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A case of Chromobacterium violaceum fatal septicemia is reported. The microorganism was isolated from six blood cultures and two suppurated skin lesions. It is the first such case described in Argentina, and it reinforces the need for prolonged treatment and careful clinical evaluation to ensure complete remission of human infections caused by this bacterium.
This is the first report of Chromobacterium violaceum strains that are aerogenic. Two pigmented strains of C. violaceum and their nonpigmented variants produced gas in glucose broth. Kliger iron agar, and triple sugar iron agar. They were similar morphologically and biochemically to other anaerogenic strains studied previously.
Chromobacterium violaceum is a gram-negative rod and is isolated from soil and water in tropical and subtropical regions. The species have pigmented and nonpigmented colony types. Infections caused by nonpigmented strains are rare. We report on two cases of infection caused by both pigmented and nonpigmented strains of C. violaceum. Two 24-year-old Korea Airline stewardesses were admitted to Inha University Hospital, Inchon, South Korea, on 9 August 1997, 3 days after an airplane accident in Guam. Both had multiple lacerations on exposed parts of their bodies. There was swelling, tenderness, and pus discharge. The wounds contained many small fragments of stones and weeds. A pigmented strain was isolated from the left hand and a nonpigmented strain was isolated from the left knee of one patient. For the other patient only a nonpigmented strain was isolated from a foot wound. The nonpigmented colonies from the left-knee and the left-foot wounds did not produce any pigment even after an extended period of incubation. The biochemical characteristics were the same for each strain except for oxidase and indole reactions. The pigmented strain was oxidase negative and indole positive, whereas the nonpigmented strains were oxidase positive and indole negative. The patients were successfully treated by debridement and with appropriate antibiotics.
A clinical isolate and a soil isolate of Chromobacterium violaceum were compared to determine differences in virulence-related characteristics. Purified lipopolysaccharide (endotoxin) from the virulent, clinical strain was more reactive than that from the avirulent soil strain as determined by the Limulus amebocyte lysate assay. There were no differences in hemolysin or cyanide production between the two strains. The virulent strain was more resistant to phagocytosis and intracellular killing by human polymorphonucleocytes. The clinical strain showed a superoxide dismutase activity 30% higher and a catalase activity fivefold higher than the activities of the soil-isolated strain. The clinical strain also was capable of producing approximately twice as much hydrogen peroxide during growth as compared with the soil isolate. This study suggests that virulence of C. violaceum may be, at least in part, associated with endotoxin, and some protection of the virulent, clinical strain from phagocytic attack is afforded by elevated levels of superoxide dismutase and catalase.
The first human infection with Chromobacterium violaceum was recorded in 1927, but since then there have been about 33 cases reported worldwide, including two from Australia. Chr. violaceum occurs in the tropics and subtropics and is generally considered to be nonpathogenic, but infection can occur in patients who are immunosuppressed and it has a high mortality rate. This paper presents the intensive care management of two cases of Chr. violaceum infection occurring in Far North Queensland. The patients' predisposition appears to have been malnourishment and alcohol abuse. The increased use of immunosuppressive drugs and the appearance of diseases such as acquired immune deficiency syndrome (AIDS) make it possible that we will see more of this condition in Australian intensive care units.
BACKGROUND: 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 variety of natural and chemically synthesized furanones for their ability to interfere with the quorum sensing mechanism using a quantitative bioassay with Chromobacterium violaceum CV026 for antagonistic and agonistic action. We were looking at the following questions: 1) Do these compounds affect growth? 2) Do these compounds activate the quorum sensing system of C. violaceum CV026? 3) Do these compounds inhibit violacein formation induced by the addition of the natural inducer N-hexanoylhomoserine lactone (HHL)? 4) Do these compounds enhance violacein formation in presence of HHL? RESULTS: The naturally produced N-acylhomoserine lactones showed a strong non-linear concentration dependent influence on violacein production in C. violaceum with a maximum at 3.7*10-8 M with HHL. Apart from the N-acylhomoserine lactones only one furanone (emoxyfurane) was found to simulate N-acylhomoserine lactone activity and induce violacein formation. The most effective substances acting negatively both on growth and quorum sensing were analogs and intermediates in synthesis of the butenolides from Streptomyces antibioticus. CONCLUSION: As the regulation of many bacterial processes is governed by quorum sensing systems, the finding of natural and synthetic furanones acting as agonists or antagonists suggests an interesting tool to control and handle detrimental AHL induced effects. Some effects are due to general toxicity; others are explained by a competitive interaction for LuxR proteins. For further experiments it is important to be aware of the fact that quorum sensing active compounds have non-linear effects. Inducers can act as inhibitors and inhibitors might be able to activate or enhance the quorum sensing system depending on chemical structure and concentration levels.
We report the second case of infection with Chromobacterium violaceum that occurred in Brazil. A farm worker living in the State of São Paulo presented fever and severe abdominal pain for four days. At hospitalization the patient was in a toxemic state and had a distended and painful abdomen. Chest X-ray and abdominal ultrasound revealed bilateral pneumonia and hypoechoic areas in the liver. The patient developed failure of multiple organs and died a few hours later. Blood culture led to isolation of C. violaceum resistant to ampicillin and cephalosporins and sensitive to chloramphenicol, tetracyclin, aminoglicosydes, and ciprofloxacin. Autopsy revealed pulmonary microabscesses and multiple abscesses in the liver. The major features of this case are generally observed in infections by C. violaceum: rapid clinical course, multiple visceral abscesses, and high mortality. Because of the antimicrobial resistance profile of this Gram-negative bacillus, for appropriate empirical antibiotic therapy it is important to consider chromobacteriosis in the differential diagnosis of severe community infections in Brazil.
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 inverted light microscopy and cell viability tests using the Trypan blue dye exclusion method and the MTT assay. The cytotoxic concentration values which cause destruction in 50% of the monolayer cells (CC50) were different depending on the sensitivity of the method. CC50 values were > or =2.07 +/- 0.08 microM for FRhK-4 cells: > or =2.23 +/- 0.11 microM for Vero cells; > or =2.54 +/- 0.18 microM for MA104 cells; and > or =2.70 +/- 0.20 microM for HEp-2 cells. Violacein showed no cytopathic inhibition of the following viruses: herpes simplex virus type 1 (HSV-1) strain 29-R/acyclovir resistant, hepatitis A virus (strains HM175 and HAF-203) and adenovirus type 5 nor did it show any antiviral activity in the MTT assay. However violacein did show a weak inhibition of viral replication: 1.42 +/- 0.68%, 14.48 +/- 5.06% and 21.47 +/- 3.74% for HSV-1 (strain KOS); 5.96 +/- 2.51%, 8.75 +/- 3.08% and 17.75 +/- 5.19% for HSV-1 (strain ATCC/VR-733); 5.13 +/- 2.38 %, 8.18 +/- 1.11% and 8.51 +/- 1.94% for poliovirus type 2; 8.30 +/- 4.24%; 13.33 +/- 4.66% and 24.27 +/- 2.18% for simian rotavirus SA11, at 0.312, 0.625 and 1.250 mM, respectively, when measured by the MTT assay.
Occurrence of Chromobacterium violaceum in six protected drinking water springs in Uganda was investigated. C. violaceum showed a contrasting occurrence, which was independent of human impact as assessed by faecal pollution indicators. It was isolated from two springs (S1 and S2) that were located close to each other (3 km) but not in the rest. In S1 C. violaceum was continuously detected, in concentrations ranging from 6 to 270 cfu 100 ml(-1), while in S2 it was detected on only one sampling occasion. C. violaceum was never detected in the investigated upper soil layers (down to 15 cm) in the immediate surroundings (50 m radius) of the springs, despite continued isolation of faecal indicators. The results of the study indicate that C. violaceum may not be ubiquitous in spring water, but could occur in significant numbers in particular potable groundwaters as an autochthonous member.
Chromobacterium violaceum, a saprophyte bacterium found commonly in soil and water in tropical and subtropical climates, is a rare cause of severe, often fatal, human disease. We report 1 confirmed and 2 suspected cases of C. violaceum septicemia, with 2 fatalities, in siblings after recreational exposure in northeastern Brazil.
Chromobacterium violaceum is a gram negative straight rod, 0.8-1.2 by 2.5 to 6.0 m, which is motile by one polar flagella and one to four lateral flagella. The organism inhabits soil and water and is often found in semitropical and tropical climates. Infections in humans are rare. We report a case of infection caused by strains of C. violaceum. A 38-year-old male patient was admitted to KyungHee University Hospital, Seoul, Korea on July 28th, 2003, after a car accident. The patient had multiple trauma and lacerations. He had an open wound in the left tibial area from which C. violaceum was isolated. The strain was resistant to ampicillin, tobramycin, ampicillin/sulbactam, ceftriaxone and cefepime, but was susceptible to amikacin, gentamicin, ciprofloxacin, levofloxacin, trimethoprim/sulfamethoxazole and piperacillin/tazobactam. The patient was treated successfully by debridement, cephapirin sodium and astromicine sulfate.
Chromobacterium violaceum is a saprophyte of soil and water in tropical and subtropical environments that is associated with rare but highly fatal infections in animals and humans. Systemic infection was diagnosed in two critically ill dogs from Florida. Fever was absent in both dogs. Both dogs were treated surgically and provided with intensive care, but only one survived. The identification of characteristic, violet-pigmented bacterial colonies on routine microbial cultures should alert microbiologists and clinicians to the likelihood of this dangerous pathogen. Because of the rapidly progressive nature of this infection, empirical antibiotic administration with fluoroquinolones should be employed pending susceptibility testing.
Chromobacterium violaceum is a Gram-negative organism which normally inhabits water and soil. Human infection is unusual and is associated with a high mortality rate. We describe a typical case of disseminated infection with Chr. violaceum in a male carpet cleaner. The possible origin and treatment of the infection is discussed.
Chromobacterium violaceum is an unusual cause of infection which may have fatality rates of over 60% when systemic illness occurs. We describe four patients infected with this organism who were successfully treated at Royal Darwin Hospital between 1991 and 1996. In tropical Australia, C. violaceum infection should be considered along with melioidosis in patients who present with a septic illness with skin lesions and/or organ abscesses after exposure to soil in the wet season.
A new antibiotic, aerocavin, has been isolated from fermentation broths of a non-pigmented strain of Chromobacterium violaceum. The structure 1 was deduced from its spectroscopic properties and X-ray diffraction analysis. Aerocavin exhibits activity in vitro against Gram-positive and Gram-negative bacteria.
Aerocyanidin, a new antibiotic containing an isonitrile group, has been isolated from fermentations of Chromobacterium violaceum ATCC 53434. Structure 1 was assigned on the bais of spectroscopic characterization of the antibiotic and of a degradation product that results from treatment with base. The antibiotic is primarily active against Gram-positive bacteria.
A novel antitumor bicyclic depsipeptide, FR901228, was isolated from a broth culture of Chromobacterium violaceum No. 968 as colorless prisms and the molecular formula was determined as C24H36N4O6S2. This antibiotic reverted the transformed morphology of a Ha-ras transformant to normal, and exhibited prominent antitumor activities against murine and human tumor cell lines both in vitro and in vivo.
The antitumor activities of FR901228, (E)-(1S,4S,10S,21R)-7-[(Z)- ethylidene]-4,21-diisopropyl-2-oxa-12,13-dithia-5,8,20,23- tetraazabicyclo[8,7,6]-tricos-16-ene-3,6,9,19,22-pentanone, isolated from Chromobacterium violaceum No. 968, were studied in animals. FR901228 (ip) prolonged the life of mice bearing such murine ascitic tumors as P388 and L1210 leukemias and B16 melanoma, and inhibited (iv) the growth of murine solid tumors (Colon 38 carcinoma, M5076 reticulum cell sarcoma and Meth A fibrosarcoma) and human solid tumors (Lu-65 and LC-6 lung carcinomas, and SC-6 stomach adenocarcinoma) implanted in normal and nude mice, respectively. Its antitumor activity was especially potent against murine Meth A fibrosarcoma and human SC-6 stomach adenocarcinoma which were refractory to mitomycin C or cisplatin. FR901228 also was more effective against mitomycin C-, cyclophosphamide-, vincristine- and 5-fluorouracil-resistant P388 leukemias than against non-resistant P388 in mice. These results suggest that FR901228 will be a new type of drug for the treatment of cancer.