here its complete genome sequence. the genome of m. abscessus (cip 104536t) consists of a 5,067,172-bp circular chromosome including 4920 predicted coding sequences (cds), an 81-kb full-length prophage and 5 is elements, and a 23-kb mercury resistance plasmid almost identical to pmm23 from mycobacte ... | 2009 | 19543527 |
| an fad-dependent pyridine nucleotide-disulfide oxidoreductase is involved in disulfide bond formation in fk228 anticancer depsipeptide. | disulfide bonds are rare in bacterial natural products, and the mechanism of disulfide bond formation in those products is unknown. here we characterize a gene and its product critical for a disulfide bond formation in fk228 anticancer depsipeptide in chromobacterium violaceum. deletion of deph drastically reduced fk228 production, whereas complementation of the deph-deletion mutant with a copy of deph on a medium copy-number plasmid not only fully restored the fk228 production but also signific ... | 2009 | 19549597 |
| synthesis, nematicidal and antimicrobial properties of bis-[4-methoxy-3-[3-(4-fluorophenyl)-6-(4-methylphenyl)-2(aryl)-tetrahydro-2h-pyrazolo[3,4-d]thiazol-5-yl]phenyl]methanes. | a new series of bis-[4-methoxy-3-[3-(4-fluorophenyl)-6-(4-methylphenyl)-2-(aryl)-3,3a,5,6-tetrahydro-2h-pyrazolo[3,4-d][1,3]thiazol-5-yl]phenyl]methanes 6a-r was synthesized by the reaction of arylidine derivative of methylene-bis-thiazolidinones 5a-c with aryl/alkyl hydrazines. chemical structures of all the new compounds were established by ir, (1)h-nmr, (13)c-nmr, ms and elemental data. the compounds 6a-r were evaluated for their nematicidal activity against ditylenchus myceliophagus and caen ... | 2009 | 19571412 |
| blocking of pseudomonas aeruginosa and ralstonia solanacearum lectins by plant and microbial branched polysaccharides used as food additives. | pseudomonas aeruginosa antibiotic resistance prompted the search for glycodecoys that would block its lectin-dependent adhesion to human cells. we have used the lectins of this pathogen, pa-il (galactophilic leca) and pa-iil (fucophilic lecb), and two additional pathogenic bacterial lectins, cv-iil (fucophilic, of chromobacterium violaceum) and rs-iil (mannophilic, of ralstonia solanacearum), for assaying the pathogenic lectin-blocking abilities of some plant and microbial polysaccharidic food a ... | 2009 | 19572540 |
| immunomodulatory, analgesic and antipyretic effects of violacein isolated from chromobacterium violaceum. | violacein was isolated from chromobacterium violaceum, a soil gram negative bacterium collected from the forest water body soil sample of kolli hills; tamil nadu, india. in the present study the immunomodulatory, analgesic and antipyretic activities of violacein were investigated in wistar rats and mice. analgesic effect was evaluated by acetic acid- induced writhing, formalin induced paw licking and hotplate tests. immunomodulatory effect was investigated by using ovalbumin- induced active paw ... | 2010 | 19576742 |
| chromobacterium piscinae sp. nov. and chromobacterium pseudoviolaceum sp. nov., from environmental samples. | two strains (lmg 3947 and lmg 3953) of motile, gram-negative, violet-pigmented bacteria, respectively isolated in 1972 and before 1953 from environmental samples and previously assigned to chromobacterium violaceum, were studied again in detail for their taxonomic position. 16s rrna gene sequence analysis showed that both strains clustered together with the type strain of chromobacterium violaceum (99.8 % sequence similarity for strain lmg 3953(t) and 98.9 % sequence similarity for lmg 3947(t)). ... | 2009 | 19622653 |
| inhibition of quorum sensing regulated bacterial functions by plant essential oils with special reference to clove oil. | to evaluate quorum sensing (qs) inhibitory activity of plant essential oils using strains of chromobacterium violaceum (cv12472 and cvo26) and pseudomonas aeruginosa (pao1). | 2009 | 19627477 |
| fatal chromobacterium violaceum septicaemia in northern laos, a modified oxidase test and post-mortem forensic family g6pd analysis. | chromobacterium violaceum is a gram negative facultative anaerobic bacillus, found in soil and stagnant water, that usually has a violet pigmented appearance on agar culture. it is rarely described as a human pathogen, mostly from tropical and subtropical areas. | 2009 | 19640274 |
| a quorum-sensing antagonist targets both membrane-bound and cytoplasmic receptors and controls bacterial pathogenicity. | quorum sensing is a process of bacterial communication involving production and detection of secreted molecules called autoinducers. gram-negative bacteria use acyl-homoserine lactone (ahl) autoinducers, which are detected by one of two receptor types. first, cytoplasmic luxr-type receptors bind accumulated intracellular ahls. ahl-luxr complexes bind dna and alter gene expression. second, membrane-bound luxn-type receptors bind accumulated extracellular ahls. ahl-luxn complexes relay information ... | 2009 | 19647512 |
| metabolic analysis of the soil microbe dechloromonas aromatica str. rcb: indications of a surprisingly complex life-style and cryptic anaerobic pathways for aromatic degradation. | initial interest in dechloromonas aromatica strain rcb arose from its ability to anaerobically degrade benzene. it is also able to reduce perchlorate and oxidize chlorobenzoate, toluene, and xylene, creating interest in using this organism for bioremediation. little physiological data has been published for this microbe. it is considered to be a free-living organism. | 2009 | 19650930 |
| enhancement of l-tryptophan 5-hydroxylation activity by structure-based modification of l-phenylalanine 4-hydroxylase from chromobacterium violaceum. | the objective of this study was to enhance l-tryptophan hydroxylation activity of l-phenylalanine 4-hydroxylase. it had been known that l-phenylalanine 4-hydroxylase from chromobacterium violaceum could convert l-tryptophan to 5-hydroxy-l-tryptophan and l-phenylalanine to l-tyrosine; however, the activity for l-tryptophan was extremely low compared to l-phenylalanine activity levels. we used the information on the crystal structures of aromatic amino acid hydroxylases to generate c. violaceuml-p ... | 2009 | 19664549 |
| quorum sensing and social networking in the microbial world. | for many years, bacterial cells were considered primarily as selfish individuals, but, in recent years, it has become evident that, far from operating in isolation, they coordinate collective behaviour in response to environmental challenges using sophisticated intercellular communication networks. cell-to-cell communication between bacteria is mediated by small diffusible signal molecules that trigger changes in gene expression in response to fluctuations in population density. this process, ge ... | 2009 | 19674996 |
| efflux-mediated drug resistance in bacteria: an update. | drug efflux pumps play a key role in drug resistance and also serve other functions in bacteria. there has been a growing list of multidrug and drug-specific efflux pumps characterized from bacteria of human, animal, plant and environmental origins. these pumps are mostly encoded on the chromosome, although they can also be plasmid-encoded. a previous article in this journal provided a comprehensive review regarding efflux-mediated drug resistance in bacteria. in the past 5 years, significant pr ... | 2009 | 19678712 |
| romidepsin inhibits ras-dependent growth transformation of nih 3t3 fibroblasts and rie-1 epithelial cells independently of ras signaling inhibition. | despite intensive effort, currently no effective anti-ras therapies have successfully reached clinical application. previous studies suggest that the histone deacetylatse (hdac) inhibitor romidepsin, which is currently in clinical trials for the treatment of multiple malignancies, can block ras-dependent signaling and growth transformation. these studies suggest that mutational activation of ras may be a useful biomarker for sensitivity to romidepsin and that the anti-tumor activity of this hdac ... | 2009 | 19682393 |
| tocopherol, carotene, phenolic contents and antibacterial properties of rose essential oil, hydrosol and absolute. | the antioxidant and antibacterial activities, and total phenolic contents of rosa damascena mill. flower extracts (absolute, essential oil and hydrosol) were investigated. the chemical compositions of these extracts were analysed by gc-ms. phenylethyl alcohol (78.38%) was found to be the main constituent of rose absolute, while citrenellol and geraniol were the major compounds (>55%) of rose essential oil and hydrosol. tocopherol and carotene levels were determined by high performance liquid chr ... | 2009 | 19688375 |
| rhizospheric pseudomonads: friends or foes? | of the different groups of soil microorganisms, pseudomonads are one of the important class, playing various roles in the plants growth and development. although they have been reported to inflict both beneficial and harmful effect on plants, they act through various mechanisms. among the different mechanisms, cyanogenesis is one of the important factors used by pseudomonads to cause positive and less studied negative effects in the rhizosphere. by employing a bioassay driven approach, we dissec ... | 2008 | 19704457 |
| update on the treatment of cutaneous t-cell lymphoma (ctcl): focus on vorinostat. | epigenetic regulation of gene transcription by small molecule inhibitors of histone deacetylases (hdac) is a novel cancer therapy. vorinostat (zolinza()) is the first fda approved hdac-inhibitor for treatment of patients with cutaneous t cell lymphoma (ctcl) who have progressive, persistent or recurrent disease on or following two systemic therapies. vorinostat was active against solid tumors and hematologic malignancies as intravenous and oral preparations in phase i development. in two phase i ... | 2007 | 19707308 |
| anti-diarrhoeal and ulcer-protective effects of violacein isolated from chromobacterium violaceum in wistar rats. | violacein was isolated from chromobacterium violaceum, a soil gram-negative bacterium collected from the forest water body soil sample from kolli hills of tamil nadu, india. in the present study the anti-diarrhoeal and ulcer-protective properties of violacein were investigated in wistar rats using castor oil, magnesium sulphate and ethanol. the intestinal transit in rats was significantly (p < 0.001) reduced and gastric emptying was delayed; 40 mg/kg of violacein elicited a greater anti-motility ... | 2009 | 19709325 |
| quorum sensing inhibition activity of garlic extract and p-coumaric acid. | the goal of this work was to investigate the influence of dmso, garlic extract and p-coumaric acid on bacterial quorum sensing (qs). | 2009 | 19709367 |
| single-residue changes in the c-terminal disulfide-bonded loop of the pseudomonas aeruginosa type iv pilin influence pilus assembly and twitching motility. | pila, the major pilin subunit of pseudomonas aeruginosa type iv pili (t4p), is a principal structural component. pila has a conserved c-terminal disulfide-bonded loop (dsl) that has been implicated as the pilus adhesinotope. structural studies have suggested that dsl is involved in intersubunit interactions within the pilus fiber. pila mutants with single-residue substitutions, insertions, or deletions in the dsl were tested for pilin stability, pilus assembly, and t4p function. mutation of eith ... | 2009 | 19717595 |
| the bacterially produced metabolite violacein is associated with survival of amphibians infected with a lethal fungus. | the disease chytridiomycosis, which is caused by the chytrid fungus batrachochytrium dendrobatidis, is associated with recent declines in amphibian populations. susceptibility to this disease varies among amphibian populations and species, and resistance appears to be attributable in part to the presence of antifungal microbial species associated with the skin of amphibians. the betaproteobacterium janthinobacterium lividum has been isolated from the skins of several amphibian species and produc ... | 2009 | 19717627 |
| protozoan-induced regulation of cyclic lipopeptide biosynthesis is an effective predation defense mechanism for pseudomonas fluorescens. | environmental bacteria are exposed to a myriad of biotic interactions that influence their function and survival. the grazing activity of protozoan predators significantly impacts the dynamics, diversification, and evolution of bacterial communities in soil ecosystems. to evade protozoan predation, bacteria employ various defense strategies. soil-dwelling pseudomonas fluorescens strains ss101 and sbw25 produce the cyclic lipopeptide surfactants (clps) massetolide and viscosin, respectively, in a ... | 2009 | 19717630 |
| chromobacterium violaceum sepsis in an infant. | chromobacterium violaceum is a rare pathogen that can cause potentially fatal infections in humans. till date, 150 cases are reported worldwide including 7 from india. we report a 6 month old infant who presented with high grade fever, respiratory distress and multiple vesicular skin lesions. chromobacterium violaceum was isolated from blood, bone marrow aspirate and from skin lesions. infant responded to treatment with piperacillin and ciprofloxacin, and is doing well on follow up. | 2009 | 19717863 |
| microbial nad metabolism: lessons from comparative genomics. | nad is a coenzyme for redox reactions and a substrate of nad-consuming enzymes, including adp-ribose transferases, sir2-related protein lysine deacetylases, and bacterial dna ligases. microorganisms that synthesize nad from as few as one to as many as five of the six identified biosynthetic precursors have been identified. de novo nad synthesis from aspartate or tryptophan is neither universal nor strictly aerobic. salvage nad synthesis from nicotinamide, nicotinic acid, nicotinamide riboside, a ... | 2009 | 19721089 |
| neonatal enteral feeding tubes as loci for colonisation by members of the enterobacteriaceae. | the objective of this study was to determine whether neonatal nasogastric enteral feeding tubes are colonised by the opportunistic pathogen cronobacter spp. (enterobacter sakazakii) and other enterobacteriaceae, and whether their presence was influenced by the feeding regime. | 2009 | 19723318 |
| color me bad: microbial pigments as virulence factors. | a hallmark feature of several pathogenic microbes is the distinctive color of their colonies when propagated in the clinical laboratory. such pigmentation comes in a variety of hues, and has often proven useful in presumptive clinical diagnosis. recent advances in microbial pigment biochemistry and the genetic basis of pigment production have sometimes revealed a more sinister aspect to these curious materials that change the color of reflected light by selective light absorbance. in many cases, ... | 2009 | 19726196 |
| n-acylhomoserine lactones involved in quorum sensing control the type vi secretion system, biofilm formation, protease production, and in vivo virulence in a clinical isolate of aeromonas hydrophila. | in this study, we delineated the role of n-acylhomoserine lactone(s) (ahls)-mediated quorum sensing (qs) in the virulence of diarrhoeal isolate ssu of aeromonas hydrophila by generating a double knockout delta ahyri mutant. protease production was substantially reduced in the delta ahyri mutant when compared with that in the wild-type (wt) strain. importantly, based on western blot analysis, the delta ahyri mutant was unable to secrete type vi secretion system (t6ss)-associated effectors, namely ... | 2009 | 19729404 |
| efficient synthesis and evaluation of quorum-sensing modulators using small molecule macroarrays. | a method for the synthesis of small molecule macroarrays of n-acylated l-homoserine lactones (ahls) is reported. a focused library of ahls was constructed, and the macroarray platform was found to be compatible with both solution and agar-overlay assays using quorum-sensing (qs) reporter strains. several qs antagonists were discovered and serve to showcase the macroarray as a straightforward technique for qs research. | 2009 | 19743816 |
| zinc-independent folate biosynthesis: genetic, biochemical, and structural investigations reveal new metal dependence for gtp cyclohydrolase ib. | gtp cyclohydrolase i (gcyh-i) is an essential zn(2+)-dependent enzyme that catalyzes the first step of the de novo folate biosynthetic pathway in bacteria and plants, the 7-deazapurine biosynthetic pathway in bacteria and archaea, and the biopterin pathway in mammals. we recently reported the discovery of a new prokaryotic-specific gcyh-i (gcyh-ib) that displays no sequence identity to the canonical enzyme and is present in approximately 25% of bacteria, the majority of which lack the canonical ... | 2009 | 19767425 |
| mediators of lipid a modification, rna degradation, and central intermediary metabolism facilitate the growth of legionella pneumophila at low temperatures. | legionella pneumophila is an aquatic bacterium that is also the agent of legionnaires' disease pneumonia. since l. pneumophila is transmitted directly from the environment to the lung, it is important to understand how legionellae survive at low temperatures. to identify genes that are needed for l. pneumophila growth at low temperature, we screened a population of mutagenized legionellae for strains that are specifically impaired for growth at 17 degrees c. from the 7,400 mutants tested, 11 dis ... | 2010 | 19768502 |
| mediators of lipid a modification, rna degradation, and central intermediary metabolism facilitate the growth of legionella pneumophila at low temperatures. | legionella pneumophila is an aquatic bacterium that is also the agent of legionnaires' disease pneumonia. since l. pneumophila is transmitted directly from the environment to the lung, it is important to understand how legionellae survive at low temperatures. to identify genes that are needed for l. pneumophila growth at low temperature, we screened a population of mutagenized legionellae for strains that are specifically impaired for growth at 17 degrees c. from the 7,400 mutants tested, 11 dis ... | 2010 | 19768502 |
| [cloning of phzir from the endophytic pseudomonas sp. g5 and its expression in escherichia coli]. | we isolated a new strain of endophytic pseudomonas g5 from the stems of chinese parsley (coriandrum sativum l.), and it is tentatively identified as pseudomonas aurantiaca according to analysis of the entire substrate utilization profiles using biolog microstation system (biolog, inc, hayward ca). an array of evidence established that many gram-negative bacteria employ quorum sensing (qs) system to regulate gene expression in response to cell density using small diffusible signal molecules, n-ac ... | 2009 | 19777809 |
| microbial growth and quorum sensing antagonist activities of herbal plants extracts. | antimicrobial and antiquorum sensing (aqs) activities of fourteen ethanolic extracts of different parts of eight plants were screened against four gram-positive, five gram-negative bacteria and four fungi. depending on the plant part extract used and the test microorganism, variable activities were recorded at 3 mg per disc. among the grampositive bacteria tested, for example, activities of laurus nobilis bark extract ranged between a 9.5 mm inhibition zone against bacillus subtilis up to a 25 m ... | 2009 | 19783935 |
| expression of phosphofructokinase in neisseria meningitidis. | neisseria meningitidis serogroup b is a pathogen that can infect diverse sites within the human host. according to the n. meningitidis genomic information and experimental observations, glucose can be completely catabolized through the entner-doudoroff pathway and the pentose phosphate pathway. the embden-meyerhof-parnas pathway is not functional, because the gene for phosphofructokinase (pfk) is not present. the phylogenetic distribution of pfk indicates that in most obligate aerobic organisms, ... | 2010 | 19797358 |
| chromobacterium violaceum endocarditis and hepatic abscesses treated successfully with meropenem and ciprofloxacin. | 2009 | 19807647 | |
| legionella pneumophila secretes an endoglucanase that belongs to the family-5 of glycosyl hydrolases and is dependent upon type ii secretion. | examination of cell-free culture supernatants revealed that legionella pneumophila strains secrete an endoglucanase activity. legionella pneumophila lspf mutants were deficient for this activity, indicating that the endoglucanase is secreted by the bacterium's type ii protein secretion (t2s) system. inactivation of cela, encoding a member of the family-5 of glycosyl hydrolases, abolished the endoglucanase activity in l. pneumophila culture supernatants. the cloned cela gene conferred activity up ... | 2009 | 19817866 |
| 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine, an effective peptide antibiotic from the epiphyte pantoea agglomerans 48b/90. | the epiphyte pantoea agglomerans 48b/90, which has been isolated from soybean leaves, belongs to the enterobacteriaceae, as does the plant pathogen erwinia amylovora, which causes fire blight on rosaceous plants such as apples and leads to severe economic losses. since p. agglomerans efficiently antagonizes phytopathogenic bacteria, the p. agglomerans strain c9-1 is used as a biocontrol agent (blightban c9-1). here we describe the bioassay-guided isolation of a peptide antibiotic that is highly ... | 2009 | 19820144 |
| phase ii multi-institutional trial of the histone deacetylase inhibitor romidepsin as monotherapy for patients with cutaneous t-cell lymphoma. | purpose romidepsin (depsipeptide or fk228) is a member of a new class of antineoplastic agents active in t-cell lymphoma, the histone deacetylase inhibitors. on the basis of observed responses in a phase i trial, a phase ii trial of romidepsin in patients with t-cell lymphoma was initiated. patients and methods the initial cohort was limited to patients with cutaneous t-cell lymphoma (ctcl), or subtypes mycosis fungoides or sézary syndrome, who had received no more than two prior cytotoxic regim ... | 2009 | 19826128 |
| inhibition of quorum-sensing signals by essential oils. | the role of quorum sensing (qs) is well known in microbial pathogenicity and antibiotic resistance. qs is responsible for motility, swarming, and biofilm production based on the signal molecules, e.g., acylated homoserine lactones (ahls) produced by micro-organisms above certain population density. the inhibition of qs may reduce pathogenicity, antibiotic resistance and biofilm formation in systemic and local infections. the homoserine lactones and other transmitters contribute to antibiotic res ... | 2010 | 19827025 |
| 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 |
| metagenomic approaches to natural products from free-living and symbiotic organisms. | 2009 | 19844642 | |
| 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 |
| beta-lactam antibiotics: from antibiosis to resistance and bacteriology. | this review focuses on the era of antibiosis that led to a better understanding of bacterial morphology, in particular the cell wall component peptidoglycan. this is an effort to take readers on a tour de force from the concept of antibiosis, to the serendipity of antibiotics, evolution of beta-lactam development, and the molecular biology of antibiotic resistance. these areas of research have culminated in a deeper understanding of microbiology, particularly in the area of bacterial cell wall s ... | 2010 | 20041868 |
| 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 |
| antitumoral activity of l-ascorbic acid-poly- d,l-(lactide-co-glycolide) nanoparticles containing violacein. | it has been demonstrated that tumoral cells have a higher uptake of ascorbic acid compared to normal cells. this differential characteristic can be used as a way to improve the specificity of antitumoral compounds if combined with polymeric drug delivery systems. the aim of this study was to prepare, characterize and evaluate the antitumoral activity of poly- d,l-(lactide-co-glycolide) 50:50 loading the antitumoral compound violacein and capped with l-ascorbic acid. nanoparticles were prepared u ... | 2010 | 20161989 |
| selsa, selenium analogs of saha as potent histone deacetylase inhibitors. | cancer treatment and therapy has moved from conventional chemotherapeutics to more mechanism-based targeted approach. disturbances in the balance of histone acetyltransferase (hat) and deacetylase (hdac) leads to a change in cell morphology, cell cycle, differentiation, and carcinogenesis. in particular, hdac plays an important role in carcinogenesis and therefore it has been a target for cancer therapy. structurally diverse group of hdac inhibitors are known. the broadest class of hdac inhibito ... | 2009 | 20167479 |
| selsa, selenium analogs of saha as potent histone deacetylase inhibitors. | cancer treatment and therapy has moved from conventional chemotherapeutics to more mechanism-based targeted approach. disturbances in the balance of histone acetyltransferase (hat) and deacetylase (hdac) leads to a change in cell morphology, cell cycle, differentiation, and carcinogenesis. in particular, hdac plays an important role in carcinogenesis and therefore it has been a target for cancer therapy. structurally diverse group of hdac inhibitors are known. the broadest class of hdac inhibito ... | 2009 | 20167479 |
| 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 |
| thiol dioxygenases: unique families of cupin proteins. | proteins in the cupin superfamily have a wide range of biological functions in archaea, bacteria and eukaryotes. although proteins in the cupin superfamily show very low overall sequence similarity, they all contain two short but partially conserved cupin sequence motifs separated by a less conserved intermotif region that varies both in length and amino acid sequence. furthermore, these proteins all share a common architecture described as a six-stranded β-barrel core, and this canonical cupin ... | 2010 | 20195658 |
| thiol dioxygenases: unique families of cupin proteins. | proteins in the cupin superfamily have a wide range of biological functions in archaea, bacteria and eukaryotes. although proteins in the cupin superfamily show very low overall sequence similarity, they all contain two short but partially conserved cupin sequence motifs separated by a less conserved intermotif region that varies both in length and amino acid sequence. furthermore, these proteins all share a common architecture described as a six-stranded β-barrel core, and this canonical cupin ... | 2010 | 20195658 |
| 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 |