Clinical presentation and treatment of 2 patients with infection caused by Chromobacterium violaceum in Vietnam.

Chromobacterium violaceum is a rare but severe and often fatal cause of disease in humans. We present 2 clinical cases of sepsis and skin abscesses / cellulitis caused by C. violaceum seen in a referral hospital for infectious diseases in Vietnam. Both patients survived, but appropriate antibiotic treatment was only installed after culture of the organism. We reviewed and summarised the characteristics of C. violaceum infection and treatment.

In vitro antibacterial-antibiofilm effect of Hypericum atomarium Boiss and chemical composition

Abstract Treatment with plant is considered an effective option against increased antibiotic resistance. In this study antibiofilm activity of methanol (CH3OH), chloroform (CHCl3), ethyl acetate (EtOAc) and water (H2O) extracts of Hypericum atomarium Boiss. which is member of Hypericum genus was evaluated in Pseudomonas aeruginosa PAO1 and antibacterial performance against Gram (+) and Gram (-) strains and also bioactive compounds of extract were analysed using by HPLC and GC-MS. According to antibacterial activity test results the extracts were effective all Gram (+) bacteria and Gram (-) Chromobacterium violaceum (MICs ranging from 0.42 µg/ml to 4.3 mg). Inhibition effect of biofilm formation was found to be different rate in extracts (methanol-63%, chloroform-52%). The major flavonoids were detected (−)-epicatechin (2388.93 µg/ml) and (+)-catechin (788.94 µg/ml). The main phenolic acids were appeared as caffeic acid 277.34 µg/ml and chlorogenic acid 261.79 µg/ml. And according to GC results α-pinene was found main compound for three solvent extracts methanol, chloroform and ethyl acetate 67.05, 62.69, 49.28% rate respectively

Successful treatment of a patient with recurrent infection of Chromobacterium violaceum.

BACKGROUND: Chromobacterium violaceum (C. violaceum) is a Gram-negative saprophytic bacterium that is widespread in tropical and subtropical environments, and belongs to conditional pathogenic bacteria. Human infection with C. violaceum is rare, and this can be fatal when the diagnosis and treatment are delayed, especially recurrent infection patients. Since clinicians lack the knowledge for C. violaceum, rapid diagnosis and early appropriate antimicrobial treatment remains challenging. CASE PRESENTATION: A 15-year-old male student was hospitalized for dark abscess, pustules, severe pain in both legs, and fever for 11 days. There were pustules with gray-white pus and red infiltrating plaques on the back, and the subcutaneous nodules could be touched in front of both tibias, with scab, rupture and necrotic tissue of the lower limb. The patient's condition rapidly progressed. Therefore, next-generation sequencing (NGS), pustular secretion and blood culture were concurrently performed. The final diagnosis for this patient was C. violaceum infection by NGS. However, no bacterial or fungal growth was observed in the pustular secretion and blood culture. After 4 weeks of treatment, the patient was discharged from the hospital without any complications associated with C. violaceum infection. CONCLUSION: Rapid diagnosis and early appropriate antimicrobial treatment is the key to the successful treatment of C. violaceum infection, especially in patients with sepsis symptoms. This case highlights that NGS is a promising tool for the rapid diagnosis of C. violaceum infection, preventing the delayed diagnosis and misdiagnosis of C. violaceum infection in patients who tested negative for pustular secretion and blood culture.

Pediatric osteomyelitis due to rare tropical multi-drug resistance (MDR) organisms: a treatment quandary.

Osteomyelits due to concurrent multi-drug resistance organisms is difficult to treat for any surgeon and infectious disease physician. An eleven-year-old boy presenting with an open fracture of the left radius and ulna after a fall in a stagnant wet field. Despite prophylactic antibiotics and surgical intervention, the open wound was infected, and Chromobacterium violaceum as well as Klebsiella pneumoniae were isolated. He was treated with six weeks of parenteral cefepime and amikacin and was discharged upon clinical improvement. Unfortunately, chronic osteomyelitis set in with persistent sinus drainage. He then underwent a second procedure for debridement of the wound and Burkholderia pseudomallei was isolated. Parenteral antibiotic therapy was initiated progressing with a marked improvement. However, the long course of antibiotics had exhausted the patient and his family, leading to a premature interruption of the parenteral antibiotic. Despite the suboptimal antibiotic course, there were no signs of relapsed osteomyelitis during subsequent review. The timely surgical intervention with appropriate sampling for subsequent microorganism isolation guided the suitability of the treatment line.

Chromobacterium violaceum infection on lower limb skin: A case report.

RATIONAL: Chromobacterium violaceum is a motile gram-negative bacterium. This bacterium commonly grows in tropical or subtropical areas in sewage and can cause opportunistic infections. PATIENT CONCERNS: A 50-year-old Chinese man had a skin ulcer in the middle of his left leg in front of the tibia. The diameter of the wound was 3.0 cm, the exudation was obvious, and necrotic tissue was attached to the wound. One week previously, he was working in a field where he accidentally punctured his left leg. DIAGNOSIS: C violaceum infection was diagnosed as per the results of pathogen culture from the infection site. INTERVENTIONS: He was treated with piperacillin/tazobactam (3.375 g/12 h iv) and levofloxacin (0.5 g/24 h iv) for 5 days. OUTCOMES: The patient showed good response to therapy and was discharged on day 18 after wound healing. LESSONS: C violaceum rarely infects humans. When an infection is suspected, samples should be immediately sent for microbial culture. Timely treatment on the basis of drug sensitivity test results can prevent further complications.

Chromobacterium paludis sp. nov., a novel bacterium isolated from a Chesapeake Bay marsh.

Two isolates of Gram-reaction-negative, motile, violet-pigmented bacteria were isolated from a small pool in marshland near the mouth of the Nanticoke River in Maryland, USA. The isolates IIBBL 257-1T and IIBBL 257-2 had identical 16S rRNA gene sequences as determined by PCR, and highly similar fatty acid and biochemical profiles. The 16S rRNA gene sequences indicated the isolates belonged to the genus Chromobacterium. Genomic sequencing of IIBBL 257-1T revealed a genome of 4.27 Mb, with a G+C content of 63.6 %. Whole genome comparisons with other members of the Chromobacterium using JSpecies and the genome blast distance phylogeny approach indicated that among described species, IIBBL 257-1T was most closely related to C. amazonense and C. phragmitis. Comparison of the IIBBL 257-1T genome with those of type strains of these species resulted in ANIb and dDDH values of ca. 85 and 30 %, respectively, for both. These results demonstrate that IIBBL 257-1T and IIBBL 257-2 represent a new taxon within the genus Chromobacterium. We propose the name Chromobacterium paludis sp. nov. for this taxon; the type strain is IIBBL 257-1T (=NRRL B-65555T=JCM 33770T).

Marine bacteria associated with shallow hydrothermal systems in the Gulf of California with the capacity to produce biofilm inhibiting compounds.

Shallow hydrothermal systems are extreme environments. The sediments and fluids emitted from the vents present unusual physical and chemical conditions compared to other marine areas, which promotes unique biodiversity that has been of great interest for biotechnology for some years. In this work, a bioprospective study was carried out to evaluate the capacity of bacteria associated with shallow hydrothermal vents to produce biofilm-inhibiting compounds. Degradation assays of N-acyl homoserine lactone (AHL) autoinducers (C6HSL) involved in the quorum sensing process were carried out on 161 strains of bacteria isolated from three shallow hydrothermal systems located in Baja California Sur (BCS), Mexico. The biosensor Chromobacterium violaceum CV026 was used. Twenty-three strains showed activity, and organic extracts were obtained with ethyl acetate. The potential of the extracts to inhibit the formation of biofilms was tested against two human pathogenic strains (Pseudomonas aeruginosa PAO1 and Aeromonas caviae ScH3), a shrimp pathogen (Vibrio parahaemolyticus M8), and two marine strains identified as producing biofilms on submerged surfaces (Virgibacillus sp C29 and Vibrio alginolyticus C96). The results showed that Vibrio alginolyticus and Brevibacillus thermoruber, as well as some thermotolerant strains (mostly Bacillus), produce compounds that inhibit bacterial biofilms (B. licheniformis, B. paralicheniformis, B. firmus, B. oceanizedimenis, B. aerius and B. sonorensis).

Chromobacteriosis (Chromobacterium violaceum) in a calf from Brazil - case report / Cromobacteriose (Chromobacterium violaceum) em um bezerro do Brasil - relato de caso

Chromobacterium violaceum is a rare opportunistic pathogen that causes highly fatal infections in domestic animals and humans. This report describes a fatal case suggestive of septicemia in a four-day-old female calf with chromobacteriosis. The calf had suppurative omphalophlebitis, suppurative fibrinous polyarthritis, anterior uveitis with bilateral fibrin deposition, fibrinous peritonitis, lymph node abscess and multifocal lymphocytic and neutrophilic encephalitis with multifocal hemorrhages. C. violaceum was isolated from the spleen and peri-renal lymph node and its identity was confirmed by PCR and sequencing. The pathogen was sensitive to azithromycin, gentamicin, enrofloxacin, norfloxacin, marbofloxacin, ciprofloxacin, erythromycin, sulphazotrim, fluorfenicol, tetracycline and doxycycline as well as resistant to penicillin, ampicillin, vancomycin, amoxicillin, amoxicillin + clavulanic acid, cephalothin, cephalexin, oxacillin, B polymyxin, neomycin and bacitracin. This is the first report of chromobacteriosis in a calf from Brazil.(AU)

Chromobacterium violaceum é um patógeno oportunista raro, que causa infecção fatal em animais domésticos e em humanos. Este relato descreve um caso fatal suspeito de septicemia em um bezerro de quatro dias, fêmea, infectado por C. violaceum. O bezerro apresentava onfaloflebite supurativa, poliartrite supurativa fibrinosa, uveíte anterior com deposição bilateral de fibrina, peritonite fibrinosa, abscesso de linfonodos e encefalite multifocal linfocítica e neutrofílica com áreas hemorrágicas multifocais. C. violaceum foi isolado no baço e no linfonodo, e sua identidade foi confirmada por PCR e sequenciamento. O patógeno foi sensível aos antibióticos azitromicina, gentamicina, enrofloxacina, norfloxacina, marbofloxacina, ciprofloxacina, eritromicina, sulfazotrim, florfenicol, tetraciclina, doxiciclina e foi resistente à penicilina, ampicilina, vancomicina, amoxicilina, amoxicilina + ácido clavulânico, cefalotina, cefalexina, oxacilina, polimixina B, neomicina e bacitracina. Este é o primeiro relato de cromobacteriose em bezerro no Brasil.(AU)

Sepsis caused by Chromobacterium violaceum - probably the first case in Europe, or Macbeth read anew.

Rare diseases, almost by definition, present us with diagnostic as well as therapeutic difficulties as. They also include infectious diseases outside endemic areas. Without expecting them, we are not preparing to fight them. Like Macbeth, we feel safe, convinced that tropical diseases do not reach us, like Birnam forest towards his castle. Nevertheless, the forest moved according to the prophecy of the three witches, and in a similar way tropical flora is moving towards us according to the predictions of environmentalists. This is illustrated by the history of the presented patient, who was admitted to hospital because of sepsis caused by Chromobacterium violaceum (CV), a Gram-negative facultatively anaerobic, oxidase-positive bacterium producing a dark violet antioxidant pigment called violacein. This is probably the first documented case report of sepsis in this part of the world. To the best of the authors' knowledge, the patient is the first to require dialysis after Chromobacterium violaceum infection.

Septicemia por Chromobacterium Violaceum en pediatría / Septicemia due to Chromobacterium Violaceum in pediatrics

Chromobacterium violaceum es una bacteria gram negativa anaerobia facultativa, que se encuentra ampliamente distribuida en el agua y el suelo en regiones tropicales y subtropicales, que se asocia con infecciones respiratorias, gastrointestinales, abscesos hepáticos, meningitis, endocarditis, síndrome hemofagocítico y sepsis fulminante. Se presentan 2 casos en niños: el primero es un varón de 8 años con lesiones en piel, fiebre y adenitis inguinal, que ingresó con un cuadro de sepsis severa, síndrome de distrés respiratorio agudo (SDRA) y falleció a las 3 h del ingreso. De los hemocultivos se aisló Chromobacterium violaceum. El segundo caso, es una niña de 12 años con antecedente de fiebre y adenopatía inguinal secundaria a herida cortopunzante en el pie homolateral, que ingresó con un cuadro de sepsis, con desarrollo de abscesos múltiples profundos. De la colección obtenida de piel y partes blandas y de un aspirado traqueal se aisló Chromobacterium violaceum. Recibió tratamiento antibiótico adecuado y posteriormente fue dada de alta. Se realizó una revisión bibliográfica de esta infección en niños y se encontraron 44 casos en todo el mundo. Algunos de éstos, se relacionaron con inmunodeficiencia de base, como la enfermedad granulomatosa crónica. La infección por esta bacteria es rara y se presenta como un cuadro grave que no responde a antibióticos habituales de uso empírico y tiene una alta tasa de mortalidad (AU)

Chromobacterium violaceum is a facultative anaerobic Gramnegative bacillus, widely distributed in water and soil in tropical and subtropical regions and associated with respiratory and gastrointestinal infections, liver abscesses, meningitis, endocarditis, hemophagocytic syndrome, and fulminant sepsis. Here two pediatric cases are presented: The first was an 8-year-old boy with skin lesions, fever, and inguinal adenitis, who was admitted with severe sepsis, acute respiratory distress syndrome (ARDS) and died three hours after. Chromobacterium violaceum was isolated from blood cultures. The second case was a 12-year-old girl with a history of fever and inguinal adenopathy secondary to a wound in the homolateral foot, who was admitted because of sepsis and multiple deep abscesses. From samples collected from the skin and soft tissues as well as tracheal aspirate Chromobacterium violaceum was isolated. Adequate antibiotic treatment was started and the patient was subsequently discharged. In a review of the literature, 44 cases worldwide were identified. Some of these cases were related to underlying immunodeficiency, such as chronic granulomatous disease. Infection with this bacterium is rare and presents with severe manifestations that do not respond to the common empirical antibiotics and are associated with a high mortality rate (AU)

Bacterial endophytes from Artemisia nilagirica (Clarke) Pamp., with antibacterial efficacy against human pathogens.

A study was conducted to isolate and characterize endophytes from Artemisia nilagirica, a traditional medicinal plant. The plant was collected from Western Ghats, India. Endophytes isolated included Arthrobacter sp. WWAT1, Pseudomonas sp. WYAT2, Microbacterium sp. WYAT3, Psychrobacter sp. WBAT4, Enterobacter sp. WWAT5, Bacillus sp. WBAT6, Kosakonia cowanii WBAT7, Bacillus sp. WBAT8, Bacillus sp. WBAT9, Chromobacterium violaceum WVAT6, Serratia sp.WPAT8 and Burkholderia sp. WYAT7. Of these two bacteria, Chromobacterium violaceum strain WVAT6 and Burkholderia sp. strain WYAT exhibited antibacterial property against human pathogens. Similar to the environmental isolates, Burkholderia sp. WYAT7 showed pleomorphism and produced different enzymes, whereas like clinical strains they showed multidrug resistance, for their survival in different environmental conditions. Chromobacterium violaceum WVAT6 exhibited rod shape morphology and showed multiple drug resistance except to erythromycin, tetracycline and gentamicin antibiotics. Both produced biofilm and enzymes such as protease and lipase. The antimicrobial compounds from these endophytes may find application in the preparation of antimicrobial formulations.

Lactonase SsoPox modulates CRISPR-Cas expression in gram-negative proteobacteria using AHL-based quorum sensing systems.

Quorum sensing (QS) is a molecular communication system that bacteria use to harmonize the regulation of genes in a cell density-dependent manner. In proteobacteria, QS is involved, among others, in virulence, biofilm formation or CRISPR-Cas gene regulation. Here, we report for the first time the effect of a QS-interfering enzyme to alter the regulation of CRISPR-Cas systems in model and clinical strains of Pseudomonas aeruginosa, as well as in the marine bacterium Chromobacterium violaceum CV12472. The expression of CRISPR-Cas genes decreased in most cases suggesting that enzymatic disruption of QS is promising for modulating phage-bacteria interactions.

Chromobacterium phragmitis sp. nov., isolated from estuarine marshes.

Thirteen isolates of Gram-stain-negative, motile, violet-pigmented bacteria were isolated from marshes along tidal portions of the Potomac and James rivers in Maryland and Virginia, USA, respectively. 16S rRNA gene sequences and fatty acid analysis revealed a high degree of relatedness among the isolates, and genomic sequencing of two isolates, IIBBL 112-1T and IIBBL 274-1 (from the Potomac and James rivers, respectively), revealed highly similar genomic sequences, with a blast-based average nucleotide identity (ANIb) of ca. 98.7 %. Phylogenetic analysis of 16S rRNA gene sequences suggested that the species most highly related to IIBBL 112-1T were Chromobacterium amazonense, Chromobacterium subtsugae and Chromobacterium sphagni. However, deletion of a 25-nucleotide sequence that may have been horizontally acquired by both IIBBL 112-1T and C. amazonense resulted in a substantially different analysis; in the latter case, the species nearest IIBBL 112-1T were Chromobacterium violaceum, Chromobacterium vaccinii and Chromobacterium piscinae. Whole-genome alignments between either IIBBL 112-1T or IIBBL 274-1 and the type strains of C. vaccinii or C. violaceum resulted in ANIb values in the range of ca. 87 %, while alignment with C. amazonense CBMAI 310T resulted in an ANIb of ca. 83 %. Collectively, these data demonstrate that IIBBL 112-1T and IIBBL 274-1 represent a new taxon within the genus Chromobacterium. We propose the name Chromobacterium phragmitis sp. nov. for this taxon; the type strain is IIBBL 112-1T (=NRRL B-67132T=JCM 31884T).

Chromobacterium violaceum in Northern Australia: A Sheep in Wolf's Clothing?

In many parts of the world, the case-fatality rate of Chromobacterium violaceum infection approaches 60%. To evaluate the spectrum of disease associated with C. violaceum in Far North Queensland (FNQ), Australia, we reviewed all culture-confirmed isolates from 1997 to 2017. There were 28 isolates, 15 represented infection, 11 were contaminants, and two charts were destroyed preventing detailed evaluation of these cases. The most common sites of infection were the skin and soft tissue and the urinary tract; there were two cases of bacteremia without focus. There were no deaths attributable to C. violaceum during the study period and only two cases required intensive care unit support, although in both patients this was not for the C. violaceum infection, but for the management of other health issues. Globally, C. violaceum has a reputation as a deadly pathogen, but in FNQ, Australia, infections usually follow a relatively benign course.

Production of N-acyl homoserine lactones by Chromobacterium haemolyticum KM2 isolated from the river water in Malaysia.

Quorum sensing (QS) is a term used to describe cell-to-cell communication that enables bacteria to orchestrate group behaviours according to density of bacterial cells. In Gram-negative bacteria, this signalling system is widely known to regulate a variety of different phenotypes such as antibiotic production and biofilm formation. In this study, we report the production of N-acyl homoserine lactones produced by Chromobacterium haemolyticum strain KM2, a bacterium isolated from a river water of a reserved tropical national park. Preliminary screening of QS activity using biosensor reporter assays indicated that C. haemolyticum strain KM2 produces both short- and long-chain AHLs. Analysis with high-resolution liquid chromatography-mass spectrometry (LC-MS/MS) analysis revealed the production of three AHLs by strain KM2: N-octanoyl-L-homoserine lactone (C8-HSL), N-dodecanoyl-L-homoserine lactone (C12-HSL), and N-3-oxo-dodecanoyl-L-homoserine lactone (OC12-HSL). This bacterial isolate also exhibited strong ß-haemolytic activity. To the best of our knowledge, this is the first documentation of QS activity and multiple AHLs production by C. haemolyticum strain KM2.

Chromobacterium violaceum: The Deadly Sepsis.

Chromobacterium violaceum is a Gram-negative facultatively anaerobic, oxidase-positive bacterium producing a dark violet antioxidant pigment called violacein. It is an opportunistic pathogen and has an ubiquitous distribution, mainly resides in water and soil of tropical and subtropical regions.An-18-year-old man referred to the emergency room with a 5-day history of progressively worsening swelling of the right cheek. He sought consult and hospitalized at another institution for three days prior this admission; however, his condition deteriorated. He had a history of having abscesses several time. Four month before this visit, he was also admitted in our hospital due to an abscess in the right thigh. Pus and blood culture were positive for Staphylococcus haemolyticus, with a total serum IgE of 2493.0 IU/ml. He recovered completely after being treated with vancomycin in this event. He had neither diabetes mellitus nor human immunodeficiency virus infection history. In this presentation, he was in a critically ill state with septic shock. Physical examination revealed diffuse, indurated, partly fluctuant, and some deep purple area of right hemifacial swelling. It was extended anteriorly from angle of mouth to retroauricular, superiorly from superior palpebra to lower border of mandible. Laboratory studies were notable for a white-cell count of 12,970/mm3 (total lymphocyte count 778.2), platelet count 96,000/mm3. The patient got norepinephrine drip and broad-spectrum antibiotic intravenously. He also underwent superficial drainage of the abscess. Unfortunately, the patient eventually succumbed. Sample from right submandibular abscess showed no growth, but blood sample was confirmed to grow C. violaceum. It showed sensitivity to ciprofloxacin, amikacin, cotrimoxazole, chloramphenicol, tetracycline.Since it was firstly described in 1927, only a few cases of human infection with C. violaceum have been reported. As shown in our case, the classical clinical manifestation was localized soft tissue infection which rapidly progressed to fulminant sepsis with a high mortality rate. A defect in host defense system might be the predisposing factor for this kind of infection in our case. As this is such a rare infection, there is no guideline on the choice of antibiotics or duration of treatment at present. Successful treatment is most likely due to early recognition, prompt surgical drainage and appropriate antibiotic. To the best of our knowledge, this is the first reported case from Indonesia that could be identified in the literature.

Necrotizing Pneumonia Caused by Chromobacterium violaceum: Report of a Rare Human Pathogen Causing Disease in an Immunodeficient Child.

Chromobacterium violaceum is a rare, potentially serious pathogen. Most clinicians have no experience with its clinical appearance or treatment. We describe a case of a child presenting with necrotizing pneumonia caused by C. violaceum. We describe case complexities, including the need for a multidisciplinary approach to diagnosis and treatment.

Nonpigmented strain of Chromobacterium violaceum causing neonatal septicemia: A rare case report.

Human infection caused by Chromobacterium violaceum is rare but has got high fatality in septicemia. Nonpigmented strains of C. violaceum have been found similar in pathogenicity to pigmented strains. Pigment production is not an exclusive character of the genus Chromobacterium because around 9%-11% strains of C. violaceum are nonpigmented. Herewith, we report a nonpigmented strain of C. violaceum from a case of neonatal septicemia that was successfully treated with gentamicin plus imipenem.

Multiple Liver Abscesses with a Skin Pustule due to Chromobacterium violaceum.

A 69-year-old woman was admitted to our hospital with the chief complaints of fever and fatigue. We initially treated the patient for a tick-borne disease after noticing a pustule on her leg; however, abdominal computed tomography (CT) showed multiple low-density areas in the liver and Chromobacterium violaceum was isolated from a blood culture. We diagnosed her with multiple liver abscesses secondary to Chromobacterium violaceum bacteremia. The patient was successfully treated with ciprofloxacin.

Chromobacterium sphagni sp. nov., an insecticidal bacterium isolated from Sphagnum bogs.

Sixteen isolates of Gram-reaction-negative, motile, violet-pigmented bacteria were isolated from Sphagnum bogs in West Virginia and Maine, USA. 16S rRNA gene sequences and fatty acid analysis revealed a high degree of relatedness among the isolates, and genome sequencing of two isolates, IIBBL 14B-1T and IIBBL 37-2 (from West Virginia and Maine, respectively), revealed highly similar genomic sequences. The average nucleotide identity (gANI) calculated for these two isolates was found to be in excess of 99 %, but did not exceed 88 % when comparing either isolate with genomic sequences of Chromobacterium violaceum ATCC 12472T, C. haemolyticum DSM 19808T, C. piscinae ND17, C. subtsugae PRAA4-1T, C. vaccinii MWU205T or C. amazonense CBMAI 310T. Collectively, gANI and 16S rRNA gene sequence comparisons suggested that isolates IIBBL 14B-1T and IIBBL 37-2 were most closely related to C. subtsugae, but represented a distinct species. We propose the name Chromobacterium sphagni sp. nov. for this taxon; the type strain is IIBBL 14B-1T (=NRRL B-67130T=JCM 31882T).