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The Chemistry of O-Polysaccharide Chains in Bacterial Lipopolysaccharides
Published in Helmut Brade, Steven M. Opal, Stefanie N. Vogel, David C. Morrison, Endotoxin in Health and Disease, 2020
Chromobacterium violaceum is generally considered as nonpathogenic but can cause infections in humans and in animals. In the NCTC 9694 O-antigen (104) two residues of d-glycero-d-galacto-hsptose are present in the repeat, of which one is α- and the other β-linked. Heptoses are typical core constituents but have also been found in some O-polysaccharides. Thus l-glycero-d-manno-heptose has been found in Pseudomonas cepacia, d-glycero-d-manno-heptose in Vibrio cholerae 03 and 021, and d-glycero-d-altro-heptose in Campylobacter jejuni 023 and 036. d-Glycero-d-galacto-heptose has only been found among gram-negative species in Chromobacterium violaceum (Table 9). It is, however, a typical component of the gram-positive bacterium Eubacterium sabbureum.
Quorum Sensing and Essential Oils
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Isabel Charlotte Soede, Gerhard Buchbauer
Abdullah et al. (2017) investigated the QSI effect of green cardamom (Elletaria cardamomum) on C. violaceum. Main compounds include terpinyl acetate (38.4%), 1,8-cineole (28.71%), and linalyl acetate (8.42%). Concentrations of 0.625 and 0.313 mg/mL inhibited QS significantly (about 75%–80% of QS decrease) with very little effect on growth. EO: Green cardamom fruits were purchased at a local market in Pakistan. The acquired EO was analyzed by GC-MS. SubMIC concentrations were used.Sensor Strain: Chromobacterium violaceum ATCC 12472Performed assay: Flask incubation assay
The Emerging Role of Histone Deacetylase Inhibitors in the Treatment of Lymphoma
Published in Gertjan J. L. Kaspers, Bertrand Coiffier, Michael C. Heinrich, Elihu Estey, Innovative Leukemia and Lymphoma Therapy, 2019
Among the first cyclic peptides were the trapoxins, fungal products isolated in 1990 from the culture broth of Helicoma ambiens (66). These compounds exhibit both potent in vitro cytotoxicity and the ability to cause the accumulation of acetylated histones (67). Depsipeptide (romidepsin, formerly known as FK228, FR901228) has emerged as a structurally similar natural product. It was first isolated from a broth culture of chromobacterium violaceum in 1994, shortly after demonstrating antitumor activity in vitro and in vivo in various malignancies (68,69). In fact, Piekarz and Bates made one of the first reports describing the activity of an HDAC inhibitor in T-cell lymphoma in 2001. This publication was among the first to report responses to depsipeptide in patients with drug-resistant CTCL. Patients with advanced or refractory disease received romidepsin as a four-hour infusion on days 1 and 5 of a 21-day cycle, with the maximum tolerated dose (MTD) being 24.9 mg/m2. DLTs included nausea, vomiting, thrombocytopenia, and atrial fibrillation (70,71).
Human probiotic bacteria attenuate Pseudomonas aeruginosa biofilm and virulence by quorum-sensing inhibition
Published in Biofouling, 2020
Myriam Anabel Díaz, Silvia Nelina González, María Rosa Alberto, Mario Eduardo Arena
The bacterial strains used were Chromobacterium violaceum CV026, P. aeruginosa PAO1, P. aeruginosa PA14, and P. aeruginosa LVP 60 water isolated (Molina et al. 2020). P. aeruginosa strains were grown in Luria Bertani (LB) broth at 37°C, and C. violaceum CV026 was grown in LB tryptone broth at 28°C, with shaking at 150rpm. The probiotic strains used were L. casei CRL 431 and L. acidophilus CRL 730 (CRL: Culture Collection of Centro de Referencia para Lactobacilos, CERELA-CONICET, Tucumán, Argentina), both of human origin (isolated from feces of healthy children) and were cultured at 37°C in LAPTg broth (peptone, 15g l−1; tryptone, 10g l−1; yeast extract, 10g l−1; glucose, 10g l−1; and Tween 80, 0.1%, v/v) under microaerophilic conditions.
Quorum sensing pathways in Gram-positive and -negative bacteria: potential of their interruption in abating drug resistance
Published in Journal of Chemotherapy, 2019
Shafiul Haque, Dinesh K. Yadav, Shekhar C. Bisht, Neelam Yadav, Vineeta Singh, Kashyap Kumar Dubey, Arshad Jawed, Mohd Wahid, Sajad Ahmad Dar
Two important synthetic furanone analogs, isocladospolide and acaterin, isolated from a marine sponge Ircinia felix226 have the potential to be used as templates for further alterations. 5H-furan-2-ones replaced with short alkyl chains show most effective antagonistic activity in comparison with their longer-alkyl-chain counterparts. The furanone compounds containing one and two bromo residues effectively inhibit biofilm formation by S. epidermidis, but do not show any effect on bacterial growth,232 suggesting the effect of furanones on biofilm formation is possibly due to its interference with bacterial communication.232 Activity of synthetic furanones against AHL mediated QS has been evaluated in mouse lungs infected with sensor E. coli harboring luxR-PluxI-gfp fusion.233 It was found that furanones either inhibit the colonizing ability of bacteria or enhance bacterial clearance from the lungs.233 Screening method in Chromobacterium violaceum CV026 strain developed by Martinelli et al.234 showed that some furanones were good QS inhibitor at low concentration. Concentration of C6-HSL has been found to be critical for the activity of a number of compounds. Suboptimal C6-HSL concentrations led to enhancement of QS, while reverse effects were noticed at optimal concentrations. Such results substantiate that the activity of a given compound varies according to its concentration as well as the concentration of QS-activating AHLs.234–236
Development of new agents for peripheral T-cell lymphoma
Published in Expert Opinion on Biological Therapy, 2019
Yuta Ito, Shinichi Makita, Kensei Tobinai
The enzyme histone deacetylase (HDAC) is involved in the remodeling of chromatin and it plays an important role in the epigenetic regulation of gene expression. In preclinical studies, inhibition of HDACs shows potential antitumor activity with pleiotropic effects, including gene regulation, cell cycle arrest, anti-angiogenesis, and activation of apoptosis. Several HDAC inhibitors, such as romidepsin, vorinostat, and belinostat, have already been approved by the US FDA for the treatment of T-cell lymphomas. Romidepsin (FR901228) is a bicyclic depsipeptide that was discovered by a Japanese investigator from cultures of Chromobacterium violaceum isolated from a sample of Japanese soil [16]. It was initially expected to be an antimicrobial agent, but preclinical studies revealed its potent inhibitory activity against HDAC class I enzymes, and prominent antitumor activities against murine and human tumor cell lines both in vitro and in vivo [17].