RESUMO
Inter-cellular signaling, referred to as quorum sensing (QS), regulates the production of virulence factors in numerous gram-negative bacteria, such as the human pathogens Pseudomonas aeruginosa and Chromobacterium violaceum. QS inhibition may provide an opportunity for the treatment of bacterial infections. This represents the initial study to examine the antibiofilm and antivirulence capabilities of rose absolute and its primary component, phenylethyl alcohol. QS inhibition was assessed by examining extracellular exopolysaccharide synthesis, biofilm development, and swarming motility in P. aeruginosa PAO1, along with violacein production in C. violaceum ATCC 12472. Molecular docking analysis was conducted to explore the mechanism by which PEA inhibits QS. Our results indicate that rose absolute and PEA caused decrease in EPS production (60.5-33.5%), swarming motility (94.7-64.5%), and biofilm formation (98.53-55.5%) in the human pathogen P. aeruginosa PAO1. Violacein production decreased by 98.1% and 62.5% with an absolute (0.5 v/v %) and PEA (2 mM). Moreover, the molecular docking analysis revealed a promising competitive interaction between PEA and AHLs. Consequently, this study offers valuable insights into the potential of rose absolute and PEA as inhibitors of QS in P. aeruginosa and C. violaceum.
Assuntos
Biofilmes , Chromobacterium , Simulação de Acoplamento Molecular , Álcool Feniletílico , Pseudomonas aeruginosa , Percepção de Quorum , Percepção de Quorum/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Chromobacterium/efeitos dos fármacos , Chromobacterium/fisiologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Álcool Feniletílico/farmacologia , Álcool Feniletílico/análogos & derivados , Álcool Feniletílico/química , Álcool Feniletílico/metabolismo , Antibacterianos/farmacologia , Antibacterianos/química , Indóis/farmacologia , Indóis/metabolismoRESUMO
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.
Assuntos
Antibacterianos , Chromobacterium , Infecções por Bactérias Gram-Negativas , Feminino , Humanos , Antibacterianos/uso terapêutico , Celulite (Flegmão)/microbiologia , Celulite (Flegmão)/tratamento farmacológico , Chromobacterium/isolamento & purificação , Chromobacterium/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/microbiologia , Sepse/microbiologia , Sepse/tratamento farmacológico , Vietnã , Criança , AdolescenteRESUMO
Natural products have a long history of success in treating bacterial infections, making them a promising source for novel antibacterial medications. Curcumin, an essential component of turmeric, has shown potential in treating bacterial infections and in this study, we covalently immobilized curcumin (Cur) onto chitosan (CS) using glutaraldehyde and tannic acid (TA), resulting in the fabrication of novel biocomposites with varying CS/Cur/TA ratios. Comprehensive characterization of these ternary biocomposites was conducted using FTIR, SEM, XPS, and XRD to assess their morphology, functional groups, and chemical structures. The inhibitory efficacy of these novel biocomposites (n = 4) against the growth and viability of Pseudomonas aeruginosa (ATCC27853) and Chromobacterium violaceum (ATCC12472) was evaluated and the most promising composite (C3) was investigated for its impact on quorum sensing (QS) and biofilm formation in these bacteria. Remarkably, this biocomposite significantly disrupted QS circuits and effectively curtailed biofilm formation in the tested pathogens without inducing appreciable toxicity. These findings underscore its potential for future in vivo studies, positioning it as a promising candidate for the development of biofilm disrupting antibacterial agents.
Assuntos
Antibacterianos , Biofilmes , Quitosana , Curcumina , Pseudomonas aeruginosa , Percepção de Quorum , Taninos , Quitosana/química , Quitosana/farmacologia , Percepção de Quorum/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Curcumina/farmacologia , Curcumina/química , Taninos/química , Taninos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Chromobacterium/efeitos dos fármacos , Testes de Sensibilidade Microbiana , PolifenóisRESUMO
Pseudomonas aeruginosa causes life-threatening diseases and is resistant to almost all conventional antibiotics. The quorum sensing (QS) system of P. aeruginosa contributes to many pathogenic factors some of which are pigment production, motility, and biofilm. The disruption of quorum sensing system may be an impactful strategy to deal with infections. The present study investigates the anti-quorum sensing property of a bioactive molecule extracted from marine epibiotic bacteria present on the surface of seaweeds. Among all the isolates tested against monitor strain Chromobacterium violaceum (MTCC 2656), the one with the highest activity was identified as Bacillus zhangzhouensis SK4. The culture supernatant was extracted with chloroform which was then partially purified by TLC and column chromatography. The probable anti-QS compound was identified as 1,2-benzenedicarboxylic acid, bis (2-methylpropyl ester) by GC-MS and NMR analysis. The treatment of P. aeruginosa MCC 3457 with the lead compound resulted in the reduced production of pyocyanin, rhamnolipids, exopolysaccharide, biofilm, and motility. The observations of light and scanning electron microscopy also supported the biofilm inhibition. The lead compound showed synergism with the meropenem antibiotic and significantly reduced MIC. The molecular docking and pharmacokinetics study predicted 1, 2-benzenedicarboxylic acid, bis (2-methylpropyl ester), a phthalate derivative as a good drug candidate. The molecular dynamics study was also performed to check the stability of the lead compound and LasR complex. Further, lead compounds did not exhibit any cytotoxicity when tested on human embryonic kidney cells. As per our knowledge, this is the first report on the anti-QS activity of B. zhangzhouensis SK4, indicating that epibiotic bacteria can be a possible source of novel compounds to deal with the multidrug resistance phenomenon.
Assuntos
Antibacterianos , Bacillus , Biofilmes , Simulação de Acoplamento Molecular , Pseudomonas aeruginosa , Percepção de Quorum , Fatores de Virulência , Percepção de Quorum/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Fatores de Virulência/metabolismo , Humanos , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Bacillus/efeitos dos fármacos , Bacillus/química , Bacillus/metabolismo , Chromobacterium/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Piocianina/metabolismo , Proteínas de Bactérias/metabolismo , Glicolipídeos/farmacologia , Glicolipídeos/química , Polissacarídeos Bacterianos/farmacologia , Polissacarídeos Bacterianos/isolamento & purificação , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/metabolismoRESUMO
An ethyl acetate extract of a marine actinomycete strain, Nocardiopsis mentallicus SCSIO 53858, isolated from a deep-sea sediment sample in the South China Sea, exhibited anti-quorum-sensing (QS) activity against Chromobacterium violaceum CV026. Guided by the anti-QS activity, a novel active compound was isolated and purified from the extract and was identified as 2,3-dimethoxycinnamic acid (2,3-DCA) through spectral data analysis. At a concentration of 150 µg/mL, 2,3-DCA exhibited robust inhibitory effects on three QS-regulated traits of C. violaceum CV026: violacein production, swarming motility, and biofilm formation, with inhibition rates of 73.9%, 65.9%, and 37.8%, respectively. The quantitative reverse transcription polymerase chain reaction results indicated that 2,3-DCA can disrupt the QS system in C. violaceum CV026 by effectively suppressing the expression of QS-related genes, including cviR, vioA, vioB, and vioE. Molecular docking analysis revealed that 2,3-DCA hinders the QS system by competitively binding to the same binding pocket on the CviR receptor as the natural signal molecule N-hexanoyl-L-homoserine lactone. Collectively, these findings suggest that 2,3-DCA exhibits promising potential as an inhibitor of QS systems, providing a potential solution to the emerging problem of bacterial resistance.
Assuntos
Antibacterianos , Chromobacterium , Indóis , Simulação de Acoplamento Molecular , Percepção de Quorum , Percepção de Quorum/efeitos dos fármacos , Chromobacterium/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/isolamento & purificação , Antibacterianos/química , Actinobacteria/química , Cinamatos/farmacologia , Cinamatos/isolamento & purificação , Cinamatos/química , Biofilmes/efeitos dos fármacos , Sedimentos Geológicos/microbiologia , Organismos Aquáticos , ChinaRESUMO
Bacteria are social microorganisms that use communication systems known as quorum sensing (QS) to regulate diverse cellular behaviors including the production of various secreted molecules. Bacterial secondary metabolites are widely studied for their bioactivities including antibiotic, antifungal, antiparasitic, and cytotoxic compounds. Besides playing a crucial role in natural bacterial niches and intermicrobial competition by targeting neighboring organisms and conferring survival advantages to the producer, these bioactive molecules may be of prime interest to develop new antimicrobials or anticancer therapies. This review focuses on bioactive compounds produced under acyl homoserine lactone-based QS regulation by Gram-negative bacteria that are pathogenic to humans and animals, including the Burkholderia, Serratia, Pseudomonas, Chromobacterium, and Pseudoalteromonas genera. The synthesis, regulation, chemical nature, biocidal effects, and potential applications of these identified toxic molecules are presented and discussed in light of their role in microbial interactions.
Assuntos
Acil-Butirolactonas , Percepção de Quorum , Percepção de Quorum/efeitos dos fármacos , Acil-Butirolactonas/metabolismo , Acil-Butirolactonas/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Bactérias Gram-Negativas/efeitos dos fármacos , Estrutura Molecular , Humanos , Burkholderia/metabolismo , Chromobacterium/efeitos dos fármacosRESUMO
Species of genus Chromobacterium have been isolated from diverse geographical settings, which exhibits significant metabolic flexibility as well as biotechnological and pathogenic properties. This study describes the isolation, characterization, draft assembly, and detailed sequence analysis of Chromobacterium piscinae strain W1B-CG-NIBSM isolated from water samples from multi use community pond. The organism was characterized by biochemical tests, Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI TOF-MS) and partial genome sequencing. The partial genomic data of Chromobacterium pisciane isolate W1B NIBSM strain was submitted to GenBank with Bio project number PRJNA803347 and accession no CP092474. An integrated genome analysis of Chromobacterium piscinae has been accomplished with PATRIC which indicates good quality genome. DNA sequencing using the illumina HiSeq 4000 system generated total length of 4,155,481 bp with 63 contig with G + C content is 62.69%. This partial genome contains 4,126 protein-coding sequences (CDS), 27 repeats region and 78 transfer RNA (tRNA) genes as well as 3 ribosomal RNA (rRNA) genes. The genomic annotation of Chromobacterium W1B depicts 2,925 proteins with functional assignments and 1201 hypothetical proteins. A repertoire of specialty genes implicated in antibiotic resistance (45 genes), drug target (6 genes), Transporter (3 genes) and virulence factor (10 genes). The genomic analysis reveals the adaptability, displays metabolic varied pathways and shows specific structural complex and various virulence factors which makes this strain multi drug resistant. The isolate was found to be highly resistant to ß-lactam antibiotics whereas it showed sensitivity towards aminoglycosides and fluoroquinolone antibiotics. Hence, the recovery of Chromobacterium piscinae from community pond evidenced for uncertain hidden source of public health hazard. To the best of authors knowledge this is first report of isolation and genomic description of C. piscinae from India.
Assuntos
Antibacterianos , Composição de Bases , Chromobacterium , Farmacorresistência Bacteriana Múltipla , Genoma Bacteriano , Filogenia , Chromobacterium/genética , Chromobacterium/efeitos dos fármacos , Chromobacterium/metabolismo , Índia , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Genômica , DNA Bacteriano/genética , Análise de Sequência de DNA , Testes de Sensibilidade MicrobianaRESUMO
Quorum sensing (QS) can regulate the pathogenicity of bacteria and the production of some virulence factors. It is a promising target for screening to find anti-virulence agents in the coming post-antibiotics era. Cyclo (L-Trp-L-Ser), one variety of cyclic dipeptides (CDPs), isolated from a marine bacterium Rheinheimera aquimaris, exhibited anti-QS activity against Chromobacterium violaceum CV026 and Pseudomonas aeruginosa PAO1. Unlike the CDPs composed of phenylalanine or tyrosine, the anti-QS activity has been widely studied; however, cyclo (L-Trp-L-Ser) and derivatives, containing one tryptophan unit and one non-aromatic amino acid, have not been systematically explored. Herein, the cyclo (L-Trp-L-Ser) and seven derivatives were synthesized and evaluated. All tryptophane-contained CDPs were able to decrease the production of violacein in C.violaceum CV026 and predicted as binding within the same pocket of receptor protein CviR, but in lower binding energy compared with the natural ligand C6HSL. As for P. aeruginosa PAO1, owning more complicated QS systems, these CDPs also exhibited inhibitory effects on pyocyanin production, swimming motility, biofilm formation, and adhesion. These investigations suggested a promising way to keep the tryptophan untouched and make modifications on the non-aromatic unit to increase the anti-QS activity and decrease the cytotoxicity, thus developing a novel CDP-based anti-virulence agent.
Assuntos
Antibacterianos/farmacologia , Dipeptídeos/farmacologia , Percepção de Quorum/efeitos dos fármacos , Triptofano/química , Células A549 , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Biofilmes/efeitos dos fármacos , Chromatiaceae/metabolismo , Chromobacterium/efeitos dos fármacos , Dipeptídeos/química , Dipeptídeos/isolamento & purificação , Humanos , Camundongos , Células NIH 3T3 , Pseudomonas aeruginosa/efeitos dos fármacos , Virulência/efeitos dos fármacosRESUMO
Pseudomonas aeruginosa is an opportunistic bacterium causing several health problems and having many virulence factors like biofilm formation on different surfaces. There is a significant need to develop new antimicrobials due to the spreading resistance to the commonly used antibiotics, partly attributed to biofilm formation. Consequently, this study aimed to investigate the anti-biofilm and anti-quorum sensing activities of Dioon spinulosum, Dyer Ex Eichler extract (DSE), against Pseudomonas aeruginosa clinical isolates. DSE exhibited a reduction in the biofilm formation by P. aeruginosa isolates both in vitro and in vivo rat models. It also resulted in a decrease in cell surface hydrophobicity and exopolysaccharide quantity of P. aeruginosa isolates. Both bright field and scanning electron microscopes provided evidence for the inhibiting ability of DSE on biofilm formation. Moreover, it reduced violacein production by Chromobacterium violaceum (ATCC 12,472). It decreased the relative expression of 4 quorum sensing genes (lasI, lasR, rhlI, rhlR) and the biofilm gene (ndvB) using qRT-PCR. Furthermore, DSE presented a cytotoxic activity with IC50 of 4.36 ± 0.52 µg/ml against human skin fibroblast cell lines. For the first time, this study reports that DSE is a promising resource of anti-biofilm and anti-quorum sensing agents.
Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Chromobacterium/efeitos dos fármacos , Extratos Vegetais/farmacologia , Infecções por Pseudomonas/prevenção & controle , Pseudomonas aeruginosa/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , Dermatopatias Bacterianas/prevenção & controle , Zamiaceae , Animais , Antibacterianos/isolamento & purificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Chromobacterium/crescimento & desenvolvimento , Chromobacterium/metabolismo , Modelos Animais de Doenças , Feminino , Regulação Bacteriana da Expressão Gênica , Indóis/metabolismo , Testes de Sensibilidade Microbiana , Extratos Vegetais/isolamento & purificação , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/patologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/metabolismo , Ratos , Dermatopatias Bacterianas/microbiologia , Dermatopatias Bacterianas/patologia , Zamiaceae/químicaRESUMO
Quorum sensing (QS)-dependent gene regulation in bacteria performs a vital role in synchronization of cell-density-dependent functions. In Chromobacterium violaceum QS-dependent cviI/R regulatory genes are activated during the mid- or late-exponential phase of growth. However, sufficient evidence is lacking on the role of QS inhibitors on gene regulation at different phases of growth. Hence, we report the role of linalool, a natural monoterpenoid on QS mediated gene regulation at different stages of growth in C. violaceum by performing biosensor, growth kinetic and gene expression studies. In vitro and in vivo studies were performed for establishing role of linalool in reducing the virulence and infection by using HEK-293 T cell lines and Caenorhabditis elegans models respectively. C. violaceum CV026 with C6-HSL was used as control. The results showed linalool to be a QS inhibitor with an estimated IC50 of 63 µg/mL for violacein inhibition. At this concentration the cell density difference (delta OD600) of 0.14 from the compound was observed indicating the quorum concentration. The expression of cviI/R was initiated at mid-log phase (~ 18 h) and reached the maximum at 36 h in control whereas in treatment it remained significantly downregulated at all time points. The expression of violacein biosynthetic genes vioA, vioC, vioD and vioE was also downregulated by linalool. Infection studies with linalool showed higher survival rates in HEK-293T cell lines and C. elegans compared to the infection control. Taken together, this study proves linalool to be a QS inhibitor capable of attenuation of QS by controlling the cell density through cviI/R downregulation at the early phase of growth and hence offering scope for its application for controlling infections.
Assuntos
Monoterpenos Acíclicos/farmacologia , Chromobacterium/efeitos dos fármacos , Chromobacterium/crescimento & desenvolvimento , Monoterpenos/farmacologia , Percepção de Quorum/efeitos dos fármacos , Fatores de Virulência , Animais , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Caenorhabditis elegans , Chromobacterium/genética , Chromobacterium/metabolismo , Regulação Bacteriana da Expressão Gênica , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Células HEK293 , Humanos , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia , Percepção de Quorum/genética , Virulência/efeitos dos fármacos , Fatores de Virulência/genéticaRESUMO
The skins of frogs of the family Ranidae are particularly rich sources of biologically active peptides, among which antimicrobial peptides (AMPs) constitute the major portion. Some of these have attracted the interest of researchers because they possess both antimicrobial and anticancer activities. In this study, with 'shotgun' cloning and MS/MS fragmentation, three AMPs, homologues of family brevinin-1 (brevinin-1HL), and temporin (temporin-HLa and temporin-HLb), were discovered from the skin secretion of the broad-folded frog, Hylarana latouchii. They exhibited various degrees of antimicrobial and antibiofilm activities against test microorganisms and hemolysis on horse erythrocytes. It was found that they could induce bacteria death through disrupting cell membranes and binding to bacterial DNA. In addition, they also showed different potencies towards human cancer cell lines. The secondary structure and physicochemical properties of each peptide were investigated to preliminarily reveal their structure-activity relationships. Circular dichroism spectrometry showed that they all adopted a canonical α-helical conformation in membrane-mimetic solvents. Notably, the prepropeptide of brevinin-1HL from H. latouchii was highly identical to that of brevinin-1GHd from Hylarana guentheri, indicating a close relationship between these two species. Accordingly, this study provides candidates for the design of novel anti-infective and antineoplastic agents to fight multidrug-resistant bacteria and malignant tumors and also offers additional clues for the taxonomy of ranid frogs.
Assuntos
Proteínas de Anfíbios/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos/farmacologia , Antineoplásicos/farmacologia , DNA Bacteriano/antagonistas & inibidores , Sequência de Aminoácidos , Proteínas de Anfíbios/química , Proteínas de Anfíbios/isolamento & purificação , Proteínas de Anfíbios/metabolismo , Animais , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Peptídeos Catiônicos Antimicrobianos/metabolismo , Peptídeos Antimicrobianos/química , Peptídeos Antimicrobianos/isolamento & purificação , Peptídeos Antimicrobianos/metabolismo , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/metabolismo , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Linhagem Celular Tumoral , Chromobacterium/efeitos dos fármacos , Chromobacterium/crescimento & desenvolvimento , DNA Bacteriano/metabolismo , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/crescimento & desenvolvimento , Eritrócitos/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Hemólise/efeitos dos fármacos , Cavalos , Humanos , Concentração Inibidora 50 , Testes de Sensibilidade Microbiana , Modelos Moleculares , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Ranidae/fisiologia , Pele/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimentoRESUMO
Chromobacterium violaceum is a Gram-negative, saprophytic bacterium that can infect humans and its virulence may be regulated by quorum sensing via N-acyl homoserine lactones. A virtual screening study with plant compounds and nonsteroidal anti-inflammatory drugs for inhibition of C. violaceum quorum sensing system has been performed. In vitro evaluation was done to validate the in silico results. Molecular docking showed that phytol, margaric acid, palmitic acid, dipyrone, ketoprofen, and phenylbutazone bound to structures of CviR proteins of different C. violaceum strains. Phytol presented higher binding affinities than AHLs and furanones, recognized inducers, and inhibitors of quorum sensing, respectively. When tested in vitro, phytol at a non-inhibitory concentration was the most efficient tested compound to reduce phenotypes regulated by quorum sensing. The results indicate that in silico compound prospection to inhibit quorum sensing may be a good tool for finding alternative lead molecules.
Assuntos
Anti-Inflamatórios , Chromobacterium , Extratos Vegetais , Percepção de Quorum , Antibacterianos/farmacologia , Anti-Inflamatórios/farmacologia , Chromobacterium/efeitos dos fármacos , Simulação de Acoplamento Molecular , Extratos Vegetais/farmacologiaRESUMO
The continuous increase in the incidence of infectious diseases and the rapid unchecked rise in multidrug-resistance to conventional antibiotics have led to the search for alternative strategies for treatment and clinical management of microbial infections. Since quorum sensing (QS) regulates numerous virulence determinants and pathogenicity in bacteria, inhibition of QS promises to be an attractive target for development of novel therapeutics. In this study, a series of cinnamic acid analogs and benzalacetone analogs were designed and synthesized, and their QS-inhibitory activities explored. We found that, among the test compounds, 4-methoxybenzalacetone (8) exhibited potent anti-quorum sensing property, as evidenced by inhibition of QS-controlled violacein production of Chromobacterium violaceum ATCC12472. The inhibitory activity of such a compound, which was the methyl keto analog of the corresponding cinnamic acid, was not only stronger than the parent cinnamic acid (1), but also superior to that of furanone, the reference drug. Based on our observations, its mechanism of quorum sensing inhibition is likely to be mediated by interference with N-acyl-homoserine lactones (AHL) synthesis. Moreover, 4-methoxybenzalacetone (8) also suppressed the production of pyocyanin, rhamnolipids and swarming motility of Pseudomonas aeruginosa, suggesting a broad spectrum of anti-QS activities of this compound. In terms of structure-activity relationship, the possible chemical substitutions on the scaffold of cinnamic acid required for QS inhibitory activity are also discussed. Since 4-methoxybenzalacetone (8) showed no toxicity to both bacteria and mammalian cells, our findings therefore indicate the anti-QS potential of this compound as a novel effective QS inhibitor.
Assuntos
Chromobacterium/fisiologia , Cinamatos/síntese química , Pseudomonas aeruginosa/fisiologia , Percepção de Quorum/efeitos dos fármacos , Animais , Linhagem Celular , Chromobacterium/efeitos dos fármacos , Cinamatos/química , Cinamatos/farmacologia , Glicolipídeos/metabolismo , Camundongos , Viabilidade Microbiana/efeitos dos fármacos , Estrutura Molecular , Pseudomonas aeruginosa/efeitos dos fármacos , Piocianina/metabolismo , Relação Estrutura-Atividade , Virulência/efeitos dos fármacosRESUMO
Cell-cell communication is critical for bacterial survival in natural habitats, in which miscellaneous regulatory networks are encompassed. However, elucidating the interaction networks of a microbial community has been hindered by the population complexity. This study reveals that γ-butyrolactone (GBL) molecules from Streptomyces species, the major antibiotic producers, can directly bind to the acyl-homoserine lactone (AHL) receptor of Chromobacterium violaceum and influence violacein production controlled by the quorum sensing (QS) system. Subsequently, the widespread responses of more Gram-negative bacterial AHL receptors to Gram-positive Streptomyces signaling molecules are unveiled. Based on the cross-talk between GBL and AHL signaling systems, combinatorial regulatory circuits (CRC) are designed and proved to be workable in Escherichia coli (E. coli). It is significant that the QS systems of Gram-positive and Gram-negative bacteria can be bridged via native Streptomyces signaling molecules. These findings pave a new path for unlocking the comprehensive cell-cell communications in microbial communities and facilitate the exploitation of innovative regulatory elements for synthetic biology.
Assuntos
4-Butirolactona/metabolismo , Acil-Butirolactonas/metabolismo , Proteínas de Bactérias/metabolismo , Bactérias Gram-Negativas/fisiologia , Bactérias Gram-Positivas/fisiologia , 4-Butirolactona/química , 4-Butirolactona/genética , 4-Butirolactona/farmacologia , Proteínas de Bactérias/genética , Chromobacterium/efeitos dos fármacos , Chromobacterium/genética , Chromobacterium/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Indóis/metabolismo , Interações Microbianas , Estrutura Molecular , Percepção de Quorum , Transdução de Sinais , Streptomyces/genética , Streptomyces/metabolismo , Biologia SintéticaRESUMO
Quorum sensing (QS) represents a major target for reducing bacterial pathogenicity and antibiotic resistance. This study identifies bergamot and aspidosperma as new potential sources of anti-QS agents. We investigated the anti-QS activity of plant materials on both Chromobacterium violaceum and Pseudomonas aeruginosa. Initially, we determined the minimum inhibitory concentrations (MICs) of plant materials using a broth microdilution method. Subsequently, we tested the effect of sub-MIC concentrations on QS-regulated traits and virulence factors production in test bacteria. Results revealed that bergamot and aspidosperma inhibited the ability of C. violaceum to produce violacein. Other QS-controlled phenotypes of C. violaceum, namely chitinolytic activity, motility, and biofilm formation, were also reduced by both plant materials. Moreover, QS-linked traits of P. aeruginosa were also reduced. Bergamot inhibited swarming but not swimming motility, while aspidosperma diminished both motility types in P. aeruginosa. Both plant materials also demonstrated antibiofilm activity and inhibited the production of protease and pyocyanin in P. aeruginosa. Furthermore, we tested the anti-QS effect of plant materials on the transcriptional level using RT-qPCR. Bergamot dramatically downregulated the C. violaceum autoinducer synthase gene cviI and the vioB gene involved in violacein biosynthesis, confirming the phenotypic observation on its anti-QS activity. Aspidosperma also reduced the expression of cviI and vioB but less drastically than bergamot. In P. aeruginosa, downregulation in the transcripts of the QS genes lasI, lasR, rhlI, and rhlR was also achieved by bergamot and aspidosperma. Therefore, data in the present study suggest the usefulness of bergamot and aspidosperma as sources of antivirulence agents.
Assuntos
Aspidosperma , Chromobacterium , Extratos Vegetais , Óleos de Plantas , Pseudomonas aeruginosa , Percepção de Quorum , Antibacterianos/farmacologia , Aspidosperma/química , Biofilmes/efeitos dos fármacos , Chromobacterium/efeitos dos fármacos , Chromobacterium/genética , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Extratos Vegetais/farmacologia , Óleos de Plantas/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/genética , Percepção de Quorum/efeitos dos fármacos , Percepção de Quorum/genética , Fatores de Virulência/genéticaRESUMO
To date, a very limited number of peptides reported as quorum sensing inhibitors. Herein, we report the synthesis and evaluation of a series of ß-turn mimetic-based peptides as potent quorum sensing inhibitors and antibiofilm formation. In this series, peptides P1, P4, and P5 showed very promising anti-quorum sensing activity on lasB-gfp reporter strain of Pseudomonas aeruginosa without affecting bacterial growth. Under our condition, these compounds also showed good anti-violacein production of Chromobacterium violaceum. In terms of antibiofilm formation, except P5, two ß-turn mimetic-based peptides P1 and P4 showed maximum inhibition of 80% total biomass of Pseudomonas aeruginosa. This report provides the first ß-turn mimetic-based scaffold for future drug development.
Assuntos
Antibacterianos/farmacologia , Chromobacterium/efeitos dos fármacos , Descoberta de Drogas , Indóis/antagonistas & inibidores , Peptídeos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Antibacterianos/síntese química , Antibacterianos/química , Chromobacterium/metabolismo , Relação Dose-Resposta a Droga , Indóis/metabolismo , Testes de Sensibilidade Microbiana , Estrutura Molecular , Peptídeos/síntese química , Peptídeos/química , Percepção de Quorum/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
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.
Assuntos
Antibacterianos/uso terapêutico , Chromobacterium/isolamento & purificação , Infecções por Bactérias Gram-Negativas/diagnóstico , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Adolescente , Chromobacterium/efeitos dos fármacos , Chromobacterium/genética , Diagnóstico Precoce , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/patologia , Humanos , Masculino , Reinfecção , Resultado do TratamentoRESUMO
The low stability of anthocyanins is a constraint in the food industry. The present work has been carried out to overcome this low stability by encapsulating fruit concentrate of underutilized plant Carissa spinarum (CS) with polyphenols in microemulsions (CSME) and nanoemulsions (CSNE). Increasing the amount of CS reduced the particle size from 1154 to 70-300 nm whereas addition of Tween 80 reduced it optimally to 5-25 nm. Degradation of anthocyanins in control and ME/NE proceeded with zero- and first-order reaction rates, respectively, at 28 °C (half-life 6, 25 and 40 days, respectively). The degradation kinetics of phenolics-flavonoids were also studied. CSNE exhibited higher anti-quorum sensing (QS) activity than CSME against Chromobacterium violaceum (73.7%); it inhibited biofilm formation by 70.1 and 64.4% in Pseudomonas aeruginosa, and Yersinia enterocolitica, respectively. This is the first report of using the more stable ME/NE to study anti-QS activity, an alternative to conventional antibiotics.
Assuntos
Antocianinas/química , Antibacterianos/farmacologia , Apocynaceae/química , Bactérias/efeitos dos fármacos , Extratos Vegetais/química , Percepção de Quorum/efeitos dos fármacos , Antocianinas/farmacologia , Fenômenos Fisiológicos Bacterianos , Biofilmes/efeitos dos fármacos , Chromobacterium/efeitos dos fármacos , Chromobacterium/fisiologia , Flavonoides/química , Flavonoides/farmacologia , Frutas/química , Cinética , Polifenóis/química , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Yersinia enterocolitica/efeitos dos fármacos , Yersinia enterocolitica/fisiologiaRESUMO
We recently and for the first time reported that ethyl acetate extracts isolated from Penicillium chrysogenum DXY-1 exhibited anti-quorum sensing (anti-QS) activity. Herein, another active molecule in the extracts was identified as chrysin by NMR and MS. A 20 µg/mL dose of chrysin inhibited violacein production regulated by QS in C. violaceum CV026 by 31.6%. A 40 µg/mL dose of chrysin suppressed pyocyanin production, elastase activity, proteolytic activity, and biofilm formation regulated by QS in P. aeruginosa PA01 by 41.4%, 13.8%, 8.3%, and 42.4%, respectively. And chrysin could inhibit the swarming activity of P. aeruginosa PA01. Further, molecular docking and CD analysis were used to address the mechanism of chrysin's activity in C. violaceum. Molecular docking results revealed that chrysin suppresses QS system by competing with the natural signal molecule C6HSL for binding to the same pocket of CviR receptor. At the same time, CD results also showed that chrysin could change the secondary structure composition of CviR, which greatly prevented the binding of C6HSL/CviR, and further playing its role on inhibiting bacterial QS system. All these data demonstate that chrysin may be used as a potential QS inhibitor to tackle increasing drug resistance.
Assuntos
Antibacterianos/farmacologia , Chromobacterium/efeitos dos fármacos , Flavonoides/farmacologia , Penicillium chrysogenum/química , Pseudomonas aeruginosa/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/isolamento & purificação , Relação Dose-Resposta a Droga , Flavonoides/química , Flavonoides/isolamento & purificação , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Estrutura Molecular , Percepção de Quorum/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Pseudomonas aeruginosa is one of the vulnerable opportunistic pathogens associated with nosocomial infections, cystic fibrosis, burn wounds and surgical site infections. Several studies have reported that quorum sensing (QS) systems are controlled the P. aeruginosa pathogenicity. Hence, the targeting of QS considered as an alternative approach to control P. aeruginosa infections. This study aimed to evaluate the anti-quorum sensing and antibiofilm inhibitory potential of Musa paradisiaca against Chromobacterium violaceum (ATCC 12472) and Pseudomonas aeruginosa. The methanol extract of M. paradisiacsa exhibits that better antibiofilm potential against P. aeruginosa. Then, the crude methanol extract was subjected to purify by column chromatography and collected the fractions. The mass-spectrometric analysis of a methanol extract of M. paradisiaca revealed that 1,8-cineole is the major compounds. 1, 8-cineole significantly inhibited the QS regulated violacein production in C. violaceum. Moreover, 1,8-cineole significantly inhibited the QS mediated virulence production and biofilm formation of P. aeruginosa without affecting their growth. The real-time PCR analysis showed the downregulation of autoinducer synthase and transcriptional regulator genes upon 1,8-cineole treatment. The findings of the present study strongly suggested that metabolite of M. paradisiaca impedes P. aeruginosa QS system and associated virulence productions.