251
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Zhou Z, Ma S. Recent Advances in the Discovery of PqsD Inhibitors as Antimicrobial Agents. ChemMedChem 2017; 12:420-425. [PMID: 28195681 DOI: 10.1002/cmdc.201700015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 02/14/2017] [Indexed: 01/24/2023]
Affiliation(s)
- Ziteng Zhou
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology, Ministry of Education, School of Pharmaceutical Sciences; Shandong University; 44, West Culture Road Jinan 250012 PR China)
| | - Shutao Ma
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology, Ministry of Education, School of Pharmaceutical Sciences; Shandong University; 44, West Culture Road Jinan 250012 PR China)
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252
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Birmes FS, Wolf T, Kohl TA, Rüger K, Bange F, Kalinowski J, Fetzner S. Mycobacterium abscessus subsp. abscessus Is Capable of Degrading Pseudomonas aeruginosa Quinolone Signals. Front Microbiol 2017; 8:339. [PMID: 28303132 PMCID: PMC5332414 DOI: 10.3389/fmicb.2017.00339] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 02/17/2017] [Indexed: 11/25/2022] Open
Abstract
Pseudomonas aeruginosa employs 2-heptyl-3-hydroxy-4(1H)-quinolone (the Pseudomonas quinolone signal, PQS) and 2-heptyl-4(1H)-quinolone (HHQ) as quorum sensing signal molecules, which contribute to a sophisticated regulatory network controlling the production of virulence factors and antimicrobials. We demonstrate that Mycobacterium abscessusT and clinical M. abscessus isolates are capable of degrading these alkylquinolone signals. Genome sequences of 50 clinical M. abscessus isolates indicated the presence of aqdRABC genes, contributing to fast degradation of HHQ and PQS, in M. abscessus subsp. abscessus strains, but not in M. abscessus subsp. bolletii and M. abscessus subsp. massiliense isolates. A subset of 18 M. a. subsp. abscessus isolates contained the same five single nucleotide polymorphisms (SNPs) compared to the aqd region of the type strain. Interestingly, representatives of these isolates showed faster PQS degradation kinetics than the M. abscessus type strain. One of the SNPs is located in the predicted promoter region of the aqdR gene encoding a putative transcriptional regulator, and two others lead to a variant of the AqdC protein termed AqdCII, which differs in two amino acids from AqdCI of the type strain. AqdC, the key enzyme of the degradation pathway, is a PQS dioxygenase catalyzing quinolone ring cleavage. While transcription of aqdR and aqdC is induced by PQS, transcript levels in a representative of the subset of 18 isolates were not significantly altered despite the detected SNP in the promoter region. However, purified recombinant AqdCII and AqdCI exhibit different kinetic properties, with approximate apparent Km values for PQS of 14 μM and 37 μM, and kcat values of 61 s-1 and 98 s-1, respectively, which may (at least in part) account for the observed differences in PQS degradation rates of the strains. In co-culture experiments of P. aeruginosa PAO1 and M. abscessus, strains harboring the aqd genes reduced the PQS levels, whereas mycobacteria lacking the aqd gene cluster even boosted PQS production. The results suggest that the presence and expression of the aqd genes in M. abscessus lead to a competitive advantage against P. aeruginosa.
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Affiliation(s)
- Franziska S Birmes
- Institute for Molecular Microbiology and Biotechnology, University of Münster Münster, Germany
| | - Timo Wolf
- Center for Biotechnology (CeBiTec) Bielefeld, Germany
| | - Thomas A Kohl
- Research Center BorstelSülfeld, Germany; German Center for Infection ResearchBorstel, Germany
| | - Kai Rüger
- Institute for Medical Microbiology and Hospital Epidemiology, Hannover Medical School Hannover, Germany
| | - Franz Bange
- Institute for Medical Microbiology and Hospital Epidemiology, Hannover Medical School Hannover, Germany
| | | | - Susanne Fetzner
- Institute for Molecular Microbiology and Biotechnology, University of Münster Münster, Germany
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253
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Host-guest interaction between Ofloxacin-β-Cyclodextrin complexes in acidic and neutral pH: A fluorescence quenching study. J Photochem Photobiol A Chem 2017. [DOI: 10.1016/j.jphotochem.2017.01.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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254
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The antibiotic resistance crisis, with a focus on the United States. J Antibiot (Tokyo) 2017; 70:520-526. [PMID: 28246379 DOI: 10.1038/ja.2017.30] [Citation(s) in RCA: 252] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 01/29/2017] [Accepted: 01/30/2017] [Indexed: 02/06/2023]
Abstract
Beginning with the discovery of penicillin by Alexander Fleming in the late 1920s, antibiotics have revolutionized the field of medicine. They have saved millions of lives each year, alleviated pain and suffering, and have even been used prophylactically for the prevention of infectious diseases. However, we have now reached a crisis where many antibiotics are no longer effective against even the simplest infections. Such infections often result in an increased number of hospitalizations, more treatment failures and the persistence of drug-resistant pathogens. Of particular concern are organisms such as methicillin-resistant Staphylococcus aureus, Clostridium difficile, multidrug and extensively drug-resistant Mycobacterium tuberculosis, Neisseria gonorrhoeae, carbapenem-resistant Enterobacteriaceae and bacteria that produce extended spectrum β-lactamases, such as Escherichia coli. To make matters worse, there has been a steady decline in the discovery of new and effective antibiotics for a number of reasons. These include increased costs, lack of adequate support from the government, poor returns on investment, regulatory hurdles and pharmaceutical companies that have simply abandoned the antibacterial arena. Instead, many have chosen to focus on developing drugs that will be used on a chronic basis, which will offer a greater profit and more return on investment. Therefore, there is now an urgent need to develop new and useful antibiotics to avoid returning to the 'pre-antibiotic era'. Some potential opportunities for antibiotic discovery include better economic incentives, genome mining, rational metabolic engineering, combinatorial biosynthesis and further exploration of the earth's biodiversity.
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255
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Garg N, Luzzatto-Knaan T, Melnik AV, Caraballo-Rodríguez AM, Floros DJ, Petras D, Gregor R, Dorrestein PC, Phelan VV. Natural products as mediators of disease. Nat Prod Rep 2017; 34:194-219. [PMID: 27874907 PMCID: PMC5299058 DOI: 10.1039/c6np00063k] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Covering: up to 2016Humans are walking microbial ecosystems, each harboring a complex microbiome with the genetic potential to produce a vast array of natural products. Recent sequencing data suggest that our microbial inhabitants are critical for maintaining overall health. Shifts in microbial communities have been correlated to a number of diseases including infections, inflammation, cancer, and neurological disorders. Some of these clinically and diagnostically relevant phenotypes are a result of the presence of small molecules, yet we know remarkably little about their contributions to the health of individuals. Here, we review microbe-derived natural products as mediators of human disease.
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Affiliation(s)
- Neha Garg
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Tal Luzzatto-Knaan
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Alexey V. Melnik
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | | | - Dimitrios J. Floros
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093
| | - Daniel Petras
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Rachel Gregor
- Department of Chemistry and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
| | - Pieter C. Dorrestein
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Vanessa V. Phelan
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, The University of Colorado Anschutz Medical Campus, Aurora, CO 80045
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256
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N-Heterocyclic choline analogues based on 1,2,3,4-tetrahydro(iso)quinoline scaffold with anticancer and anti-infective dual action. Pharmacol Rep 2017; 69:575-581. [PMID: 31994086 DOI: 10.1016/j.pharep.2017.01.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 12/29/2016] [Accepted: 01/27/2017] [Indexed: 01/12/2023]
Abstract
BACKGROUND Pharmacological effects of biologically active "small molecules" can be improved by their targeted modification, which affects drug delivery and interaction with tumor cells and microorganisms. We aimed to evaluate anticancer and antimicrobial activity of lipid-like choline derivatives modified via simultaneous introduction of tetrahydro(iso)quinoline based pharmacophore system at nitrogen atom and long chain alkyl substituent at oxygen atom. METHODS Target compounds were synthesized under phase-transfer catalysis conditions followed by quaternization, and evaluated for cytotoxicity and NO-generation ability on HT-1080 and MG-22A tumor cell lines and NIH 3T3 normal mouse fibroblasts, and screened for antimicrobial activity against gram-positive (Staphylococcus aureus and Bacillus cereus) and gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa and Proteus mirabilis) and fungi (Candida albicans and Aspergillus niger). Inhibitory action of active compounds towards E. coli DNA gyrase was investigated. RESULTS Target compounds exhibit high selective cytotoxicity (LC50 < 1 μg/mL) and NO-induction ability, and reveal strong antimicrobial activity with MIC and MBC/MFC values of 0.5-32 μg/mL, predominantly vs. gram-positive bacteria and fungi. Tested substances displayed inhibitory effect towards E. coli DNA gyrase, though less than ciprofloxacin. Tetrahydroisoquinoline derivatives and compounds possessing substituents with chain length of 10 and 11 carbon atoms have highest indices of activities. CONCLUSIONS Lipid-like N-heterocyclic choline analogues based on 1,2,3,4-tetrahydro(iso)quinoline scaffold, possessing very high cytotoxicity with attendant strong antimicrobial activity are the leads for developing effective dual action therapeutics.
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257
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Tsoung J, Bogdan AR, Kantor S, Wang Y, Charaschanya M, Djuric SW. Synthesis of Fused Pyrimidinone and Quinolone Derivatives in an Automated High-Temperature and High-Pressure Flow Reactor. J Org Chem 2017; 82:1073-1084. [DOI: 10.1021/acs.joc.6b02520] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Jennifer Tsoung
- Discovery
Chemistry and Technologies, AbbVie, Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Andrew R. Bogdan
- Discovery
Chemistry and Technologies, AbbVie, Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Stanislaw Kantor
- Discovery
Chemistry and Technologies, AbbVie, Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Ying Wang
- Discovery
Chemistry and Technologies, AbbVie, Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Manwika Charaschanya
- Department
of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66047, United States
| | - Stevan W. Djuric
- Discovery
Chemistry and Technologies, AbbVie, Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
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258
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Zhang MZ, Jia CY, Gu YC, Mulholland N, Turner S, Beattie D, Zhang WH, Yang GF, Clough J. Synthesis and antifungal activity of novel indole-replaced streptochlorin analogues. Eur J Med Chem 2016; 126:669-674. [PMID: 27936445 DOI: 10.1016/j.ejmech.2016.12.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 11/29/2016] [Accepted: 12/01/2016] [Indexed: 12/13/2022]
Abstract
Based on examples of the successful applications in drug discovery of bioisosterism, a series of streptochlorin analogues in which indole has been replaced by other heterocycles has been designed and synthesized, as a continuation of our studies aimed at the discovery of novel streptochlorin analogues with improved antifungal activity. Biological testing showed that most of the indole-replaced streptochlorin analogues were inactive, though compound 6f had a broad spectrum of antifungal activity with significant activity against Alternaria solani. The SAR study demonstrated that indole ring is an essential moiety for the antifungal activity of streptochlorin analogues, promoting the idea of indole ring as a framework that might be exploited in the future.
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Affiliation(s)
- Ming-Zhi Zhang
- Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing 210095, PR China; Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
| | - Chen-Yang Jia
- Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing 210095, PR China; Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China
| | - Yu-Cheng Gu
- Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom
| | - Nick Mulholland
- Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom
| | - Sarah Turner
- Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom
| | - David Beattie
- Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom
| | - Wei-Hua Zhang
- Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Guang-Fu Yang
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China
| | - John Clough
- Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom
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259
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Quinn RA, Whiteson K, Lim YW, Zhao J, Conrad D, LiPuma JJ, Rohwer F, Widder S. Ecological networking of cystic fibrosis lung infections. NPJ Biofilms Microbiomes 2016; 2:4. [PMID: 28649398 PMCID: PMC5460249 DOI: 10.1038/s41522-016-0002-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 07/13/2016] [Accepted: 07/27/2016] [Indexed: 11/22/2022] Open
Abstract
In the context of a polymicrobial infection, treating a specific pathogen poses challenges because of unknown consequences on other members of the community. The presence of ecological interactions between microbes can change their physiology and response to treatment. For example, in the cystic fibrosis lung polymicrobial infection, antimicrobial susceptibility testing on clinical isolates is often not predictive of antibiotic efficacy. Novel approaches are needed to identify the interrelationships within the microbial community to better predict treatment outcomes. Here we used an ecological networking approach on the cystic fibrosis lung microbiome characterized using 16S rRNA gene sequencing and metagenomics. This analysis showed that the community is separated into three interaction groups: Gram-positive anaerobes, Pseudomonas aeruginosa, and Staphylococcus aureus. The P. aeruginosa and S. aureus groups both anti-correlate with the anaerobic group, indicating a functional antagonism. When patients are clinically stable, these major groupings were also stable, however, during exacerbation, these communities fragment. Co-occurrence networking of functional modules annotated from metagenomics data supports that the underlying taxonomic structure is driven by differences in the core metabolism of the groups. Topological analysis of the functional network identified the non-mevalonate pathway of isoprenoid biosynthesis as a keystone for the microbial community, which can be targeted with the antibiotic fosmidomycin. This study uses ecological theory to identify novel treatment approaches against a polymicrobial disease with more predictable outcomes.
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Affiliation(s)
- Robert A Quinn
- Department of Biology, San Diego State University, San Diego, CA 92182 USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA 92093 USA
| | - Katrine Whiteson
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, CA 92697 USA
| | - Yan Wei Lim
- Department of Biology, San Diego State University, San Diego, CA 92182 USA
| | - Jiangchao Zhao
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI 48109 USA
- Division of Agriculture, Department of Animal Science, University of Arkansas, Fayetteville, AR 72701 USA
| | - Douglas Conrad
- Department of Medicine, University of California at San Diego, La Jolla, CA 92037 USA
| | - John J LiPuma
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI 48109 USA
| | - Forest Rohwer
- Department of Biology, San Diego State University, San Diego, CA 92182 USA
| | - Stefanie Widder
- CUBE, Department of Microbiology and Ecosystem Science, University of Vienna, Althanstr.14 A-1090, Vienna, Austria
- CeMM - Research Center, for Molecular Medicine of the Austrian Academy of Sciences, Lazarettg, 14, A-1090 Vienna, Austria
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260
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Geddis SM, Carro L, Hodgkinson JT, Spring DR. Divergent Synthesis of Quinolone Natural Products from Pseudonocardia sp. CL38489. European J Org Chem 2016; 2016:5799-5802. [PMID: 28111524 PMCID: PMC5215369 DOI: 10.1002/ejoc.201601195] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Indexed: 12/21/2022]
Abstract
Two divergent synthetic routes are reported offering access to four quinolone natural products from Pseudonocardia sp. CL38489. Key steps to the natural products involved a regioselective epoxidation, an intramolecular Buchwald-Hartwig amination and a final acid-catalysed 1,3-allylic-alcohol rearrangement to give two of the natural products in one step. This study completes the synthesis of all eight antibacterial quinolone natural products reported in the family. In addition, this modular strategy enables an improved synthesis towards two natural products previously reported.
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Affiliation(s)
- Stephen M. Geddis
- Department of ChemistryUniversity of CambridgeLensfield RoadCB2 1EWCambridgeUK
| | - Laura Carro
- Department of ChemistryUniversity of CambridgeLensfield RoadCB2 1EWCambridgeUK
| | - James T. Hodgkinson
- Department of ChemistryUniversity of CambridgeLensfield RoadCB2 1EWCambridgeUK
| | - David R. Spring
- Department of ChemistryUniversity of CambridgeLensfield RoadCB2 1EWCambridgeUK
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261
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Unravelling the Genome-Wide Contributions of Specific 2-Alkyl-4-Quinolones and PqsE to Quorum Sensing in Pseudomonas aeruginosa. PLoS Pathog 2016; 12:e1006029. [PMID: 27851827 PMCID: PMC5112799 DOI: 10.1371/journal.ppat.1006029] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 10/28/2016] [Indexed: 12/18/2022] Open
Abstract
The pqs quorum sensing (QS) system is crucial for Pseudomonas aeruginosa virulence both in vitro and in animal models of infection and is considered an ideal target for the development of anti-virulence agents. However, the precise role played by each individual component of this complex QS circuit in the control of virulence remains to be elucidated. Key components of the pqs QS system are 2-heptyl-4-hydroxyquinoline (HHQ), 2-heptyl-3-hydroxy-4-quinolone (PQS), 2-heptyl-4-hydroxyquinoline N-oxide (HQNO), the transcriptional regulator PqsR and the PQS-effector element PqsE. To define the individual contribution of each of these components to QS-mediated regulation, transcriptomic analyses were performed and validated on engineered P. aeruginosa strains in which the biosynthesis of 2-alkyl-4-quinolones (AQs) and expression of pqsE and pqsR have been uncoupled, facilitating the identification of the genes controlled by individual pqs system components. The results obtained demonstrate that i) the PQS biosynthetic precursor HHQ triggers a PqsR-dependent positive feedback loop that leads to the increased expression of only the pqsABCDE operon, ii) PqsE is involved in the regulation of diverse genes coding for key virulence determinants and biofilm development, iii) PQS promotes AQ biosynthesis, the expression of genes involved in the iron-starvation response and virulence factor production via PqsR-dependent and PqsR-independent pathways, and iv) HQNO does not influence transcription and hence does not function as a QS signal molecule. Overall this work has facilitated identification of the specific regulons controlled by individual pqs system components and uncovered the ability of PQS to contribute to gene regulation independent of both its ability to activate PqsR and to induce the iron-starvation response. Many bacterial pathogens control virulence gene expression and the development of antibiotic-resistant biofilms via intercellular communication through ‘quorum sensing’ (QS). QS systems depend on the synthesis, secretion and perception of diffusible signalling molecules that enable bacteria to synchronize their behaviour at the population level and are considered ideal targets for the development of anti-virulence drugs. Pseudomonas aeruginosa employs several overlapping QS circuits including the pqs system to control the expression of virulence determinants. The pqs QS system relies on multiple 2-alkyl-4-quinolones (AQs), including the Pseudomonas Quinolone Signal (PQS), as signal molecules. However, the individual contributions of key AQs and the effector proteins PqsR and PqsE within the auto-regulated pqs system have not been elucidated because of their inter-dependence. By constructing P. aeruginosa strains with multiple mutations in the pqs system and determining their transcriptomes in the presence or absence of PqsR, PqsE or exogenously supplied AQs, we define the distinct regulons involved and characterize a novel PQS signalling pathway independent of PqsR and the iron-starvation response.
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262
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Barr HL, Halliday N, Barrett DA, Williams P, Forrester DL, Peckham D, Williams K, Smyth AR, Honeybourne D, L Whitehouse J, Nash EF, Dewar J, Clayton A, Knox AJ, Cámara M, Fogarty AW. Diagnostic and prognostic significance of systemic alkyl quinolones for P. aeruginosa in cystic fibrosis: A longitudinal study. J Cyst Fibros 2016; 16:230-238. [PMID: 27773591 PMCID: PMC5345566 DOI: 10.1016/j.jcf.2016.10.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 10/02/2016] [Accepted: 10/06/2016] [Indexed: 11/30/2022]
Abstract
Background Pulmonary P. aeruginosa infection is associated with poor outcomes in cystic fibrosis (CF) and early diagnosis is challenging, particularly in those who are unable to expectorate sputum. Specific P. aeruginosa 2-alkyl-4-quinolones are detectable in the sputum, plasma and urine of adults with CF, suggesting that they have potential as biomarkers for P. aeruginosa infection. Aim To investigate systemic 2-alkyl-4-quinolones as potential biomarkers for pulmonary P. aeruginosa infection. Methods A multicentre observational study of 176 adults and 68 children with CF. Cross-sectionally, comparisons were made between current P. aeruginosa infection using six 2-alkyl-4-quinolones detected in sputum, plasma and urine against hospital microbiological culture results. All participants without P. aeruginosa infection at baseline were followed up for one year to determine if 2-alkyl-4-quinolones were early biomarkers of pulmonary P. aeruginosa infection. Results Cross-sectional analysis: the most promising biomarker with the greatest diagnostic accuracy was 2-heptyl-4-hydroxyquinoline (HHQ). In adults, areas under the ROC curves (95% confidence intervals) for HHQ analyses were 0.82 (0.75–0.89) in sputum, 0.76 (0.69–0.82) in plasma and 0.82 (0.77–0.88) in urine. In children, the corresponding values for HHQ analyses were 0.88 (0.77–0.99) in plasma and 0.83 (0.68–0.97) in urine. Longitudinal analysis: Ten adults and six children had a new positive respiratory culture for P. aeruginosa in follow-up. A positive plasma HHQ test at baseline was significantly associated with a new positive culture for P. aeruginosa in both adults and children in follow-up (odds ratio (OR) = 6.67;-95% CI:-1.48–30.1;-p = 0.01 and OR = 70; 95% CI: 5–956;-p < 0.001 respectively). Conclusions AQs measured in sputum, plasma and urine may be used to diagnose current infection with P. aeruginosa in adults and children with CF. These preliminary data show that plasma HHQ may have potential as an early biomarker of pulmonary P. aeruginosa. Further studies are necessary to evaluate if HHQ could be used in clinical practice to aid early diagnosis of P. aeruginosa infection in the future.
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Affiliation(s)
- Helen L Barr
- Division of Respiratory Medicine, University of Nottingham, City Hospital Campus, Nottingham, UK.
| | - Nigel Halliday
- School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - David A Barrett
- Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham, UK
| | - Paul Williams
- School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Douglas L Forrester
- Division of Respiratory Medicine, University of Nottingham, City Hospital Campus, Nottingham, UK
| | - Daniel Peckham
- Leeds Adult Cystic Fibrosis Centre, St James's University Hospital, Leeds, UK
| | - Kate Williams
- Leeds Adult Cystic Fibrosis Centre, St James's University Hospital, Leeds, UK
| | - Alan R Smyth
- Division of Child Health, Obstetrics and Gynaecology, University of Nottingham, UK
| | - David Honeybourne
- West Midlands Adult CF Centre, Heart of England, NHS Foundation Trust, Birmingham, UK
| | - Joanna L Whitehouse
- West Midlands Adult CF Centre, Heart of England, NHS Foundation Trust, Birmingham, UK
| | - Edward F Nash
- West Midlands Adult CF Centre, Heart of England, NHS Foundation Trust, Birmingham, UK
| | - Jane Dewar
- Wolfson Cystic Fibrosis Centre, Department of Respiratory Medicine, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Andrew Clayton
- Wolfson Cystic Fibrosis Centre, Department of Respiratory Medicine, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Alan J Knox
- Division of Respiratory Medicine, University of Nottingham, City Hospital Campus, Nottingham, UK
| | - Miguel Cámara
- School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Andrew W Fogarty
- Division of Epidemiology and Public Health, University of Nottingham, Clinical Sciences Building, University of Nottingham, Nottingham, UK
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263
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Aminov R. History of antimicrobial drug discovery: Major classes and health impact. Biochem Pharmacol 2016; 133:4-19. [PMID: 27720719 DOI: 10.1016/j.bcp.2016.10.001] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 10/04/2016] [Indexed: 12/12/2022]
Abstract
The introduction of antibiotics into clinical practice revolutionized the treatment and management of infectious diseases. Before the introduction of antibiotics, these diseases were the leading cause of morbidity and mortality in human populations. This review presents a brief history of discovery of the main antimicrobial classes (arsphenamines, β-lactams, sulphonamides, polypeptides, aminoglycosides, tetracyclines, amphenicols, lipopeptides, macrolides, oxazolidinones, glycopeptides, streptogramins, ansamycins, quinolones, and lincosamides) that have changed the landscape of contemporary medicine. Given within a historical timeline context, the review discusses how the introduction of certain antimicrobial classes affected the morbidity and mortality rates due to bacterial infectious diseases in human populations. Problems of resistance to antibiotics of different classes are also extensively discussed.
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Affiliation(s)
- Rustam Aminov
- School of Medicine and Dentistry, University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom.
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264
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Maura D, Hazan R, Kitao T, Ballok AE, Rahme LG. Evidence for Direct Control of Virulence and Defense Gene Circuits by the Pseudomonas aeruginosa Quorum Sensing Regulator, MvfR. Sci Rep 2016; 6:34083. [PMID: 27678057 PMCID: PMC5039717 DOI: 10.1038/srep34083] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 09/01/2016] [Indexed: 12/21/2022] Open
Abstract
Pseudomonas aeruginosa defies eradication by antibiotics and is responsible for acute and chronic human infections due to a wide variety of virulence factors. Currently, it is believed that MvfR (PqsR) controls the expression of many of these factors indirectly via the pqs and phnAB operons. Here we provide strong evidence that MvfR may also bind and directly regulate the expression of additional 35 loci across the P. aeruginosa genome, including major regulators and virulence factors, such as the quorum sensing (QS) regulators lasR and rhlR, and genes involved in protein secretion, translation, and response to oxidative stress. We show that these anti-oxidant systems, AhpC-F, AhpB-TrxB2 and Dps, are critical for P. aeruginosa survival to reactive oxygen species and antibiotic tolerance. Considering that MvfR regulated compounds generate reactive oxygen species, this indicates a tightly regulated QS self-defense anti-poisoning system. These findings also challenge the current hierarchical regulation model of P. aeruginosa QS systems by revealing new interconnections between them that suggest a circular model. Moreover, they uncover a novel role for MvfR in self-defense that favors antibiotic tolerance and cell survival, further demonstrating MvfR as a highly desirable anti-virulence target.
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Affiliation(s)
- Damien Maura
- Department of Surgery, Massachusetts General Hospital, Boston MA 02114, USA.,Department of Microbiology and Immunobiology, Harvard Medical School, Boston MA 02115, USA.,Shriners Hospitals for Children Boston, Boston, 02114, Massachusetts, USA
| | - Ronen Hazan
- Department of Surgery, Massachusetts General Hospital, Boston MA 02114, USA.,Department of Microbiology and Immunobiology, Harvard Medical School, Boston MA 02115, USA.,Shriners Hospitals for Children Boston, Boston, 02114, Massachusetts, USA.,Institute of Dental Sciences and School of Dental Medicine, Hebrew University, Jerusalem P.O.B 12272, 91120, Israel
| | - Tomoe Kitao
- Department of Surgery, Massachusetts General Hospital, Boston MA 02114, USA.,Department of Microbiology and Immunobiology, Harvard Medical School, Boston MA 02115, USA.,Shriners Hospitals for Children Boston, Boston, 02114, Massachusetts, USA
| | - Alicia E Ballok
- Department of Surgery, Massachusetts General Hospital, Boston MA 02114, USA.,Department of Microbiology and Immunobiology, Harvard Medical School, Boston MA 02115, USA.,Shriners Hospitals for Children Boston, Boston, 02114, Massachusetts, USA
| | - Laurence G Rahme
- Department of Surgery, Massachusetts General Hospital, Boston MA 02114, USA.,Department of Microbiology and Immunobiology, Harvard Medical School, Boston MA 02115, USA.,Shriners Hospitals for Children Boston, Boston, 02114, Massachusetts, USA
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265
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Hooper DC, Jacoby GA. Topoisomerase Inhibitors: Fluoroquinolone Mechanisms of Action and Resistance. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a025320. [PMID: 27449972 DOI: 10.1101/cshperspect.a025320] [Citation(s) in RCA: 252] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Quinolone antimicrobials are widely used in clinical medicine and are the only current class of agents that directly inhibit bacterial DNA synthesis. Quinolones dually target DNA gyrase and topoisomerase IV binding to specific domains and conformations so as to block DNA strand passage catalysis and stabilize DNA-enzyme complexes that block the DNA replication apparatus and generate double breaks in DNA that underlie their bactericidal activity. Resistance has emerged with clinical use of these agents and is common in some bacterial pathogens. Mechanisms of resistance include mutational alterations in drug target affinity and efflux pump expression and acquisition of resistance-conferring genes. Resistance mutations in one or both of the two drug target enzymes are commonly in a localized domain of the GyrA and ParC subunits of gyrase and topoisomerase IV, respectively, and reduce drug binding to the enzyme-DNA complex. Other resistance mutations occur in regulatory genes that control the expression of native efflux pumps localized in the bacterial membrane(s). These pumps have broad substrate profiles that include other antimicrobials as well as quinolones. Mutations of both types can accumulate with selection pressure and produce highly resistant strains. Resistance genes acquired on plasmids confer low-level resistance that promotes the selection of mutational high-level resistance. Plasmid-encoded resistance is because of Qnr proteins that protect the target enzymes from quinolone action, a mutant aminoglycoside-modifying enzyme that also modifies certain quinolones, and mobile efflux pumps. Plasmids with these mechanisms often encode additional antimicrobial resistances and can transfer multidrug resistance that includes quinolones.
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Affiliation(s)
- David C Hooper
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts 02114
| | - George A Jacoby
- Lahey Hospital and Medical Center, Burlington, Massachusetts 01805
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266
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Song S, Zhao D, Sun J, Miao Q, Liu X, Wang Y, Zhong L, Xu M, Zhang P. Development of a UPLC-MS/MS method for the determination of lomefloxacin in rabbit aqueous humor and its application to a pharmacokinetic study. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1033-1034:187-192. [PMID: 27565567 DOI: 10.1016/j.jchromb.2016.08.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 08/05/2016] [Accepted: 08/14/2016] [Indexed: 10/21/2022]
Abstract
Lomefloxacin is a kind of synthetic fluoroquinolone antibiotic, which is used for the treatment of infectious diseases. In this study, a rapid and efficient liquid chromatography-tandem mass spectrometric assay was developed to determine the concentration of lomefloxacin in rabbit aqueous humor quantitatively. Aqueous humor samples were extracted by protein precipitation. Ofloxacin was chosen as internal standard. The chromatographic separation was achieved on a Kinetex C18 (50mm×2.10mm, 2.6μm, Phenomenex Corp, USA) column, with a gradient of methanol (0.1% formic acid) and water (0.1% formic acid). Multiple reaction monitoring (MRM) with positive ionization mode was used for the mass analysis. The validation of this method was based on the European Medicines Agency (2011) [1] and US FDA Guidelines (2001) [2]. The calibration range of aqueous humor samples was 5-1200ng/mL with r=0.9990 (n=6). For all QC samples, Inter-and intra-run precisions were less than 15% and accuracies were between 80%-120%. In conclusion, the assay was rapid, sensitive and able to determinate the lomefloxacin in rabbit aqueous humor accurately. At the same time, this method was successfully applied to study the pharmacokinetics of lomefloxacin hydrochloride eye drops and lomefloxacin hydrochloride ophthalmic gel in rabbit aqueous humor.
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Affiliation(s)
- Shiwen Song
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Dongyang Zhao
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Jing Sun
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Qiuyan Miao
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Xiaojie Liu
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Yanling Wang
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Lu Zhong
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Meng Xu
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Peng Zhang
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China.
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267
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Baig N, Polisetti S, Morales-Soto N, Dunham SJB, Sweedler JV, Shrout JD, Bohn PW. Label-free molecular imaging of bacterial communities of the opportunistic pathogen Pseudomonas aeruginosa. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2016; 9930:993004. [PMID: 29670306 PMCID: PMC5901720 DOI: 10.1117/12.2236695] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Biofilms, such as those formed by the opportunistic human pathogen Pseudomonas aeruginosa are complex, matrix enclosed, and surface-associated communities of cells. Bacteria that are part of a biofilm community are much more resistant to antibiotics and the host immune response than their free-floating counterparts. P. aeruginosa biofilms are associated with persistent and chronic infections in diseases such as cystic fibrosis and HIV-AIDS. P. aeruginosa synthesizes and secretes signaling molecules such as the Pseudomonas quinolone signal (PQS) which are implicated in quorum sensing (QS), where bacteria regulate gene expression based on population density. Processes such as biofilms formation and virulence are regulated by QS. This manuscript describes the powerful molecular imaging capabilities of confocal Raman microscopy (CRM) and surface enhanced Raman spectroscopy (SERS) in conjunction with multivariate statistical tools such as principal component analysis (PCA) for studying the spatiotemporal distribution of signaling molecules, secondary metabolites and virulence factors in biofilm communities of P. aeruginosa. Our observations reveal that the laboratory strain PAO1C synthesizes and secretes 2-alkyl-4-hydroxyquinoline N-oxides and 2-alkyl-4-hydroxyquinolones in high abundance, while the isogenic acyl homoserine lactone QS-deficient mutant (ΔlasIΔrhlI) strain produces predominantly 2-alkyl-quinolones during biofilm formation. This study underscores the use of CRM, along with traditional biological tools such as genetics, for studying the behavior of microbial communities at the molecular level.
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Affiliation(s)
- Nameera Baig
- Department of Chemistry & Biochemistry and Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Sneha Polisetti
- Department of Chemistry & Biochemistry and Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Nydia Morales-Soto
- Department of Civil and Environmental Engineering and Earth Sciences and Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
- Eck Institute for Global Health, University of Notre Dame, USA
| | - Sage J B Dunham
- Department of Chemistry and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Jonathan V Sweedler
- Department of Chemistry and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Joshua D Shrout
- Department of Civil and Environmental Engineering and Earth Sciences and Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
- Eck Institute for Global Health, University of Notre Dame, USA
| | - Paul W Bohn
- Department of Chemistry & Biochemistry and Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, USA
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268
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Zamotaiev OM, Shvadchak V, Sych TP, Melnychuk NA, Yushchenko D, Mely Y, Pivovarenko VG. Environment-sensitive quinolone demonstrating long-lived fluorescence and unusually slow excited-state intramolecular proton transfer kinetics. Methods Appl Fluoresc 2016; 4:034004. [PMID: 28355165 DOI: 10.1088/2050-6120/4/3/034004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A new small fluorescent dye based on 3-hydroxybenzo[g]quinolone, a benzo-analogue of Pseudomonas quinolone signal species, has been synthesized. The dye demonstrates interesting optical properties, with absorption in the visible region, two band emission due to an excited-state intramolecular proton transfer (ESIPT) reaction and high fluorescence quantum yield in both protic and aprotic media. Time-resolved fluorescence spectroscopy shows that the ESIPT reaction time is unusually long (up to 8 ns), indicating that both forward and backward ESIPT reactions are very slow in comparison to other 3-hydroxyquinolones. In spite of these slow rate constants, the ESIPT reaction was found to show a reversible character as a result of the very long lifetimes of both N* and T* forms (up to 16 ns). The ESIPT reaction rate is mainly controlled by the hydrogen bond donor ability in protic solvents and the polarity in aprotic solvents. Using large unilamellar vesicles and giant unilamellar vesicles of different lipid compositions, the probe was shown to preferentially label liquid disordered phases.
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Affiliation(s)
- O M Zamotaiev
- Department of Chemistry, National Taras Shevchenko University of Kyiv, 01601 Kyiv, Ukraine
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269
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Nguyen AT, Jones JW, Cámara M, Williams P, Kane MA, Oglesby-Sherrouse AG. Cystic Fibrosis Isolates of Pseudomonas aeruginosa Retain Iron-Regulated Antimicrobial Activity against Staphylococcus aureus through the Action of Multiple Alkylquinolones. Front Microbiol 2016; 7:1171. [PMID: 27512392 PMCID: PMC4961689 DOI: 10.3389/fmicb.2016.01171] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 07/14/2016] [Indexed: 01/03/2023] Open
Abstract
Cystic fibrosis (CF) is a hereditary disease that predisposes individuals to pulmonary dysfunction and chronic infections. Early infection of the CF lung with Staphylococcus aureus is common, while Pseudomonas aeruginosa becomes dominant as disease progresses. Emergence of P. aeruginosa likely depends on the action of multiple 2-alkyl-4-(1H)-quinolones (AQ) secreted by this organism. We recently showed that antimicrobial activity against S. aureus is enhanced by iron depletion and is dependent upon multiple AQ metabolites. Two of these AQs, the Pseudomonas quinolone signal [PQS; 2-heptyl-3-hydroxy-4(1H)-quinolone] and 2-heptyl-4-hydroxyquinoline (HHQ), are quorum sensing molecules that activate the expression of multiple microbicidal factors. Here we show for the first time that HHQ also exhibits innate antimicrobial activity against S. aureus. We further show that iron depletion potentiates the antistaphylococcal activity of HHQ, as well as 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO), another AQ that functions as a cytochrome B inhibitor. Notably, we found that deletion of the genes for the terminal biosynthetic steps for either PQS or HQNO results in overproduction of the HHQ intermediate, likely maintaining the ability of these mutants to mediate antimicrobial activity. Compensatory increases in HHQ were also observed in PQS-deficient CF isolates, which also retained the ability to mediate iron-regulated antimicrobial activity against S. aureus. These studies demonstrate that iron-regulated antimicrobial activity of P. aeruginosa against S. aureus is due to the cumulative effects of multiple AQ metabolites, both the production and activity of which are modulated by environmental iron levels.
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Affiliation(s)
- Angela T Nguyen
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland Baltimore, MD, USA
| | - Jace W Jones
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland Baltimore, MD, USA
| | - Miguel Cámara
- Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham Nottingham, UK
| | - Paul Williams
- Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham Nottingham, UK
| | - Maureen A Kane
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland Baltimore, MD, USA
| | - Amanda G Oglesby-Sherrouse
- Department of Pharmaceutical Sciences, School of Pharmacy, University of MarylandBaltimore, MD, USA; Department of Microbiology and Immunology, School of Medicine, University of MarylandBaltimore, MD, USA
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270
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Morkunas B, Gal B, Galloway WRJD, Hodgkinson JT, Ibbeson BM, Tan YS, Welch M, Spring DR. Discovery of an inhibitor of the production of the Pseudomonas aeruginosa virulence factor pyocyanin in wild-type cells. Beilstein J Org Chem 2016; 12:1428-33. [PMID: 27559393 PMCID: PMC4979876 DOI: 10.3762/bjoc.12.137] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 06/30/2016] [Indexed: 12/16/2022] Open
Abstract
Pyocyanin is a small molecule produced by Pseudomonas aeruginosa that plays a crucial role in the pathogenesis of infections by this notorious opportunistic pathogen. The inhibition of pyocyanin production has been identified as an attractive antivirulence strategy for the treatment of P. aeruginosa infections. Herein, we report the discovery of an inhibitor of pyocyanin production in cultures of wild-type P. aeruginosa which is based around a 4-alkylquinolin-2(1H)-one scaffold. To the best of our knowledge, this is the first reported example of pyocyanin inhibition by a compound based around this molecular framework. The compound may therefore be representative of a new structural sub-class of pyocyanin inhibitors, which could potentially be exploited in in a therapeutic context for the development of critically needed new antipseudomonal agents. In this context, the use of wild-type cells in this study is notable, since the data obtained are of direct relevance to native situations. The compound could also be of value in better elucidating the role of pyocyanin in P. aeruginosa infections. Evidence suggests that the active compound reduces the level of pyocyanin production by inhibiting the cell–cell signalling mechanism known as quorum sensing. This could have interesting implications; quorum sensing regulates a range of additional elements associated with the pathogenicity of P. aeruginosa and there is a wide range of other potential applications where the inhibition of quorum sensing is desirable.
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Affiliation(s)
- Bernardas Morkunas
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, UK
| | - Balint Gal
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK
| | | | - James T Hodgkinson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK
| | - Brett M Ibbeson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK
| | - Yaw Sing Tan
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK; Bioinformatics Institute, ASTAR, 30 Biopolis Street, #07-01 Matrix, Singapore 138671
| | - Martin Welch
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, UK
| | - David R Spring
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK
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271
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Wang J, Wang XH, Liu X, Li J, Shi XP, Song YL, Zeng KW, Zhang L, Tu PF, Shi SP. Synthesis of Unnatural 2-Substituted Quinolones and 1,3-Diketones by a Member of Type III Polyketide Synthases from Huperzia serrata. Org Lett 2016; 18:3550-3. [DOI: 10.1021/acs.orglett.6b01501] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Juan Wang
- Modern
Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
- School
of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100102, China
| | - Xiao-Hui Wang
- Modern
Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Xiao Liu
- Modern
Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Jun Li
- Modern
Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Xiao-Ping Shi
- Modern
Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
- School
of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100102, China
| | - Yue-Lin Song
- Modern
Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Ke-Wu Zeng
- State
Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing 100191, China
| | - Le Zhang
- Modern
Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
- School
of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100102, China
| | - Peng-Fei Tu
- Modern
Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - She-Po Shi
- Modern
Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
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272
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Bellili A, Pan Y, Al Mogren MM, Lau KC, Hochlaf M. Electronic, structural and vibrational induced effects upon ionization of 2-quinolinone. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2016; 164:1-7. [PMID: 27060413 DOI: 10.1016/j.saa.2016.03.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/22/2016] [Accepted: 03/27/2016] [Indexed: 06/05/2023]
Abstract
Using first principle methodologies, we characterize the lowest electronic states of 2-quinolinone(+) cation. The ground state of this ion is of X˜(2)A(″) nature. We deduce the adiabatic ionization energy of 2-quinolinone to be equal 8.249eV using the explicitly correlated coupled cluster level and where zero point vibrational energy, core-valence and scalar relativistic effects are taken into account. We examine also the ionization induced structural changes and vibrational shifts and analyze the electron density differences between the neutral and ionic species. These data show that the formation of 2-quinolinone(+)X˜(2)A(″) from 2-quinolinone affects strongly the HNCO group, whereas the carbon skeletal is perturbed when the upper electronic cationic states are populated. The comparison to 2-pyridone allows the elucidation of the effect of benzene ring fused with this heterocyclic ring. Since quinolones and pyridones are both model systems of DNA bases, these findings might help in understanding the charge redistribution in these biological entities upon ionization.
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Affiliation(s)
- A Bellili
- Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 bd Descartes, 77454 Marne-la-Vallée, France
| | - Y Pan
- Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong
| | - M M Al Mogren
- Chemistry Department, Faculty of Science, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia
| | - K C Lau
- Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong.
| | - M Hochlaf
- Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 bd Descartes, 77454 Marne-la-Vallée, France.
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273
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Welsh MA, Blackwell HE. Chemical probes of quorum sensing: from compound development to biological discovery. FEMS Microbiol Rev 2016; 40:774-94. [PMID: 27268906 DOI: 10.1093/femsre/fuw009] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2016] [Indexed: 01/20/2023] Open
Abstract
Bacteria can utilize chemical signals to coordinate the expression of group-beneficial behaviors in a method of cell-cell communication called quorum sensing (QS). The discovery that QS controls the production of virulence factors and biofilm formation in many common pathogens has driven an explosion of research aimed at both deepening our fundamental understanding of these regulatory networks and developing chemical agents that can attenuate QS signaling. The inherently chemical nature of QS makes studying these pathways with small molecule tools a complementary approach to traditional microbiology techniques. Indeed, chemical tools are beginning to yield new insights into QS regulation and provide novel strategies to inhibit QS. Here, we review the most recent advances in the development of chemical probes of QS systems in Gram-negative bacteria, with an emphasis on the opportunistic pathogen Pseudomonas aeruginosa We first describe reports of novel small molecule modulators of QS receptors and QS signal synthases. Next, in several case studies, we showcase how chemical tools have been deployed to reveal new knowledge of QS biology and outline lessons for how researchers might best target QS to combat bacterial virulence. To close, we detail the outstanding challenges in the field and suggest strategies to overcome these issues.
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Affiliation(s)
- Michael A Welsh
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA
| | - Helen E Blackwell
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA
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274
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Metal-assisted polyatomic SIMS and laser desorption/ionization for enhanced small molecule imaging of bacterial biofilms. Biointerphases 2016; 11:02A325. [PMID: 26945568 DOI: 10.1116/1.4942884] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Mass spectrometry imaging (MSI) has become an important analytical tool for many sectors of science and medicine. As the application of MSI expands into new areas of inquiry, existing methodologies must be adapted and improved to meet emerging challenges. Particularly salient is the need for small molecule imaging methods that are compatible with complex multicomponent systems, a challenge that is amplified by the effects of analyte migration and matrix interference. With a focus on microbial biofilms from the opportunistic pathogen Pseudomonas aeruginosa, the relative advantages of two established microprobe-based MSI techniques-polyatomic secondary ion mass spectrometry (SIMS) and laser desorption/ionization-are compared, with emphasis on exploring the effect of surface metallization on small molecule imaging. A combination of qualitative image comparison and multivariate statistical analysis demonstrates that sputtering microbial biofilms with a 2.5 nm layer of gold selectively enhances C60-SIMS ionization for several molecular classes including rhamnolipids and 2-alkyl-quinolones. Metallization also leads to the reduction of in-source fragmentation and subsequent ionization of media-specific background polymers, which improves spectral purity and image quality. These findings show that the influence of metallization upon ionization is strongly dependent on both the surface architecture and the analyte class, and further demonstrate that metal-assisted C60-SIMS is a viable method for small molecule imaging of intact molecular ions in complex biological systems.
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275
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Quinn RA, Phelan VV, Whiteson KL, Garg N, Bailey BA, Lim YW, Conrad DJ, Dorrestein PC, Rohwer FL. Microbial, host and xenobiotic diversity in the cystic fibrosis sputum metabolome. THE ISME JOURNAL 2016; 10:1483-98. [PMID: 26623545 PMCID: PMC5029181 DOI: 10.1038/ismej.2015.207] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 10/19/2015] [Accepted: 10/12/2015] [Indexed: 12/21/2022]
Abstract
Cystic fibrosis (CF) lungs are filled with thick mucus that obstructs airways and facilitates chronic infections. Pseudomonas aeruginosa is a significant pathogen of this disease that produces a variety of toxic small molecules. We used molecular networking-based metabolomics to investigate the chemistry of CF sputa and assess how the microbial molecules detected reflect the microbiome and clinical culture history of the patients. Metabolites detected included xenobiotics, P. aeruginosa specialized metabolites and host sphingolipids. The clinical culture and microbiome profiles did not correspond to the detection of P. aeruginosa metabolites in the same samples. The P. aeruginosa molecules that were detected in sputum did not match those from laboratory cultures. The pseudomonas quinolone signal (PQS) was readily detectable from cultured strains, but absent from sputum, even when its precursor molecules were present. The lack of PQS production in vivo is potentially due to the chemical nature of the CF lung environment, indicating that culture-based studies of this pathogen may not explain its behavior in the lung. The most differentially abundant molecules between CF and non-CF sputum were sphingolipids, including sphingomyelins, ceramides and lactosylceramide. As these highly abundant molecules contain the inflammatory mediator ceramide, they may have a significant role in CF hyperinflammation. This study demonstrates that the chemical makeup of CF sputum is a complex milieu of microbial, host and xenobiotic molecules. Detection of a bacterium by clinical culturing and 16S rRNA gene profiling do not necessarily reflect the active production of metabolites from that bacterium in a sputum sample.
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Affiliation(s)
- Robert A Quinn
- Department of Biology, San Diego State
University, San Diego, CA, USA
- Skaggs School of Pharmacy and
Pharmaceutical Sciences, University of California at San Diego, La
Jolla, CA, USA
| | - Vanessa V Phelan
- Skaggs School of Pharmacy and
Pharmaceutical Sciences, University of California at San Diego, La
Jolla, CA, USA
| | - Katrine L Whiteson
- Department of Molecular Biology and
Biochemistry, University of California Irvine, Irvine,
CA, USA
| | - Neha Garg
- Skaggs School of Pharmacy and
Pharmaceutical Sciences, University of California at San Diego, La
Jolla, CA, USA
| | - Barbara A Bailey
- Department of Mathematics and Statistics,
San Diego State University, San Diego, CA,
USA
| | - Yan Wei Lim
- Department of Biology, San Diego State
University, San Diego, CA, USA
| | - Douglas J Conrad
- Department of Medicine, University of
California at San Diego, La Jolla, CA,
USA
| | - Pieter C Dorrestein
- Skaggs School of Pharmacy and
Pharmaceutical Sciences, University of California at San Diego, La
Jolla, CA, USA
| | - Forest L Rohwer
- Department of Biology, San Diego State
University, San Diego, CA, USA
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276
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Nguyen AT, Oglesby-Sherrouse AG. Interactions between Pseudomonas aeruginosa and Staphylococcus aureus during co-cultivations and polymicrobial infections. Appl Microbiol Biotechnol 2016; 100:6141-6148. [PMID: 27236810 DOI: 10.1007/s00253-016-7596-3] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/26/2016] [Accepted: 04/28/2016] [Indexed: 02/06/2023]
Abstract
Pseudomonas aeruginosa and Staphylococcus aureus are versatile bacterial pathogens and common etiological agents in polymicrobial infections. Microbial communities containing both of these pathogens are shaped by interactions ranging from parasitic to mutualistic, with the net impact of these interactions in many cases resulting in enhanced virulence. Polymicrobial communities of these organisms are further defined by multiple aspects of the host environment, with important implications for disease progression and therapeutic outcomes. This mini-review highlights the impact of these interactions on the host and individual pathogens, the molecular mechanisms that underlie these interactions, and host-specific factors that drive interactions between these two important pathogens.
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Affiliation(s)
- Angela T Nguyen
- School of Pharmacy, Department of Pharmaceutical Sciences, University of Maryland, Baltimore, MD, 21201, USA
| | - Amanda G Oglesby-Sherrouse
- School of Pharmacy, Department of Pharmaceutical Sciences, University of Maryland, Baltimore, MD, 21201, USA. .,School of Medicine, Department of Microbiology and Immunology, University of Maryland, Baltimore, MD, 21201, USA.
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277
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Monzon O, Yang Y, Li Q, Alvarez PJ. Quorum sensing autoinducers enhance biofilm formation and power production in a hypersaline microbial fuel cell. Biochem Eng J 2016. [DOI: 10.1016/j.bej.2016.01.023] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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278
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Gokgoz NB, Akbulut BS. Proteomics Evidence for the Activity of the Putative Antibacterial Plant Alkaloid (-)-Roemerine: Mainstreaming Omics-Guided Drug Discovery. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2016; 19:478-89. [PMID: 26230533 DOI: 10.1089/omi.2015.0056] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Discovery of new antibacterials with novel mechanisms is important to counteract the ingenious resistance mechanisms of bacteria. In this connection, omics-guided drug discovery offers a rigorous method in the quest of new antibacterials. (-)-Roemerine is a plant alkaloid that has been reported to possess putative antibacterial activity against Escherichia coli, Bacillus subtilis, and Salmonella typhimurium. The aim of the present study was to characterize the activity of (-)-roemerine in Escherichia coli TB1 using proteomics tools. With (-)-roemerine treatment, we found limited permeability through the outer membrane and repression of transport proteins involved in carbohydrate metabolism, resulting in poor carbon source availability. The shortfall of intracellular carbon sources in turn led to impaired cell growth. The reduction in the abundance of proteins related to translational machinery, amino acid biosynthesis, and metabolism was accompanied by a nutrient-limited state. The latter finding could suggest a metabolic shutdown in E. coli cells. High osmolarity was clearly not one of the reasons of bacterial death by (-)-roemerine. These observations collectively attest to the promise of plant omics and profiling of putative drug candidates using proteomics tools. Omics-guided drug discovery deserves greater attention in mainstream pharmacology so as to better understand the plants' medicinal potentials.
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279
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Kasper SH, Bonocora RP, Wade JT, Musah RA, Cady NC. Chemical Inhibition of Kynureninase Reduces Pseudomonas aeruginosa Quorum Sensing and Virulence Factor Expression. ACS Chem Biol 2016; 11:1106-17. [PMID: 26785289 DOI: 10.1021/acschembio.5b01082] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The opportunistic pathogen Pseudomonas aeruginosa utilizes multiple quorum sensing (QS) pathways to coordinate an arsenal of virulence factors. We previously identified several cysteine-based compounds inspired by natural products from the plant Petiveria alliacea which are capable of antagonizing multiple QS circuits as well as reducing P. aeruginosa biofilm formation. To understand the global effects of such compounds on virulence factor production and elucidate their mechanism of action, RNA-seq transcriptomic analysis was performed on P. aeruginosa PAO1 exposed to S-phenyl-l-cysteine sulfoxide, the most potent inhibitor from the prior study. Exposure to this inhibitor down-regulated expression of several QS-regulated virulence operons (e.g., phenazine biosynthesis, type VI secretion systems). Interestingly, many genes that were differentially regulated pertain to the related metabolic pathways that yield precursors of pyochelin, tricarboxylic acid cycle intermediates, phenazines, and Pseudomonas quinolone signal (PQS). Activation of the MexT-regulon was also indicated, including the multidrug efflux pump encoded by mexEF-oprN, which has previously been shown to inhibit QS and pathogenicity. Deeper investigation of the metabolites involved in these systems revealed that S-phenyl-l-cysteine sulfoxide has structural similarity to kynurenine, a precursor of anthranilate, which is critical for P. aeruginosa virulence. By supplementing exogenous anthranilate, the QS-inhibitory effect was reversed. Finally, it was shown that S-phenyl-l-cysteine sulfoxide competitively inhibits P. aeruginosa kynureninase (KynU) activity in vitro and reduces PQS production in vivo. The kynurenine pathway has been implicated in P. aeruginosa QS and virulence factor expression; however, this is the first study to show that targeted inhibition of KynU affects P. aeruginosa gene expression and QS, suggesting a potential antivirulence strategy.
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Affiliation(s)
- Stephen H. Kasper
- Colleges
of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, New York, United States
| | - Richard P. Bonocora
- Wadsworth
Center, New York State Department of Health, Albany, New York, United States
| | - Joseph T. Wade
- Wadsworth
Center, New York State Department of Health, Albany, New York, United States
- Department
of Biomedical Sciences, School of Public Health, University at Albany, Albany, New York, United States
| | - Rabi Ann Musah
- Department
of Chemistry, University at Albany, SUNY, Albany, New York, United States
| | - Nathaniel C. Cady
- Colleges
of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, New York, United States
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280
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Natural product discovery: past, present, and future. ACTA ACUST UNITED AC 2016; 43:155-76. [DOI: 10.1007/s10295-015-1723-5] [Citation(s) in RCA: 535] [Impact Index Per Article: 66.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 12/14/2015] [Indexed: 11/29/2022]
Abstract
Abstract
Microorganisms have provided abundant sources of natural products which have been developed as commercial products for human medicine, animal health, and plant crop protection. In the early years of natural product discovery from microorganisms (The Golden Age), new antibiotics were found with relative ease from low-throughput fermentation and whole cell screening methods. Later, molecular genetic and medicinal chemistry approaches were applied to modify and improve the activities of important chemical scaffolds, and more sophisticated screening methods were directed at target disease states. In the 1990s, the pharmaceutical industry moved to high-throughput screening of synthetic chemical libraries against many potential therapeutic targets, including new targets identified from the human genome sequencing project, largely to the exclusion of natural products, and discovery rates dropped dramatically. Nonetheless, natural products continued to provide key scaffolds for drug development. In the current millennium, it was discovered from genome sequencing that microbes with large genomes have the capacity to produce about ten times as many secondary metabolites as was previously recognized. Indeed, the most gifted actinomycetes have the capacity to produce around 30–50 secondary metabolites. With the precipitous drop in cost for genome sequencing, it is now feasible to sequence thousands of actinomycete genomes to identify the “biosynthetic dark matter” as sources for the discovery of new and novel secondary metabolites. Advances in bioinformatics, mass spectrometry, proteomics, transcriptomics, metabolomics and gene expression are driving the new field of microbial genome mining for applications in natural product discovery and development.
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281
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Kirkpatrick CL, Martins D, Redder P, Frandi A, Mignolet J, Chapalay JB, Chambon M, Turcatti G, Viollier PH. Growth control switch by a DNA-damage-inducible toxin-antitoxin system in Caulobacter crescentus. Nat Microbiol 2016; 1:16008. [PMID: 27572440 DOI: 10.1038/nmicrobiol.2016.8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 01/19/2016] [Indexed: 11/09/2022]
Abstract
Bacterial toxin-antitoxin systems (TASs) are thought to respond to various stresses, often inducing growth-arrested (persistent) sub-populations of cells whose housekeeping functions are inhibited. Many such TASs induce this effect through the translation-dependent RNA cleavage (RNase) activity of their toxins, which are held in check by their cognate antitoxins in the absence of stress. However, it is not always clear whether specific mRNA targets of orthologous RNase toxins are responsible for their phenotypic effect, which has made it difficult to accurately place the multitude of TASs within cellular and adaptive regulatory networks. Here, we show that the TAS HigBA of Caulobacter crescentus can promote and inhibit bacterial growth dependent on the dosage of HigB, a toxin regulated by the DNA damage (SOS) repressor LexA in addition to its antitoxin HigA, and the target selectivity of HigB's mRNA cleavage activity. HigB reduced the expression of an efflux pump that is toxic to a polarity control mutant, cripples the growth of cells lacking LexA, and targets the cell cycle circuitry. Thus, TASs can have outcome switching activity in bacterial adaptive (stress) and systemic (cell cycle) networks.
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Affiliation(s)
- Clare L Kirkpatrick
- Department of Microbiology &Molecular Medicine, Institute of Genetics &Genomics in Geneva (iGE3), Faculty of Medicine/CMU, University of Geneva, Rue Michel-Servet 1, 1211 Genève 4, Switzerland
| | - Daniel Martins
- Department of Microbiology &Molecular Medicine, Institute of Genetics &Genomics in Geneva (iGE3), Faculty of Medicine/CMU, University of Geneva, Rue Michel-Servet 1, 1211 Genève 4, Switzerland
| | - Peter Redder
- Department of Microbiology &Molecular Medicine, Institute of Genetics &Genomics in Geneva (iGE3), Faculty of Medicine/CMU, University of Geneva, Rue Michel-Servet 1, 1211 Genève 4, Switzerland
| | - Antonio Frandi
- Department of Microbiology &Molecular Medicine, Institute of Genetics &Genomics in Geneva (iGE3), Faculty of Medicine/CMU, University of Geneva, Rue Michel-Servet 1, 1211 Genève 4, Switzerland
| | - Johann Mignolet
- Department of Microbiology &Molecular Medicine, Institute of Genetics &Genomics in Geneva (iGE3), Faculty of Medicine/CMU, University of Geneva, Rue Michel-Servet 1, 1211 Genève 4, Switzerland
| | - Julien Bortoli Chapalay
- Biomolecular Screening Facility, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Marc Chambon
- Biomolecular Screening Facility, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Gerardo Turcatti
- Biomolecular Screening Facility, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Patrick H Viollier
- Department of Microbiology &Molecular Medicine, Institute of Genetics &Genomics in Geneva (iGE3), Faculty of Medicine/CMU, University of Geneva, Rue Michel-Servet 1, 1211 Genève 4, Switzerland
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282
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Reen FJ, Shanahan R, Cano R, O'Gara F, McGlacken GP. A structure activity-relationship study of the bacterial signal molecule HHQ reveals swarming motility inhibition in Bacillus atrophaeus. Org Biomol Chem 2016; 13:5537-41. [PMID: 25880413 DOI: 10.1039/c5ob00315f] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The sharp rise in antimicrobial resistance has been matched by a decline in the identification and clinical introduction of new classes of drugs to target microbial infections. Thus new approaches are being sought to counter the pending threat of a post-antibiotic era. In that context, the use of non-growth limiting small molecules, that target virulence behaviour in pathogens, has emerged as a solution with real clinical potential. We have previously shown that two signal molecules (HHQ and PQS) from the nosocomial pathogen Pseudomonas aeruginosa have modulatory activity towards other microorganisms. This current study involves the synthesis and evaluation of analogues of HHQ towards swarming and biofilm virulence behaviour in Bacillus atrophaeus, a soil bacterium and co-inhibitor with P. aeruginosa. Compounds with altered C6-C8 positions on the anthranilate-derived ring of HHQ, display a surprising degree of biological specificity, with certain candidates displaying complete motility inhibition. In contrast, anti-biofilm activity of the parent molecule was completely lost upon alteration at any position indicating a remarkable degree of specificity and delineation of phenotype.
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Affiliation(s)
- F Jerry Reen
- BIOMERIT Research Centre, Department of Microbiology, University College Cork, Ireland.
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283
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H J, Omanakuttan A, Pandurangan N, S Vargis V, Maneesh M, G Nair B, B Kumar G. Clove bud oil reduces kynurenine and inhibits pqs A gene expression in P. aeruginosa. Appl Microbiol Biotechnol 2016; 100:3681-92. [PMID: 26821927 DOI: 10.1007/s00253-016-7313-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 01/07/2016] [Accepted: 01/10/2016] [Indexed: 11/29/2022]
Abstract
Quorum sensing (QS), a communication system involved in virulence of pathogenic bacteria like Pseudomonas aeruginosa is a promising target to combat multiple drug resistance. In vitro studies using clove bud oil (CBO) in P. aeruginosa revealed a concentration dependent attenuation of a variety of virulence factors including motility, extracellular DNA, exopolysaccharides and pigment production. Furthermore, treatment with CBO demonstrated a distinct dose-dependent reduction in biofilm formation as well as promoting dispersion of already formed biofilm, observations that were also supported by porcine skin ex vivo studies. Expression studies of genes involved in signalling systems of P. aeruginosa indicated a specific decrease in transcription of pqsA, but not in the lasI or rhlI levels. Additionally, the expression of vfr and gacA genes, involved in regulation, was also not affected by CBO treatment. CBO also influenced the PQS signalling pathway by decreasing the levels of kynurenine, an effect which was reversed by the addition of exogenous kynurenine. Though the synthesis of the signalling molecules of the Las and Rhl pathways was not affected by CBO, their activity was significantly affected, as observed by decrease in levels of their various effectors. Molecular modelling studies demonstrated that eugenol, the major component of CBO, favourably binds to the QS receptor by hydrophobic interactions as well as by hydrogen bonding with Arg61 and Tyr41 which are key amino acid residues of the LasR receptor. These results thus elucidate the molecular mechanism underlying the action of CBO and provide the basis for the identification of an attractive QS inhibitor.
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Affiliation(s)
- Jayalekshmi H
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Clappana P. O, Kollam, Kerala, 690525, India
| | - Athira Omanakuttan
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Clappana P. O, Kollam, Kerala, 690525, India
| | - N Pandurangan
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Clappana P. O, Kollam, Kerala, 690525, India
| | - Vidhu S Vargis
- Department of Sciences, Amrita Vishwa Vidyapeetham, Amritanagar P. O, Coimbatore, 641112, India
| | - M Maneesh
- Pushpagiri Institute of Medical Sciences and Research Centre, Tiruvalla, Kerala, 689101, India
| | - Bipin G Nair
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Clappana P. O, Kollam, Kerala, 690525, India
| | - Geetha B Kumar
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Clappana P. O, Kollam, Kerala, 690525, India.
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284
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Abstract
Extracellular DNA is an important component of the biofilm matrix. Now, Pseudomonas aeruginosa is shown to control autolysis through the production of HQNO, a quorum-sensing-regulated respiratory poison. Thus, HQNO-driven autolysis links programmed cell death with quorum sensing and biofilm formation.
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Affiliation(s)
- Anna C Zemke
- Pulmonary and Critical Care Medicine and, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jennifer M Bomberger
- Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA.
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285
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Drees SL, Li C, Prasetya F, Saleem M, Dreveny I, Williams P, Hennecke U, Emsley J, Fetzner S. PqsBC, a Condensing Enzyme in the Biosynthesis of the Pseudomonas aeruginosa Quinolone Signal: CRYSTAL STRUCTURE, INHIBITION, AND REACTION MECHANISM. J Biol Chem 2016; 291:6610-24. [PMID: 26811339 PMCID: PMC4807248 DOI: 10.1074/jbc.m115.708453] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Indexed: 01/02/2023] Open
Abstract
Pseudomonas aeruginosa produces a number of alkylquinolone-type secondary metabolites best known for their antimicrobial effects and involvement in cell-cell communication. In the alkylquinolone biosynthetic pathway, the β-ketoacyl-(acyl carrier protein) synthase III (FabH)-like enzyme PqsBC catalyzes the condensation of octanoyl-coenzyme A and 2-aminobenzoylacetate (2-ABA) to form the signal molecule 2-heptyl-4(1H)-quinolone. PqsBC, a potential drug target, is unique for its heterodimeric arrangement and an active site different from that of canonical FabH-like enzymes. Considering the sequence dissimilarity between the subunits, a key question was how the two subunits are organized with respect to the active site. In this study, the PqsBC structure was determined to a 2 Å resolution, revealing that PqsB and PqsC have a pseudo-2-fold symmetry that unexpectedly mimics the FabH homodimer. PqsC has an active site composed of Cys-129 and His-269, and the surrounding active site cleft is hydrophobic in character and approximately twice the volume of related FabH enzymes that may be a requirement to accommodate the aromatic substrate 2-ABA. From physiological and kinetic studies, we identified 2-aminoacetophenone as a pathway-inherent competitive inhibitor of PqsBC, whose fluorescence properties could be used for in vitro binding studies. In a time-resolved setup, we demonstrated that the catalytic histidine is not involved in acyl-enzyme formation, but contributes to an acylation-dependent increase in affinity for the second substrate 2-ABA. Introduction of Asn into the PqsC active site led to significant activity toward the desamino substrate analog benzoylacetate, suggesting that the substrate 2-ABA itself supplies the asparagine-equivalent amino function that assists in catalysis.
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Affiliation(s)
| | | | | | | | | | - Paul Williams
- Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Ulrich Hennecke
- Organic Chemistry Institute, University of Münster, D-48149 Münster, Germany and the Centre for Biomolecular Sciences
| | | | - Susanne Fetzner
- From the Institute for Molecular Microbiology and Biotechnology and
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286
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Das D, Biswas A, Karmakar U, Chand S, Samanta R. C6-Selective Direct Alkylation of Pyridones with Diazo Compounds under Rh(III)-Catalyzed Mild Conditions. J Org Chem 2016; 81:842-8. [DOI: 10.1021/acs.joc.5b02349] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Debapratim Das
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Aniruddha Biswas
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Ujjwal Karmakar
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Santanu Chand
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Rajarshi Samanta
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
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287
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Liquid Chromatography-Mass Spectrometry-Based Rapid Secondary-Metabolite Profiling of Marine Pseudoalteromonas sp. M2. Mar Drugs 2016; 14:24. [PMID: 26805856 PMCID: PMC4728520 DOI: 10.3390/md14010024] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 01/05/2016] [Accepted: 01/11/2016] [Indexed: 02/01/2023] Open
Abstract
The ocean is a rich resource of flora, fauna, and food. A wild-type bacterial strain showing confluent growth on marine agar with antibacterial activity was isolated from marine water, identified using 16S rDNA sequence analysis as Pseudoalteromonas sp., and designated as strain M2. This strain was found to produce various secondary metabolites including quinolone alkaloids. Using high-resolution mass spectrometry (MS) and nuclear magnetic resonance (NMR) analysis, we identified nine secondary metabolites of 4-hydroxy-2-alkylquinoline (pseudane-III, IV, V, VI, VII, VIII, IX, X, and XI). Additionally, this strain produced two novel, closely related compounds, 2-isopentylqunoline-4-one and 2-(2,3-dimetylbutyl)qunoline-4-(1H)-one, which have not been previously reported from marine bacteria. From the metabolites produced by Pseudoalteromonas sp. M2, 2-(2,3-dimethylbutyl)quinolin-4-one, pseudane-VI, and pseudane-VII inhibited melanin synthesis in Melan-A cells by 23.0%, 28.2%, and 42.7%, respectively, wherein pseudane-VII showed the highest inhibition at 8 µg/mL. The results of this study suggest that liquid chromatography (LC)-MS/MS-based metabolite screening effectively improves the efficiency of novel metabolite discovery. Additionally, these compounds are promising candidates for further bioactivity development.
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288
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Suresh Kumar A, Prabhakar Reddy T, Madhavachary R, Ramachary DB. Rawal's catalyst as an effective stimulant for the highly asymmetric Michael addition of β-keto esters to functionally rich nitro-olefins. Org Biomol Chem 2016; 14:5494-9. [DOI: 10.1039/c5ob02178b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A general approach to the asymmetric synthesis of highly substituted dihydroquinolines was achieved through neighboring ortho-amino group engaged sequential Michael/amination/dehydration reactions.
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Affiliation(s)
- A. Suresh Kumar
- School of Chemistry
- University of Hyderabad
- Hyderabad 500 046
- India
| | | | - R. Madhavachary
- School of Chemistry
- University of Hyderabad
- Hyderabad 500 046
- India
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289
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Chatterjee M, Anju C, Biswas L, Anil Kumar V, Gopi Mohan C, Biswas R. Antibiotic resistance in Pseudomonas aeruginosa and alternative therapeutic options. Int J Med Microbiol 2016; 306:48-58. [DOI: 10.1016/j.ijmm.2015.11.004] [Citation(s) in RCA: 157] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 11/18/2015] [Accepted: 11/26/2015] [Indexed: 01/05/2023] Open
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290
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Salahinejad M, Mirshojaei SF. Quantitative structure–activity relationship analysis to elucidate the clearance mechanisms of Tc-99m labeled quinolone antibiotics. J Radioanal Nucl Chem 2016. [DOI: 10.1007/s10967-015-4333-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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291
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Frydenlund Michelsen C, Hossein Khademi SM, Krogh Johansen H, Ingmer H, Dorrestein PC, Jelsbak L. Evolution of metabolic divergence in Pseudomonas aeruginosa during long-term infection facilitates a proto-cooperative interspecies interaction. ISME JOURNAL 2015; 10:1323-36. [PMID: 26684729 PMCID: PMC5029194 DOI: 10.1038/ismej.2015.220] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 10/20/2015] [Accepted: 10/25/2015] [Indexed: 02/08/2023]
Abstract
The effect of polymicrobial interactions on pathogen physiology and how it can act either to limit pathogen colonization or to potentiate pathogen expansion and virulence are not well understood. Pseudomonas aeruginosa and Staphylococcus aureus are opportunistic pathogens commonly found together in polymicrobial human infections. However, we have previously shown that the interactions between these two bacterial species are strain dependent. Whereas P. aeruginosa PAO1, a commonly used laboratory strain, effectively suppressed S. aureus growth, we observed a commensal-like interaction between the human host-adapted strain, DK2-P2M24-2003, and S. aureus. In this study, characterization by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) imaging mass spectrometry (IMS) and mass spectral (MS) molecular networking revealed a significant metabolic divergence between P. aeruginosa PAO1 and DK2-P2M24-2003, which comprised several virulence factors and signaling 4-hydroxy-2-alkylquinoline (HAQ) molecules. Strikingly, a further modulation of the HAQ profile was observed in DK2-P2M24-2003 during interaction with S. aureus, resulting in an area with thickened colony morphology at the P. aeruginosa–S. aureus interface. In addition, we found an HAQ-mediated protection of S. aureus by DK2-P2M24-2003 from the killing effect of tobramycin. Our findings suggest a model where the metabolic divergence manifested in human host-adapted P. aeruginosa is further modulated during interaction with S. aureus and facilitate a proto-cooperative P. aeruginosa–S. aureus relationship.
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Affiliation(s)
| | | | - Helle Krogh Johansen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark.,The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Hørsholm, Denmark
| | - Hanne Ingmer
- Department of Veterinary Disease Biology, Food Safety and Zoonoses, University of Copenhagen, Frederiksberg C, Denmark
| | - Pieter C Dorrestein
- Department of Pharmacology, University of California at San Diego, La Jolla, CA, USA.,Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, CA, USA.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA, USA
| | - Lars Jelsbak
- Department of Systems Biology, Technical University of Denmark, Lyngby, Denmark
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292
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Liu YC, Chan KG, Chang CY. Modulation of Host Biology by Pseudomonas aeruginosa Quorum Sensing Signal Molecules: Messengers or Traitors. Front Microbiol 2015; 6:1226. [PMID: 26617576 PMCID: PMC4637427 DOI: 10.3389/fmicb.2015.01226] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 10/20/2015] [Indexed: 12/21/2022] Open
Abstract
Bacterial cells sense their population density and respond accordingly by producing various signal molecules to the surrounding environments thereby trigger a plethora of gene expression. This regulatory pathway is termed quorum sensing (QS). Plenty of bacterial virulence factors are controlled by QS or QS-mediated regulatory systems and QS signal molecules (QSSMs) play crucial roles in bacterial signaling transduction. Moreover, bacterial QSSMs were shown to interfere with host cell signaling and modulate host immune responses. QSSMs not only regulate the expression of bacterial virulence factors but themselves act in the modulation of host biology that can be potential therapeutic targets.
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Affiliation(s)
- Yi-Chia Liu
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee Dundee, UK
| | - Kok-Gan Chan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya Kuala Lumpur, Malaysia
| | - Chien-Yi Chang
- Centre for Bacterial Cell Biology, Medical School, Newcastle University Newcastle upon Tyne, UK ; Interdisciplinary Computing and Complex BioSystems (ICOS) Research Group, School of Computing Science, Newcastle University Newcastle upon Tyne, UK
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293
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Thakur V, Sharma D, Das P. Ethyl 3-(2,4-dioxocyclohexyl)propanoate as a novel precursor for N-substituted 4,4a,5,6-tetrahydroquinoline-2,7(1H,3H)-diones and their corresponding 3,4-dihydro-7-hydroxyquinolin-2(1H)-ones and 7-hydroxyquinolin-2(1H)-ones synthesis. Mol Divers 2015; 20:29-40. [DOI: 10.1007/s11030-015-9643-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 10/19/2015] [Indexed: 11/25/2022]
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294
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Vonnegut CL, Shonkwiler AM, Khalifa MM, Zakharov LN, Johnson DW, Haley MM. Facile Synthesis and Properties of 2-λ(5)-Phosphaquinolines and 2-λ(5)-Phosphaquinolin-2-ones. Angew Chem Int Ed Engl 2015; 54:13318-22. [PMID: 26361244 PMCID: PMC4624000 DOI: 10.1002/anie.201507696] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 08/24/2015] [Indexed: 01/02/2023]
Abstract
Treatment of 2-ethynylanilines with P(OPh)3 gives either 2,2-diphenoxy-2-λ(5)-phosphaquinolines or 2-phenoxy-2-λ(5)-phosphaquinolin-2-ones under transition-metal-free conditions. This reaction offers access to an underexplored heterocycle, which opens up the study of the fundamental nature of the N=P(V) double bond and its potential for delocalization within a cyclic π-electron system. This heterocycle can serve as a carbostyril mimic, with application as a bioisostere for pharmaceuticals based on the 2-quinolinone scaffold. It also holds promise as a new fluorophore, since initial screening reveals quantum yields upwards of 40%, Stokes shifts of 50-150 nm, and emission wavelengths of 380-540 nm. The phosphaquinolin-2-ones possess one of the strongest solution-state dimerization constants for a D-A system (130 M(-1)) owing to the close proximity of a strong acceptor (P=O) and a strong donor (phosphonamidate N-H), which suggests that they might hold promise as new hydrogen-bonding hosts for optoelectronic sensing.
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Affiliation(s)
- Chris L Vonnegut
- Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon, Eugene, OR 97403-1253 (USA)
| | - Airlia M Shonkwiler
- Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon, Eugene, OR 97403-1253 (USA)
| | - Muhammad M Khalifa
- Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon, Eugene, OR 97403-1253 (USA)
| | - Lev N Zakharov
- CAMCOR-Center for Advanced Materials Characterization in Oregon, University of Oregon, Eugene, OR 97403-1443 (USA)
| | - Darren W Johnson
- Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon, Eugene, OR 97403-1253 (USA).
| | - Michael M Haley
- Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon, Eugene, OR 97403-1253 (USA).
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295
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Chan KG, Liu YC, Chang CY. Inhibiting N-acyl-homoserine lactone synthesis and quenching Pseudomonas quinolone quorum sensing to attenuate virulence. Front Microbiol 2015; 6:1173. [PMID: 26539190 PMCID: PMC4609879 DOI: 10.3389/fmicb.2015.01173] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 10/09/2015] [Indexed: 01/27/2023] Open
Abstract
Bacteria sense their own population size, tune the expression of responding genes, and behave accordingly to environmental stimuli by secreting signaling molecules. This phenomenon is termed as quorum sensing (QS). By exogenously manipulating the signal transduction bacterial population behaviors could be controlled, which may be done through quorum quenching (QQ). QS related regulatory networks have been proven their involvement in regulating many virulence determinants in pathogenic bacteria in the course of infections. Interfering with QS signaling system could be a novel strategy against bacterial infections and therefore requires more understanding of their fundamental mechanisms. Here we review the development of studies specifically on the inhibition of production of N-acyl-homoserine lactone (AHL), a common proteobacterial QS signal. The opportunistic pathogen, Pseudomonas aeruginosa, equips the alkylquinolone (AQ)-mediated QS which also plays crucial roles in its pathogenicity. The studies in QQ targeting on AQ are also discussed.
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Affiliation(s)
- Kok-Gan Chan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya Kuala Lumpur, Malaysia
| | - Yi-Chia Liu
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee Dundee, UK
| | - Chien-Yi Chang
- Centre for Bacterial Cell Biology, Medical School, Newcastle University Newcastle upon Tyne, UK ; Interdisciplinary Computing and Complex BioSystems Research Group, School of Computing Science, Newcastle University Newcastle upon Tyne, UK
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296
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Vonnegut CL, Shonkwiler AM, Khalifa MM, Zakharov LN, Johnson DW, Haley MM. Facile Synthesis and Properties of 2‐λ
5
‐Phosphaquinolines and 2‐λ
5
‐Phosphaquinolin‐2‐ones. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201507696] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Chris L. Vonnegut
- Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon, Eugene, OR 97403‐1253 (USA)
| | - Airlia M. Shonkwiler
- Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon, Eugene, OR 97403‐1253 (USA)
| | - Muhammad M. Khalifa
- Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon, Eugene, OR 97403‐1253 (USA)
| | - Lev N. Zakharov
- CAMCOR—Center for Advanced Materials Characterization in Oregon, University of Oregon, Eugene, OR 97403‐1443 (USA)
| | - Darren W. Johnson
- Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon, Eugene, OR 97403‐1253 (USA)
| | - Michael M. Haley
- Department of Chemistry & Biochemistry and Materials Science Institute, University of Oregon, Eugene, OR 97403‐1253 (USA)
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297
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Baig NF, Dunham SJB, Morales-Soto N, Shrout JD, Sweedler JV, Bohn PW. Multimodal chemical imaging of molecular messengers in emerging Pseudomonas aeruginosa bacterial communities. Analyst 2015; 140:6544-52. [PMID: 26331158 DOI: 10.1039/c5an01149c] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Two label-free molecular imaging techniques, confocal Raman microscopy (CRM) and secondary ion mass spectrometry (SIMS), are combined for in situ characterization of the spatiotemporal distributions of quinolone metabolites and signaling molecules in communities of the pathogenic bacterium Pseudomonas aeruginosa. Dramatic molecular differences are observed between planktonic and biofilm modes of growth for these bacteria. We observe patterned aggregation and a high abundance of N-oxide quinolines in early biofilms and swarm zones of P. aeruginosa, while the concentrations of these secreted components in planktonic cells and agar plate colonies are below CRM and SIMS detection limits. CRM, in conjunction with principal component analysis (PCA) is used to distinguish between the two co-localized isomeric analyte pairs 4-hydroxy-2-heptylquinoline-N-oxide (HQNO)/2-heptyl-3-hydroxyquinolone (PQS) and 4-hydroxy-2-nonylquinoline-N-oxide (NQNO)/2-nonyl-hydroxyquinolone (C9-PQS) based on differences in their vibrational fingerprints, illustrating how the technique can be used to guide tandem-MS and tandem-MS imaging analysis. Because N-oxide quinolines are ubiquitous and expressed early in biofilms, these analytes may be fundamentally important for early biofilm formation and the growth and organization of P. aeruginosa microbial communities. This study underscores the advantages of using multimodal molecular imaging to study complex biological systems.
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Affiliation(s)
- Nameera F Baig
- Department of Chemistry and Biochemistry and Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, USA.
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298
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Rhodococcus erythropolis BG43 Genes Mediating Pseudomonas aeruginosa Quinolone Signal Degradation and Virulence Factor Attenuation. Appl Environ Microbiol 2015; 81:7720-9. [PMID: 26319870 DOI: 10.1128/aem.02145-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/22/2015] [Indexed: 01/25/2023] Open
Abstract
Rhodococcus erythropolis BG43 is able to degrade the Pseudomonas aeruginosa quorum sensing signal molecules PQS (Pseudomonas quinolone signal) [2-heptyl-3-hydroxy-4(1H)-quinolone] and HHQ [2-heptyl-4(1H)-quinolone] to anthranilic acid. Based on the hypothesis that degradation of HHQ might involve hydroxylation to PQS followed by dioxygenolytic cleavage of the heterocyclic ring and hydrolysis of the resulting N-octanoylanthranilate, the genome was searched for corresponding candidate genes. Two gene clusters, aqdA1B1C1 and aqdA2B2C2, each predicted to code for a hydrolase, a flavin monooxygenase, and a dioxygenase related to 1H-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase, were identified on circular plasmid pRLCBG43 of strain BG43. Transcription of all genes was upregulated by PQS, suggesting that both gene clusters code for alkylquinolone-specific catabolic enzymes. An aqdR gene encoding a putative transcriptional regulator, which was also inducible by PQS, is located adjacent to the aqdA2B2C2 cluster. Expression of aqdA2B2C2 in Escherichia coli conferred the ability to degrade HHQ and PQS to anthranilic acid; however, for E. coli transformed with aqdA1B1C1, only PQS degradation was observed. Purification of the recombinant AqdC1 protein verified that it catalyzes the cleavage of PQS to form N-octanoylanthranilic acid and carbon monoxide and revealed apparent Km and kcat values for PQS of ∼27 μM and 21 s(-1), respectively. Heterologous expression of the PQS dioxygenase gene aqdC1 or aqdC2 in P. aeruginosa PAO1 quenched the production of the virulence factors pyocyanin and rhamnolipid and reduced the synthesis of the siderophore pyoverdine. Thus, the toolbox of quorum-quenching enzymes is expanded by new PQS dioxygenases.
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299
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Kaur J, Pethani BP, Kumar S, Kim M, Sunna A, Kautto L, Penesyan A, Paulsen IT, Nevalainen H. Pseudomonas aeruginosa inhibits the growth of Scedosporium aurantiacum, an opportunistic fungal pathogen isolated from the lungs of cystic fibrosis patients. Front Microbiol 2015; 6:866. [PMID: 26379643 PMCID: PMC4547459 DOI: 10.3389/fmicb.2015.00866] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 08/07/2015] [Indexed: 12/25/2022] Open
Abstract
The filamentous fungus Scedosporium aurantiacum and the bacterium Pseudomonas aeruginosa are opportunistic pathogens isolated from lungs of the cystic fibrosis (CF) patients. P. aeruginosa has been known to suppress the growth of a number of CF related fungi such as Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans. However, the interactions between P. aeruginosa and S. aurantiacum have not been investigated in depth. Hence we assessed the effect of P. aeruginosa reference strain PAO1 and two clinical isolates PASS1 and PASS2 on the growth of two clinical S. aurantiacum isolates WM 06.482 and WM 08.202 using solid plate assays and liquid cultures, in a synthetic medium mimicking the nutrient condition in the CF sputum. Solid plate assays showed a clear inhibition of growth of both S. aurantiacum strains when cultured with P. aeruginosa strains PASS1 and PAO1. The inhibitory effect was confirmed by confocal microscopy. In addition to using chemical fluorescent stains, strains tagged with yfp (P. aeruginosa PASS1) and mCherry (S. aurantiacum WM 06.482) were created to facilitate detailed microscopic observations on strain interaction. To our knowledge, this is the first study describing successful genetic transformation of S. aurantiacum. Inhibition of growth was observed only in co-cultures of P. aeruginosa and S. aurantiacum; the cell fractions obtained from independent bacterial monocultures failed to initiate a response against the fungus. In the liquid co-cultures, biofilm forming P. aeruginosa strains PASS1 and PAO1 displayed higher inhibition of fungal growth when compared to PASS2. No change was observed in the inhibition pattern when direct cell contact between the bacterial and fungal strains was prevented using a separation membrane suggesting the involvement of extracellular metabolites in the fungal inhibition. However, one of the most commonly described bacterial virulence factors, pyocyanin, had no effect against either of the S. aurantiacum strains. This study shows that P. aeruginosa has a substantial inhibitory effect on the growth of the recently described CF fungal pathogen S. aurantiacum. The findings also highlighted that P. aeruginosa biofilm formation is important but not crucial for inhibiting the growth of S. aurantiacum in a lung- mimicking environment.
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Affiliation(s)
- Jashanpreet Kaur
- Department of Chemistry and Biomolecular Sciences, Macquarie University Sydney, NSW, Australia ; Biomolecular Frontiers Research Centre, Macquarie University Sydney, NSW, Australia
| | - Bhavin P Pethani
- Department of Chemistry and Biomolecular Sciences, Macquarie University Sydney, NSW, Australia ; Biomolecular Frontiers Research Centre, Macquarie University Sydney, NSW, Australia
| | - Sheemal Kumar
- Department of Chemistry and Biomolecular Sciences, Macquarie University Sydney, NSW, Australia ; Biomolecular Frontiers Research Centre, Macquarie University Sydney, NSW, Australia
| | - Minkyoung Kim
- Department of Chemistry and Biomolecular Sciences, Macquarie University Sydney, NSW, Australia ; Biomolecular Frontiers Research Centre, Macquarie University Sydney, NSW, Australia
| | - Anwar Sunna
- Department of Chemistry and Biomolecular Sciences, Macquarie University Sydney, NSW, Australia ; Biomolecular Frontiers Research Centre, Macquarie University Sydney, NSW, Australia
| | - Liisa Kautto
- Department of Chemistry and Biomolecular Sciences, Macquarie University Sydney, NSW, Australia ; Biomolecular Frontiers Research Centre, Macquarie University Sydney, NSW, Australia
| | - Anahit Penesyan
- Department of Chemistry and Biomolecular Sciences, Macquarie University Sydney, NSW, Australia ; Biomolecular Frontiers Research Centre, Macquarie University Sydney, NSW, Australia
| | - Ian T Paulsen
- Department of Chemistry and Biomolecular Sciences, Macquarie University Sydney, NSW, Australia ; Biomolecular Frontiers Research Centre, Macquarie University Sydney, NSW, Australia
| | - Helena Nevalainen
- Department of Chemistry and Biomolecular Sciences, Macquarie University Sydney, NSW, Australia ; Biomolecular Frontiers Research Centre, Macquarie University Sydney, NSW, Australia
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300
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Demuez M, González-Fernández C, Ballesteros M. Algicidal microorganisms and secreted algicides: New tools to induce microalgal cell disruption. Biotechnol Adv 2015; 33:1615-25. [PMID: 26303095 DOI: 10.1016/j.biotechadv.2015.08.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/11/2015] [Accepted: 08/15/2015] [Indexed: 11/29/2022]
Abstract
Cell disruption is one of the most critical steps affecting the economy and yields of biotechnological processes for producing biofuels from microalgae. Enzymatic cell disruption has shown competitive results compared to mechanical or chemical methods. However, the addition of enzymes implies an associated cost in the overall production process. Recent studies have employed algicidal microorganisms to perform enzymatic cell disruption and degradation of microalgae biomass in order to reduce this associated cost. Algicidal microorganisms induce microalgae growth inhibition, death and subsequent lysis. Secreted algicidal molecules and enzymes produced by bacteria, cyanobacteria, viruses and the microalga themselves that are capable of inducing algal death are classified, and the known modes of action are described along with insights into cell-to-cell interaction and communication. This review aims to provide information regarding microalgae degradation by microorganisms and secreted algicidal substances that would be useful for microalgae cell breakdown in biofuels production processes. A better understanding of algae-to-algae communication and the specific mechanisms of algal cell lysis is expected to be an important breakthrough for the broader application of algicidal microorganisms in biological cell disruption and the production of biofuels from microalgae biomass.
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Affiliation(s)
- Marie Demuez
- IMDEA Energy Institute, Biotechnological Processes for Energy Production Unit, Av. Ramón de la Sagra 3, 28935 Móstoles, Spain.
| | - Cristina González-Fernández
- IMDEA Energy Institute, Biotechnological Processes for Energy Production Unit, Av. Ramón de la Sagra 3, 28935 Móstoles, Spain.
| | - Mercedes Ballesteros
- IMDEA Energy Institute, Biotechnological Processes for Energy Production Unit, Av. Ramón de la Sagra 3, 28935 Móstoles, Spain; CIEMAT, Renewable Energy Division, Biofuels Unit, Av. Complutense 40, 28040 Madrid, Spain.
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