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Quni S, Zhang Y, Liu L, Liu M, Zhang L, You J, Cui J, Liu X, Wang H, Li D, Zhou Y. NF-κB-Signaling-Targeted Immunomodulatory Nanoparticle with Photothermal and Quorum-Sensing Inhibition Effects for Efficient Healing of Biofilm-Infected Wounds. ACS APPLIED MATERIALS & INTERFACES 2024; 16:25757-25772. [PMID: 38738757 DOI: 10.1021/acsami.4c03142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2024]
Abstract
The development of therapeutics with high antimicrobial activity and immunomodulatory effects is urgently needed for the treatment of infected wounds due to the increasing danger posed by recalcitrant-infected wounds. In this study, we developed light-controlled antibacterial, photothermal, and immunomodulatory biomimetic N/hPDA@M nanoparticles (NPs). This nanoplatform was developed by loading flavonoid naringenin onto hollow mesoporous polydopamine NPs in a π-π-stacked configuration and encasing them with macrophage membranes. First, our N/hPDA@M NPs efficiently neutralized inflammatory factors present within the wound microenvironment by the integration of macrophage membranes. Afterward, the N/hPDA@M NPs effectively dismantled bacterial biofilms through a combination of the photothermal properties of PDA and the quorum sensing inhibitory effects of naringenin. It is worth noting that N/hPDA@M NPs near-infrared-enhanced release of naringenin exhibited specificity toward the NF-κB-signaling pathway, effectively mitigating the inflammatory response. This innovative design not only conferred remarkable antibacterial properties upon the N/hPDA@M NPs but also endowed them with the capacity to modulate inflammatory responses, curbing excessive inflammation and steering macrophage polarization toward the M2 phenotype. As a result, this multifaceted approach significantly contributes to expediting the healing process of infected skin wounds.
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Affiliation(s)
- Sezhen Quni
- Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun 130021, Jilin, China
- School of Stomatology, Jilin University, Jilin 130021, Changchun, China
| | - Yidi Zhang
- Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun 130021, Jilin, China
- School of Stomatology, Jilin University, Jilin 130021, Changchun, China
| | - Lijun Liu
- Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun 130021, Jilin, China
- School of Stomatology, Jilin University, Jilin 130021, Changchun, China
| | - Manxuan Liu
- Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun 130021, Jilin, China
- School of Stomatology, Jilin University, Jilin 130021, Changchun, China
| | - Lu Zhang
- Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun 130021, Jilin, China
- School of Stomatology, Jilin University, Jilin 130021, Changchun, China
| | - Jiaqian You
- Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun 130021, Jilin, China
- School of Stomatology, Jilin University, Jilin 130021, Changchun, China
| | - Jing Cui
- Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun 130021, Jilin, China
- School of Stomatology, Jilin University, Jilin 130021, Changchun, China
| | - Xiuyu Liu
- Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun 130021, Jilin, China
- School of Stomatology, Jilin University, Jilin 130021, Changchun, China
| | - Hanchi Wang
- Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun 130021, Jilin, China
- School of Stomatology, Jilin University, Jilin 130021, Changchun, China
| | - Daowei Li
- Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun 130021, Jilin, China
- School of Stomatology, Jilin University, Jilin 130021, Changchun, China
| | - Yanmin Zhou
- Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun 130021, Jilin, China
- School of Stomatology, Jilin University, Jilin 130021, Changchun, China
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Peng B, Li Y, Yin J, Ding W, Fazuo W, Xiao Z, Yin H. A bibliometric analysis on discovering anti-quorum sensing agents against clinically relevant pathogens: current status, development, and future directions. Front Microbiol 2023; 14:1297843. [PMID: 38098670 PMCID: PMC10720721 DOI: 10.3389/fmicb.2023.1297843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 11/10/2023] [Indexed: 12/17/2023] Open
Abstract
Background Quorum sensing is bacteria's ability to communicate and regulate their behavior based on population density. Anti-quorum sensing agents (anti-QSA) is promising strategy to treat resistant infections, as well as reduce selective pressure that leads to antibiotic resistance of clinically relevant pathogens. This study analyzes the output, hotspots, and trends of research in the field of anti-QSA against clinically relevant pathogens. Methods The literature on anti-QSA from the Web of Science Core Collection database was retrieved and analyzed. Tools such as CiteSpace and Alluvial Generator were used to visualize and interpret the data. Results From 1998 to 2023, the number of publications related to anti-QAS research increased rapidly, with a total of 1,743 articles and reviews published in 558 journals. The United States was the largest contributor and the most influential country, with an H-index of 88, higher than other countries. Williams was the most productive author, and Hoiby N was the most cited author. Frontiers in Microbiology was the most prolific and the most cited journal. Burst detection indicated that the main frontier disciplines shifted from MICROBIOLOGY, CLINICAL, MOLECULAR BIOLOGY, and other biomedicine-related fields to FOOD, MATERIALS, NATURAL PRODUCTS, and MULTIDISCIPLINARY. In the whole research history, the strongest burst keyword was cystic-fibrosis patients, and the strongest burst reference was Lee and Zhang (2015). In the latest period (burst until 2023), the strongest burst keyword was silver nanoparticle, and the strongest burst reference was Whiteley et al. (2017). The co-citation network revealed that the most important interest and research direction was anti-biofilm/anti-virulence drug development, and timeline analysis suggested that this direction is also the most active. The key concepts alluvial flow visualization revealed seven terms with the longest time span and lasting until now, namely Escherichia coli, virulence, Pseudomonas aeruginosa, virulence factor, bacterial biofilm, gene expression, quorum sensing. Comprehensive analysis shows that nanomaterials, marine natural products, and artificial intelligence (AI) may become hotspots in the future. Conclusion This bibliometric study reveals the current status and trends of anti-QSA research and may assist researchers in identifying hot topics and exploring new research directions.
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Affiliation(s)
- Bo Peng
- Institute for Environmental and Climate Research, Jinan University, Guangzhou, China
| | - Yanqun Li
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Jiajia Yin
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Wenping Ding
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Wang Fazuo
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Zhihui Xiao
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Hao Yin
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- Sanya Institute of Ocean Eco-Environmental Engineering, Sanya, China
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Mellini M, Letizia M, Caruso L, Guiducci A, Meneghini C, Heeb S, Williams P, Cámara M, Visca P, Imperi F, Leoni L, Rampioni G. RsaL-driven negative regulation promotes heterogeneity in Pseudomonas aeruginosa quorum sensing. mBio 2023; 14:e0203923. [PMID: 37843294 PMCID: PMC10746200 DOI: 10.1128/mbio.02039-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 09/05/2023] [Indexed: 10/17/2023] Open
Abstract
In its canonical interpretation, quorum sensing (QS) allows single cells in a bacterial population to synchronize gene expression and hence perform specific tasks collectively once the quorum cell density is reached. However, growing evidence in different bacterial species indicates that considerable cell-to-cell variation in the QS activation state occurs during growth, often resulting in coexisting subpopulations of cells in which QS is active (quorate cells) or inactive (non-quorate cells). Heterogeneity has been observed in the las QS system of the opportunistic pathogen Pseudomonas aeruginosa. However, the molecular mechanisms underlying this phenomenon have not yet been defined. The las QS system consists of an incoherent feedforward loop in which the LasR transcriptional regulator activates the expression of the lasI synthase gene and rsaL, coding for the lasI transcriptional repressor RsaL. Here, single-cell-level gene expression analyses performed in ad hoc engineered biosensor strains and deletion mutants revealed that direct binding of RsaL to the lasI promoter region increases heterogeneous activation of the las QS system. Experiments performed with a dual-fluorescence reporter system showed that the LasR-dependent expression of lasI and rsaL does not correlate in single cells, indicating that RsaL acts as a brake that stochastically limits the transition of non-quorate cells to the quorate state in a subpopulation of cells expressing high levels of this negative regulator. Interestingly, the rhl QS system that is not controlled by an analogous RsaL protein showed higher homogeneity with respect to the las system. IMPORTANCE Single-cell analyses can reveal that despite experiencing identical physico-chemical conditions, individual bacterial cells within a monoclonal population may exhibit variations in gene expression. Such phenotypic heterogeneity has been described for several aspects of bacterial physiology, including QS activation. This study demonstrates that the transition of non-quorate cells to the quorate state is a graded process that does not occur at a specific cell density and that subpopulations of non-quorate cells also persist at high cell density. Here, we provide a mechanistic explanation for this phenomenon, showing that a negative feedback regulatory loop integrated into the las system has a pivotal role in promoting cell-to-cell variation in the QS activation state and in limiting the transition of non-quorate cells to the quorate state in P. aeruginosa.
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Affiliation(s)
- Marta Mellini
- Department of Science, University Roma Tre, Rome, Italy
| | | | | | | | | | - Stephan Heeb
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Paul Williams
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Miguel Cámara
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Paolo Visca
- Department of Science, University Roma Tre, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Francesco Imperi
- Department of Science, University Roma Tre, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Livia Leoni
- Department of Science, University Roma Tre, Rome, Italy
| | - Giordano Rampioni
- Department of Science, University Roma Tre, Rome, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
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Ballante F, Turkina MV, Ntzouni M, Magnusson KE, Vikström E. Modified N-acyl-L-homoserine lactone compounds abrogate Las-dependent quorum-sensing response in human pathogen Pseudomonas aeruginosa. Front Mol Biosci 2023; 10:1264773. [PMID: 37908228 PMCID: PMC10613653 DOI: 10.3389/fmolb.2023.1264773] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 09/25/2023] [Indexed: 11/02/2023] Open
Abstract
Quorum sensing (QS) is a mode of cell-cell communication that bacteria use to sense population density and orchestrate collective behaviors. The common opportunistic human pathogen Pseudomonas aeruginosa employs QS to regulate a large set of genes involved in virulence and host-pathogen interactions. The Las circuit positioned on the top of the QS hierarchy in P. aeruginosa makes use of N-acyl-L-homoserine lactones (AHLs) as signal molecules, like N-3-oxo-dodecanoyl-L-homoserine lactone (3O-C12-HSL). Disabling QS circuits by certain small-molecule compounds, known as quorum-sensing inhibitors (QSIs), has been proposed as a strategy to attenuate bacterial pathogenicity. In this study, four new AHL analogs were designed by incorporating a tert-butoxycarbonyl Boc group in amide and β-keto (3-oxo) moiety. Compounds were evaluated on a molecular and phenotypic basis as a QSI using the screening strategy linked to the assignment of the Las QS system in P. aeruginosa. Using a LasR-based bioreporter, we found that the compounds decreased LasR-controlled light activity and competed efficiently with natural 3O-C12-HSL. The compounds reduced the production of the cognate 3O-C12-HSL and certain virulence traits, like total protease activity, elastase activity, pyocyanin production, and extracellular DNA release. Furthermore, a quantitative proteomic approach was used to study the effect of the compounds on QS-regulated extracellular proteins. Among the four compounds tested, one of them showed the most significant difference in the appearance of the 3O-C12-HSL-responsive reference proteins related to QS communication and virulence, i.e., a distinct activity as a QSI. Moreover, by combining experimental data with computational chemistry, we addressed the effect of LasR protein flexibility on docking precision and assessed the advantage of using a multi-conformational docking procedure for binding mode prediction of LasR modulators. Thus, the four new AHL compounds were tested for their interaction with the AHL-binding site in LasR to identify the key interferences with the activity of LasR. Our study provides further insight into molecular features that are required for small-molecule modulation of LasR-dependent QS communication in P. aeruginosa. This should facilitate rational design of the next generation of antivirulence tools to study and manipulate QS-controlled fitness in bacteria and, thereby, handle bacterial infections in a new way.
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Affiliation(s)
- Flavio Ballante
- Chemical Biology Consortium Sweden (CBCS), Science for Life Laboratory, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Maria V. Turkina
- Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
| | - Maria Ntzouni
- Core Facility, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
| | - Karl-Eric Magnusson
- Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
| | - Elena Vikström
- Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
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Moore-Machacek A, Gloe A, O'Leary N, Reen FJ. Efflux, Signaling and Warfare in a Polymicrobial World. Antibiotics (Basel) 2023; 12:antibiotics12040731. [PMID: 37107093 PMCID: PMC10135244 DOI: 10.3390/antibiotics12040731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/30/2023] [Accepted: 04/04/2023] [Indexed: 04/29/2023] Open
Abstract
The discovery void of antimicrobial development has occurred at a time when the world has seen a rapid emergence and spread of antimicrobial resistance, the 'perfect storm' as it has often been described. While the discovery and development of new antibiotics has continued in the research sphere, the pipeline to clinic has largely been fed by derivatives of existing classes of antibiotics, each prone to pre-existing resistance mechanisms. A novel approach to infection management has come from the ecological perspective whereby microbial networks and evolved communities already possess small molecular capabilities for pathogen control. The spatiotemporal nature of microbial interactions is such that mutualism and parasitism are often two ends of the same stick. Small molecule efflux inhibitors can directly target antibiotic efflux, a primary resistance mechanism adopted by many species of bacteria and fungi. However, a much broader anti-infective capability resides within the action of these inhibitors, borne from the role of efflux in key physiological and virulence processes, including biofilm formation, toxin efflux, and stress management. Understanding how these behaviors manifest within complex polymicrobial communities is key to unlocking the full potential of the advanced repertoires of efflux inhibitors.
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Affiliation(s)
| | - Antje Gloe
- School of Microbiology, University College Cork, T12 K8AF Cork, Ireland
- Institute for Pharmaceutical Microbiology, University of Bonn, D-53113 Bonn, Germany
| | - Niall O'Leary
- School of Microbiology, University College Cork, T12 K8AF Cork, Ireland
| | - F Jerry Reen
- School of Microbiology, University College Cork, T12 K8AF Cork, Ireland
- Synthesis and Solid-State Pharmaceutical Centre, University College Cork, T12 K8AF Cork, Ireland
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6
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Kilic T, Bali EB. Biofilm control strategies in the light of biofilm-forming microorganisms. World J Microbiol Biotechnol 2023; 39:131. [PMID: 36959476 DOI: 10.1007/s11274-023-03584-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 03/15/2023] [Indexed: 03/25/2023]
Abstract
Biofilm is a complex consortium of microorganisms attached to biotic or abiotic surfaces and live in self-produced or acquired extracellular polymeric substances (EPSs). EPSs are mainly formed by lipids, polysaccharides, proteins, and extracellular DNAs. The adherence to the surface of microbial communities is seen in food, medical, dental, industrial, and environmental fields. Biofilm development in food processing areas challenges food hygiene, and human health. In addition, bacterial attachment and biofilm formation on medical implants inside human tissue can cause multiple critical chronic infections. More than 30 years of international research on the mechanisms of biofilm formation have been underway to address concerns about bacterial biofilm infections. Antibiofilm strategies contain cold atmospheric plasma, nanotechnological, phage-based, antimicrobial peptides, and quorum sensing inhibition. In the last years, the studies on environmentally-friendly techniques such as essential oils and bacteriophages have been intensified to reduce microbial growth. However, the mechanisms of the biofilm matrix formation are still unclear. This review aims to discuss the latest antibiofilm therapeutic strategies against biofilm-forming bacteria.
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Affiliation(s)
- Tugba Kilic
- Department of Medical Services and Techniques, Program of Medical Laboratory Techniques, Vocational School of Health Services, Gazi University, Ankara, 06830, Turkey.
| | - Elif Burcu Bali
- Department of Medical Services and Techniques, Program of Medical Laboratory Techniques, Vocational School of Health Services, Gazi University, Ankara, 06830, Turkey
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7
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Aljohani AM, El-Chami C, Alhubail M, Ledder RG, O’Neill CA, McBain AJ. Escherichia coli Nissle 1917 inhibits biofilm formation and mitigates virulence in Pseudomonas aeruginosa. Front Microbiol 2023; 14:1108273. [PMID: 36970701 PMCID: PMC10031955 DOI: 10.3389/fmicb.2023.1108273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 01/31/2023] [Indexed: 03/10/2023] Open
Abstract
In the quest for mitigators of bacterial virulence, cell-free supernatants (CFS) from 25 human commensal and associated bacteria were tested for activity against Pseudomonas aeruginosa. Among these, Escherichia coli Nissle 1917 CFS significantly inhibited biofilm formation and dispersed extant pseudomonas biofilms without inhibiting planktonic bacterial growth. eDNA was reduced in biofilms following exposure to E. coli Nissle CFS, as visualized by confocal microscopy. E. coli Nissle CFS also showed a significant protective effect in a Galleria mellonella-based larval virulence assay when administrated 24 h before challenge with the P. aeruginosa. No inhibitory effects against P. aeruginosa were observed for other tested E. coli strains. According to proteomic analysis, E. coli Nissle CFS downregulated the expression of several P. aeruginosa proteins involved in motility (Flagellar secretion chaperone FliSB, B-type flagellin fliC, Type IV pilus assembly ATPase PilB), and quorum sensing (acyl-homoserine lactone synthase lasI and HTH-type quorum-sensing regulator rhlR), which are associated with biofilm formation. Physicochemical characterization of the putative antibiofilm compound(s) indicates the involvement of heat-labile proteinaceous factors of greater than 30 kDa molecular size.
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Affiliation(s)
- Ahmad M. Aljohani
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
- Ministry of Education, Riyadh, Saudi Arabia
| | - Cecile El-Chami
- Division of Musculoskeletal and Dermatological Science, Faculty of Biology, Medicine and Health, School of Biological Science, The University of Manchester, Manchester, United Kingdom
| | - Muna Alhubail
- Division of Musculoskeletal and Dermatological Science, Faculty of Biology, Medicine and Health, School of Biological Science, The University of Manchester, Manchester, United Kingdom
| | - Ruth G. Ledder
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Catherine A. O’Neill
- Division of Musculoskeletal and Dermatological Science, Faculty of Biology, Medicine and Health, School of Biological Science, The University of Manchester, Manchester, United Kingdom
| | - Andrew J. McBain
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
- *Correspondence: Andrew J. McBain,
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8
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Yang H, Xu Z, Xu Z, Li Y. Mini-Review of Biofilm Interactions with Surface Materials in Industrial Piping System. MEMBRANES 2023; 13:125. [PMID: 36837628 PMCID: PMC9961356 DOI: 10.3390/membranes13020125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
The growth of biofilm, which is caused by microorganism accumulation and growth on wetted surfaces, may damage industrial piping systems, increase maintenance and cleaning costs for the system sterilization, and even divulge the immune system into high risk. This article systematically analyzes the biofilm interactions with piping surface materials from the perspectives of physical convection, and biological and chemical adhesion. The thermodynamics of the flow, bacterial surface sensing, and bio-communication are the most critical factors for biofilm attachment. Furthermore, experimental analysis methods as well as biofilm control and removal approaches, are also included in this study. Finally, the resistance and growth of biofilm, as well as the practical and advanced methodology to control the biofilm and challenges associated with technology, are also discussed. Moreover, this paper may also offer a significant reference for the practice and strategic applications to address the biofilm resistance issues in industrial piping.
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Affiliation(s)
- Haoyi Yang
- NUS College of Design and Engineering, National University of Singapore, Singapore 118429, Singapore
| | - Zezheng Xu
- UNSW Environment Leadership Program, The University of New South Wales, Kensington, NSW 2052, Australia
| | - Zetong Xu
- Qingdao Huanghai Vocational Institute, Qingdao 266555, China
| | - Yuanzhe Li
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
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9
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Polizzi A, Donzella M, Nicolosi G, Santonocito S, Pesce P, Isola G. Drugs for the Quorum Sensing Inhibition of Oral Biofilm: New Frontiers and Insights in the Treatment of Periodontitis. Pharmaceutics 2022; 14:pharmaceutics14122740. [PMID: 36559234 PMCID: PMC9781207 DOI: 10.3390/pharmaceutics14122740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/01/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
Chemical molecules are used by microorganisms to communicate with each other. Quorum sensing is the mechanism through which microorganisms regulate their population density and activity with chemical signaling. The inhibition of quorum sensing, called quorum quenching, may disrupt oral biofilm formation, which is the main etiological factor of oral diseases, including periodontitis. Periodontitis is a chronic inflammatory disorder of infectious etiology involving the hard and soft periodontal tissues and which is related to various systemic disorders, including cardiovascular diseases, diabetes and obesity. The employment of adjuvant therapies to traditional scaling and root planing is currently being studied to further reduce the impact of periodontitis. In this sense, using antibiotics and antiseptics involves non-negligible risks, such as antibiotic resistance phenomena and hinders the re-establishment of eubiosis. Different quorum sensing signal molecules have been identified in periodontal pathogenic oral bacteria. In this regard, quorum sensing inhibitors are emerging as some interesting solutions for the management of periodontitis. Therefore, the aim of this review is to summarize the current state of knowledge on the mechanisms of quorum sensing signal molecules produced by oral biofilm and to analyze the potential of quorum sensing inhibitors for the management of periodontitis.
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Affiliation(s)
- Alessandro Polizzi
- Department of General Surgery and Surgical-Medical Specialties, School of Dentistry, University of Catania, Via Sofia 78, 95125 Catania, Italy
- Department of Surgical Sciences (DISC), University of Genova, 16132 Genoa, Italy
| | - Martina Donzella
- Department of General Surgery and Surgical-Medical Specialties, School of Dentistry, University of Catania, Via Sofia 78, 95125 Catania, Italy
| | - Giada Nicolosi
- Department of General Surgery and Surgical-Medical Specialties, School of Dentistry, University of Catania, Via Sofia 78, 95125 Catania, Italy
| | - Simona Santonocito
- Department of General Surgery and Surgical-Medical Specialties, School of Dentistry, University of Catania, Via Sofia 78, 95125 Catania, Italy
- Correspondence: (S.S.); (G.I.); Tel.: +39-095-378-2638 (S.S. & G.I.)
| | - Paolo Pesce
- Department of Surgical Sciences (DISC), University of Genova, 16132 Genoa, Italy
| | - Gaetano Isola
- Department of General Surgery and Surgical-Medical Specialties, School of Dentistry, University of Catania, Via Sofia 78, 95125 Catania, Italy
- Correspondence: (S.S.); (G.I.); Tel.: +39-095-378-2638 (S.S. & G.I.)
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10
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Murray EJ, Dubern JF, Chan WC, Chhabra SR, Williams P. A Pseudomonas aeruginosa PQS quorum-sensing system inhibitor with anti-staphylococcal activity sensitizes polymicrobial biofilms to tobramycin. Cell Chem Biol 2022; 29:1187-1199.e6. [PMID: 35259345 PMCID: PMC9605878 DOI: 10.1016/j.chembiol.2022.02.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 07/16/2021] [Accepted: 02/15/2022] [Indexed: 12/23/2022]
Abstract
As single- and mixed-species biofilms, Staphylococcus aureus and Pseudomonas aeruginosa cause difficult-to-eradicate chronic infections. In P. aeruginosa, pseudomonas quinolone (PQS)-dependent quorum sensing regulates virulence and biofilm development that can be attenuated via antagonists targeting the transcriptional regulator PqsR (MvfR). Here, we exploited a quinazolinone (QZN) library including PqsR agonists and antagonists for their activity against S. aureus alone, when co-cultured with P. aeruginosa, and in combination with the aminoglycoside tobramycin. The PqsR inhibitor, QZN 34 killed planktonic Gram-positives but not Gram-negatives. QZN 34 prevented S. aureus biofilm formation, severely damaged established S. aureus biofilms, and perturbed P. aeruginosa biofilm development. Although P. aeruginosa protected S. aureus from tobramycin in mixed biofilms, the combination of aminoglycoside antibiotic with QZN 34 eradicated the mixed-species biofilm. The mechanism of action of QZN 34 toward Gram-positive bacteria is shown to involve membrane perturbation and dissipation of transmembrane potential.
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Affiliation(s)
- Ewan J Murray
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Jean-Frédéric Dubern
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Weng C Chan
- School of Pharmacy, Biodiscovery Institute, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Siri Ram Chhabra
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Paul Williams
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
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11
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Letizia M, Mellini M, Fortuna A, Visca P, Imperi F, Leoni L, Rampioni G. PqsE Expands and Differentially Modulates the RhlR Quorum Sensing Regulon in Pseudomonas aeruginosa. Microbiol Spectr 2022; 10:e0096122. [PMID: 35604161 PMCID: PMC9241726 DOI: 10.1128/spectrum.00961-22] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/02/2022] [Indexed: 12/22/2022] Open
Abstract
In the opportunistic pathogen Pseudomonas aeruginosa, many virulence traits are finely regulated by quorum sensing (QS), an intercellular communication system that allows the cells of a population to coordinate gene expression in response to cell density. The key aspects underlying the functionality of the complex regulatory network governing QS in P. aeruginosa are still poorly understood, including the interplay between the effector protein PqsE and the transcriptional regulator RhlR in controlling the QS regulon. Different studies have focused on the characterization of PqsE- and RhlR-controlled genes in genetic backgrounds in which RhlR activity can be modulated by PqsE and pqsE expression is controlled by RhlR, thus hampering identification of the distinct regulons controlled by PqsE and RhlR. In this study, a P. aeruginosa PAO1 mutant strain with deletion of multiple QS elements and inducible expression of pqsE and/or rhlR was generated and validated. Transcriptomic analyses performed on this genetic background allowed us to unambiguously define the regulons controlled by PqsE and RhlR when produced alone or in combination. Transcriptomic data were validated via reverse transcription-quantitative PCR (RT-qPCR) and transcriptional fusions. Overall, our results showed that PqsE has a negligible effect on the P. aeruginosa transcriptome in the absence of RhlR, and that multiple RhlR subregulons exist with distinct dependency on PqsE. Overall, this study contributes to untangling the regulatory link between the pqs and rhl QS systems mediated by PqsE and RhlR and clarifying the impact of these QS elements on the P. aeruginosa transcriptome. IMPORTANCE The ability of Pseudomonas aeruginosa to cause difficult-to-treat infections relies on its capacity to fine-tune the expression of multiple virulence traits via the las, rhl, and pqs QS systems. Both the pqs effector protein PqsE and the rhl transcriptional regulator RhlR are required for full production of key virulence factors in vitro and pathogenicity in vivo. While it is known that PqsE can stimulate the ability of RhlR to control some virulence factors, no data are available to allow clear discrimination of the PqsE and RhlR regulons. The data produced in this study demonstrate that PqsE mainly impacts the P. aeruginosa transcriptome via an RhlR-dependent pathway and splits the RhlR regulon into PqsE-dependent and PqsE-independent subregulons. Besides contributing to untangling of the complex QS network of P. aeruginosa, our data confirm that both PqsE and RhlR are suitable targets for the development of antivirulence drugs.
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Affiliation(s)
| | - Marta Mellini
- Department of Science, Roma Tre University, Rome, Italy
| | | | - Paolo Visca
- Department of Science, Roma Tre University, Rome, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Francesco Imperi
- Department of Science, Roma Tre University, Rome, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Livia Leoni
- Department of Science, Roma Tre University, Rome, Italy
| | - Giordano Rampioni
- Department of Science, Roma Tre University, Rome, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
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12
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Collalto D, Giallonardi G, Fortuna A, Meneghini C, Fiscarelli E, Visca P, Imperi F, Rampioni G, Leoni L. In vitro Activity of Antivirulence Drugs Targeting the las or pqs Quorum Sensing Against Cystic Fibrosis Pseudomonas aeruginosa Isolates. Front Microbiol 2022; 13:845231. [PMID: 35547141 PMCID: PMC9083110 DOI: 10.3389/fmicb.2022.845231] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/16/2022] [Indexed: 01/24/2023] Open
Abstract
The chronic lung infection caused by Pseudomonas aeruginosa is a major cause of morbidity and mortality in cystic fibrosis (CF) patients. Antivirulence drugs targeting P. aeruginosa quorum sensing (QS) systems are intensively studied as antibiotics substitutes or adjuvants. Previous studies, carried out in non-CF P. aeruginosa reference strains, showed that the old drugs niclosamide and clofoctol could be successfully repurposed as antivirulence drugs targeting the las and pqs QS systems, respectively. However, frequent emergence of QS-defective mutants in the CF lung undermines the use of QS inhibitors in CF therapy. Here, QS signal production and susceptibility to niclosamide and clofoctol have been investigated in 100 P. aeruginosa CF isolates, with the aim of broadening current knowledge on the potential of anti-QS compounds in CF therapy. Results showed that 85, 78, and 69% of the CF isolates from our collection were proficient for the pqs, rhl, and las QS systems, respectively. The ability of both niclosamide and clofoctol to inhibit QS and virulence in vitro was highly variable and strain-dependent. Niclosamide showed an overall low range of activity and its negative effect on las signal production did not correlate with a decreased production of virulence factors. On the other hand, clofoctol displayed a broader QS inhibitory effect in CF isolates, with consequent reduction of the pqs-controlled virulence factor pyocyanin. Overall, this study highlights the importance of testing new antivirulence drugs against large panels of P. aeruginosa CF clinical isolates before proceeding to further pre-clinical studies and corroborates previous evidence that strains naturally resistant to QS inhibitors occur among CF isolates. However, it is also shown that resistance to pqs inhibitors is less frequent than resistance to las inhibitors, thus supporting the development of pqs inhibitors for antivirulence therapy in CF.
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Affiliation(s)
| | - Giulia Giallonardi
- Department of Science, Roma Tre University, Rome, Italy.,Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | | | | | - Ersilia Fiscarelli
- Laboratory of Cystic Fibrosis Microbiology, Diagnostic Medicine and Laboratory, Bambino Gesú Hospital, Rome, Italy
| | - Paolo Visca
- Department of Science, Roma Tre University, Rome, Italy.,Santa Lucia Foundation (IRCCS), Rome, Italy
| | - Francesco Imperi
- Department of Science, Roma Tre University, Rome, Italy.,Santa Lucia Foundation (IRCCS), Rome, Italy
| | - Giordano Rampioni
- Department of Science, Roma Tre University, Rome, Italy.,Santa Lucia Foundation (IRCCS), Rome, Italy
| | - Livia Leoni
- Department of Science, Roma Tre University, Rome, Italy
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13
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OUIDIR T, GABRIEL B, CHABANE YNAIT. Overview of multi-species biofilms in different ecosystems: wastewater treatment, soil and oral cavity. J Biotechnol 2022; 350:67-74. [DOI: 10.1016/j.jbiotec.2022.03.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 03/21/2022] [Accepted: 03/23/2022] [Indexed: 01/27/2023]
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14
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Ruiz CH, Osorio-Llanes E, Trespalacios MH, Mendoza-Torres E, Rosales W, Gómez CMM. Quorum Sensing Regulation as a Target for Antimicrobial Therapy. Mini Rev Med Chem 2021; 22:848-864. [PMID: 34856897 DOI: 10.2174/1389557521666211202115259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 05/20/2021] [Accepted: 09/04/2021] [Indexed: 11/22/2022]
Abstract
Some bacterial species use a cell-to-cell communication mechanism called Quorum Sensing (QS). Bacteria release small diffusible molecules, usually termed signals which allow the activation of beneficial phenotypes that guarantee bacterial survival and the expression of a diversity of virulence genes in response to an increase in population density. The study of the molecular mechanisms that relate signal molecules with bacterial pathogenesis is an area of growing interest due to its use as a possible therapeutic alternative through the development of synthetic analogues of autoinducers as a strategy to regulate bacterial communication as well as the study of bacterial resistance phenomena, the study of these relationships is based on the structural diversity of natural or synthetic autoinducers and their ability to inhibit bacterial QS, which can be approached with a molecular perspective from the following topics: i) Molecular signals and their role in QS regulation; ii) Strategies in the modulation of Quorum Sensing; iii) Analysis of Bacterial QS circuit regulation strategies; iv) Structural evolution of natural and synthetic autoinducers as QS regulators. This mini-review allows a molecular view of the QS systems, showing a perspective on the importance of the molecular diversity of autoinducer analogs as a strategy for the design of new antimicrobial agents.
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Affiliation(s)
- Caterine Henríquez Ruiz
- Grupo de Investigación en Química Orgánica y Biomédica. Faculty of Basic Sciences. Universidad del Atlántico. Barranquilla. Colombia
| | - Estefanie Osorio-Llanes
- Faculty of Exact and Natural sciences. Grupo de Investigación Avanzada en Biomedicina. Universidad Libre. Barranquilla. Colombia
| | - Mayra Hernández Trespalacios
- Grupo de Investigación en Química Orgánica y Biomédica. Faculty of Basic Sciences. Universidad del Atlántico. Barranquilla. Colombia
| | - Evelyn Mendoza-Torres
- Faculty of Health Sciences. Grupo de Investigación Avanzada en Biomedicina-Universidad Libre. Barranquilla. Colombia
| | - Wendy Rosales
- Faculty of Exact and Natural sciences. Grupo de Investigación Avanzada en Biomedicina. Universidad Libre. Barranquilla. Colombia
| | - Carlos Mario Meléndez Gómez
- Grupo de Investigación en Química Orgánica y Biomédica. Faculty of Basic Sciences. Universidad del Atlántico. Barranquilla. Colombia
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15
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Antibacterial, Antibiofilm, and Efflux Pump Inhibitory Properties of the Crude Extract and Fractions from Acacia macrostachya Stem Bark. ScientificWorldJournal 2021; 2021:5381993. [PMID: 34720766 PMCID: PMC8553507 DOI: 10.1155/2021/5381993] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 09/27/2021] [Accepted: 10/13/2021] [Indexed: 12/03/2022] Open
Abstract
Microbial infections remain a public health problem due to the upsurge of bacterial resistance. In this study, the antibacterial, antibiofilm, and efflux pump inhibitory activities of the stem bark of Acacia macrostachya, an indigenous African medicinal plant, were investigated. In traditional medicine, the plant is used in the treatment of microbial infections and inflammatory conditions. A crude methanol extract obtained by Soxhlet extraction was partitioned by column chromatography to obtain the petroleum ether, ethyl acetate, and methanol fractions. Antibacterial, efflux pump inhibition and antibiofilm formation activities were assessed by the high-throughput spot culture growth inhibition (HT-SPOTi), ethidium bromide accumulation, and the crystal violet retention assay, respectively. The minimum inhibitory concentrations (MICs) of the crude extract and major fractions ranged from 250 to ≥500 μg/mL. At a concentration of 3.9–250 μg/mL, all extracts demonstrated >80% inhibition of biofilm formation in S. aureus. In P. aeruginosa, the EtOAc fraction showed the highest antibiofilm activity (59–69%) while the pet-ether fraction was most active against E. coli biofilms (45–67%). Among the test samples, the crude extract, methanol, and ethyl acetate fractions showed remarkable efflux pump inhibition in S. aureus, E. coli, and P. aeruginosa. At ½ MIC, the methanol fraction demonstrated significant accumulation of EtBr in E. coli having superior efflux inhibition over the standard EPIs: chlorpromazine and verapamil. Tannins, flavonoids, triterpenoids, phytosterols, coumarins, and saponins were identified in preliminary phytochemical studies. Stigmasterol was identified in the EtOAc fraction. This study justifies the use of A. macrostachya in the treatment of infections in traditional medicine and highlights its potential as a source of bioactive compounds that could possibly interact with some resistance mechanisms in bacteria to combat antimicrobial resistance.
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16
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Liu H, Xiao M, Zuo J, He X, Lu P, Li Y, Zhao Y, Xia F. Vanillic acid combats Vibrio alginolyticus by cell membrane damage and biofilm reduction. JOURNAL OF FISH DISEASES 2021; 44:1799-1809. [PMID: 34310732 DOI: 10.1111/jfd.13498] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/09/2021] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
Antibiotics are the most powerful weapon against bacterial infectious diseases in aquaculture. However, the indiscriminate usage of antibiotics often culminates in the emerging development of antibiotic-resistant bacteria, making it imperative to search for novel types of antimicrobial agents. This study investigated the antibacterial and antivirulence effects of vanillic acid (VA) against the fish pathogen, Vibrio alginolyticus. We showed that VA had a good anti-Vibrio activity with minimal inhibitory concentration (MIC) of 1.0 mg/ml. In addition, VA wielded its antibacterial action in a dose-/time-dependent manner by causing cell membrane damage and increasing membrane permeability, which is evidenced by increasing the conductivity and malondialdehyde content in the treated cell cultures and the scanning electron microscopy images. Furthermore, VA significantly reduced the biofilm-forming capability, mobility and exotoxin production (protease and exopolysaccharide) and downregulation of the expression of biofilm- and virulence-associated genes (sypG, fliS, fliK, lafA, lafK, asp and luxR) was seen in the V. alginolyticus that exposed to VA at subinhibitory concentrations. Overall, our findings suggested that VA may be of interest for treating V. alginolyticus-associated infections in aquaculture.
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Affiliation(s)
- Huan Liu
- School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi'an, China
- Shaanxi Research Institute of Agriculture Products Processing Technology, Xi'an, China
| | - Miao Xiao
- School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi'an, China
| | - Jing Zuo
- School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi'an, China
| | - Xiaoxian He
- School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi'an, China
| | - Ping Lu
- School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi'an, China
| | - Yingyu Li
- School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi'an, China
| | - Yanni Zhao
- School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi'an, China
- Shaanxi Research Institute of Agriculture Products Processing Technology, Xi'an, China
| | - Fei Xia
- School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi'an, China
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17
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Fortuna A, Bähre H, Visca P, Rampioni G, Leoni L. The two Pseudomonas aeruginosa DksA stringent response proteins are largely interchangeable at the whole transcriptome level and in the control of virulence-related traits. Environ Microbiol 2021; 23:5487-5504. [PMID: 34327807 DOI: 10.1111/1462-2920.15693] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/22/2021] [Accepted: 07/27/2021] [Indexed: 11/29/2022]
Abstract
The stringent response regulator DksA plays a key role in Gram negative bacteria adaptation to challenging environments. Intriguingly, the plant and human pathogen Pseudomonas aeruginosa is unique as it expresses two functional DksA paralogs: DksA1 and DksA2. However, the role of DksA2 in P. aeruginosa adaptive strategies has been poorly investigated so far. Here, RNA-Seq analysis and phenotypic assays showed that P. aeruginosa DksA1 and DksA2 proteins are largely interchangeable. Relative to wild type P. aeruginosa, transcription of 1779 genes was altered in a dksA1 dksA2 double mutant, and the wild type expression level of ≥90% of these genes was restored by in trans complementation with either dksA1 or dksA2. Interestingly, the expression of a small sub-set of genes seems to be preferentially or exclusively complemented by either dksA1 or dksA2. In addition, evidence has been provided that the DksA-dependent regulation of virulence genes expression is independent and hierarchically dominant over two major P. aeruginosa regulatory circuits, i.e., quorum sensing and cyclic-di-GMP signalling systems. Our findings support the prominent role of both DksA paralogs in P. aeruginosa environmental adaptation.
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Affiliation(s)
| | - Heike Bähre
- Research Core Unit Metabolomics, Hannover Medical School, Hannover, Germany
| | - Paolo Visca
- Department of Science, University Roma Tre, Rome, Italy
| | | | - Livia Leoni
- Department of Science, University Roma Tre, Rome, Italy
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18
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Li Y, Li X, Hao Y, Liu Y, Dong Z, Li K. Biological and Physiochemical Methods of Biofilm Adhesion Resistance Control of Medical-Context Surface. Int J Biol Sci 2021; 17:1769-1781. [PMID: 33994861 PMCID: PMC8120469 DOI: 10.7150/ijbs.59025] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 04/01/2021] [Indexed: 12/12/2022] Open
Abstract
The formation of biofilms on medical-context surfaces gives the EPS embedded bacterial community protection and additional advantages that planktonic cells would not have such as increased antibiotic resistance and horizontal gene transfer. Bacterial cells tend to attach to a conditioning layer after overcoming possible electrical barriers and go through two phases of attachments: reversible and irreversible. In the first, bacterial attachment to the surface is reversible and occurs quickly whilst the latter is permanent and takes place over a longer period of time. Upon reaching a certain density in the bacterial community, quorum sensing causes phenotypical changes leading to a loss in motility and the production of EPS. This position paper seeks to address the problem of bacterial adhesion and biofilm formation for the medical surfaces by comparing inhabiting physicochemical interactions and biological mechanisms. Several physiochemical methodologies (e.g. ultrasonication, alternating magnetic field and chemical surface coating) and utilizing biological mechanisms (e.g. quorum quenching and EPS degrading enzymes) were suggested. The possible strategical applications of each category were suggested and evaluated to a balanced position to possibly eliminate the adhesion and formation of biofilms on medical-context surfaces.
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Affiliation(s)
- Yuanzhe Li
- School of Materials Science & Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Xiang Li
- School of Chemistry and Biomolecules Engineering, National University of Singapore, Singapore, 637551, Singapore
| | - Yu Hao
- School of Chemistry and Biomolecules Engineering, National University of Singapore, Singapore, 637551, Singapore
| | - Yang Liu
- School of Materials Science & Engineering, Nanyang Technological University, Singapore, 639798, Singapore
- School of Mechanical Engineering, Xiangtan University, Xiangtan, 411105, China
| | - ZhiLi Dong
- School of Materials Science & Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Kexin Li
- Hwa Chong International School, Singapore, 269783, Singapore
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19
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Effect of Bromination on the Quorum Sensing-Inhibiting Properties of Indole-3-Carboxaldehydes in Chromobacterium violaceum AHL System. MICROBIOLOGY RESEARCH 2021. [DOI: 10.3390/microbiolres12020025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Quorum sensing (QS) is a form of bacterial communication involved in the production of virulence factors in many species. As a result, inhibition of quorum sensing may be of use in mitigating pathogenesis. The signaling molecule indole is currently being investigated as a target for quorum sensing inhibition (QSI) and the indole derivative indole-3-carboxaldehyde (ICA) has been shown to inhibit quorum sensing-mediated behaviors in Escherichia coli. In this study, we investigate bromination as a method of increasing the QSI capabilities of indole carboxaldehydes. The IC50 values of three monobrominated indole carboxaldehydes (5-bromoindole-3-carboxaldehyde, 6-bromoindole-3-carboxaldehyde, and 7-bromoindole-3-carboxaldehyde) were determined and compared to the IC50 value of ICA. The bromination of these indole carboxaldehydes reduced the IC50 values between 2- and 13-fold, indicating that bromination significantly increases the potency of these indole carboxaldehydes.
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20
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Modulation of quorum sensing-associated virulence in bacteria: carbohydrate as a key factor. Arch Microbiol 2021; 203:1881-1890. [PMID: 33641039 DOI: 10.1007/s00203-021-02235-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 12/11/2020] [Accepted: 02/11/2021] [Indexed: 01/21/2023]
Abstract
Quorum sensing (QS) is a method of inter-cellular communication that permits bacteria to dispense information about cell density and to synchronize the gene expression accordingly. Gram-positive and Gram-negative bacteria utilize distinct quorum sensing mechanisms for effective pathogenesis. Virulence factor production by pathogenic bacteria is one of the important traits that is under the control of QS. A growing body of evidence has indicated the role of the nutritional environment notably by carbohydrates in dictating the QS-associated virulence gene regulation. The modulation of QS by carbohydrates mitigates the survival and establishment of the pathogen within its host which in turn leads to an increase in morbidity and mortality. This mini-review throws light on the predilection of pathogenic bacteria to rapidly regulate its QS-linked virulence gene expression based on the changing nutrient levels that assist them in prospering within diverse niches.
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21
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Topka-Bielecka G, Dydecka A, Necel A, Bloch S, Nejman-Faleńczyk B, Węgrzyn G, Węgrzyn A. Bacteriophage-Derived Depolymerases against Bacterial Biofilm. Antibiotics (Basel) 2021; 10:175. [PMID: 33578658 PMCID: PMC7916357 DOI: 10.3390/antibiotics10020175] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/03/2021] [Accepted: 02/06/2021] [Indexed: 12/11/2022] Open
Abstract
In addition to specific antibiotic resistance, the formation of bacterial biofilm causes another level of complications in attempts to eradicate pathogenic or harmful bacteria, including difficult penetration of drugs through biofilm structures to bacterial cells, impairment of immunological response of the host, and accumulation of various bioactive compounds (enzymes and others) affecting host physiology and changing local pH values, which further influence various biological functions. In this review article, we provide an overview on the formation of bacterial biofilm and its properties, and then we focus on the possible use of phage-derived depolymerases to combat bacterial cells included in this complex structure. On the basis of the literature review, we conclude that, although these bacteriophage-encoded enzymes may be effective in destroying specific compounds involved in the formation of biofilm, they are rarely sufficient to eradicate all bacterial cells. Nevertheless, a combined therapy, employing depolymerases together with antibiotics and/or other antibacterial agents or factors, may provide an effective approach to treat infections caused by bacteria able to form biofilms.
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Affiliation(s)
- Gracja Topka-Bielecka
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (G.T.-B.); (A.D.); (A.N.); (B.N.-F.); (G.W.)
| | - Aleksandra Dydecka
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (G.T.-B.); (A.D.); (A.N.); (B.N.-F.); (G.W.)
| | - Agnieszka Necel
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (G.T.-B.); (A.D.); (A.N.); (B.N.-F.); (G.W.)
| | - Sylwia Bloch
- Laboratory of Phage Therapy, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Kładki 24, 80-822 Gdańsk, Poland;
| | - Bożena Nejman-Faleńczyk
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (G.T.-B.); (A.D.); (A.N.); (B.N.-F.); (G.W.)
| | - Grzegorz Węgrzyn
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (G.T.-B.); (A.D.); (A.N.); (B.N.-F.); (G.W.)
| | - Alicja Węgrzyn
- Laboratory of Phage Therapy, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Kładki 24, 80-822 Gdańsk, Poland;
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22
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Baldelli V, D'Angelo F, Pavoncello V, Fiscarelli EV, Visca P, Rampioni G, Leoni L. Identification of FDA-approved antivirulence drugs targeting the Pseudomonas aeruginosa quorum sensing effector protein PqsE. Virulence 2021; 11:652-668. [PMID: 32423284 PMCID: PMC7549961 DOI: 10.1080/21505594.2020.1770508] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The ability of the bacterial pathogen Pseudomonas aeruginosa to cause both chronic and acute infections mainly relies on its capacity to finely modulate the expression of virulence factors through a complex network of regulatory circuits, including the pqs quorum sensing (QS) system. While in most QS systems the signal molecule/receptor complexes act as global regulators that modulate the expression of QS-controlled genes, the main effector protein of the pqs system is PqsE. This protein is involved in the synthesis of the QS signal molecules 2-alkyl-4(1H)-quinolones (AQs), but it also modulates the expression of genes involved in virulence factors production and biofilm formation via AQ-independent pathway(s). P. aeruginosa pqsE mutants disclose attenuated virulence in plant and animal infection models, hence PqsE is considered a good target for the development of antivirulence drugs against P. aeruginosa. In this study, the negative regulation exerted by PqsE on its own transcription has been exploited to develop a screening system for the identification of PqsE inhibitors in a library of FDA-approved drugs. This led to the identification of nitrofurazone and erythromycin estolate, two antibiotic compounds that reduce the expression of PqsE-dependent virulence traits and biofilm formation in the model strain P. aeruginosa PAO1 at concentrations far below those affecting the bacterial growth rate. Notably, both drugs reduce the production of the PqsE-controlled virulence factor pyocyanin also in P. aeruginosa strains isolated from cystic fibrosis patients, and do not antagonize the activity of antibiotics commonly used to treat P. aeruginosa infection.
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Affiliation(s)
| | | | | | | | - Paolo Visca
- Department of Science, University Roma Tre , Rome, Italy
| | | | - Livia Leoni
- Department of Science, University Roma Tre , Rome, Italy
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23
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Behzadi P, Baráth Z, Gajdács M. It's Not Easy Being Green: A Narrative Review on the Microbiology, Virulence and Therapeutic Prospects of Multidrug-Resistant Pseudomonas aeruginosa. Antibiotics (Basel) 2021; 10:42. [PMID: 33406652 PMCID: PMC7823828 DOI: 10.3390/antibiotics10010042] [Citation(s) in RCA: 109] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/29/2020] [Accepted: 12/31/2020] [Indexed: 12/11/2022] Open
Abstract
Pseudomonas aeruginosa is the most frequent cause of infection among non-fermenting Gram-negative bacteria, predominantly affecting immunocompromised patients, but its pathogenic role should not be disregarded in immunocompetent patients. These pathogens present a concerning therapeutic challenge to clinicians, both in community and in hospital settings, due to their increasing prevalence of resistance, and this may lead to prolonged therapy, sequelae, and excess mortality in the affected patient population. The resistance mechanisms of P. aeruginosa may be classified into intrinsic and acquired resistance mechanisms. These mechanisms lead to occurrence of resistant strains against important antibiotics-relevant in the treatment of P. aeruginosa infections-such as β-lactams, quinolones, aminoglycosides, and colistin. The occurrence of a specific resistotype of P. aeruginosa, namely the emergence of carbapenem-resistant but cephalosporin-susceptible (Car-R/Ceph-S) strains, has received substantial attention from clinical microbiologists and infection control specialists; nevertheless, the available literature on this topic is still scarce. The aim of this present review paper is to provide a concise summary on the adaptability, virulence, and antibiotic resistance of P. aeruginosa to a readership of basic scientists and clinicians.
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Affiliation(s)
- Payam Behzadi
- Department of Microbiology, College of Basic Sciences, Shahr-e-Qods Branch, Islamic Azad University, Tehran 37541-374, Iran;
| | - Zoltán Baráth
- Department of Prosthodontics, Faculty of Dentistry, University of Szeged, Tisza Lajos körút 62-64, 6720 Szeged, Hungary;
| | - Márió Gajdács
- Institute of Medical Microbiology, Faculty of Medicine, Semmelweis University, 1089 Budapest, Hungary
- Department of Pharmacodynamics and Biopharmacy, Faculty of Pharmacy, University of Szeged, 6720 Szeged, Hungary
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Grossman S, Soukarieh F, Richardson W, Liu R, Mashabi A, Emsley J, Williams P, Cámara M, Stocks MJ. Novel quinazolinone inhibitors of the Pseudomonas aeruginosa quorum sensing transcriptional regulator PqsR. Eur J Med Chem 2020; 208:112778. [PMID: 32927392 PMCID: PMC7684530 DOI: 10.1016/j.ejmech.2020.112778] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 08/07/2020] [Accepted: 08/20/2020] [Indexed: 01/14/2023]
Abstract
Rising numbers of cases of multidrug- and extensively drug-resistant Pseudomonas aeruginosa over recent years have created an urgent need for novel therapeutic approaches to cure potentially fatal infections. One such approach is virulence attenuation where anti-virulence compounds, designed to reduce pathogenicity without affording bactericidal effects, are employed to treat infections. P. aeruginosa uses the pqs quorum sensing (QS) system, to coordinate the expression of a large number of virulence determinants as well as bacterial-host interactions and hence represents an excellent anti-virulence target. We report the synthesis and identification of a new series of thiazole-containing quinazolinones capable of inhibiting PqsR, the transcriptional regulator of the pqs QS system. The compounds demonstrated high potency (IC50 < 300 nM) in a whole-cell assay, using a mCTX:PpqsA-lux-based bioreporter for the P. aeruginosa PAO1-L and PA14 strains. Structural evaluation defined the binding modes of four analogues in the ligand-binding domain of PqsR through X-ray crystallography. Further work showed the ability of 6-chloro-3((2-pentylthiazol-4-yl)methyl)quinazolin-4(3H)-one (18) and 6-chloro-3((2-hexylthiazol-4-yl)methyl)quinazolin-4(3H)-one (19) to attenuate production of the PqsR-regulated virulence factor pyocyanin. Compounds 18 and 19 showed a low cytotoxic profile in the A549 human epithelial lung cell line making them suitable candidates for further pre-clinical evaluation.
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Affiliation(s)
- Scott Grossman
- School of Pharmacy, University of Nottingham Biodiscovery Institute, University Park, Nottingham, Nottinghamshire, NG7 2RD, UK
| | - Fadi Soukarieh
- School of Life Sciences, University of Nottingham Biodiscovery Institute, University Park, Nottingham, Nottinghamshire, NG7 2RD, UK; National Biofilms Innovation Centre, University of Nottingham Biodiscovery Institute, University Park, Nottingham, Nottinghamshire, NG7 2RD, UK
| | - William Richardson
- School of Pharmacy, University of Nottingham Biodiscovery Institute, University Park, Nottingham, Nottinghamshire, NG7 2RD, UK
| | - Ruiling Liu
- School of Pharmacy, University of Nottingham Biodiscovery Institute, University Park, Nottingham, Nottinghamshire, NG7 2RD, UK
| | - Alaa Mashabi
- School of Pharmacy, University of Nottingham Biodiscovery Institute, University Park, Nottingham, Nottinghamshire, NG7 2RD, UK
| | - Jonas Emsley
- School of Pharmacy, University of Nottingham Biodiscovery Institute, University Park, Nottingham, Nottinghamshire, NG7 2RD, UK; National Biofilms Innovation Centre, University of Nottingham Biodiscovery Institute, University Park, Nottingham, Nottinghamshire, NG7 2RD, UK
| | - Paul Williams
- School of Life Sciences, University of Nottingham Biodiscovery Institute, University Park, Nottingham, Nottinghamshire, NG7 2RD, UK; National Biofilms Innovation Centre, University of Nottingham Biodiscovery Institute, University Park, Nottingham, Nottinghamshire, NG7 2RD, UK
| | - Miguel Cámara
- School of Life Sciences, University of Nottingham Biodiscovery Institute, University Park, Nottingham, Nottinghamshire, NG7 2RD, UK; National Biofilms Innovation Centre, University of Nottingham Biodiscovery Institute, University Park, Nottingham, Nottinghamshire, NG7 2RD, UK
| | - Michael J Stocks
- School of Pharmacy, University of Nottingham Biodiscovery Institute, University Park, Nottingham, Nottinghamshire, NG7 2RD, UK; National Biofilms Innovation Centre, University of Nottingham Biodiscovery Institute, University Park, Nottingham, Nottinghamshire, NG7 2RD, UK.
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S LP, A U, S J GF. Investigation on the biofilm eradication potential of selected medicinal plants against methicillin-resistant Staphylococcus aureus. BIOTECHNOLOGY REPORTS (AMSTERDAM, NETHERLANDS) 2020; 28:e00523. [PMID: 32995315 PMCID: PMC7502823 DOI: 10.1016/j.btre.2020.e00523] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 08/24/2020] [Accepted: 08/30/2020] [Indexed: 11/25/2022]
Abstract
Biofilms are multi-species bacterial communities with complex structures that create antibiotic resistance, cause life-threatening infections, thereby considerable economic loss; needed new approaches. Medicinal plants are focused as new alternatives for their therapeutic and antimicrobial effects. Our present study, Azadirachta indica, Moringa oleifera, Murraya koenigii, and Psidium guajava extracts were investigated against MRSA. The preliminary antimicrobial study showed pet. ether extract of A. indica and ethanolic extract of P. guajava showed a MIC value of 125 μg/mL and MBC value of 500 μg/mL. These extracts showed biofilm inhibition in the range of 60.0-83.9 % and did not possess any hemolytic activity to the human erythrocytes. The plant species investigated in this study had different degrees of antibiofilm activity against MRSA. However, we suggest that A. indica and P. guajava are promising candidates and further investigation is needed to isolate the antimicrobial compounds for the management of MRSA and its mechanism of activity.
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Affiliation(s)
- Lakshmana Prabu S
- Department of Pharmaceutical Technology, University College of Engineering (BIT Campus), Anna University, Tiruchirappalli, India
| | - Umamaheswari A
- Department of Pharmaceutical Technology, University College of Engineering (BIT Campus), Anna University, Tiruchirappalli, India
| | - Grace Felciya S J
- Department of Pharmaceutical Technology, University College of Engineering (BIT Campus), Anna University, Tiruchirappalli, India
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Park OJ, Kwon Y, Park C, So YJ, Park TH, Jeong S, Im J, Yun CH, Han SH. Streptococcus gordonii: Pathogenesis and Host Response to Its Cell Wall Components. Microorganisms 2020; 8:microorganisms8121852. [PMID: 33255499 PMCID: PMC7761167 DOI: 10.3390/microorganisms8121852] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 11/23/2020] [Accepted: 11/23/2020] [Indexed: 02/08/2023] Open
Abstract
Streptococcus gordonii, a Gram-positive bacterium, is a commensal bacterium that is commonly found in the skin, oral cavity, and intestine. It is also known as an opportunistic pathogen that can cause local or systemic diseases, such as apical periodontitis and infective endocarditis. S. gordonii, an early colonizer, easily attaches to host tissues, including tooth surfaces and heart valves, forming biofilms. S. gordonii penetrates into root canals and blood streams, subsequently interacting with various host immune and non-immune cells. The cell wall components of S. gordonii, which include lipoteichoic acids, lipoproteins, serine-rich repeat adhesins, peptidoglycans, and cell wall proteins, are recognizable by individual host receptors. They are involved in virulence and immunoregulatory processes causing host inflammatory responses. Therefore, S.gordonii cell wall components act as virulence factors that often progressively develop diseases through overwhelming host responses. This review provides an overview of S. gordonii, and how its cell wall components could contribute to the pathogenesis and development of therapeutic strategies.
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Affiliation(s)
- Ok-Jin Park
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
| | - Yeongkag Kwon
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
| | - Chaeyeon Park
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
| | - Yoon Ju So
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
| | - Tae Hwan Park
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
| | - Sungho Jeong
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
| | - Jintaek Im
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
| | - Cheol-Heui Yun
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea;
- Institute of Green Bio Science Technology, Seoul National University, Pyeongchang 25354, Korea
| | - Seung Hyun Han
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
- Correspondence: ; Tel.: +82-2-880-2310
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27
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Chilczuk T, Monson R, Schmieder P, Christov V, Enke H, Salmond G, Niedermeyer THJ. Ambigols from the Cyanobacterium Fischerella ambigua Increase Prodigiosin Production in Serratia spp. ACS Chem Biol 2020; 15:2929-2936. [PMID: 33143417 DOI: 10.1021/acschembio.0c00554] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
When a library of 573 cyanobacteria extracts was screened for inhibition of the quorum sensing regulated prodigiosin production of Serratia marcescens, an extract of the cyanobacterium Fischerella ambigua (Näg.) Gomont 108b was found to drastically increase prodigiosin production. Bioactivity-guided isolation of the active compounds resulted in the two new natural products ambigol D and E along with the known ambigols A and C. Ambigol C treatment increased prodiginine production of Serratia sp. ATCC 39006 (S39006) by a factor of 10, while ambigols A and D were found to have antibiotic activity against this strain. The RNA-Seq of S39006 treated with ambigol C and subsequent differential gene expression and functional enrichment analyses indicated a significant downregulation of genes associated with the translation machinery and fatty acid biosynthesis in Serratia, as well as increased expression of genes related to the uptake of l-proline. These results suggest that the ambigols increase prodiginine production in S39006 not by activating the SmaIR quorum sensing system but possibly by increasing the precursor supply of l-proline and malonyl-CoA.
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Affiliation(s)
- Tomasz Chilczuk
- Department of Pharmaceutical Biology/Pharmacognosy, Institute of Pharmacy, University of Halle-Wittenberg, Halle, Germany
| | - Rita Monson
- Department of Biochemistry, University of Cambridge, Hopkins Building, Downing Site, Cambridge, CB2 1QW, United Kingdom
| | - Peter Schmieder
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Department of NMR-Supported Structural Biology, Berlin, Germany
| | - Vesselin Christov
- Zentrum für medizinische Grundlagenforschung, University of Halle-Wittenberg, Halle, Germany
| | | | - George Salmond
- Department of Biochemistry, University of Cambridge, Hopkins Building, Downing Site, Cambridge, CB2 1QW, United Kingdom
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Ostovar G, Naughton KL, Boedicker JQ. Computation in bacterial communities. Phys Biol 2020; 17:061002. [PMID: 33035198 DOI: 10.1088/1478-3975/abb257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Bacteria across many scales are involved in a dynamic process of information exchange to coordinate activity and community structure within large and diverse populations. The molecular components bacteria use to communicate have been discovered and characterized, and recent efforts have begun to understand the potential for bacterial signal exchange to gather information from the environment and coordinate collective behaviors. Such computations made by bacteria to coordinate the action of a population of cells in response to information gathered by a multitude of inputs is a form of collective intelligence. These computations must be robust to fluctuations in both biological, chemical, and physical parameters as well as to operate with energetic efficiency. Given these constraints, what are the limits of computation by bacterial populations and what strategies have evolved to ensure bacterial communities efficiently work together? Here the current understanding of information exchange and collective decision making that occur in microbial populations will be reviewed. Looking toward the future, we consider how a deeper understanding of bacterial computation will inform future direction in microbiology, biotechnology, and biophysics.
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Affiliation(s)
- Ghazaleh Ostovar
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, United States of America
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29
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Dapunt U, Prior B, Oelkrug C, Kretzer JP. IgY Targeting Bacterial Quorum-Sensing Molecules in Implant-Associated Infections. Molecules 2020; 25:molecules25174027. [PMID: 32899313 PMCID: PMC7504788 DOI: 10.3390/molecules25174027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 09/01/2020] [Indexed: 12/27/2022] Open
Abstract
Background: Implant-associated infections are still a major complication in the field of orthopedics. Bacteria can form biofilms on implant surfaces, making them more difficult to detect and treat. Since standard antibiotic therapy is often impaired in biofilm infections, particular interest is directed towards finding treatment alternatives. Biofilm-formation is a well-organized process during which bacteria communicate via quorum-sensing molecules (QSM). The aim of this study was to inhibit bacterial communication by directing avian IgY against specific QSM. Methods: Chicken were immunized against the following QSM: (1) AtlE, a member of the autolysin family which mediates attachment to a surface in Staphylococcus epidermidis; (2) GroEL, the bacterial heat shock protein; (3) PIA (polysaccharide intercellular adhesion), which is essential for cell–cell adhesion in biofilms. Staphylococcus epidermidis biofilms were grown and inhibition of biofilm-formation by IgYs was evaluated. Additionally, human osteoblasts were cultivated and biocompatibility of IgYs was tested. Results: We were able to demonstrate that all IgYs reduced biofilm-formation, also without prior immunization. Therefore, the response was probably not specific with regard to the QSM. Osteoblasts were activated by all IgYs which was demonstrated by microscopy and an increased release of IL-8. Conclusions: In conclusion, avian IgY inhibits biofilm-formation, though the underlying mechanism is not yet clear. However, adverse effects on local tissue cells (osteoblasts) were also observed.
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Affiliation(s)
- Ulrike Dapunt
- Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstrasse 200a, 69118 Heidelberg, Germany
- Correspondence: ; Tel.: +49/6221-5625000
| | - Birgit Prior
- Department of Anesthesiology, Heidelberg University Hospital, Im Neuenheimer Feld 672, 69120 Heidelberg, Germany;
| | - Christopher Oelkrug
- Oelkrug Enterprises UG (haftungsbeschraenkt), Gerhart Hauptmann Str. 10, 59387 Ascheberg, Germany;
| | - Jan Philippe Kretzer
- Laboratory of Biomechanics and Implant Research, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstrasse 200a, 69118 Heidelberg, Germany;
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Mansuri A, Lokhande K, Kore S, Gaikwad S, Nawani N, Swamy KV, Junnarkar M, Pawar S. Antioxidant, anti-quorum sensing, biofilm inhibitory activities and chemical composition of Patchouli essential oil: in vitro and in silico approach. J Biomol Struct Dyn 2020; 40:154-165. [PMID: 32838699 DOI: 10.1080/07391102.2020.1810124] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The interest in naturally occurring essential oils from medicinal plants has increased extremely over the last decade markedly because they possess antimicrobial and antioxidant protective properties against different chronic diseases. Extensive survival of drug-resistant infectious bacteria depends on quorum sensing (QS) signaling network which raises the need for alternative antibacterial compounds. The aim of this study was to examine the phytochemical compounds of patchouli essential oil (PEO) and to assess its antioxidant activity. Antioxidant studies estimated by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method showed that the PEO has effective antioxidant activity (IC50 19.53 µg/mL). QS inhibitory activity of PEO was examined by employing the biosensor strain, Chromobacterium violaceum CV12472. At sub-lethal concentrations, PEO potentially reduced the QS regulated violacein synthesis in CV12472 without inhibiting its cell proliferation. Moreover, it also effectively reduced the production of some QS regulated virulence factors and biofilm development in P. aeruginosa PAO1 without hindering its growth. Phytochemical analysis of PEO was done by GC/MS technique. Molecular docking of PEO major compounds with QS (LasR and FabI) and biofilm regulator proteins (MvfR and Sialidase) of PAO1 was evaluated. These phytocompounds showed potential hydrogen binding interactions with these proteins. The overall results, in vitro and in silico, suggest that PEO could be applied as biocontrol agent against antibiotic resistance pathogens. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Afrin Mansuri
- Microbial Diversity Research Centre, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pune, India
| | - Kiran Lokhande
- Bioinformatics Research Laboratory, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pune, India
| | - Supriya Kore
- Microbial Diversity Research Centre, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pune, India
| | - Swapnil Gaikwad
- Microbial Diversity Research Centre, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pune, India
| | - Neelu Nawani
- Microbial Diversity Research Centre, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pune, India
| | - K Venkateswara Swamy
- Bioinformatics Research Laboratory, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pune, India
| | - Manisha Junnarkar
- Microbial Diversity Research Centre, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pune, India
| | - Sarika Pawar
- Microbial Diversity Research Centre, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pune, India
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31
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Sharma A, Singh P, Sarmah BK, Nandi SP. Quorum sensing: its role in microbial social networking. Res Microbiol 2020; 171:159-164. [PMID: 32592751 DOI: 10.1016/j.resmic.2020.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 10/24/2022]
Abstract
Twentieth century observed a huge paradigm shift in the field of sociobiology, which moved from social intelligence of animals to microbes. Quorum Sensing Molecules (QSMs) are the small chemical molecules, which establish the mode of communication among microbes, and is called Quorum Sensing (QS). These molecules are crucial for determining the decisions of large groups of cells, which is a density-dependent process. Thus, this mechanism draws a very thin line between bacteria that are actually prokaryotes and clustered bacteria mimicking eukaryotes. This review discusses about the designs of microbial communication networks, and the role of QS in plant-microbe interaction.
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Affiliation(s)
- Angkita Sharma
- Amity Institute of Biotechnology, Amity University, Noida, 201313, Uttar Pradesh, India.
| | - Pooja Singh
- Amity Institute of Biotechnology, Amity University, Noida, 201313, Uttar Pradesh, India.
| | - Bidyut Kr Sarmah
- DBT-AAU Centre, Assam Agricultural University, Jorhat, 785013, Assam, India.
| | - Shoma Paul Nandi
- Amity Institute of Biotechnology, Amity University, Noida, 201313, Uttar Pradesh, India.
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32
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Vishwakarma J, V.L S. Unraveling the anti-biofilm potential of green algal sulfated polysaccharides against Salmonella enterica and Vibrio harveyi. Appl Microbiol Biotechnol 2020; 104:6299-6314. [DOI: 10.1007/s00253-020-10653-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 04/08/2020] [Accepted: 04/29/2020] [Indexed: 01/06/2023]
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Rezzoagli C, Granato ET, Kümmerli R. Harnessing bacterial interactions to manage infections: a review on the opportunistic pathogen Pseudomonas aeruginosa as a case example. J Med Microbiol 2020; 69:147-161. [PMID: 31961787 PMCID: PMC7116537 DOI: 10.1099/jmm.0.001134] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
During infections, bacterial pathogens can engage in a variety of interactions with each other, ranging from the cooperative sharing of resources to deadly warfare. This is especially relevant in opportunistic infections, where different strains and species often co-infect the same patient and interact in the host. Here, we review the relevance of these social interactions during opportunistic infections using the human pathogen Pseudomonas aeruginosa as a case example. In particular, we discuss different types of pathogen-pathogen interactions, involving both cooperation and competition, and elaborate on how they impact virulence in multi-strain and multi-species infections. We then review evolutionary dynamics within pathogen populations during chronic infections. We particuarly discuss how local adaptation through niche separation, evolutionary successions and antagonistic co-evolution between pathogens can alter virulence and the damage inflicted on the host. Finally, we outline how studying bacterial social dynamics could be used to manage infections. We show that a deeper appreciation of bacterial evolution and ecology in the clinical context is important for understanding microbial infections and can inspire novel treatment strategies.
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Affiliation(s)
- Chiara Rezzoagli
- Department of Quantitative Biomedicine, University of Zurich, Zurich, Switzerland
| | - Elisa T. Granato
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Rolf Kümmerli
- Department of Quantitative Biomedicine, University of Zurich, Zurich, Switzerland
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Paluch E, Rewak-Soroczyńska J, Jędrusik I, Mazurkiewicz E, Jermakow K. Prevention of biofilm formation by quorum quenching. Appl Microbiol Biotechnol 2020; 104:1871-1881. [PMID: 31927762 PMCID: PMC7007913 DOI: 10.1007/s00253-020-10349-w] [Citation(s) in RCA: 157] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/26/2019] [Accepted: 01/03/2020] [Indexed: 02/08/2023]
Abstract
Quorum sensing (QS) is a mechanism that enables microbial communication. It is based on the constant secretion of signaling molecules to the environment. The main role of QS is the regulation of vital processes in the cell such as virulence factor production or biofilm formation. Due to still growing bacterial resistance to antibiotics that have been overused, it is necessary to search for alternative antimicrobial therapies. One of them is quorum quenching (QQ) that disrupts microbial communication. QQ-driving molecules can decrease or even completely inhibit the production of virulence factors (including biofilm formation). There are few QQ strategies that comprise the use of the structural analogues of QS receptor autoinductors (AI). They may be found in nature or be designed and synthesized via chemical engineering. Many of the characterized QQ molecules are enzymes with the ability to degrade signaling molecules. They can also impede cellular signaling cascades. There are different techniques used for testing QS/QQ, including chromatography-mass spectroscopy, bioluminescence, chemiluminescence, fluorescence, electrochemistry, and colorimetry. They all enable qualitative and quantitative measurements of QS/QQ molecules. This article gathers the information about the mechanisms of QS and QQ, and their effect on microbial biofilm formation. Basic methods used to study QS/QQ, as well as the medical and biotechnological applications of QQ, are also described. Basis research methods are also described as well as medical and biotechnological application.
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Affiliation(s)
- E Paluch
- Department of Microbiology, Faculty of Medicine, Wroclaw Medical University, Tytusa Chałubińskiego 4, 50-376, Wrocław, Poland.
| | - J Rewak-Soroczyńska
- Institute of Low Temperature and Structure Research, Polish Academy of Science, Okólna 2, 50-422, Wroclaw, Poland
| | - I Jędrusik
- Institute of Genetics and Microbiology, University of Wrocław, Przybyszewskiego 63/77, 51-148, Wrocław, Poland
| | - E Mazurkiewicz
- Institute of Genetics and Microbiology, University of Wrocław, Przybyszewskiego 63/77, 51-148, Wrocław, Poland
| | - K Jermakow
- Department of Microbiology, Faculty of Medicine, Wroclaw Medical University, Tytusa Chałubińskiego 4, 50-376, Wrocław, Poland
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Mellini M, Di Muzio E, D’Angelo F, Baldelli V, Ferrillo S, Visca P, Leoni L, Polticelli F, Rampioni G. In silico Selection and Experimental Validation of FDA-Approved Drugs as Anti-quorum Sensing Agents. Front Microbiol 2019; 10:2355. [PMID: 31649658 PMCID: PMC6796623 DOI: 10.3389/fmicb.2019.02355] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 09/27/2019] [Indexed: 12/13/2022] Open
Abstract
The emergence of antibiotic resistant bacterial pathogens is increasing at an unprecedented pace, calling for the development of new therapeutic options. Small molecules interfering with virulence processes rather than growth hold promise as an alternative to conventional antibiotics. Anti-virulence agents are expected to decrease bacterial virulence and to pose reduced selective pressure for the emergence of resistance. In the opportunistic pathogen Pseudomonas aeruginosa the expression of key virulence traits is controlled by quorum sensing (QS), an intercellular communication process that coordinates gene expression at the population level. Hence, QS inhibitors represent promising anti-virulence agents against P. aeruginosa. Virtual screenings allow fast and cost-effective selection of target ligands among vast libraries of molecules, thus accelerating the time and limiting the cost of conventional drug-discovery processes, while the drug-repurposing approach is based on the identification of off-target activity of FDA-approved drugs, likely endowed with low cytotoxicity and favorable pharmacological properties. This study aims at combining the advantages of virtual screening and drug-repurposing approaches to identify new QS inhibitors targeting the pqs QS system of P. aeruginosa. An in silico library of 1,467 FDA-approved drugs has been screened by molecular docking, and 5 hits showing the highest predicted binding affinity for the pqs QS receptor PqsR (also known as MvfR) have been selected. In vitro experiments have been performed by engineering ad hoc biosensor strains, which were used to verify the ability of hit compounds to decrease PqsR activity in P. aeruginosa. Phenotypic analyses confirmed the impact of the most promising hit, the antipsychotic drug pimozide, on the expression of P. aeruginosa PqsR-controlled virulence traits. Overall, this study highlights the potential of virtual screening campaigns of FDA-approved drugs to rapidly select new inhibitors of important bacterial functions.
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Affiliation(s)
- Marta Mellini
- Department of Science, University Roma Tre, Rome, Italy
| | | | | | | | | | - Paolo Visca
- Department of Science, University Roma Tre, Rome, Italy
| | - Livia Leoni
- Department of Science, University Roma Tre, Rome, Italy
| | - Fabio Polticelli
- Department of Science, University Roma Tre, Rome, Italy
- National Institute of Nuclear Physics, Roma Tre Section, Rome, Italy
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Tyrosol from marine Fungi, a novel Quorum sensing inhibitor against Chromobacterium violaceum and Pseudomonas aeruginosa. Bioorg Chem 2019; 91:103140. [DOI: 10.1016/j.bioorg.2019.103140] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/12/2019] [Accepted: 07/19/2019] [Indexed: 11/30/2022]
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Timing Is Everything: Impact of Naturally Occurring Staphylococcus aureus AgrC Cytoplasmic Domain Adaptive Mutations on Autoinduction. J Bacteriol 2019; 201:JB.00409-19. [PMID: 31358609 PMCID: PMC6755735 DOI: 10.1128/jb.00409-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 07/22/2019] [Indexed: 01/19/2023] Open
Abstract
Virulence factor expression in Staphylococcus aureus is regulated via autoinducing peptide (AIP)-dependent activation of the sensor kinase AgrC, which forms an integral part of the agr quorum sensing system. In response to bound AIP, the cytoplasmic domain of AgrC (AgrC-cyt) undergoes conformational changes resulting in dimerization, autophosphorylation, and phosphotransfer to the response regulator AgrA. Naturally occurring mutations in AgrC-cyt are consistent with repositioning of key functional domains, impairing dimerization and restricting access to the ATP-binding pocket. Strains harboring specific AgrC-cyt mutations exhibit reduced AIP autoinduction efficiency and a timing-dependent attenuation of cytotoxicity which may confer a survival advantage during established infection by promoting colonization while restricting unnecessary overproduction of exotoxins. Mutations in the polymorphic Staphylococcus aureusagr locus responsible for quorum sensing (QS)-dependent virulence gene regulation occur frequently during host adaptation. In two genomically closely related S. aureus clinical isolates exhibiting marked differences in Panton-Valentine leukocidin production, a mutation conferring an N267I substitution was identified in the cytoplasmic domain of the QS sensor kinase, AgrC. This natural mutation delayed the onset and accumulation of autoinducing peptide (AIP) and showed reduced responsiveness to exogenous AIPs. Other S. aureus strains harboring naturally occurring AgrC cytoplasmic domain mutations were identified, including T247I, I311T, A343T, L245S, and F264C. These mutations were associated with reduced cytotoxicity, delayed/reduced AIP production, and impaired sensitivity to exogenous AIP. Molecular dynamics simulations were used to model the AgrC cytoplasmic domain conformational changes arising. Although mutations were localized in different parts of the C-terminal domain, their impact on molecular structure was manifested by twisting of the leading helical hairpin α1-α2, accompanied by repositioning of the H-box and G-box, along with closure of the flexible loop connecting the two and occlusion of the ATP-binding site. Such conformational rearrangements of key functional subdomains in these mutants highlight the cooperative response of molecular structure involving dimerization and ATP binding and phosphorylation, as well as the binding site for the downstream response element AgrA. These appear to increase the threshold for agr activation via AIP-dependent autoinduction, thus reducing virulence and maintaining S. aureus in an agr-downregulated “colonization” mode. IMPORTANCE Virulence factor expression in Staphylococcus aureus is regulated via autoinducing peptide (AIP)-dependent activation of the sensor kinase AgrC, which forms an integral part of the agr quorum sensing system. In response to bound AIP, the cytoplasmic domain of AgrC (AgrC-cyt) undergoes conformational changes resulting in dimerization, autophosphorylation, and phosphotransfer to the response regulator AgrA. Naturally occurring mutations in AgrC-cyt are consistent with repositioning of key functional domains, impairing dimerization and restricting access to the ATP-binding pocket. Strains harboring specific AgrC-cyt mutations exhibit reduced AIP autoinduction efficiency and a timing-dependent attenuation of cytotoxicity which may confer a survival advantage during established infection by promoting colonization while restricting unnecessary overproduction of exotoxins.
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Silva KPT, Boedicker JQ. A neural network model predicts community-level signaling states in a diverse microbial community. PLoS Comput Biol 2019; 15:e1007166. [PMID: 31233492 PMCID: PMC6611639 DOI: 10.1371/journal.pcbi.1007166] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 07/05/2019] [Accepted: 06/06/2019] [Indexed: 11/19/2022] Open
Abstract
Signal crosstalk within biological communication networks is common, and such crosstalk can have unexpected consequences for decision making in heterogeneous communities of cells. Here we examined crosstalk within a bacterial community composed of five strains of Bacillus subtilis, with each strain producing a variant of the quorum sensing peptide ComX. In isolation, each strain produced one variant of the ComX signal to induce expression of genes associated with bacterial competence. When strains were combined, a mixture of ComX variants was produced resulting in variable levels of gene expression. To examine gene regulation in mixed communities, we implemented a neural network model. Experimental quantification of asymmetric crosstalk between pairs of strains parametrized the model, enabling the accurate prediction of activity within the full five-strain network. Unlike the single strain system in which quorum sensing activated upon exceeding a threshold concentration of the signal, crosstalk within the five-strain community resulted in multiple community-level quorum sensing states, each with a unique combination of quorum sensing activation among the five strains. Quorum sensing activity of the strains within the community was influenced by the combination and ratio of strains as well as community dynamics. The community-level signaling state was altered through an external signal perturbation, and the output state depended on the timing of the perturbation. Given the ubiquity of signal crosstalk in diverse microbial communities, the application of such neural network models will increase accuracy of predicting activity within microbial consortia and enable new strategies for control and design of bacterial signaling networks. Bacteria can communicate with each other using chemical signals to activate genetic expression in a process known as quorum sensing. Quorum sensing in bacteria is known to regulate a number collective behaviors in bacteria such as biofilm formation, antibiotic production and production of virulence factors which leads to bacterial infections. In a community, different species of bacteria can crosstalk using these signals, such that they regulate each other’s quorum sensing activation. Crosstalk can be either excitatory or inhibitory towards quorum sensing activation. Generally, in a bacterial community, it is not straightforward to understand how cells utilize mixtures of quorum sensing signals to regulate quorum sensing activation. To address this issue, we used a neural network approach in which we were able to predict patterns of quorum sensing activation in a diverse community of Bacillus subtilis cells producing five different signals and we observed that quorum sensing activation depended on signal concentration, species ratio and time sensitive external perturbations. Our findings can be useful in systematically controlling quorum sensing and potentially devising better strategies to fight bacterial infections.
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Affiliation(s)
- Kalinga Pavan T. Silva
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California, United States of America
| | - James Q. Boedicker
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California, United States of America
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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Silva KPT, Yusufaly TI, Chellamuthu P, Boedicker JQ. Disruption of microbial communication yields a two-dimensional percolation transition. Phys Rev E 2019; 99:042409. [PMID: 31108688 DOI: 10.1103/physreve.99.042409] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Indexed: 06/09/2023]
Abstract
Bacteria communicate with each other to coordinate macroscale behaviors including pathogenesis, biofilm formation, and antibiotic production. Empirical evidence suggests that bacteria are capable of communicating at length scales far exceeding the size of individual cells. Several mechanisms of signal interference have been observed in nature, and how interference influences macroscale activity within microbial populations is unclear. Here we examined the exchange of quorum sensing signals to coordinate microbial activity over long distances in the presence of a variable amount of interference through a neighboring signal-degrading strain. As the level of interference increased, communication over large distances was disrupted and at a critical amount of interference, large-scale communication was suppressed. We explored this transition in experiments and reaction-diffusion models, and confirmed that this transition is a two-dimensional percolation transition. These results demonstrate the utility of applying physical models to emergence in complex biological networks to probe robustness and universal quantitative features.
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Affiliation(s)
- Kalinga Pavan T Silva
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA
| | - Tahir I Yusufaly
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA
| | - Prithiviraj Chellamuthu
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA
| | - James Q Boedicker
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
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40
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Shah S, Gaikwad S, Nagar S, Kulshrestha S, Vaidya V, Nawani N, Pawar S. Biofilm inhibition and anti-quorum sensing activity of phytosynthesized silver nanoparticles against the nosocomial pathogen Pseudomonas aeruginosa. BIOFOULING 2019; 35:34-49. [PMID: 30727758 DOI: 10.1080/08927014.2018.1563686] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Quorum sensing (QS), the communication signaling network, regulates biofilm formation and several virulence factors in Pseudomonas aeruginosa PAO1, a nosocomial opportunistic pathogen. QS is considered to be a challenging target for compounds antagonistic to virulent factors. Biologically synthesized silver nanoparticles (AgNPs) are reported as anti-QS and anti-biofilm drugs against bacterial infections. The present study reports on the synthesis and characterization of Piper betle (Pb) mediated AgNPs (Pb-AgNPs). The anti-QS activity of Pb-AgNPs against Chromobacterium violaceum and the potential effect of Pb-AgNPs on QS-regulated phenotypes in PAO1 were studied. FTIR analysis exhibited that Pb-AgNPs had been capped by phytochemical constituents of Pb. Eugenol is one of the active phenolic phytochemicals in Pb leaves, therefore molecular docking of eugenol-conjugated AgNPs on QS regulator proteins (LasR, LasI and MvfR) was performed. Eugenol-conjugated AgNPs showed considerable binding interactions with QS-associated proteins. These results provide novel insights into the development of phytochemically conjugated nanoparticles as promising anti-infective candidates.
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Affiliation(s)
- Saloni Shah
- a Microbial Diversity Research Centre , Dr. D. Y. Patil Biotechnology and Bioinformatics Institute , Dr. D. Y. Patil Vidyapeeth , Pune , India
| | - Swapnil Gaikwad
- a Microbial Diversity Research Centre , Dr. D. Y. Patil Biotechnology and Bioinformatics Institute , Dr. D. Y. Patil Vidyapeeth , Pune , India
| | - Shuchi Nagar
- b Bioinformatics Research Laboratory , Dr. D. Y. Patil Biotechnology and Bioinformatics Institute , Dr. D. Y. Patil Vidyapeeth , Pune , India
| | - Shatavari Kulshrestha
- a Microbial Diversity Research Centre , Dr. D. Y. Patil Biotechnology and Bioinformatics Institute , Dr. D. Y. Patil Vidyapeeth , Pune , India
| | - Viniti Vaidya
- a Microbial Diversity Research Centre , Dr. D. Y. Patil Biotechnology and Bioinformatics Institute , Dr. D. Y. Patil Vidyapeeth , Pune , India
| | - Neelu Nawani
- a Microbial Diversity Research Centre , Dr. D. Y. Patil Biotechnology and Bioinformatics Institute , Dr. D. Y. Patil Vidyapeeth , Pune , India
| | - Sarika Pawar
- a Microbial Diversity Research Centre , Dr. D. Y. Patil Biotechnology and Bioinformatics Institute , Dr. D. Y. Patil Vidyapeeth , Pune , India
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Blöcher R, Rodarte Ramírez A, Castro-Escarpulli G, Curiel-Quesada E, Reyes-Arellano A. Design, Synthesis, and Evaluation of Alkyl-Quinoxalin-2(1 H)-One Derivatives as Anti- Quorum Sensing Molecules, Inhibiting Biofilm Formation in Aeromonas caviae Sch3. Molecules 2018; 23:molecules23123075. [PMID: 30477243 PMCID: PMC6321446 DOI: 10.3390/molecules23123075] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 11/18/2018] [Accepted: 11/20/2018] [Indexed: 01/05/2023] Open
Abstract
With the increasing antibiotic resistance of bacterial strains, alternative methods for infection control are in high demand. Quorum sensing (QS) is the bacterial communication system based on small molecules. QS is enables bacterial biofilm formation and pathogenic development. The interruption of QS has become a target for drug discovery, but remains in the early experimental phase. In this study, we synthesized a set of six compounds based on a scaffold (alkyl-quinoxalin-2(1H)-one), new in the anti-QS of Gram-negative bacteria Aeromonas caviae Sch3. By quantifying biofilm formation, we were able to monitor the effect of these compounds from concentrations of 1 to 100 µM. Significant reduction in biofilm formation was achieved by 3-hexylylquinoxalin-2(1H)-one (11), 3-hexylylquinoxalin-2(1H)-one-6-carboxylic acid (12), and 3-heptylylquinoxalin-2(1H)-one-6-carboxylic acid (14), ranging from 11% to 59% inhibition of the biofilm. This pilot study contributes to the development of anti-QS compounds to overcome the clinical challenge of resistant bacteria strains.
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Affiliation(s)
- René Blöcher
- Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional (ENCB-IPN), Departamento de Química Orgánica, Ciudad de México 11340, México.
| | - Ariel Rodarte Ramírez
- Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional (ENCB-IPN), Laboratorio de Investigación Clínica y Ambiental, Departamento de Microbiología, Ciudad de México 11340, México.
| | - Graciela Castro-Escarpulli
- Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional (ENCB-IPN), Laboratorio de Investigación Clínica y Ambiental, Departamento de Microbiología, Ciudad de México 11340, México.
| | - Everardo Curiel-Quesada
- Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional (ENCB-IPN), Departamento de Bioquímica, Ciudad de México 11340, México.
| | - Alicia Reyes-Arellano
- Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional (ENCB-IPN), Departamento de Química Orgánica, Ciudad de México 11340, México.
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Water-soluble cranberry extract inhibits Vibrio cholerae biofilm formation possibly through modulating the second messenger 3', 5' - Cyclic diguanylate level. PLoS One 2018; 13:e0207056. [PMID: 30403745 PMCID: PMC6221352 DOI: 10.1371/journal.pone.0207056] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 10/24/2018] [Indexed: 01/28/2023] Open
Abstract
Quorum sensing (QS) and nucleotide-based second messengers are vital signaling systems that regulate bacterial physiology in response to changing environments. Disrupting bacterial signal transduction is a promising direction to combat infectious diseases, and QS and the second messengers are undoubtedly potential targets. In Vibrio cholerae, both QS and the second messenger 3’, 5’—cyclic diguanylate (c-di-GMP) play a central role in controlling motility, motile-to-sessile life transition, and virulence. In this study, we found that water-soluble extract from the North American cranberry could significantly inhibit V. cholerae biofilm formation during the development/maturation stage by reducing the biofilm matrix production and secretion. The anti-biofilm effect by water-soluble cranberry extract was possibly through modulating the intracellular c-di-GMP level and was independent of QS and the QS master regulator HapR. Our results suggest an opportunity to explore more functional foods to fight stubborn infections through interference with the bacterial signaling systems.
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D'Angelo F, Baldelli V, Halliday N, Pantalone P, Polticelli F, Fiscarelli E, Williams P, Visca P, Leoni L, Rampioni G. Identification of FDA-Approved Drugs as Antivirulence Agents Targeting the pqs Quorum-Sensing System of Pseudomonas aeruginosa. Antimicrob Agents Chemother 2018; 62:e01296-18. [PMID: 30201815 PMCID: PMC6201120 DOI: 10.1128/aac.01296-18] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 09/01/2018] [Indexed: 12/11/2022] Open
Abstract
The long-term use of antibiotics has led to the emergence of multidrug-resistant bacteria. A promising strategy to combat bacterial infections aims at hampering their adaptability to the host environment without affecting growth. In this context, the intercellular communication system quorum sensing (QS), which controls virulence factor production and biofilm formation in diverse human pathogens, is considered an ideal target. Here, we describe the identification of new inhibitors of the pqs QS system of the human pathogen Pseudomonas aeruginosa by screening a library of 1,600 U.S. Food and Drug Administration-approved drugs. Phenotypic characterization of ad hoc engineered strains and in silico molecular docking demonstrated that the antifungal drugs clotrimazole and miconazole, as well as an antibacterial compound active against Gram-positive pathogens, clofoctol, inhibit the pqs system, probably by targeting the transcriptional regulator PqsR. The most active inhibitor, clofoctol, specifically inhibited the expression of pqs-controlled virulence traits in P. aeruginosa, such as pyocyanin production, swarming motility, biofilm formation, and expression of genes involved in siderophore production. Moreover, clofoctol protected Galleria mellonella larvae from P. aeruginosa infection and inhibited the pqs QS system in P. aeruginosa isolates from cystic fibrosis patients. Notably, clofoctol is already approved for clinical treatment of pulmonary infections caused by Gram-positive bacterial pathogens; hence, this drug has considerable clinical potential as an antivirulence agent for the treatment of P. aeruginosa lung infections.
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Affiliation(s)
| | | | - Nigel Halliday
- Centre for Biomolecular Sciences and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Paolo Pantalone
- Centre for Biomolecular Sciences and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Fabio Polticelli
- Department of Science, University Roma Tre, Rome, Italy
- National Institute of Nuclear Physics, Roma Tre Section, Rome, Italy
| | - Ersilia Fiscarelli
- Laboratory of Cystic Fibrosis Microbiology, Bambino Gesú Hospital, Rome, Italy
| | - Paul Williams
- Centre for Biomolecular Sciences and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Paolo Visca
- Department of Science, University Roma Tre, Rome, Italy
| | - Livia Leoni
- Department of Science, University Roma Tre, Rome, Italy
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Liu Y, Qin Q, Defoirdt T. Does quorum sensing interference affect the fitness of bacterial pathogens in the real world? Environ Microbiol 2018; 20:3918-3926. [DOI: 10.1111/1462-2920.14446] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/05/2018] [Accepted: 10/09/2018] [Indexed: 12/18/2022]
Affiliation(s)
- Yiying Liu
- College of Marine Sciences, South China Agricultural University; Guangzhou China
| | - Qiwei Qin
- College of Marine Sciences, South China Agricultural University; Guangzhou China
| | - Tom Defoirdt
- Center for Microbial Ecology and Technology (CMET); Ghent University; Ghent Belgium
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45
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Ilina P, Ma X, Sintim HO, Tammela P. Miniaturized whole-cell bacterial bioreporter assay for identification of quorum sensing interfering compounds. J Microbiol Methods 2018; 154:40-45. [PMID: 30300658 DOI: 10.1016/j.mimet.2018.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 10/05/2018] [Accepted: 10/05/2018] [Indexed: 11/19/2022]
Abstract
The continuing emergence and spread of antibiotic-resistant bacteria is worrisome and new strategies to curb bacterial infections are being sought. The interference of bacterial quorum sensing (QS) signaling has been suggested as a prospective antivirulence strategy. The AI-2 QS system is present in multiple bacterial species and has been shown to be correlated with pathogenicity. To facilitate the discovery of novel compounds interfering with AI-2 QS, we established a high-throughput setup of whole-cell bioreporter assay, which can be performed in either 96- or 384-well format. Agonistic or antagonistic activities of the test compounds against Escherichia coli LsrB-type AI-2 QS system are monitored by measuring the level of β-galactosidase expression. A control strain expressing β-galactosidase in quorum sensing-independent manner is included into the assay for false-positive detection.
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Affiliation(s)
- Polina Ilina
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Xiaochu Ma
- Institute for Drug Discovery, Department of Chemistry, Purdue University Center for Cancer Research, Purdue University, United States
| | - Herman O Sintim
- Institute for Drug Discovery, Department of Chemistry, Purdue University Center for Cancer Research, Purdue University, United States
| | - Päivi Tammela
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland.
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Colino CI, Millán CG, Lanao JM. Nanoparticles for Signaling in Biodiagnosis and Treatment of Infectious Diseases. Int J Mol Sci 2018; 19:E1627. [PMID: 29857492 PMCID: PMC6032068 DOI: 10.3390/ijms19061627] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/25/2018] [Accepted: 05/26/2018] [Indexed: 01/09/2023] Open
Abstract
Advances in nanoparticle-based systems constitute a promising research area with important implications for the treatment of bacterial infections, especially against multidrug resistant strains and bacterial biofilms. Nanosystems may be useful for the diagnosis and treatment of viral and fungal infections. Commercial diagnostic tests based on nanosystems are currently available. Different methodologies based on nanoparticles (NPs) have been developed to detect specific agents or to distinguish between Gram-positive and Gram-negative microorganisms. Also, biosensors based on nanoparticles have been applied in viral detection to improve available analytical techniques. Several point-of-care (POC) assays have been proposed that can offer results faster, easier and at lower cost than conventional techniques and can even be used in remote regions for viral diagnosis. Nanoparticles functionalized with specific molecules may modulate pharmacokinetic targeting recognition and increase anti-infective efficacy. Quorum sensing is a stimuli-response chemical communication process correlated with population density that bacteria use to regulate biofilm formation. Disabling it is an emerging approach for combating its pathogenicity. Natural or synthetic inhibitors may act as antibiofilm agents and be useful for treating multi-drug resistant bacteria. Nanostructured materials that interfere with signal molecules involved in biofilm growth have been developed for the control of infections associated with biofilm-associated infections.
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Affiliation(s)
- Clara I Colino
- Area of Pharmacy and Pharmaceutical Technology, Department of Pharmaceutical Sciences, University of Salamanca, 37007 Salamanca, Spain.
- The Institute for Biomedical Research of Salamanca, 37007 Salamanca, Spain.
| | - Carmen Gutiérrez Millán
- Area of Pharmacy and Pharmaceutical Technology, Department of Pharmaceutical Sciences, University of Salamanca, 37007 Salamanca, Spain.
- The Institute for Biomedical Research of Salamanca, 37007 Salamanca, Spain.
| | - José M Lanao
- Area of Pharmacy and Pharmaceutical Technology, Department of Pharmaceutical Sciences, University of Salamanca, 37007 Salamanca, Spain.
- The Institute for Biomedical Research of Salamanca, 37007 Salamanca, Spain.
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Fructose furoic acid ester: An effective quorum sensing inhibitor against uropathogenic Escherichia coli. Bioorg Chem 2018; 79:310-318. [PMID: 29800818 DOI: 10.1016/j.bioorg.2018.05.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 05/05/2018] [Accepted: 05/14/2018] [Indexed: 12/12/2022]
Abstract
Uropathogenic Escherichia coli (UPEC) are the most common cause of UTI, accounting for more than 90% infections in the normal and unobstructed urinary tracts. Multi-drug resistance (MDR) is an emerging threat to the mankind and hence, there is an urge to develop alternative therapies. Targeting quorum sensing (QS), a cell-cell communication process regulates various biofilm and virulence factors would be a most promising alternate which curbs the pathogenesis without killing the bacteria, unlike antibiotics. SdiA, a quorum regulator is well-known to control the behavioural changes of UPEC in establishing biofilm and virulence. Therefore, we have hypothesized that the SdiA-selective inhibitors derived from the plant, Melia dubia using the molecular docking would be a remarkable therapeutic candidate to down regulate the UPEC biofilm and virulence phenotypes. In this study, we have designed, synthesized and characterized the fructose-furoic acid ester by NMR and ESI-MS. In vitro studies revealed that the QSI-MD selectively inhibits UPEC adherence and confocal laser scanning microscopy (CLSM) analysis showed the effectiveness of QSI-MD to inhibit the UPEC biofilm. Genetic studies using qRT-PCR revealed the down-regulation of quorum sensing regulated genes (fimA, csgA, espA). Based on the findings, we could propose that the QSI-MD could possibly act through SdiA and show target-specific inhibition of biofilm and virulence. It is notable that more than 70 bacterial species execute their communication through the SdiA homologues (LuxIR system). Hence, the QSI-MD could be further developed as a broad-spectrum anti-infective drug.
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48
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Bodede O, Shaik S, Chenia H, Singh P, Moodley R. Quorum sensing inhibitory potential and in silico molecular docking of flavonoids and novel terpenoids from Senegalia nigrescens. JOURNAL OF ETHNOPHARMACOLOGY 2018; 216:134-146. [PMID: 29408657 DOI: 10.1016/j.jep.2018.01.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/19/2018] [Accepted: 01/26/2018] [Indexed: 06/07/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Senegalia nigrescens is used in traditional medicine for the treatment of dysentery and convulsions. AIMS OF THE STUDY This study was aimed at identifying bioactive compounds from S. nigrescens and carrying out in vitro and in silico anti-quorum sensing studies on the compounds. MATERIALS AND METHODS Extracts of S. nigrescens were chromatographed repeatedly. The isolated compounds were characterised using NMR spectroscopy and mass spectrometry. The anti-quorum sensing potential of S. nigrescens crude extracts and selected phytochemicals was quantified using Chromobacterium violaceum quorum sensing-controlled violacein inhibition assays. Qualitative modulation of quorum sensing activity and signal synthesis was investigated using agar diffusion double ring assays and C. violaceum. Molecular docking was conducted to explore the binding conformations of ent-kaurene diterpenes and flavonoids into the binding sites of quorum sensing regulator proteins, CviR and CviR'. RESULTS Phytochemical investigation of S. nigrescens resulted in the isolation of a new ent-kaurene diterpenoid (ent-kaur-15-en-18,20-diol) alongside ent-kaur-15-en-18-ol, being isolated for the first time from a plant species. Other compounds isolated included 30-hydroxylup-20(29)-en-3β-ol, 3β-hydroxy-20(29)-en-lupan-30-al, lupeol, stigmasterol, a long chain alcohol (tetracosan-1-ol) and three flavonoids (melanoxetin, quercetin and quercetin-3-O-methyl ether). Structures of isolated compounds were elucidated using different spectroscopic techniques including 1D and 2D NMR. Inhibition of violacein production was concentration-dependent, with 56.52% inhibition being obtained with 200 µg of quercetin-3-O-methyl ether, while 53.38% inhibition was obtained with 600 µg of quercetin. Agar diffusion double ring assays indicated CviI synthase/CviR receptor modulation by S. nigrescens phytochemicals, suggesting that quorum signal synthesis was down-regulated and/or targeting binding of signal to the receptor. The computed binding energy data suggested that the flavonoids had a stronger tendency to inhibit both CviR and CviR' with varying binding affinities. CONCLUSION S. nigrescens crude extracts together with the novel ent-kaurenoids and flavonoids demonstrated potential anti-quorum sensing activity. S. nigrescens may thus represent a source of anti-quorum sensing therapeutic candidates for the control of existing and emerging infectious diseases.
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Affiliation(s)
- Olusola Bodede
- School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
| | - Shakira Shaik
- School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
| | - Hafizah Chenia
- School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
| | - Parvesh Singh
- School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
| | - Roshila Moodley
- School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa.
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Antibiotic Hybrids: the Next Generation of Agents and Adjuvants against Gram-Negative Pathogens? Clin Microbiol Rev 2018. [PMID: 29540434 DOI: 10.1128/cmr.00077-17] [Citation(s) in RCA: 171] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The global incidence of drug-resistant Gram-negative bacillary infections has been increasing, and there is a dire need to develop novel strategies to overcome this problem. Intrinsic resistance in Gram-negative bacteria, such as their protective outer membrane and constitutively overexpressed efflux pumps, is a major survival weapon that renders them refractory to current antibiotics. Several potential avenues to overcome this problem have been at the heart of antibiotic drug discovery in the past few decades. We review some of these strategies, with emphasis on antibiotic hybrids either as stand-alone antibacterial agents or as adjuvants that potentiate a primary antibiotic in Gram-negative bacteria. Antibiotic hybrid is defined in this review as a synthetic construct of two or more pharmacophores belonging to an established agent known to elicit a desired antimicrobial effect. The concepts, advances, and challenges of antibiotic hybrids are elaborated in this article. Moreover, we discuss several antibiotic hybrids that were or are in clinical evaluation. Mechanistic insights into how tobramycin-based antibiotic hybrids are able to potentiate legacy antibiotics in multidrug-resistant Gram-negative bacilli are also highlighted. Antibiotic hybrids indeed have a promising future as a therapeutic strategy to overcome drug resistance in Gram-negative pathogens and/or expand the usefulness of our current antibiotic arsenal.
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50
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Rhodes NJ, Cruce CE, O'Donnell JN, Wunderink RG, Hauser AR. Resistance Trends and Treatment Options in Gram-Negative Ventilator-Associated Pneumonia. Curr Infect Dis Rep 2018; 20:3. [PMID: 29511909 DOI: 10.1007/s11908-018-0609-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW Hospital-acquired and ventilator-associated pneumonia (VAP) are frequent causes of infection among critically ill patients. VAP is the most common hospital-acquired bacterial infection among mechanically ventilated patients. Unfortunately, many of the nosocomial Gram-negative bacteria that cause VAP are increasingly difficult to treat. Additionally, the evolution and dissemination of multi- and pan-drug resistant strains leave clinicians with few treatment options. VAP patients represent a dynamic population at risk for antibiotic failure and under-dosing due to altered antibiotic pharmacokinetic parameters. Since few antibiotic agents have been approved within the last 15 years, and no new agents specifically targeting VAP have been approved to date, it is anticipated that this problem will worsen. Given the public health crisis posed by resistant Gram-negative bacteria, it is essential to establish a firm understanding of the current epidemiology of VAP, the changing trends in Gram-negative resistance in VAP, and the current issues in drug development for Gram-negative bacteria that cause VAP. RECENT FINDINGS Rapid identification technologies and phenotypic methods, new therapeutic strategies, and novel treatment paradigms have evolved in an attempt to improve treatment outcomes for VAP; however, clinical data supporting alternative treatment strategies and adjunctive therapies remain sparse. Importantly, new classes of antimicrobials, novel virulence factor inhibitors, and beta-lactam/beta-lactamase inhibitor combinations are currently in development. Conscientious stewardship of new and emerging therapeutic agents will be needed to ensure they remain effective well into the future.
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Affiliation(s)
- Nathaniel J Rhodes
- Department of Pharmacy Practice, Midwestern University, Chicago College of Pharmacy, 555 31st St., Downers Grove, IL, 60515, USA. .,Department of Pharmacy, Northwestern Memorial Hospital, Chicago, IL, USA.
| | - Caroline E Cruce
- Department of Pharmacy Practice, Midwestern University, Chicago College of Pharmacy, 555 31st St., Downers Grove, IL, 60515, USA.,Department of Pharmacy, Northwestern Memorial Hospital, Chicago, IL, USA
| | - J Nicholas O'Donnell
- Department of Pharmacy Practice, Albany College of Pharmacy and Health Sciences, Albany, NY, USA
| | - Richard G Wunderink
- Department of Internal Medicine, Division of Pulmonary Critical Care, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Alan R Hauser
- Department of Internal Medicine, Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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