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At least 19 recordsLinked to original sources

PubMed1997

Case report and review of Chromobacterium sepsis--a gram-negative sepsis mimicking melioidosis.

Chromobacterium violaceum has recently been recognised as a pathogen which can cause life-threatening disease. It is the only Chromobacterium species which is pathogenic to humans. Due to its unfamiliarity, clinicians often do not appreciate its importance when it is isolated in sterile cultures and may dismiss it as a "containment". It is therefore important for us to be aware of this infection and its clinical spectrum since it is a disease of the tropics. We report a paediatric case of documented Chromobacterium sepsis in Singapore who presented like septicaemic melioidosis associated with diminished T-cell numbers. A review of both fatal and non-fatal Chromobacterium, infections is also included.

Child↗

PubMed1982

Isolation of Chromobacterium spp. from foods, soil, and water.

Chromobacterium violaceum, a soil and water inhabitant, has been implicated in human disease with a high mortality rate, particularly in the southeastern United States. The psychrotrophic Chromobacterium lividum has been isolated from foods, water, and soil, but is not considered pathogenic. To determine the distribution of Chromobacterium spp. in soil, water, and foods in the Gainesville area, we evaluated Bennett, Ryalls and Moss, and Aeromonas membrane agars for their ability to recover these organisms from various samples when incubated at 25 or 35 degrees C. Bennett agar was best for the isolation of both species when incubated at 25 degrees C; however, at 35 degrees C, Aeromonas membrane agar gave the highest recoveries of C. violaceum. C. violaceum was recovered only from soil and water, whereas C. lividum was frequently recovered from foods as well as soil and water.

Chromobacterium↗

PubMed1962

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.

Chromobacterium↗

PubMed1963

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 fungus mycelium. The ease of decomposition varied, however, and polysaccharide from C. violaceum over a period of 1 month was more resistant than corn stalks, Rhodes grass, bean straw, and orange leaves. During the first week, it was as resistant to decay as pine needles. The C. violaceum polysaccharide was more effective in binding or aggregating the soil than all others tested. It also reduced the bulk density of Greenfield sandy loam and increased hydraulic conductivity in neutral soil.

Chromobacterium↗

PubMed1964

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 lost the capacity to bind the polymer into a matrix. Gelatinous strains growing in Tryptone did not produce a matrix, but rather elaborated polysaccharide free into the medium. The effect of Tryptone was not one of selection of nongelatinous variants. Growth and polysaccharide synthesis in a defined medium were greatest when amino acids were substituted for ammonia as a nitrogen source. Best growth and polysaccharide yield occurred when the ratio of carbohydrate to nitrogen was in the order of 10:1. Depolymerization of formed polymer occurred in cultures grown with Casamino Acids as the nitrogen source. Calcium ion stimulated polysaccharide formation. Iron, although stimulating growth, inhibited polysaccharide formation.

Amino Acids↗

PubMed1965

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 methionine on cyanide formation in a chemically defined medium was observed, and the amount of cyanide formed was found to be dependent on the concentrations of the two substances. Cyanide formation by nonproliferating cells was stimulated by preincubation with glycine and methionine. Cyanide formation by adapted cells in the presence of glycine and methionine was stimulated by succinate, malate, or fumarate, and depressed by azide and 2,4-dinitrophenol. Methionine could be replaced by betaine, dimethylglycine, and choline.

2,4-Dinitrophenol↗

PubMed2002

Chromobacterium violaceum septicemia.

Chromobacterium violaceum is an extremely rare human pathogen. We report a rare case of septicemia with multiple abscesses and otitis media in a newborn caused by chromobacterium violaceum.

Bacteremia↗

PubMed2000

Chromobacterium violaceum diarrhea.

This is the first case of Chromobacterium violaceum diarrhoea from coastal Karnataka reported in a 2 year 10 months old girl. Stool culture yielded Chromobacterium violaceum and was sensitive to ampicillin, gentamicin, chloramphenicol, erythromycin and septran. Patient completely recovered with ampicillin and gentamicin.

Child, Preschool↗

PubMed1975

Metabolism of N-carbobenzoxyl-L-tryptophan by Chromobacterium violaceum.

Chromobacterium violaceum (ATCC 12472) metabolizes N-carbobenzoxyl-L-tryptophan into its 2', 3'-dehydro-derivative, and indole-3-propionic acid into indole-3-acrylic acid. The biotransformation accurs in resting cell incubations, and in growing cultures of the bacterium. Tryptophan in fermentation media enhances the ability of Chromobacterium violaceum to perform the conversion by an undetermined mechanism. The amino acid also prevents stored cultures from losing the ability to accomplish the biotransformation. The reaction apparently requires oxygen, and preliminary experiments suggest that it is catalyzed by a dehydrogenase.

Acrylates↗

PubMed2005

Effect of temperature, pH, and metals on the stability and activity of phenylalanine hydroxylase from Chromobacterium violaceum.

Phenylalanine hydroxylase (PAH) is a non-heme iron dioxygenase catalyzing the conversion of phenylalanine to tyrosine and is present in both prokaryotic and eukaryotic organisms. A relatively simple PAH is expressed by Chromobacterium violaceum, a gram-negative bacterium found in tropical and subtropical regions. The effects of temperature, pH and metals on the stability and catalytic activity of Chromobacterium violaceum PAH were determined by steady-state kinetics, circular dichroism (CD) and differential scanning calorimetry (DSC). The kcat and KM for phenylalanine were determined between 7 and 40 degrees C. The KM remained constant between 20 and 40 degrees C but rapidly increased below 20 degrees C. The half-life of the enzyme at 47 degrees C is 66+/-4 min in the presence of Fe(II) and 8+/-1 min in the presence of EDTA. The melting temperature of the protein determined by CD and DSC is 53+/-2 degrees C in the presence of EDTA and 63+/-2 degrees C in the presence of Fe(II). Co(II) stabilizes the enzyme (Tm=63+/-2 degrees C) and inhibits the catalytic activity by displacing iron from the active site. The optimum pH for catalytic activity and stability is 7.4. In conclusion, PAH is adapted for optimal phenylalanine binding at temperatures above 20 degrees C and Fe(II) enhances the resistance of the enzyme to thermal denaturation.

Binding Sites↗

PubMed2004

[Violacein: a molecule of biological interest originating from the soil-borne bacterium Chromobacterium violaceum].

INTRODUCTION: 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. EXEGESIS: Chromobacterium violaceum is a soil-borne bacterium producing a characteristic antibiotic termed violacein. It is part of a series of compounds released by C. violaceum to oppose competitors and predators in the soil and water environments. Violacein, and one of these compounds, i.e. structure FR901228, exhibit antiparasitic and antitumoral activities of potential medical interest. Genes involved in the synthesis of these compounds are available, the genome sequence of C. violaceum (strain ATCC 12472) being published. CONCLUSIONS: The above example, involving Chromobacterium, is not an exception: soil constitutes a reservoir of molecules, enzymatic activities and micro-organisms of biological interest, the study of which will undoubtedly lead to developments in fields as diverse as agronomy or animal and human therapeutics.

Agriculture↗

PubMed1998

Inhibition of lipases from Chromobacterium viscosum and Rhizopus oryzae by tetrahydrolipstatin.

Tetrahydrolipstatin is known as an inhibitor for pancreatic lipase but not for microbial lipases. In this paper we demonstrate that in the presence of water-insoluble substrates like tributyrin or olive oil, tetrahydrolipstatin inhibits the lipases of Chromobacterium viscosum and Rhizopus oryzae, although with different potency. In contrast to porcine pancreatic lipase, which forms an irreversible and covalent enzyme-inhibitor complex with tetrahydrolipstatin, the inhibition of the microbial lipases is reversible as the inhibitor can be removed from the enzyme-inhibitor complex by solvent extraction. Moreover, after inhibition of Chromobacterium viscosum lipase tetrahydrolipstatin remains chemically unchanged.

2-Propanol↗

PubMed1998

Preliminary study on hydrophobic interaction chromatography of Chromobacterium viscosum lipase on polypropylene glycol immobilized on Sepharose.

The purification of Chromobacterium viscosum lipase was performed using a polypropylene glycol-Sepharose gel. The influence of the mobile phase composition on the chromatographic behaviour of Chromobacterium viscosum lipase was studied and it was found that the retention of lipase depends on the salt used and increased with ionic strength. Using 20% (w/v) ammonium sulphate in the eluent, a total retention of lipase on the column was obtained.

Bacterial Proteins↗

PubMed1999

Hydrophobic interaction chromatography of Chromobacterium viscosum lipase on polypropylene glycol immobilised on Sepharose.

The fractionation of Chromobacterium viscosum lipase was performed using a polypropylene glycol-Sepharose gel. The influence of mobile phase composition on the adsorption of lipase on the gel was studied and it was found that the retention of lipase depends on the salt used and increased with increasing the ionic strength. The retention was not strongly affected by changing the pH value of the mobile phase. By using 20% (w/v) ammonium sulphate in phosphate buffer a total retention of lipase on the column was obtained and by simply decreasing the ionic strength of the buffer, desorption of lipase could be achieved. The chromatographic purification of Chromobacterium viscosum lipase by hydrophobic interaction chromatography on Sepharose CL-6B modified by covalent immobilisation of 1,4-butanediol diglycidyl ether, polyethylene glycol and polypropylene glycol was also compared.

Butylene Glycols↗

PubMed2001

Chromobacterium violaceum: a review of pharmacological and industiral perspectives.

Violet-pigmented bacteria, which have been described since the end of the 19th century, are occasionally the causative agent of septicemia and sometimes cause fatal infection in human and animals. Bacteria, producing violet colonies due to the production of a nondiffusible pigment violacein, were classified as a redefined genus Chromobacterium. Chromobacterium violaceum is gram-negative, and saprophyte from soil and water is normally considered nonpathogenic to human, but is an opportunistic pathogen of extreme virulence for human and animals. The biosynthesis and biological activities of violacein and the diverse effects of this pigment have been studied. Besides violacein, C. violaceum produces other antibiotics, such as aerocyanidin and aerocavin, which exhibit in vitro activity against both gram-negative and gram-positive bacteria. 3,6-Dihydroxyindoxazene and Y-TO678h exhibit a selective activity against gram-negative bacteria. Arphamenine A and B, and FR901228, that enhanced immunoresponse, and potentiators of beta-lactam antibiotics and chelators such as ferrioxamine exhibit important clinical potential applications. Lipopolysaccharides and polyhydroxyesters together with several enzymes appear as important metabolites with biotechnological applications. Many of these metabolites were already studied at the genome level.

Anti-Bacterial Agents↗

PubMed1993

Nonfatal and fatal infections caused by Chromobacterium violaceum.

Human infection caused by Chromobacterium violaceum is rare, but when it occurs it is associated with a high mortality rate. We report the cases of two patients with infection due to Chromobacterium violaceum. One patient presented early in the course of disease and survived after receiving appropriate antibiotic therapy. The other patient presented late in the course of disease and died of fulminant sepsis with abscesses in multiple organs. We discuss the similarity between C. violaceum infection and the septicemic form of melioidosis.

Adult↗

PubMed1976

Effective method for activity assay of lipase from Chromobacterium viscosum.

A method was devised for activity assay of the lipase [triacylglycerol acyl-hydrolase, EC 3.1.1.3] excreted from Chromobacterium viscosum into the culture medium; olive oil emulsified with the aid of Adekatol 45-S-8 (a non-ionic detergent, the ethoxylate of linear sec-alcohols having chain lengths of 10--16 carbon atoms) was used as the substrate. This method was specifically effective for Chromobacterium lipase acitvity assay, and was approximately twice as sensitive as the conventional method, in which polyvinyl alcohol is used for the emulsification of the substrate.

Chromobacterium↗

PubMed1982

DNA:rRNA hybridization studies of Chromobacterium fluviatile.

Hybrids were prepared between 14C-labelled rRNA from each of nine species of Gram-negative bacteria and the DNA of Chromobacterium fluviatile. Two parameters were determined for each hybrid - the T m(e), which is the temperature at which 50% of the hybrid was denatured, and the percentage of rRNA bound under defined stringent conditions. The former gives a measure of the stability of the duplex once formed and the latter probability reflects the amount of the genome involved in the coding of rRNA. These parameters were used as a measure of the relatedness of C. fluviatile to each of the other nine species. The results suggest that C. fluviatile is more closely related to C. violaceum than to any other species tested. The taxonomic relationship of C. fluviatile to other Gram-negative bacteria was assessed by incorporating the results into a database already published by De Ley et al. (1978), and the use of principal components analysis was explored as an alternative way of presenting such data. This analysis confirmed the isolated position of C. fluviatile but, until further isolates are studied, it seems best to retain the species in the genus Chromobacterium.

Chromobacterium↗