Publications

characteristics and biotechnological applications of microbial cholesterol oxidases.	microbial cholesterol oxidase is an enzyme of great commercial value, widely employed by laboratories routinely devoted to the determination of cholesterol concentrations in serum, other clinical samples, and food. in addition, the enzyme has potential applications as a biocatalyst which can be used as an insecticide and for the bioconversion of a number of sterols and non-steroidal alcohols. the enzyme has several biological roles, which are implicated in the cholesterol metabolism, the bacteri ...	2009	19495743
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
distribution of n-acylhomoserine lactone-producing fluorescent pseudomonads in the phyllosphere and rhizosphere of potato (solanum tuberosum l.).	four hundred and fifty nine isolates of fluorescent pseudomonads were obtained from the leaves and roots of potato plants. of these, 20 leaf isolates and 28 root isolates induced violacein production in two n-acylhomoserine lactone (ahl)-reporter strains-chromobacterium violaceum cv026 and vir24. vir24 is a new reporter strain for long n-acyl-chain-homoserine lactones, which can not be detected by cv026. thin-layer chromatography revealed that the isolates produced multiple ahl molecules. we com ...	2009	21566390
computational analysis suggests that virulence of chromobacterium violaceum might be linked to biofilm formation and poly-nag biosynthesis.	groups of genes that produce exopolysaccharide with a n-acetyl-d-glucosamine monomer are in the genome of several pathogenic bacteria. chromobacterium violaceum, an opportunistic pathogen, has the operon hmshfr-cv2940, whose proteins can synthesize such polysaccharide. in this work, multiple alignments among proteins from bacteria that synthesize such polysaccharide were used to verify the existence of amino acids that might be critical for pathogen activity. three-dimensional models were genera ...	2009	21637531
culturable heterotrophic bacteria in seawater and mytilus galloprovincialis from a mediterranean area (northern ionian sea-italy).	although mar piccolo of taranto (ionian sea, italy) is one of the most important mytilus galloprovincialis farming areas, data concerning the natural bacterial microbiota of these mussels and their surrounding environment are still scant. this study was carried out seasonally, throughout a year, to determine culturable heterotrophic bacteria both in the water and mussels samples collected at three sampling sites in the northern ionian sea: s. vito, lido gandoli and lido silvana. culturable heter ...	2009	18301997
secondary metabolites produced by the marine bacterium halobacillus salinus that inhibit quorum sensing-controlled phenotypes in gram-negative bacteria.	certain bacteria use cell-to-cell chemical communication to coordinate community-wide phenotypic expression, including swarming motility, antibiotic biosynthesis, and biofilm production. here we present a marine gram-positive bacterium that secretes secondary metabolites capable of quenching quorum sensing-controlled behaviors in several gram-negative reporter strains. isolate c42, a halobacillus salinus strain obtained from a sea grass sample, inhibits bioluminescence production by vibrio harve ...	2009	19060172
septicemia in a neonatal calf associated with chromobacterium violaceum.	chromobacterium violaceum infections are highly fatal and rarely reported in domestic animals. this report describes a fatal case of c. violaceum septicemia in a 7-day-old female beef calf. the calf had necrosuppurative omphalophlebitis, necrotizing interstitial pneumonia, necrosuppurative hepatitis and splenitis, anterior uveitis with hypopyon, suppurative polyarthritis, and disseminated hemorrhagic meningitis with multifocal necrotizing encephalitis. histologically, clusters of gram-negative b ...	2009	19112118
enhanced production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer with manipulated variables and its properties.	cupriavidus sp. usmaa1020, a local isolate was able to biosynthesis poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [p(3hb-co-4hb)] copolymer with various 4hb precursors as the sole carbon source. manipulation of the culture conditions such as cell concentration, phosphate ratio and culture aeration significantly affected the synthesis of p(3hb-co-4hb) copolymer and 4hb composition. p(3hb-co-4hb) copolymer with 4hb compositions ranging from 23 to 75 mol% 4hb with various mechanical and thermal prop ...	2009	19189144
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
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
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
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
comparative metagenomics of daphnia symbionts.	shotgun sequences of dna extracts from whole organisms allow a comprehensive assessment of possible symbionts. the current project makes use of four shotgun datasets from three species of the planktonic freshwater crustaceans daphnia: one dataset from clones of d. pulex and d. pulicaria and two datasets from one clone of d. magna. we analyzed these datasets with three aims: first, we search for bacterial symbionts, which are present in all three species. second, we search for evidence for cyanob ...	2009	19383155
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
chromobacterium violaceum infection in a provincial hospital in sri lanka.		2008	19189802
rapid hydrolysis of quorum-sensing molecules in the gut of lepidopteran larvae.	microorganisms compete for nutrients and living space in the gut of plant-feeding insect larvae, such as spodoptera spp. their physiological activities and their organization are generally controlled or synchronised by "autoinducers", such as n-acylhomoserinelactones (ahls). due to the strongly alkaline milieu in the insect gut, the lactone ring of ahls is rapidly and spontaneously opened. further degradation to the inactive components homoserine and the acyl moiety is then achieved by a microbi ...	2008	18642255
inhibition of bacterial quorum sensing-regulated behaviors by tremella fuciformis extract.	quorum sensing (qs), or the control of gene expression in response to cell density, is used by both gram-negative and gram-positive bacteria to regulate a variety of physiological functions. increasing evidence implies that certain eukaryotes produce qs-inhibitory compounds. in this work, we tested tremella fuciformis for their ability to inhibit qs-regulated behaviors. t. fuciformis fruiting bodies were dried and extracted using 75% (v/v) aqueous methanol. the crude extract was redissolved in a ...	2008	18661179
antibacterial activity of halogenated sesquiterpenes from malaysian laurencia spp.	during our studies on malaysian laurencia species, brominated metabolites, tiomanene, acetylmajapolene b, and acetylmajapolene a were isolated from an unrecorded species collected at pulau tioman, pahang along with known majapolene b and majapolene a. acetylmajapolene a was a mixture of diastereomers as in the case of majapolene a. tiomanene may be a plausible precursor for acetylmajapolenes b and a. in addition, three known halogenated sesquiterpenes and two known halogenated c(15) acetogenins ...	2008	18718619
polyhydroxyalkanoate (pha) production using waste vegetable oil by pseudomonas sp. strain dr2.	to produce polyhydroxyalkanoate (pha) from inexpensive substrates by bacteria, vegetable-oil-degrading bacteria were isolated from a rice field using enrichment cultivation. the isolated pseudomonas sp. strain dr2 showed clear orange or red spots of accumulated pha granules when grown on phosphate and nitrogen limited medium containing vegetable oil as the sole carbon source and stained with nile blue a. up to 37.34% (w/w) of intracellular pha was produced from corn oil, which consisted of three ...	2008	18756101
fatal wound infection caused by chromobacterium violaceum in ho chi minh city, vietnam.	chromobacterium violaceum is a proteobacterium found in soil and water in tropical regions which rarely causes infection in humans. here, we report a fatal bacteremia caused by chromobacterium violaceum in vietnam. we describe a number of clinical, microbiological, and molecular aspects associated with this bacterial infection.	2008	18799697
successful treatment of chromobacterium violaceum sepsis in south africa.	chromobacterium violaceum sepsis is extremely rare and usually fatal. a very few cases of c. violaceum infection have been reported from africa, but never from south africa. as far as could be ascertained, this infection has never been reported in a patient with leukaemia. we describe what we believe to be the first such case of c. violaceum sepsis, in a 16-year-old female patient with acute biphenotypic leukaemia, which developed during the neutropenic phase after intensive chemotherapy. the in ...	2008	18809561
kinetic isotope effects on aromatic and benzylic hydroxylation by chromobacterium violaceum phenylalanine hydroxylase as probes of chemical mechanism and reactivity.	phenylalanine hydroxylase from chromobacterium violaceum (cvpheh) is a non-heme iron monooxygenase that catalyzes the hydroxylation of phenylalanine to tyrosine. in this study, we used deuterium kinetic isotope effects to probe the chemical mechanisms of aromatic and benzylic hydroxylation to compare the reactivities of bacterial and eukaryotic aromatic amino acid hydroxylases. the (d) k cat value for the reaction of cvpheh with [(2)h 5]phenylalanine is 1.2 with 6-methyltetrahydropterin and 1.4 ...	2008	18817418
cellulose biosynthesis by the beta-proteobacterium, chromobacterium violaceum.	the chromobacterium violaceum atcc 12472 genome was sequenced by the brazilian national genome project consortium. previous annotation reported the presence of cellulose biosynthesis genes in that genome. analysis of these genes showed that, as observed in other bacteria, they are organized in two operons. in the present work, experimental evidences of the presence of cellulose in the extracellular matrix of the biofilm produced by c. violaceum in static cultures are shown. biofilm samples were ...	2008	18820969
pseudogulbenkiania subflava gen. nov., sp. nov., isolated from a cold spring.	a yellow-coloured bacterial strain, designated bp-5(t), was isolated from a water sample of a cold spring located in the hsinchu area of northern taiwan. cells of the strain were gram-negative, non-spore-forming rods with a polar flagellum. the isolate was able to grow at 15-42 degrees c, 0-1 % nacl and ph 6-8. the predominant fatty acids were summed feature 3 (c(16 : 1)omega7c and/or iso-c(15 : 0) 2-oh), c(16 : 0) and c(18 : 1)omega7c. the major respiratory quinone was ubiquinone 8. the dna g+c ...	2008	18842860
amphibian chemical defense: antifungal metabolites of the microsymbiont janthinobacterium lividum on the salamander plethodon cinereus.	disease has spurred declines in global amphibian populations. in particular, the fungal pathogen batrachochytrium dendrobatidis has decimated amphibian diversity in some areas unaffected by habitat loss. however, there is little evidence to explain how some amphibian species persist despite infection or even clear the pathogen beyond detection. one hypothesis is that certain bacterial symbionts on the skin of amphibians inhibit the growth of the pathogen. an antifungal strain of janthinobacteriu ...	2008	18949519
anthranilate synthase subunit organization in chromobacterium violaceum.	tryptophan is an aromatic amino acid used for protein synthesis and cellular growth. chromobacterium violaceum atcc 12472 uses two tryptophan molecules to synthesize violacein, a secondary metabolite of pharmacological interest. the genome analysis of this bacterium revealed that the genes trpa-f and paba-b encode the enzymes of the tryptophan pathway in which the first reaction is the conversion of chorismate to anthranilate by anthranilate synthase (as), an enzyme complex. in the present study ...	2008	18949702
the violacein biosynthetic enzyme vioe shares a fold with lipoprotein transporter proteins.	vioe, an unusual enzyme with no characterized homologues, plays a key role in the biosynthesis of violacein, a purple pigment with antibacterial and cytotoxic properties. without bound cofactors or metals, vioe, from the bacterium chromobacterium violaceum, mediates a 1,2 shift of an indole ring and oxidative chemistry to generate prodeoxyviolacein, a precursor to violacein. our 1.21 a resolution structure of vioe shows that the enzyme shares a core fold previously described for lipoprotein tran ...	2008	18171675
crystal structure of vioe, a key player in the construction of the molecular skeleton of violacein.	violacein and the indolocarbazoles are naturally occurring bisindole products with various biological activities, including antitumor activity. although these compounds have markedly different molecular skeletons, their biosynthetic pathways share the same intermediate "compound x," which is produced from l-tryptophan via indole-3-pyruvic acid imine. compound x is a short-lived intermediate that is spontaneously converted to chromopyrrolic acid for indolocarbazole biosynthesis, whereas vioe tran ...	2008	18171677
paludibacterium yongneupense gen. nov., sp. nov., isolated from a wetland, yongneup, in korea.	a cream-coloured bacterial strain, 5yn8-15(t), was isolated from a wetland, yongneup, in the inje region of the republic of korea. the bacterium was facultatively anaerobic, gram-negative, motile with a single polar flagellum and curved-rod-shaped. based on 16s rrna gene sequence analysis, strain 5yn8-15(t) is a member of the betaproteobacteria. closely related taxa were gulbenkiania mobilis e4fc31(t) (94.9% sequence similarity), chromobacterium species (94.1-94.4%), aquitalea magnusonii tro-001 ...	2008	18175708
n-acylhomoserine lactone regulates violacein production in chromobacterium violaceum type strain atcc 12472.	in tests, chromobacterium violaceum atcc 12472 produced several n-acyl-l-homoserine lactones (ahls). of these, n-(3-hydroxydecanoyl)-l-homoserine lactone was dominant, and controlled violacein production by quorum sensing. strain vir07, an ahl-deficient mutant, did not produce violacein. violacein production in vir07 was induced by adding long-chain ahls (c10-c16), but was inhibited by adding short-chain ahls (c4-c8). strain vir07 showed the response of violacein production when ahls diffused fr ...	2008	18177311
diversity and quorum-sensing signal production of proteobacteria associated with marine sponges.	marine sponges are hosts to diverse and dense bacterial communities and thus provide a potential environment for quorum sensing. quorum sensing, a key factor in cell-cell communication and bacterial colonization of higher animals, might be involved in the symbiotic interactions between bacteria and their sponge hosts. given that marine proteobacteria are known to produce n-acyl homoserine lactone (ahl) signal molecules, we tested the production of ahls by alpha- and gammaproteobacteria isolated ...	2008	18211268
structural basis for mannose recognition by a lectin from opportunistic bacteria burkholderia cenocepacia.	chronic colonization of the lungs by opportunist bacteria such as pseudomonas aeruginosa and members of the bcc (burkholderia cepacia complex) is the major cause of morbidity and mortality among cf (cystic fibrosis) patients. pa-iil (lecb gene), a soluble lectin from ps. aeruginosa, has been the subject of much interest because of its very strong affinity for fucose. orthologues have been identified in the opportunist bacteria ralstonia solanacearum, chromobacterium violaceum and burkholderia of ...	2008	18215132
diversity in antifungal activity of strains of chromobacterium violaceum from the brazilian amazon.	chromobacterium violaceum is a free-living gram-negative bacterium found in soil and aquatic habitats; abundantly present in the brazilian amazon, it is an important example of exploitable microbial diversity of the tropics. in this study, 24 strains from the brazilian amazon and atcc 12472(t) were investigated for biocontrol potential of seven fungi pathogenic to soybean [glycine max (l.) merril] seed. both cells and the supernatants of two brazilian strains, 07-1 and 27-1, together with atcc 1 ...	2008	18347828
bacteria flora and heavy metals in cultivated oysters crassostrea iredalei of setiu wetland, east coast peninsular malaysia.	slipper oyster crassostrea iredalei is a species of good demand for its sweet flavor and white coloured flesh. the filter feeding nature predisposes oysters to accumulation of pathogenic and heavy metals in waters impacted by sewage pollutions and may thus render the oysters unfit for human consumption. a study was undertaken to investigate the presence of bacteria flora and heavy metal concentrations in cultivated oysters crassostrea iredalei at setiu wetland, terengganu, the only source of cul ...	2008	18369732
prevalence of bacterial pathogens and their anti-microbial resistance in tilapia and their pond water in trinidad.	in trinidad, tilapia (oreonchromis spp.) is one of the most important fresh water food fish and the number of farms has been increasing annually. a study was conducted in the local tilapia industry to determine the microbial quality of pond water, prevalence of bacterial pathogens and their anti-microbial resistance using the disk diffusion method. seventy-five apparently healthy fish and 15 pond water samples from three of the four commercial tilapia fish farms in the country were processed. th ...	2008	18387142
gene expression of the arsenic resistance operon in chromobacterium violaceum atcc 12472.	chromobacterium violaceum atcc 12472 presents an arsrcb-type operon, which is involved in arsenic resistance. the regulating protein of this resistance system (arsr) does not have the small conserved site (elcvdcl) to link to the metalloid, as observed in escherichia coli, and is thus considered to be an atypical arsr protein, like that observed in acidithiobacillus ferrooxidans. in the present study, the gene expression profile of the ars operon under induction at different concentrations of ar ...	2008	18388983
chromobacterium aquaticum sp. nov., isolated from spring water samples.	strain cc-seya-1t, a motile, gram-negative, non-violet-pigmented bacterium, was isolated on nutrient agar from spring-water samples collected from yang-ming mountain, taipei county, taiwan. 16s rrna gene sequence studies showed that the strain clustered with chromobacterium violaceum (96.8 % similarity) and chromobacterium subtsugae (96.5 % similarity), followed by aquitalea magnusonii (95.8 % similarity). the fatty acid profile was slightly different from those reported for c. violaceum, c. sub ...	2008	18398186
degradation of n-acyl homoserine lactone quorum sensing signal molecules by forest root-associated fungi.	a collection of mycorrhizal and nonmycorrhizal root-associated fungi coming from forest environments was screened for their ability to degrade n-acyl homoserine lactones (ahl) or to prevent ahl recognition by producing quorum sensing inhibitors (qsi). no production of qs-inhibitors or -activators was detected using the two biosensors chromobacterium violaceum cv026 and agrobacterium tumefaciens in the culture supernatant of these fungi. however, the ability to degrade c6- and 3o,c6-hsl was detec ...	2008	18400006
ppsy: a vector for the stable cloning and expression of streptomycete single gene phenotypes in escherichia coli.	ppsy is a 12kb cloning vector derived from the incw plasmid r388, which provides a rapid and easy way to stably clone phenotypes encoded in dna segments <10kb. in the present study three different genes were amplified by pcr, cloned into pgem-t easy and sub-cloned into the ecori site of ppsy. the first gene, vioa, is a fad-dependent l-tryptophan amino acid oxygenase from the high g+c gram-negative bacterium chromobacterium violaceum. vioa is involved in the synthesis of the indolocarbazole antit ...	2008	18406459
kinetics of thermal unfolding of phenylalanine hydroxylase variants containing different metal cofactors (feii, coii, and znii) and their isokinetic relationship.	the kinetics of thermal unfolding of apo- and holo-chromobacterium violaceum phenylalanine hydroxylase (cpah) was investigated using circular dichroism (cd) over the temperature range 44-76 degrees c. in addition to the native cofactor (feii), the unfolding kinetics of holo-cpah was characterized using znii and coii as cofactors. kinetic profiles for apo- and holo-cpah showed a single-phase exponential rise in the cd signal at lambda=222 nm and a first-order dependence on protein concentration. ...	2008	18433092
chromobacterium violaceum cellulitis and sepsis following cutaneous marine trauma.	chromobacterium violaceum is a gram-negative bacillary organism that characteristically produces the purple pigment violacein. documented as the cause of clinically relevant human infections in only 35 cases in the united states, c violaceum is particularly seen in patients with a history of cutaneous injury or trauma. we report the case of an 18-year-old woman who was struck by a propeller in a boating accident and sustained multiple deep lacerations of her right lower extremity. shortly after ...	2008	18441852
neonatal septicaemia in calabar, nigeria.	a three-year survey of neonatal septicaemia (363 bacteriologically proven cases) in the university of calabar teaching hospital, calabar, has demonstrated that the dominant blood isolate was staphylococcus aureus (53%) followed by unclassified coliforms (20%), an unexpected chromobacterium violaceum (5%). the incidence of neonatal septicaemia was 54.9 per 1000 live births for inborn infants. the predominant organisms were largely susceptible to gentamicin, ceftriazone and cefuroxime with a morta ...	2008	18453516
hydrogen peroxide linked to lysine oxidase activity facilitates biofilm differentiation and dispersal in several gram-negative bacteria.	the marine bacterium pseudoalteromonas tunicata produces an antibacterial and autolytic protein, alpp, which causes death of a subpopulation of cells during biofilm formation and mediates differentiation, dispersal, and phenotypic variation among dispersal cells. the alpp homologue (loda) in the marine bacterium marinomonas mediterranea was recently identified as a lysine oxidase which mediates cell death through the production of hydrogen peroxide. here we show that alpp in p. tunicata also act ...	2008	18502869
purification and characterization of chromobacterium sp. ds-1 cholesterol oxidase with thermal, organic solvent, and detergent tolerance.	a new screening method for 6beta-hydroperoxycholest-4-en-3-one (hceo)-forming cholesterol oxidase was devised in this study. as the result of the screening, a novel cholesterol oxidase producer (strain ds-1) was isolated and identified as chromobacterium sp. extracellular cholesterol oxidase of strain ds-1 was purified from the culture supernatant. the molecular mass of the purified enzyme was 58 kda. this enzyme showed a visible adsorption spectrum having peaks at 355 and 450 nm, like a typical ...	2008	18512056
lipases at interfaces: unique interfacial properties as globular proteins.	the adsorption behavior of two globular proteins, lipase from rhizomucor miehei and beta-lactoglobulin, at inert oil/water and air/water interfaces was studied by the pendant drop technique. the kinetics and adsorption isotherms were interpreted for both proteins in different environments. it was found that the adopted mathematical models well describe the adsorption behavior of the proteins at the studied interfaces. one of the main findings is that unique interfacial properties were observed f ...	2008	18512870
chromobacterium haemolyticum sp. nov., a strongly haemolytic species.	a gram-negative bacterium, strain mda0585(t), isolated from a sputum culture, was characterized by a polyphasic approach. the 16s rrna gene and a conserved portion of the dna gyrase a gene were sequenced and analysed phylogenetically. strain mda0585(t) showed the closest relationships with chromobacterium violaceum atcc 12472(t) and chromobacterium subtsugae praa4-1(t) (96.1 % and 96.3 % 16s rrna gene sequence similarity, respectively). the cellular fatty acids of strain mda0585(t) consisted mai ...	2008	18523185
the 1.25 a resolution structure of phosphoribosyl-atp pyrophosphohydrolase from mycobacterium tuberculosis.	phosphoribosyl-atp pyrophosphohydrolase is the second enzyme in the histidine-biosynthetic pathway, irreversibly hydrolyzing phosphoribosyl-atp to phosphoribosyl-amp and pyrophosphate. it is encoded by the hise gene, which is present as a separate gene in many bacteria and archaea but is fused to hisi in other bacteria, fungi and plants. because of its essentiality for growth in vitro, hise is a potential drug target for tuberculosis. the crystal structures of two native (uncomplexed) forms of h ...	2008	18560150
human chromobacterium violaceum infection in southeast asia: case reports and literature review.	chromobacterium violaceum infection in humans is a rare tropical and subtropical disease. the awareness of this organism is limited in spite its ubiquitous distribution. several cases have been reported from southeast asia. a localized infection followed by an overwhelming septicemia and metastatic lesions is the usual pattern of this illness. optimal antimicrobial treatment and duration are unknown. consequently, the outcome is usually fatal. the study reported two patients who suffered from fu ...	2008	18564684
isolation and characterization of two groups of novel marine bacteria producing violacein.	thirteen strains of novel marine bacteria producing a purple pigment were isolated from the pacific coast of japan. they were divided into two groups based on their 16s ribosomal rna gene sequences, and both groups of bacteria belonged to the genus pseudoalteromonas. the uv-visible spectrum of the pigment was identical to those of violacein, a pigment produced by several species of bacteria including chromobacterium violaceum, an opportunistic pathogen. further analysis of the chemical structure ...	2008	17968625
a study of natural attenuation processes involved in a microcosm model of a crude oil-impacted wetland sediment in the niger delta.	sediment sample from a previously impacted ochani stream was recreated in four glass chambers (a-d) as microcosms. the aim was to model and compare natural attenuation processes to forced aeration for remediation of a crude oil-impacted ecosystem. the initial hydrocarbon concentration was 90,212 mg/kg of sediment. after 60 days, the natural attenuation processes of photooxidation, evaporation, volatilization and biodegradation accounted for 31.9% of the total hydrocarbon removed while 13% was at ...	2008	17988860
improved activity of enzymes in mixed cationic reverse micelles with imidazolium-based surfactants.	this work reports the significant enhancement in performance of interfacially active enzymes, chromobacterium viscosum (cv) lipase and horseradish peroxidase (hrp) in mixed reverse micelles of cetyltrimethylammonium bromide (ctab) and imidazolium-based amphiphiles having varying tail lengths. lipase activity in these mixed systems was always higher than that in the individual cationic reverse micelles of ctab or any imidazolium surfactant, highest being observed in the mixed system of ctab (50 m ...	2008	18067868
diversity of chromobacterium violaceum isolates from aquatic environments of state of pará, brazilian amazon.	the present study intended to characterize the phenotypic and genetic diversity of brazilian isolates of chromobacterium violaceum from aquatic environments within the amazon region. nineteen isolates showed morphological properties of c. violaceum and the majority grew at 44 degrees c. low temperatures, in contrast, showed to be inhibitory to their growth, as eleven isolates did not grow at 10 degrees c and nine did not produce pigmentation, clearly indicating an inhibition of their metabolism. ...	2008	19057818
[successful treatment of a case with fatal sepsis caused by chromobacterium violaceum].		2007	18282432
one step engineering of t7-expression strains for protein production: increasing the host-range of the t7-expression system.	the t7-expression system has been very useful for protein expression in escherichia coli. however, it is often desirable to over-express proteins in species other than e. coli. here, we constructed an inducible broad-host-range t7-expression transposon, which allows simple one-step construction of t7-expression strains in various species, providing the option to over-express proteins of interest in a broader host-range. this transposon contains the t7 rna polymerase driven by the lacuv5 promoter ...	2007	17716915
[sepsis caused by pigmented and no pigmented chromobacterium violaceum].	chromobacterium violaceum sepsis is rare but associated with a high mortality rate. we report a fatal case of c. violaceum sepsis in a 6 years old venezuelan indian boy. clinical manifestations were fever and swelling in the right inguinal region. the initial diagnosis was an appendicular plastron. appendicectomy was performed and during surgery a right psoas abscess was identified that resulted culture positive for pigmented c. violaceum. blood cultures were positive for a pigmented and non pig ...	2007	17989847
effect of the pretreatment of lipase with organic solvents on its conformation and activity in reverse micelles.	the activity and conformation of chromobacterium viscosum lipase-pretreated with various organic solvents were investigated. the pretreatment of lipase led to a substantial increase of enzyme activity in aot (sodium bis [2-ethyl -1-hexyl] sulfosuccinate)/isooctane/water reverse micelles. among the organic solvents used, n-hexane was found to be most effective. it was observed that higher hexane content with shorter agitation time and vice versa had almost the same effect on the initial activity ...	2007	18025586
n-acyl homoserine lactones are degraded via an amidolytic activity in comamonas sp. strain d1.	comamonas strain d1 enzymatically inactivates quorum-sensing (qs) signal molecules of the n-acyl homoserine lactone (n-ahsl) family, and exhibits the broadest inactivation range of known bacteria. it degrades n-ahsl with acyl-side chains ranging from 4 to 16 carbons, with or without 3-oxo or 3-hydroxy substitutions. n-ahsl degradation yields hsl but not n-acyl homoserine: strain d1 therefore harbors an amidohydrolase activity. strain d1 is the fifth bacterium species in which an n-ahsl amidohydr ...	2007	17136382
the serratia-type hemolysin of chromobacterium violaceum.	chromobacterium violaceum is a gram-negative opportunistic human pathogen and an inhabitant of tropical soils and waterways. although known primarily for the synthesis of the pigment violacein, and more recently as a reporter strain for quorum sensing, clinical reports of chromobacteriosis comprise the largest block of published literature on this organism. genome sequencing has revealed many potential virulence factors in this microorganism, and this paper establishes the presence in c. violace ...	2007	17169000
crystallization and preliminary x-ray diffraction analysis of omega-amino acid:pyruvate transaminase from chromobacterium violaceum.	the enzyme omega-transaminase catalyses the conversion of chiral omega-amines to ketones. the recombinant enzyme from chromobacterium violaceum has been purified to homogeneity. the enzyme was crystallized from peg 4000 using the microbatch method. data were collected to 1.7 a resolution from a crystal belonging to the triclinic space group p1, with unit-cell parameters a = 58.9, b = 61.9, c = 63.9 a, alpha = 71.9, beta = 87.0, gamma = 74.6 degrees . data were also collected to 1.95 a from a sec ...	2007	17277454
cloning and high-level production of a chitinase from chromobacterium sp. and the role of conserved or nonconserved residues on its catalytic activity.	a gene encoding an alkaline (pi of 8.67) chitinase was cloned and sequenced from chromobacterium sp. strain c-61. the gene was composed of 1,611 nucleotides and encoded a signal sequence of 26 n-terminal amino acids and a mature protein of 510 amino acids. two chitinases of 54 and 52 kda from both recombinant escherichia coli and c-61 were detected on sds-page. maximum chitinase activity was obtained in the culture supernatant of recombinant e. coli when cultivated in tb medium for 6 days at 37 ...	2007	17294188
evaluation of different compounds as quorum sensing inhibitors in pseudomonas aeruginosa.	quorum sensing (qs) controls systems affecting the pathogenicity of many microorganisms; its interruption has an anti-pathogenic effect and can be used in the treatment of bacterial infections. in this study we evaluated qs regulation by pseudomonas aeruginosa strains and qs inhibition (qsi) by different compounds. the inhibitory activity of 3 macrolide and 3 lincosamide drugs, resveratrol, garlic extract and n-acetylcysteine was tested on 4 p. aeruginosa strains isolated from cystic fibrosis (c ...	2007	17855182
sepsis by chromobacterium violaceum: first case report from colombia.	chromobacterium violaceum is found in tropical and subtropical regions; it is the only chromobacterium species pathogenic for humans. due to its rare presentation, physicians often ignore the importance of this pathogen. we report a fulminant fatal case of bacteremia in a 38-year-old colombian man. the clinical manifestations were fever, thoracic pain, respiratory failure and death. his condition, from the beginning of clinical diagnosis, went into continuous deterioration, till his death, withi ...	2007	17874003
[chromobacterium violaceum septicemia: first case report in the french west indies].	we report a fatal case of chromobacterium violaceum septicemia in a 42-year-old farm worker living in the french west indies. the bacteria found in the muddy soil and the stagnant water of tropical and subtropical regions is rarely a source of human infection.	2007	17905550
biosynthesis of violacein: a genuine intermediate, protoviolaceinic acid, produced by vioabde, and insight into vioc function.	a biosynthetic intermediate of violacein produced by the mixed enzymes of vioabde was elucidated to be 5-(5-hydroxy-1h-indol-3-yl)-3-(1h-indol-3-yl)-1h-pyrrole-2-carboxylic acid, named protoviolaceinic acid, indicating that vioc, responsible for the final biosynthetic step, works to oxygenate at the 2-position of the right side indole ring, and that the oxygenation reaction to form the central pyrrolidone core proceeds in a non-enzymatic fashion.	2007	17925955
violacein: properties and biological activities.	the violet pigment violacein is an indole derivative, isolated mainly from bacteria of the genus chromobacterium, which exhibits important antitumoral, antimicrobial and antiparasitary properties. furthermore, the formulation of violacein in different polymeric carriers developed so far offers alternative approaches to overcoming physiological barriers and undesirable physicochemical properties in vivo, thus improving its efficacy.	2007	17927569
fatal septicemia caused by chromobacterium violaceum in a child from colombia.	a 4-year old child living in colombia presented with a history of fever and severe abdominal pain for four days. the patient developed pneumonia, septic shock, multiple organ failure and died on the fifth day of hospitalization. chromobacterium violaceum was isolated from admission blood cultures and was resistant to ampicillin, cephalosporins, carbapenems and aminoglycosides.	2007	18157408
fatal septicaemia due to chromobacterium violaceum.	human infection caused by chromobacterium violaceum is rare but when it occurs, it is associated with a high mortality rate. this is a report of a young adult male who presented as a surgical emergency and succumbed soon after. the most common feature of this infection is sepsis, followed by cutaneous involvement and liver abscesses. chromobacterium infection as a differential in a case of sepsis is important for clinicians to suspect, especially in tropical countries.	2007	18198747
nonionic surfactants: a key to enhance the enzyme activity at cationic reverse micellar interface.	the primary objective of the present study is to understand how the different nonionic surfactants modify the anisotropic interface of cationic water-in-oil (w/o) microemulsions and thus influences the catalytic efficiency of surface-active enzymes. activity of chromobacterium viscosum lipase (cv-lipase) was estimated in several mixed reverse micelles prepared from ctab and four different nonionic surfactants, brij-30, brij-92, tween-20, and tween-80/water/isooctane/n-hexanol at different z ([co ...	2007	17348695
stereochemical course of tryptophan dehydrogenation during biosynthesis of the calcium-dependent lipopeptide antibiotics.	[reaction: see text] hydrogen atoms are abstracted from the c2' and c3'-pro-s positions of an (s)-tryptophanyl precursor, with overall syn stereochemistry, during the biosynthesis of the c-terminal z-2',3'-dehydrotryptophan residue of the calcium-dependent lipopeptide antibiotics (cdas) in streptomyces coelicolor. the absence of beta-hydroxytryptophanyl, or other possible intermediates, further suggests a direct dehydrogenation mechanism similar to that proposed for the l-tryptophan 2',3'-oxidas ...	2007	17355143
inhibitory effects of histone deacetylase inhibitor depsipeptide on benzo(a)pyrene- and cyclophosphamide-induced genotoxicity in swiss albino mice.	depsipeptide (fk228 or fr901228) was evaluated in the mouse bone marrow micronucleus test for its possible protective effect against chromosomal damage induced by benzo(a)pyrene and cyclophosphamide. three doses of depsipeptide (0.5, 1, and 1.5 mg/kg body weight) were given intravenously to mice for 7 consecutive days prior to administration of genotoxins under investigation. all the three doses of depsipeptide were effective in exerting a protective effect against both benzo(a)pyrene and cyclop ...	2007	17365146
the effect of quorum-sensing blockers on the formation of marine microbial communities and larval attachment.	we studied the effect of the quorum-sensing (qs) blockers 5-hydroxy-3[(1r)-1-hydroxypropyl]-4-methylfuran-2(5h)-one (fur1), (5r)-3,4-dihydroxy-5-[(1s)-1,2-dihydroxyethyl]furan-2(5h)-one (fur2) and triclosan (tri) on the formation of bacterial biofilms, and the effect of these biofilms on the larval attachment of the polychaete hydroides elegans and the bryozoan bugula neritina. 14-day-old subtidal biofilms were harvested from artificial substrata and were allowed to develop in the laboratory wit ...	2007	17371321
genetic organization of the biosynthetic gene cluster for the indolocarbazole k-252a in nonomuraea longicatena jcm 11136.	indolocarbazole metabolite k-252a is a natural product that was previously reported as a potent protein kinase c inhibitor with in vitro and in vivo potency. from a biosynthetic viewpoint, this compound possesses structurally interesting features such as an unusual furanosyl sugar moiety, which are absent in the well-studied staurosporine and rebeccamycin. a cosmid library from genomic dna of nonomuraea longicatena jcm 11136 was constructed and screened for the presence of genes to be involved i ...	2007	17396254
characterization of a gene cluster responsible for the biosynthesis of anticancer agent fk228 in chromobacterium violaceum no. 968.	a gene cluster responsible for the biosynthesis of anticancer agent fk228 has been identified, cloned, and partially characterized in chromobacterium violaceum no. 968. first, a genome-scanning approach was applied to identify three distinctive c. violaceum no. 968 genomic dna clones that code for portions of nonribosomal peptide synthetase and polyketide synthase. next, a gene replacement system developed originally for pseudomonas aeruginosa was adapted to inactivate the genomic dna-associated ...	2007	17400765
signal mimics derived from a metagenomic analysis of the gypsy moth gut microbiota.	bacterial signaling is an important part of community life, but little is known about the signal transduction pathways of the as-yet-uncultured members of microbial communities. to address this gap, we aimed to identify genes directing the synthesis of signals in uncultured bacteria associated with the midguts of gypsy moth larvae. we constructed a metagenomic library consisting of dna extracted directly from the midgut microbiota and analyzed it using an intracellular screen designated metrex, ...	2007	17435000
chromobacterium subtsugae sp. nov., a betaproteobacterium toxic to colorado potato beetle and other insect pests.	strain praa4-1(t), a motile, gram-negative, violet-pigmented bacterium, was isolated from maryland forest soil and found to be orally toxic to colorado potato beetle larvae and other insects. morphological, biological, biochemical and molecular characterization revealed that this strain was most similar to chromobacterium violaceum, the type species and only currently recognized member of the genus chromobacterium. dna-dna hybridization with c. violaceum atcc 12472(t) was 27 %. phylogenetic anal ...	2007	17473247
gulbenkiania mobilis gen. nov., sp. nov., isolated from treated municipal wastewater.	a bacterial strain (e4fc31(t)) isolated from treated municipal wastewater was characterized phenotypically and phylogenetically. cells were gram-negative, curved rods with a polar flagellum. the isolate was catalase-, oxidase- and arginine dihydrolase-positive, and able to grow between 15 and 45 degrees c and between ph 5.5 and 9.0. the predominant fatty acids were c(16 : 1)/iso-c(15 : 0) 2-oh and c(16 : 0), the major respiratory quinone was ubiquinone 8 and the g+c content of the genomic dna wa ...	2007	17473267
dietary phytochemicals as quorum sensing inhibitors.	quorum sensing (qs) is a cell density dependent expression of species in bacteria mediated by hormone like compounds called autoinducers (ai). several processes responsible for successful establishment of bacterial infection are mediated by qs. inhibition of qs is therefore being considered as a new target for antimicrobial chemotherapy. dietary phytochemicals are secondary metabolites in plants known to have several health benefits including antimicrobial activity. however, their ability to inh ...	2007	17499938
analysis of chromobacterium sp. natural isolates from different brazilian ecosystems.	chromobacterium violaceum is a free-living bacterium able to survive under diverse environmental conditions. in this study we evaluate the genetic and physiological diversity of chromobacterium sp. isolates from three brazilian ecosystems: brazilian savannah (cerrado), atlantic rain forest and amazon rain forest. we have analyzed the diversity with molecular approaches (16s rrna gene sequences and amplified ribosomal dna restriction analysis) and phenotypic surveys of antibiotic resistance and b ...	2007	17584942
inhibition of quorum sensing-regulated behaviors by scorzonera sandrasica.	many gram-negative bacteria use n-acyl homoserine lactone signal molecules to monitor their own population density and coordinate gene regulation in a process called quorum sensing (qs). increasing evidence implies that certain eukaryotes produce qs-inhibitory compounds. in this work, we tested 46 terrestrial plants materials for their ability to inhibit qs-regulated behaviors in different bacterial species. plant materials were dried and extracted using different solvents. the chloroform-solubl ...	2007	17597339
toxicity of chromobacterium subtsugae to southern green stink bug (heteroptera: pentatomidae) and corn rootworm (coleoptera: chrysomelidae).	diabrotica spp. (coleoptera: chrysomelidae) beetles and southern green stink bugs, nezara viridula (l.) (heteroptera: pentatomidae), are pests on corn, zea mays l., and soybean, glycine max (l.) merr., as well as on cucurbits. control of these insects has depended on chemicals. an alternative to chemical control is the use of biologicals. use of bacteria, fungi, viruses, pheromones, and metabolites to control these insects can potentially improve resistance management and reduce pesticide use. o ...	2007	17598525
chromobacterium violaceum infection in taiwan: a case report and literature review.	chromobacterium violaceum is a facultative anaerobic, gram-negative bacillus which inhabits stagnant water in tropical and subtropical regions. we describe the case of an 80-year-old female patient with c. violaceum bacteremia due to traumatic wound infected by contaminated water and soil. she had persistent fever, hypotension and neutrophilic leukocytosis on admission. two sets of blood cultures yielded c. violaceum. the patient was successfully treated with levofloxacin. since the first case f ...	2007	17639170
fatal septicaemia from chromobacterium violaceum: case reports and review of the literature.	chromobacterium violaceum rarely causes infection in humans and its mechanism of pathogenicity is not well understood. human infection carries a high mortality rate with a fulminating clinical progression. a high index of suspicion is required for diagnosis, and is based on recovering the organisms from blood cultures or other appropriate specimens. we present three cases of human infection managed in a tertiary referral hospital in hong kong with a review of the literature.	2006	16760554
unusual entropy-driven affinity of chromobacterium violaceum lectin cv-iil toward fucose and mannose.	the purple pigmented bacterium chromobacterium violaceum is a dominant component of tropical soil microbiota that can cause rare but fatal septicaemia in humans. its sequenced genome provides insight into the abundant potential of this organism for biotechnological and pharmaceutical applications and allowed an orf encoding a protein that is 60% identical to the fucose binding lectin (pa-iil) from pseudomonas aeruginosa and the mannose binding lectin (rs-iil) from ralstonia solanacearum to be id ...	2006	16768446
physicochemical studies on cetylammonium bromide and its modified (mono-, di-, and trihydroxyethylated) head group analogues. their micellization characteristics in water and thermodynamic and structural aspects of water-in-oil microemulsions formed with them along with n-hexanol and isooctane.	the micellization behavior of cetylammonium bromide and its mono-, di-, and trihydroxyethylated head group analogues and water/oil (w/o) microemulsion formation with them have been studied with detailed thermodynamic and structural considerations. the critical micellar concentration, micellar aggregation number, and behavior of the surfactants at the air/solution interface have been studied in detail. the results have been analyzed and discussed. the formation of the w/o microemulsion stabilized ...	2006	16771402
[chromobacterium violaceum peritonitis: case report and literature review].	we report a case of chromobacterium violaceum infection and we review the literature for all published cases. c. violaceum grew from a peritoneal fluid of a 47-year-old woman operated on for peritonitis following perforative gastroduodenal ulcer. she was just coming back from a 1-month-holyday in french guyana, where she might have been in contact with this micro-organism. the patient fully recovered after surgical management associated with antibiotic therapy consisting of ofloxacin plus pipera ...	2006	16829475
reevaluation of the violacein biosynthetic pathway and its relationship to indolocarbazole biosynthesis.	the biosynthetic pathways for violacein and for indolocarbazoles (rebeccamycin, staurosporine) include a decarboxylative fusion of two tryptophan units. however, in the case of violacein, one of the tryptophans experiences an unusual 1-->2 shift of the indole ring. the violacein biosynthetic gene cluster was previously reported to consist of four genes, vioabcd. here we studied the violacein pathway through expression of vio genes in escherichia coli and streptomyces albus. a pair of genes (vioa ...	2006	16874749
cytotoxic activity of violacein in human colon cancer cells.	several studies have shown that violacein, a purple pigment extracted from chromobacterium violaceum, is capable to induce apoptosis in a variety of cancer cells, including those leukemia cell lines. herein, we examined the effects of violacein on reactive oxygen species (ros) production during the apoptotic colon cancer cell death. we demonstrate that violacein mediates ros production followed by activation of caspase-3, release of cytochrome c, and calcium release to citosol in caco-2 cells. m ...	2006	16889929
[soft tissue infection in a diabetic patient from a subtropical region].		2006	16956538
mouse and human cell activation by n-dodecanoyl-dl-homoserine lactone, a chromobacterium violaceum autoinducer.	chromobacterium violaceum produces autoinducers, including homoserine lactones (hsls), for genetic regulation. among the seven hsls derived from c. violaceum we evaluated, only c(12)-hsl stimulated the production of inflammatory cytokines in mammalian monocytic cell lines through the activation of the nf-kappab signaling pathway besides their quorum-sensing role, like 3-oxo-c(12)-hsl from pseudomonas aeruginosa.	2006	16982829
chromobacterium violaceum: a case report of an unusual bacterium causing puerperal sepsis.	human infections by chromobacterium violaceum are rare. till date 6 cases have been reported from southern and eastern parts of india. we report here a case of puerperal sepsis by c. violaceum, probably the first case from eastern part of orissa. the patient was successfully treated with amikacin and gatifloxacin.	2006	17001920
structures of human n-acetylglucosamine kinase in two complexes with n-acetylglucosamine and with adp/glucose: insights into substrate specificity and regulation.	n-acetylglucosamine (glcnac), a major component of complex carbohydrates, is synthesized de novo or salvaged from lysosomally degraded glycoconjugates and from nutritional sources. the salvage pathway requires that glcnac kinase converts glcnac to glcnac-6-phosphate, a component utilized in udp-glcnac biosynthesis or energy metabolism. glcnac kinase belongs to the sugar kinase/hsp70/actin superfamily that catalyze phosphoryl transfer from atp to their respective substrates, and in most cases cat ...	2006	17010375
antioxidant properties of violacein: possible relation on its biological function.	violacein, a violet pigment produced by chromobacterium violaceum, has attracted much attention in recent literature due to its pharmacological properties. in this work, the antioxidant properties of violacein were investigated. the reactivity with oxygen and nitrogen reactive species and 1,1-diphenyl-2-picryl-hydrazyl (dpph), a stable free radical, was evaluated. epr studies were carried out to evaluate the reactivity with the hydroxyl radical. the action of violacein against lipid peroxidation ...	2006	17011197
effect of counterions on the activity of lipase in cationic water-in-oil microemulsions.	this paper delineates how the different counterions affect the physicochemical properties of the aqueous aggregates and thereby the lipase activities at the interface of cationic water-in-oil microemulsions. to this end, we have synthesized a series of cetyltrimethylammonium-based surfactants, 1-14, having aliphatic, aliphatic with aromatic substitution at the alpha position, and aromatic carboxylate anion as the counterion. the physicochemical characterizations of these aqueous aggregates were ...	2006	17014111
in vitro testing for genotoxicity of violacein assessed by comet and micronucleus assays.	chromobacterium violaceum is a gram (-) bacteria found in water samples and soils from tropical and subtropical regions of the world. violacein, the major pigment produced by these bacteria, has been shown to have antibiotic, antitumoral and trypanocidal activities. in the present work, the genotoxicity of violacein was investigated in four different cell lines by using the alkaline comet assay and in vero cells using the micronucleus test. in the alkaline comet assay, violacein, when tested at ...	2006	16359912
anaerobic nitrate-dependent iron(ii) bio-oxidation by a novel lithoautotrophic betaproteobacterium, strain 2002.	microbial nitrate-dependent fe(ii) oxidation is known to contribute to iron biogeochemical cycling; however, the microorganisms responsible are virtually unknown. in an effort to elucidate this microbial metabolic process in the context of an environmental system, a 14-cm sediment core was collected from a freshwater lake and geochemically characterized concurrently with the enumeration of the nitrate-dependent fe(ii)-oxidizing microbial community and subsequent isolation of a nitrate-dependent ...	2006	16391108
anti-quorum sensing activity of medicinal plants in southern florida.	bacterial intercellular communication, or quorum sensing (qs), controls the pathogenesis of many medically important organisms. anti-qs compounds are known to exist in marine algae and have the ability to attenuate bacterial pathogenicity. we hypothesized that terrestrial plants traditionally used as medicines may also produce anti-qs compounds. to test this hypothesis, 50 medicinal plants from southern florida were screened for anti-qs activity using two biomonitor strains, chromobacterium viol ...	2006	16406418
[chromobacteriosis in ilhéus, bahia: epidemiologic, clinical and laboratorial investigation].	in april/2004, a group of people traveled to a farm in a town in the south of bahia and afterwards, three teenagers from the same family developed symptoms of severe septicemia and two died. the health department carried out an epidemiologic, clinical, laboratory and environmental investigation that resulted in the identification of chromobacterium violaceum, in biological material from one of them, water and soil. this is the first report of the disease in bahia state.	2006	16410927
detection of chromobacterium violaceum by multiplex pcr targeting the prgi, spao, invg, and sipb genes.	based on the recently completed genomic sequence of chromobacterium violaceum american type culture collection (atcc) 12472 a multiplex pcr assay targeting the prgi, spao, invg, and sipb genes of the salmonella spi-1 homologue type-iii secretion system was developed. pcr products of 255bp (prgi), 749bp (spao), 1685bp (invg), and 1752bp (sipb) were successfully amplified simultaneously in a single reaction with all chr. violaceum strains investigated whereas other bacteria tested negative. the de ...	2006	16423655