| phagocyte nadph oxidase, but not inducible nitric oxide synthase, is essential for early control of burkholderia cepacia and chromobacterium violaceum infection in mice. | reactive oxygen and nitrogen intermediates have critical, partially overlapping roles in host defense against a variety of pathogens. using mice deficient in generating phagocyte superoxide (p47(phox)(-/-)) and mice deficient in generating inducible nitric oxide synthase (inos(-/-)), we examined the roles of these reactive species in host defense against burkholderia cepacia and chromobacterium violaceum, organisms known to have unusual virulence in chronic granulomatous disease. intraperitoneal ... | 2003 | 12496167 |
| genetic diversity and spoilage potentials among pseudomonas spp. isolated from fluid milk products and dairy processing plants. | degradation of milk components through various enzymatic activities associated with the contamination of dairy products by pseudomonas spp. can reduce the shelf life of processed milk. reliable methods for differentiating among pseudomonas spp. strains are necessary to identify and eliminate specific sources of bacterial contamination from dairy processing systems. to that end, we assessed the genetic diversity and dairy product spoilage potentials among a total of 338 pseudomonas spp. isolates ... | 2003 | 12513987 |
| characteristics of massilia timonae and massilia timonae-like isolates from human patients, with an emended description of the species. | the description of massilia timonae, a nonfermentative aerobic gram-negative rod, was based on a single strain. a subsequent report of a second isolate has been recently published. phenotypic descriptions of these two strains were based primarily on commercial test kit results. we have identified three additional strains as m. timonae by 16s rrna sequence analysis and have characterized them phenotypically in parallel with the type strain of m. timonae, cip 105350, by conventional test methods. ... | 2003 | 12517847 |
| evaluation of microscan autoscan for identification of pseudomonas aeruginosa isolates from cystic fibrosis patients. | accurate identification of gram-negative bacilli from cystic fibrosis (cf) patients is essential. only 57% (108 of 189) of nonmucoid strains and 40% (24 of 60) of mucoid strains were definitively identified as pseudomonas aeruginosa with microscan autoscan. most common misidentifications were pseudomonas fluorescens-pseudomonas putida (i.e., the strain was either p. fluorescens or p. putida, but the system did not make the distinction and yielded the result p. fluorescens/putida) and alcaligenes ... | 2003 | 12517904 |
| quorum sensing in rhizobium sp. strain ngr234 regulates conjugal transfer (tra) gene expression and influences growth rate. | rhizobium sp. strain ngr234 forms symbiotic, nitrogen-fixing nodules on a wide range of legumes via functions largely encoded by the plasmid pngr234a. the pngr234a sequence revealed a region encoding plasmid replication (rep) and conjugal transfer (tra) functions similar to those encoded by the rep and tra genes from the tumor-inducing (ti) plasmids of agrobacterium tumefaciens, including homologues of the ti plasmid quorum-sensing regulators trai, trar, and tram. in a. tumefaciens, trai, a luxi ... | 2003 | 12533456 |
| detection of other microbial species by salmonella: expression of the sdia regulon. | salmonella, escherichia, and klebsiella do not encode any recognized type of n-acylhomoserine lactone (ahl) synthase, and consistent with this, they do not synthesize ahls under any conditions tested. however, they do encode an ahl receptor of the luxr family, named sdia. mudj fusions in four loci are known to respond to plasmid-encoded sdia in salmonella, but only the rck locus has been described. here we report the location and sequence analysis of the remaining three loci. the srg-6::mudj is ... | 2003 | 12562806 |
| quorum-sensing system and stationary-phase sigma factor (rpos) of the onion pathogen burkholderia cepacia genomovar i type strain, atcc 25416. | bacterial strains belonging to burkholderia cepacia can be human opportunistic pathogens, plant pathogens, and plant growth promoting and have remarkable catabolic activity. b. cepacia consists of several genomovars comprising what is now known as the b. cepacia complex. here we report the quorum-sensing system of a genomovar i onion rot type strain atcc 25416. quorum sensing is a cell-density-dependent regulatory response which involves the production of n-acyl homoserine lactone (hsl) signal m ... | 2003 | 12620866 |
| inactivation of gacs does not affect the competitiveness of pseudomonas chlororaphis in the arabidopsis thaliana rhizosphere. | quorum-sensing-controlled processes are considered to be important for the competitiveness of microorganisms in the rhizosphere. they affect cell-cell communication, biofilm formation, and antibiotic production, and the gacs-gaca two-component system plays a role as a key regulator. in spite of the importance of this system for the regulation of various processes, strains with a gac(-) phenotype are readily recovered from natural habitats. to analyze the influence of quorum sensing and the influ ... | 2003 | 12620875 |
| violacein and its beta-cyclodextrin complexes induce apoptosis and differentiation in hl60 cells. | violacein, a pigment isolated from chromobacterium violaceum, has been reported to have multiple biological activities including in vitro antitumor effects. certain anticancer agents are known to induce apoptosis in human tumor cell lines. in this work, our aim was to investigate the effectiveness of violacein/beta-cyclodextrin (beta-cd)-containing systems to produce lethal effects in the human promyelocytic leukemia cell line hl60. using the mtt tetrazolium reduction test, ic(50) for the inclus ... | 2003 | 12628314 |
| glucose-6-phosphate dehydrogenase deficiency, neutrophil dysfunction and chromobacterium violaceum sepsis. | | 1987 | 3681551 |
| automated identification systems and burkholderia pseudomallei. | | 2003 | 12682195 |
| evaluation of the vitek 2 id-gnb assay for identification of members of the family enterobacteriaceae and other nonenteric gram-negative bacilli and comparison with the vitek gni+ card. | we evaluated the vitek 2 id-gnb identification card (biomérieux, inc., durham, n.c.) for its ability to identify members of the family enterobacteriaceae and other gram-negative bacilli that are isolated in clinical microbiology laboratories. using 482 enteric stock cultures and 103 strains of oxidase-positive, gram-negative glucose-fermenting and nonfermenting bacilli that were maintained at -70 degrees c and passaged three times before use, we inoculated cards according to the manufacturer's d ... | 2003 | 12734254 |
| picosecond dynamics of a peptide from the acetylcholine receptor interacting with a neurotoxin probed by tailored tryptophan fluorescence. | a tryptophan analog, dehydro-n-acetyl-l-tryptophanamide (delta-nata), which is produced enzymatically via l-tryptophan 2',3'-oxidase from chromobacterium violaceum, is newly used for time-resolved fluorescence. the absorption and emission maxima of delta-nata at 332 and 417 nm, respectively, in 20% dimethylformamide-water are significantly shifted to the red with respect to those of tryptophan in water, permitting us to measure its fluorescence in the presence of tryptophan residues. we demonstr ... | 2003 | 12785053 |
| comparison of the in vitro activity of ciprofloxacin and 24 other antimicrobial agents against clinical strains of chromobacterium violaceum. | eleven clinical strains of chromobacterium violaceum were tested for their susceptibility to 25 antimicrobial agents. ciprofloxacin was the most active of the compounds tested although norfloxacin and pefloxacin were highly active. no resistance was detected to mezlocillin, piperacillin, apalcillin, imipenem, and aztreonam while a single strain was resistant to ticarcillin. among the cephalosporin/cephamycin group only cefotetan showed good in vitro activity. gentamicin was more active than amik ... | 1988 | 3168426 |
| fatal septicaemia caused by chromobacterium violaceum. | we report a case of chromobacterium violaceum septicaemia in a 10-year old boy admitted to hospital in september 2001, two weeks after he suffered a crush injury of the left foot. in spite of surgical debridement and antibiotics his condition worsened and he developed multiple liver and lung abscesses. he died one week after admission and a blood culture grew chromobacterium violaceum. | 2003 | 12795018 |
| necrotizing fasciitis due to vibrio alginolyticus in an immunocompetent patient. | we describe a patient with a history of asthma and remote use of steroids the development of necrotizing fascitis due to vibrio alginolyticus after an injury from a coral reef during bathing in the caribbean sea off colombia. the patient recovered with aggressive surgical debridement and antibiotics. | 2003 | 12843111 |
| chromobacterium violaceum bacteremia: a case report. | chromobacterium violaceum is confined in tropical and subtropical regions, which can cause life-threatening disease. it is the only chromobacterium species that is pathogenic to humans. because of its rarity, clinicians often do not appreciate its importance when it is isolated. we report a fulminate fatal case of c. violaceum bacteremia in a 20-year-old male taiwanese. the clinical manifestations were fever and abdominal pain, followed by shock and pulmonary septic embolism. emergent laparotomy ... | 2003 | 12886967 |
| the ti plasmid of agrobacterium tumefaciens harbors an attm-paralogous gene, aiib, also encoding n-acyl homoserine lactonase activity. | the agrobacterium tumefaciens c58 genome contains three putative n-acyl homoserine lactone (acyl-hsl) hydrolases, which are closely related to the lactonase aiia of bacillus. when expressed in escherichia coli, two of the putative acyl-hsl hydrolases, attm and aiib, conferred the ability to degrade acyl-hsls on the host. in erwinia strain 6276, the lactonases reduced the endogenous acyl-hsl level and the bacterial virulence in planta. | 2003 | 12902298 |
| novel bacteria degrading n-acylhomoserine lactones and their use as quenchers of quorum-sensing-regulated functions of plant-pathogenic bacteria. | bacteria degrading the quorum-sensing (qs) signal molecule n-hexanoylhomoserine lactone were isolated from a tobacco rhizosphere. twenty-five isolates degrading this homoserine lactone fell into six groups according to their genomic rep-pcr and rrs pcr-rflp profiles. representative strains from each group were identified as members of the genera pseudomonas, comamonas, variovorax and rhodococcus: all these isolates degraded n-acylhomoserine lactones other than the hexanoic acid derivative, albei ... | 2003 | 12904538 |
| bacterial chemistry-iii: preliminary studies on trypanosomal activities of chromobacterium violaceum products. | it has been found that the pigment-i from chromobacterium violaceum, 3-[1,2-dihydro5-(5-hydroxy-1h-indol-3-yl)-2-oxo-3h-pyrrol-3-yli diene] 1,3-dihydro-2h-indol-2-one, has trypanocide activity. the formylated derivatives, pigment-iii, immobilized 100% of the trypanosoma cruzi at a level of 46 microm after 48 h of interaction with a total growth inhibition in the same period. pigment-i exhibited low toxicity and a dna synthesis inhibition similar to that of nifurtimox, a known trypanocide compoun ... | 1989 | 2512826 |
| in situ activation of the quorum-sensing transcription factor trar by cognate and noncognate acyl-homoserine lactone ligands: kinetics and consequences. | conjugal transfer of ti plasmids of agrobacterium tumefaciens is controlled by a quorum-sensing system composed of the transcriptional activator trar and its acyl-homoserine lactone quormone n-(3-oxo-octanoyl)-l-homoserine lactone (3-oxo-c8-hsl). the population density dependence of quorum-sensing systems can often be circumvented by addition of the quormone to cultures at low cell numbers. however, the quorum-dependent activation of ti plasmid conjugal transfer exhibited a lag of almost 8 h whe ... | 2003 | 13129937 |
| outbreaks of disease in animals associated with chromobacterium violaceum. i. the disease in swine. | | 1954 | 13162910 |
| [isolation of chromobacterium violaceum from hepatic lesions seen in a monkey cercopithecus cephus; study and pathogenecity]. | | 1954 | 13218378 |
| [not available]. | | 1955 | 13329728 |
| 5-hydroxytryptophan formation and tryptophan metabolism in chromobacterium violaceum. | | 1956 | 13341050 |
| the isolation of d-glycero-d-galactoheptose and other sugar components from the specific polysaccharide of chromobacterium violaceum (bn). | | 1957 | 13459897 |
| the isolation of d-fucosamine from the specific polysaccharide of chromobacterium violaceum (nctc 7917). | | 1958 | 13607435 |
| production of hemolysis by chromobacterium violaceum. | | 1959 | 13626901 |
| nutritional requirements of chromobacterium violaceum. | | 1959 | 13630861 |
| accumulation of indole compounds in cultures of chromobacterium violaceum. | | 1961 | 13695636 |
| the extracellular polysaccharide of gelatinous strains of chromobacterium violaceum. | | 1960 | 13812063 |
| isolation of guanosine 2',3'-cyclic phosphate from chromobacterium violaceum. | | 1962 | 13898776 |
| divergent pathways of indole metabolism in chromobacterium violaceum. | | 1962 | 13987555 |
| intracellular nucleotides isolated from chromobacterium violaceum. | | 1962 | 13989398 |
| isolation of a new amino sugar from chromobacterium violaceum. | smith, e. j. (duke university, durham, n.c.), j. m. leatherwood, and r. w. wheat. isolation of a new amino sugar from chromobacterium violaceum. j. bacteriol. 84:1007-1010. 1962.-an investigation of the amino sugars and reducing compounds of a lipopolysaccharide of chromobacterium violaceum revealed the presence of a previously unreported cationic reducing compound. evidence indicates that the compound is a 6-deoxyhexosamine with an amino group at other than the c-2 position. | 1962 | 13989399 |
| studies on the cell wall of chromobacterium violaceum: the separation of lipopolysaccharide and mucopeptide by phenol extraction of whole cells. | | 1963 | 14000218 |
| characterization of a 4-amino-4:6-dideoxy aldohexose from chromobacterium violaceum. | | 1962 | 14000219 |
| extracellular accumulation of pyrroles in bacterial cultures. | aerobacter aerogenes, paracolobactrum aerogenoides, spirillum serpens, and gelatinous strains of chromobacterium violaceum produced an extracellular, ether-soluble, ehrlich-positive substance when grown in media prepared with gelatin hydrolysate. the substance has been tentatively identified as pyrrole-2-carboxylic acid. both hydroxy-l-proline and allo-d-hydroxyproline have been shown to be precursors of the material. gelatinous strains of chromobacterium violaceum, but not the other positive cu ... | 1963 | 14023126 |
| decomposition and binding action of a polysaccharide from chromobacterium violacium in soil. | martin, j. p. (university of california, riverside) and s. j. richards. decomposition and binding action of a polysaccharide from chromobacterium violaceum in soil. j. bacteriol. 85:1288-1294. 1963.-the decomposition rate and binding effect in soil of a polysaccharide from chromobacterium violaceum was compared with that of a variety of bacterial and plant polysaccharides and more complex organic residues. most of the polysaccharides tested decomposed more readily than mature plant residues and ... | 1963 | 14047219 |
| modification of host responses to bacterial endotoxins. i. specificity of pyrogenic tolerance and the role of hypersensitivity in pyrogenicity, lethality, and skin reactivity. | evidence is presented suggesting that the apparent non-specificity of pyrogenic tolerance observed with gram-negative bacterial endotoxins is due to related antigenic determinants associated with the macromolecular toxins. this is based on results obtained in rabbits from pyrogenic cross-tolerance tests with selected endotoxins. in these tests, purified endotoxins from escherichia coli (coo8) and chromobacterium violaceum (cv) gave results one might expect with non-reciprocal cross-reacting anti ... | 1963 | 14078002 |
| 6-hydroxytryptophan formation by chromobacterium violaceum. | | 1964 | 14206055 |
| factors influencing growth and polysaccharide formation by strains of chromobacterium violaceum. | corpe, william a. (columbia university, new york, n.y.). factors influencing growth and polysaccharide formation by strains of chromobacterium violaceum. j. bacteriol. 88:1433-1441. 1964.-gelatinous chromobacterium violaceum strains elaborate a fibrous exopolysaccharide that forms a matrix in which growing cells are embedded. stable, nongelatinous variants arising from gelatinous cultures were of two types: (i) those that had lost the ability to produce polysaccharide, and (ii) those that had lo ... | 1964 | 14234803 |
| cyanide formation by chromobacterium violaceum. | michaels, ruth (columbia university, new york, n.y.), and w. a. corpe. cyanide formation by chromobacterium violaceum. j. bacteriol. 89:106-112. 1965.-the formation of cyanide by a chromobacterium violaceum strain was studied with growing cultures and with nonproliferating cells grown in complex and chemically defined media. most of the cyanide was produced during the log-phase growth of the organism, and accumulated in the culture supernatant fluid. a synergistic effect of glycine and methionin ... | 1965 | 14255648 |
| formation of 5-hydroxytryptophan from tryptophan by chromobacterium violaceum. | | 1955 | 14394084 |
| the complete genome sequence of chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability. | chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) approximately 500 orfs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) widespread utilization of quorum sensing for control of inducible systems, all of ... | 2003 | 14500782 |
| production of acylated homoserine lactones by different serotypes of vibrio anguillarum both in culture and during infection of rainbow trout. | onehundred and forty-eight out of onehundred and fifty strains of vibrio anguillarum isolated from vibriosis in danish marine aquaculture produced bacterial communication signals, acylated homoserine lactones, eliciting a response in the agrobacterium tumefaciens (pzlr4) monitoring system. one strain, a serotype o4, induced a strong response in the chromobacterium violaceum (cv026) monitoring system. profiles of ahls determined by tlc separation revealed the presence of at least four ahls and a ... | 2003 | 14529176 |
| use of 16s rrna gene sequencing for rapid identification and differentiation of burkholderia pseudomallei and b. mallei. | burkholderia pseudomallei and b. mallei, the causative agents of melioidosis and glanders, respectively, are designated category b biothreat agents. current methods for identifying these organisms rely on their phenotypic characteristics and an extensive set of biochemical reactions. we evaluated the use of 16s rrna gene sequencing to rapidly identify these two species and differentiate them from each other as well as from closely related species and genera such as pandoraea spp., ralstonia spp. ... | 2003 | 14532197 |
| cytotoxicity and potential antiviral evaluation of violacein produced by chromobacterium violaceum. | natural products are an inexhaustible source of compounds with promising pharmacological activities including antiviral action. violacein, the major pigment produced by chromobacterium violaceum, has been shown to have antibiotic, antitumoral and anti-trypanosoma cruzi activities. the goal of the present work was to evaluate the cytotoxicity of violacein and also its potential antiviral properties. the cytotoxicity of violacein was investigated by three methods: cell morphology evaluation by inv ... | 2003 | 14595466 |
| beta-lactamase activity in chromobacterium violaceum. | a strain of chromobacterium violaceum isolated from a fatally infected patient was found to produce a beta-lactamase. when the organism was grown in drug-free medium, beta-lactamase activity was barely detectable, but when it was grown in the presence of penicillin g, a much larger amount of activity was produced. the beta lactamase was active primarily against cephalosporins; it was sensitive to inhibition by cloxacillin but resistant to p-chloromercuribenzoate. thus this enzyme closely resembl ... | 1976 | 977998 |
| evaluation of two miniaturized systems, microscan w/a and bbl crystal e/nf, for identification of clinical isolates of aeromonas spp. | fifty-two clinical strains and 22 type and reference aeromonas strains, previously genetically characterized by 16s rrna gene restriction fragment length polymorphism, were identified in parallel with the microscan walk/away and bbl crystal enteric/nonfermenter systems. the former identified only 14.8% of the isolates correctly, and the latter identified only 20.3% correctly, which indicates that neither of these systems is useful for this purpose. | 2003 | 14662969 |
| quorum sensing in nitrogen-fixing rhizobia. | members of the rhizobia are distinguished for their ability to establish a nitrogen-fixing symbiosis with leguminous plants. while many details of this relationship remain a mystery, much effort has gone into elucidating the mechanisms governing bacterium-host recognition and the events leading to symbiosis. several signal molecules, including plant-produced flavonoids and bacterially produced nodulation factors and exopolysaccharides, are known to function in the molecular conversation between ... | 2003 | 14665677 |
| chlamydomonas reinhardtii secretes compounds that mimic bacterial signals and interfere with quorum sensing regulation in bacteria. | the unicellular soil-freshwater alga chlamydomonas reinhardtii was found to secrete substances that mimic the activity of the n-acyl-l-homoserine lactone (ahl) signal molecules used by many bacteria for quorum sensing regulation of gene expression. more than a dozen chemically separable but unidentified substances capable of specifically stimulating the lasr or cepr but not the luxr, ahyr, or cvir ahl bacterial quorum sensing reporter strains were detected in ethyl acetate extracts of c. reinhar ... | 2004 | 14671013 |
| pathogenicity of nonpigmented cultures of chromobacterium violaceum. | nonpigmented cultures of chromobacterium violaceum have been found to be similar to pigmented cultures in their virulence for mice and the pathology of their infections. clinicians and microbiologists should be prepared to consider nonpigmented c. violaceum in their differential diagnoses of infections caused by gram-negative bacteria. the laboratorian who is not aware of this possibility is likely to erroneously identify nonpigmented strains of c. violaceum as members of closely associated gene ... | 1977 | 874071 |
| osteomyelitis associated with chromobacterium violaceum sepsis. a case report. | | 1979 | 479248 |
| the respiratory system of chromobacterium violaceum grown under conditions of high and low cyanide evolution. | the particulate fraction of disrupted chromobacterium violaceum grown under cyanide-evolving conditions was unable to oxidize ascorbate plus n,n,n',n'-tetra-methyl-p-phenylenediamine (tmpd), but oxidized nadh and succinate by a linear respiratory pathway which was very resistant to inhibition by cyanide. when the bacteria were grown under conditions where little cyanide evolution occurred, particulate fractions developed the ability to oxidize ascorbate-tmpd by a pathway highly sensitive to cyan ... | 1975 | 172598 |
| a new method of synthesis and antibacterial activity evaluation of piper amides. | several natural piper amides and their mimics were synthesized by developing a new strategy of amide formation. the piper amides were tested against both gram +ve and gram -ve bacterial strains and found that they are particularly more active against staphylococcus aureus and chromobacterium violaceum strains. | 2004 | 14974622 |
| quorum sensing in the dimorphic fungus candida albicans is mediated by farnesol. | the inoculum size effect in the dimorphic fungus candida albicans results from production of an extracellular quorum-sensing molecule (qsm). this molecule prevents mycelial development in both a growth morphology assay and a differentiation assay using three chemically distinct triggers for germ tube formation (gtf): l-proline, n-acetylglucosamine, and serum (either pig or fetal bovine). in all cases, the presence of qsm prevents the yeast-to-mycelium conversion, resulting in actively budding ye ... | 2001 | 11425711 |
| novel pathway of salicylate degradation by streptomyces sp. strain wa46. | a novel salicylate-degrading streptomyces sp., strain wa46, was identified by uv fluorescence on solid minimal medium containing salicylate; trace amounts of gentisate were detected by high-pressure liquid chromatography when strain wa46 was grown with salicylate. pcr amplification of wa46 dna with degenerate primers for gentisate 1,2-dioxygenase (gdo) genes produced an amplicon of the expected size. sequential pcr with nested gdo primers was then used to identify a salicylate degradation gene c ... | 2004 | 15006746 |
| biogenic production of cyanide and its application to gold recovery. | chromobacterium violaceum is a cyanogenic (cyanide-producing) microorganism. cyanide is used on an industrial scale to complex and recover gold from ores or concentrates of ores bearing the precious metal. a potentially useful approach in gold mining operations could be to produce cyanide biologically in relatively small quantities at the ore surface. in this study, c. violaceum grown in nutrient broth formed a biofilm and could complex and solubilize 100% of the gold on glass test slides within ... | 2001 | 11420652 |
| production of n-acylhomoserine lactone signal molecules by gram-negative soil-borne and plant-associated bacteria. | quorum-sensing control mediated by n-acylhomoserine lactone (ahl) signal molecules has been established as a key feature in the regulation of various metabolic traits in many bacteria. approximately 300 strains representing 6 genera and 18 species of soil-borne and plant-associated gram-negative bacteria isolated in various regions of the former ussr using two reporter systems were screened for ahl production. the production was observed in 17.5% of the screened bacterial strains. positive respo ... | 2003 | 15058194 |
| comparative genomics of gene-family size in closely related bacteria. | the wealth of genomic data in bacteria is helping microbiologists understand the factors involved in gene innovation. among these, the expansion and reduction of gene families appears to have a fundamental role in this, but the factors influencing gene family size are unclear. | 2004 | 15059260 |
| unraveling the function of the rhodospirillum rubrum activator of polyhydroxybutyrate (phb) degradation: the activator is a phb-granule-bound protein (phasin). | efficient hydrolysis of native poly(3-hydroxybutyrate) (nphb) granules in vitro by soluble phb depolymerase of rhodospirillum rubrum requires pretreatment of nphb with an activator compound present in r. rubrum cells (j. m. merrick and m. doudoroff, j. bacteriol. 88:60-71, 1964). edman sequencing of the purified activator (17.4 kda; matrix-assisted laser desorption ionization-time of flight mass spectrometry) revealed identity to a hypothetical protein deduced from a partially sequenced r. rubru ... | 2004 | 15060050 |
| methods for detecting acylated homoserine lactones produced by gram-negative bacteria and their application in studies of ahl-production kinetics. | in the process of evaluating the role of acylated homoserine lactones (ahls) in food-spoiling gram-negative bacteria, we have combined a range of bacterial ahl monitor systems to determine the ahl-profile and the kinetics of ahl-production. ahl production from 148 strains of enterobacteriaceae isolated from foods was tested using escherichia coli psb403 (luxr), agrobacterium tumefaciens a136 (trar) and both induction and inhibition of chromobacterium violaceum cv026 (cvir). all strains except on ... | 2001 | 11240047 |
| transcriptional control of the hydrogen cyanide biosynthetic genes hcnabc by the anaerobic regulator anr and the quorum-sensing regulators lasr and rhlr in pseudomonas aeruginosa. | virulence factors of pseudomonas aeruginosa include hydrogen cyanide (hcn). this secondary metabolite is maximally produced at low oxygen tension and high cell densities during the transition from exponential to stationary growth phase. the hcnabc genes encoding hcn synthase were identified on a genomic fragment complementing an hcn-deficient mutant of p. aeruginosa pao1. the hcna promoter was found to be controlled by the fnr-like anaerobic regulator anr and by the quorum-sensing regulators las ... | 2000 | 11092854 |
| structure of spa15, a type iii secretion chaperone from shigella flexneri with broad specificity. | type iii secretion (tts) systems are used by many gram-negative pathogens to inject virulence proteins into the cells of their hosts. several of these virulence effectors require tts chaperones that maintain them in a secretion-competent state. whereas most chaperones bind only one effector, spa15 from the human pathogen shigella flexneri and homologous chaperones bind several seemingly unrelated effectors, and were proposed to form a special subgroup. its 1.8 a crystal structure confirms this s ... | 2004 | 15088068 |
| closure of rrna related gaps in the chromobacterium violaceum genome with the pcr-assisted contig extension (pace) protocol. | in the finishing phase of the chromobacterium violaceum genome project, the shotgun sequences were assembled into 57 contigs that were then organized into 19 scaffolds, using the information from shotgun and cosmid clones. among the 38 ends resulting from the 19 scaffolds, 10 ended with sequences corresponding to rrna genes (seven ended with the 5s rrna gene and three ended with the 16s rrna gene). the 28 non-ribosomal ends were extended using the pcr-assisted contig extension (pace) methodology ... | 2004 | 15100987 |
| gene expression in chromobacterium violaceum. | the repertoire of 4,431 open reading frames (orfs), eight rrna operons and 98 trna genes of chromobacterium violaceum must be expressed in a regulated manner for successful adaptation to a wide variety of environmental conditions. to accomplish this feat, the organism relies on protein machineries involved in transcription, rna processing and translation. analysis of the c. violaceum genome showed that transcription initiation, elongation and termination are performed by the five well-known rna ... | 2004 | 15100988 |
| bacteriophages and insertion sequences of chromobacterium violaceum atcc 12472. | a fluid genome is a great advantage to prokaryotes, enabling quick adaptation to various types of ecological niches and to diverse environmental selective pressures. a substantial portion of these sudden changes is mediated by lateral gene transfer (lgt), through genetic recombination mechanisms, such as transformation, conjugation and transduction. the recent sequencing of several organisms has offered a new approach to the study of lgt, using comparison and analysis of nucleotide sequences dis ... | 2004 | 15100989 |
| genetic analysis of violacein biosynthesis by chromobacterium violaceum. | chromobacterium violaceum presents a distinctive phenotypic characteristic, the production of a deep violet pigment named violacein. although the physiological function of this pigment is not well understood, the sequencing of the genome of this bacterium has given some insight into the mechanisms and control of violacein production. it was found that erythrose-4-phosphate (e4p), a precursor to aromatic amino acid biosynthesis, is produced by the non-oxidative portion of the hexose monophosphate ... | 2004 | 15100990 |
| chemotaxis and flagellar genes of chromobacterium violaceum. | the availability of the complete genome of the gram-negative beta-proteobacterium chromobacterium violaceum has increasingly impacted our understanding of this microorganism. this review focuses on the genomic organization and structural analysis of the deduced proteins of the chemosensory adaptation system of c. violaceum. c. violaceum has multiple homologues of most chemotaxis genes, organized mostly in clusters in the bacterial genome. we found at least 67 genes, distributed in 10 gene cluste ... | 2004 | 15100991 |
| tolerance to stress and environmental adaptability of chromobacterium violaceum. | chromobacterium violaceum is a gram-negative bacterium, abundant in a variety of ecosystems in tropical and subtropical regions, including the water and borders of the negro river, a major component of the amazon basin. as a free-living microorganism, c. violaceum is exposed to a series of variable conditions, such as different sources and abundance of nutrients, changes in temperature and ph, toxic compounds and uv rays. these variations, and the wide range of environments, require great adapta ... | 2004 | 15100992 |
| transport genes of chromobacterium violaceum: an overview. | the complete genome sequence of the free-living bacterium chromobacterium violaceum has been determined by a consortium of laboratories in brazil. almost 500 open reading frames (orfs) coding for transport-related membrane proteins were identified in c. violaceum, which represents 11% of all genes found. the main class of transporter proteins is the primary active transporters (212 orfs), followed by electrochemical potential-driven transporters (154 orfs) and channels/pores (62 orfs). other cla ... | 2004 | 15100993 |
| drug resistance in chromobacterium violaceum. | chromobacterium violaceum is a free-living bacterium commonly found in aquatic habitats of tropical and subtropical regions of the world. this bacterium is able to produce a large variety of products of biotechnological and pharmacological use. although c. violaceum is considered to be non-pathogenic, some cases of severe infections in humans and other animals have been reported. genomic data on the type strain atcc 12472(t) has provided a comprehensive basis for detailed studies of pathogenicit ... | 2004 | 15100994 |
| chromobacterium violaceum genome: molecular mechanisms associated with pathogenicity. | chromobacterium violaceum is a versatile, gram-negative beta-protebacterium that grows in a variety of ecosystems in tropical and subtropical areas, such as the water and borders of the negro river, in the amazon region of brazil. although it is a saprophyte and is generally considered non-pathogenic, sporadic cases of human infection have been described, mainly in young children and in immunodeficient individuals. although rare, infections with c. violaceum are characterized by rapid disseminat ... | 2004 | 15100995 |
| energetic metabolism of chromobacterium violaceum. | chromobacterium violaceum is a free-living microorganism, normally exposed to diverse environmental conditions; it has a versatile energy-generating metabolism. this bacterium is capable of exploiting a wide range of energy resources by using appropriate oxidases and reductases. this allows c. violaceum to live in both aerobic and anaerobic conditions. in aerobic conditions, c. violaceum is able to grow in a minimal medium with simple sugars, such as glucose, fructose, galactose, and ribose; bot ... | 2004 | 15100996 |
| dna repair in chromobacterium violaceum. | chromobacterium violaceum is a gram-negative beta-proteobacterium that inhabits a variety of ecosystems in tropical and subtropical regions, including the water and banks of the negro river in the brazilian amazon. this bacterium has been the subject of extensive study over the last three decades, due to its biotechnological properties, including the characteristic violacein pigment, which has antimicrobial and anti-tumoral activities. c. violaceum promotes the solubilization of gold in a mercur ... | 2004 | 15100997 |
| identification of chromobacterium violaceum genes with potential biotechnological application in environmental detoxification. | chromobacterium violaceum is a gram-negative bacterium found in a wide variety of tropical and subtropical ecosystems. the complete genome sequence of c. violaceum atcc 12472 is now available, and it has considerable biotechnological potential for various applications, such as environmental detoxification, as well as medical and agricultural use. we examined the biotechnological potential of c. violaceum for environmental detoxification. three operons, comprising the ars operon, involved in arse ... | 2004 | 15100998 |
| molecular mechanism of violacein-mediated human leukemia cell death. | violacein, a pigment isolated from chromobacterium violaceum in the amazon river, presents diverse biologic properties and attracts interest as a consequence of its antileukemic activity. elucidation of the molecular mechanism mediating this activity will provide further relevant information for understanding its effects on the cellular physiology of untransformed cells and for considering its possible clinical application. here, we show that violacein causes apoptosis in hl60 leukemic cells but ... | 2004 | 15130948 |
| identification of the catalytic motif of the microbial ribosome inactivating cytotoxin colicin e3. | colicin e3 is a cytotoxic ribonuclease that specifically cleaves 16s rrna at the ribosomal a-site to abolish protein synthesis in sensitive escherichia coli cells. we have performed extensive mutagenesis of the 96-residue colicin e3 cytotoxic domain (e3 rrnase), assayed mutant colicins for in vivo cytotoxicity, and tested the corresponding e3 rrnase domains for their ability to inactivate ribosome function in vitro. from 21 alanine mutants, we identified five positions where mutation resulted in ... | 2004 | 15133158 |
| the ett2 gene cluster, encoding a second type iii secretion system from escherichia coli, is present in the majority of strains but has undergone widespread mutational attrition. | ett2 is a second cryptic type iii secretion system in escherichia coli which was first discovered through the analysis of genome sequences of enterohemorrhagic e. coli o157:h7. comparative analyses of escherichia and shigella genome sequences revealed that the ett2 gene cluster is larger than was previously thought, encompassing homologues of genes from the spi-1, spi-2, and spi-3 salmonella pathogenicity islands. ett2-associated genes, including regulators and chaperones, were found at the same ... | 2004 | 15150243 |
| burkholderia cenocepacia phage bcepmu and a family of mu-like phages encoding potential pathogenesis factors. | we have isolated bcepmu, a mu-like bacteriophage whose host range includes human pathogenic burkholderia cenocepacia (formally b. cepacia genomovar iii) isolates, and determined its complete 36748 bp genomic sequence. like enteric bacteriophage mu, the bcepmu genomic dna is flanked by variable host sequences, a result of transposon-mediated replication. the bcepmu genome encodes 53 proteins, including capsid assembly components related to those of mu, and tail sheath and tube proteins related to ... | 2004 | 15184022 |
| biofilm development and cell death in the marine bacterium pseudoalteromonas tunicata. | the newly described green-pigmented bacterium pseudoalteromonas tunicata (d2) produces target-specific inhibitory compounds against bacteria, algae, fungi, and invertebrate larvae and is frequently found in association with living surfaces in the marine environment. as part of our studies on the ecology of p. tunicata and its interaction with marine surfaces, we examined the ability of p. tunicata to form biofilms under continuous culture conditions within the laboratory. p. tunicata biofilms ex ... | 2004 | 15184116 |
| use of sinorhizobium meliloti as an indicator for specific detection of long-chain n-acyl homoserine lactones. | population-density-dependent gene expression in gram-negative bacteria involves the production of signal molecules characterized as n-acyl homoserine lactones (ahls). the synthesis of ahls by numerous microorganisms has been identified by using biosensor strains based on the agrobacterium tumefaciens and chromobacterium violaceum quorum-sensing systems. the symbiotic nitrogen-fixing bacterium sinorhizobium meliloti is rapidly becoming a model organism for the study of quorum sensing. this organi ... | 2004 | 15184178 |
| displacements of prohead protease genes in the late operons of double-stranded-dna bacteriophages. | most of the known prohead maturation proteases in double-stranded-dna bacteriophages are shown, by computational methods, to fall into two evolutionarily independent clans of serine proteases, herpesvirus assemblin-like and clpp-like. phylogenetic analysis suggests that these two types of phage prohead protease genes displaced each other multiple times while preserving their exact location within the late operons of the phage genomes. | 2004 | 15205439 |
| identification of burkholderia cenocepacia genes required for bacterial survival in vivo. | burkholderia cenocepacia (formerly burkholderia cepacia complex genomovar iii) causes chronic lung infections in patients with cystic fibrosis. in this work, we used a modified signature-tagged mutagenesis (stm) strategy for the isolation of b. cenocepacia mutants that cannot survive in vivo. thirty-seven specialized plasposons, each carrying a unique oligonucleotide tag signature, were constructed and used to examine the survival of 2,627 b. cenocepacia transposon mutants, arranged in pools of ... | 2004 | 15213146 |
| effects of natural and chemically synthesized furanones on quorum sensing in chromobacterium violaceum. | cell to cell signaling systems in gram-negative bacteria rely on small diffusible molecules such as the n-acylhomoserine lactones (ahl). these compounds are involved in the production of antibiotics, exoenzymes, virulence factors and biofilm formation. they belong to the class of furanone derivatives which are frequently found in nature as pheromones, flavor compounds or secondary metabolites. to obtain more information on the relation between molecular structure and quorum sensing, we tested a ... | 2004 | 15233843 |
| pretreatment with dna-damaging agents permits selective killing of checkpoint-deficient cells by microtubule-active drugs. | cell-cycle checkpoint mechanisms, including the p53- and p21-dependent g(2) arrest that follows dna damage, are often lost during tumorigenesis. we have exploited the ability of dna-damaging drugs to elicit this checkpoint, and we show here that such treatment allows microtubule drugs, which cause cell death secondary to mitotic arrest, to kill checkpoint-deficient tumor cells while sparing checkpoint-competent cells. low doses of the dna-damaging drug doxorubicin cause predominantly g(2) arrest ... | 2000 | 10683383 |
| identification of a bifunctional enzyme mnmc involved in the biosynthesis of a hypermodified uridine in the wobble position of trna. | the gene encoding the bifunctional enzyme mnmc that catalyzes the two last steps in the biosynthesis of 5-methylaminomethyl-2-thiouridine (mnm5s2u) in trna has been previously mapped at about 50 min on the escherichia coli k12 chromosome, but to date the identity of the corresponding enzyme has not been correlated with any of the known open reading frames (orfs). using the protein fold-recognition approach, we predicted that the 74-kda product of the yfck orf located at 52.6 min and annotated as ... | 2004 | 15247431 |
| where does bacterial replication start? rules for predicting the oric region. | three methods, based on dna asymmetry, the distribution of dnaa boxes and dnaa gene location, were applied to identify the putative replication origins in 120 chromosomes. the chromosomes were classified according to the agreement of these methods and the applicability of these methods was evaluated. dna asymmetry is the most universal method of putative oric identification in bacterial chromosomes, but it should be applied together with other methods to achieve better prediction. the three meth ... | 2004 | 15258248 |
| the global regulator genes from biocontrol strain serratia plymuthica ic1270: cloning, sequencing, and functional studies. | the biocontrol activity of various fluorescent pseudomonads towards plant-pathogenic fungi is dependent upon the gaca/gacs-type two-component system of global regulators and the rpos transcription sigma factor. in particular, these components are required for the production of antifungal antibiotics and exoenzymes. to investigate the effects of these global regulators on the expression of biocontrol factors by plant-associated bacteria other than pseudomonas spp., gaca/gacs and rpos homologues w ... | 2004 | 15262936 |
| a simple screening protocol for the identification of quorum signal antagonists. | quorum sensing (qs) is a mechanism by which diverse microorganisms can control specific processes in response to population density. a relatively well-known form of qs among proteobacteria involves production and subsequent response to acylated homoserine lactones (ahls). quorum sensing inhibition (qsi), targeting ahl-dependent signaling, has been reported as a strategy for the control of biofilm formation used by several marine organisms. we developed a simple soft agar overlay protocol, based ... | 2004 | 15279939 |
| different patterns of evolution for duplicated dna repair genes in bacteria of the xanthomonadales group. | dna repair genes encode proteins that protect organisms against genetic damage generated by environmental agents and by-products of cell metabolism. the importance of these genes in life maintenance is supported by their high conservation, and the presence of duplications of such genes may be easily traced, especially in prokaryotic genomes. | 2004 | 15333143 |
| flow microcalorimetric studies of phenol and its chlorinated derivatives and a theoretical evaluation of their possible inhibition mode on chromobacterium violaceum respiration. | the general belief that chemical structure determines the biological effect of drugs has led to several techniques to establish structure-activity relationships (sar) that is useful in the development of more active compounds. predicting toxic effects based on sar, one can obtain toxicological data with a low cost-benefit ratio. chlorophenols that represent a class of toxic agents frequently used in industrial processes are not satisfactorily described in the literature in relation to their toxi ... | 2004 | 15336391 |
| in search of rnase p rna from microbial genomes. | a simple procedure has been developed to quickly retrieve and validate the dna sequence encoding the rna subunit of ribonuclease p (rnase p rna) from microbial genomes. rnase p rna sequences were identified from 94% of bacterial and archaeal complete genomes where previously no rnase p rna was annotated. a sequence was found in camelpox virus, highly conserved in all orthopoxviruses (including smallpox virus), which could fold into a putative rnase p rna in terms of conserved primary features an ... | 2004 | 15337843 |
| in vivo phosphorylation of partner switching regulators correlates with stress transmission in the environmental signaling pathway of bacillus subtilis. | exposure of bacteria to diverse growth-limiting stresses induces the synthesis of a common set of proteins which provide broad protection against future, potentially lethal stresses. among bacillus subtilis and its relatives, this general stress response is controlled by the sigmab transcription factor. signals of environmental and energy stress activate sigmab through a multicomponent network that functions via a partner switching mechanism, in which protein-protein interactions are governed by ... | 2004 | 15342582 |
| quorum sensing-dependent regulation and blockade of exoprotease production in aeromonas hydrophila. | in aeromonas hydrophila, the ahyi gene encodes a protein responsible for the synthesis of the quorum sensing signal n-butanoyl-l-homoserine lactone (c4-hsl). inactivation of the ahyi gene on the a. hydrophila chromosome abolishes c4-hsl production. the exoprotease activity of a. hydrophila consists of both serine protease and metalloprotease activities; in the ahyi-negative strain, both are substantially reduced but can be restored by the addition of exogenous c4-hsl. in contrast, mutation of th ... | 1999 | 10496895 |
| characterization of pseudomonas aeruginosa enoyl-acyl carrier protein reductase (fabi): a target for the antimicrobial triclosan and its role in acylated homoserine lactone synthesis. | the pseudomonas aeruginosa fabi structural gene, encoding enoyl-acyl carrier protein (acp) reductase, was cloned and sequenced. nucleotide sequence analysis revealed that fabi is probably the last gene in a transcriptional unit that includes a gene encoding an atp-binding protein of an abc transporter of unknown function. the fabi protein was similar in size and primary sequence to other bacterial enoyl-acp reductases, and it contained signature motifs for the fad-dependent pyridine nucleotide r ... | 1999 | 10464225 |
| [violacein: a molecule of biological interest originating from the soil-borne bacterium chromobacterium violaceum]. | soil micro-organisms have evolved functions that allow them to withstand the strong competition for survival that characterizes most of their habitats. the production of antibiotic or antifungal compounds is one of these mechanisms. the relevant molecules often exhibit valuable therapeutic properties. | 2004 | 15363621 |
| complete genomic sequence of bacteriophage b3, a mu-like phage of pseudomonas aeruginosa. | bacteriophage b3 is a transposable phage of pseudomonas aeruginosa. in this report, we present the complete dna sequence and annotation of the b3 genome. dna sequence analysis revealed that the b3 genome is 38,439 bp long with a g+c content of 63.3%. the genome contains 59 proposed open reading frames (orfs) organized into at least three operons. of these orfs, the predicted proteins from 41 orfs (68%) display significant similarity to other phage or bacterial proteins. many of the predicted b3 ... | 2004 | 15375138 |
| metal solubilization from metal-containing solid materials by cyanogenic chromobacterium violaceum. | different cyanogenic bacterial strains (chromobacterium violaceum, pseudomonas fluorescens, bacillus megaterium) were cultivated under cyanide-forming conditions in the presence of metal-containing solids such as nickel powder or electronic scrap. all microorganisms were able to form water-soluble metal cyanides, however, with different efficiencies. c. violaceum was able to mobilize nickel as tetracyanonickelate [ni(cn)4(2-)] from fine-grained nickel powder. gold was microbially solubilized as ... | 2004 | 15380664 |