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Liu DR, Yan QX, Zou ZB, Xie CL, Yang XW, Jia AQ. Cladosporium sphaerospermum extract inhibits quorum sensing associated virulence factors of Serratia marcescens. Biofilm 2023; 6:100146. [PMID: 37560185 PMCID: PMC10406620 DOI: 10.1016/j.bioflm.2023.100146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/30/2023] [Accepted: 07/31/2023] [Indexed: 08/11/2023] Open
Abstract
Serratia marcescens is now becoming a propensity for its highly antimicrobial-resistant clinical infections. Currently, it provides a novel strategy to prevent and control microbial infection by regulating S. marcescens quorum sensing (QS). Deep-sea-derived fungi are rich in QS bioactive constituents. In this work, the extracts from Cladosporium sphaerospermum SCSGAF0054 showed potent QS-related virulence factors and biofilm-inhibiting activities against S. marcescens NJ01. The swimming motility and multiple virulence factors such as prodigiosin, exopolysaccharide (EPS), lipase, protease and hemolysin were moderately inhibited by the extracts at varied concentrations. The confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM) images revealed that C. sphaerospermum extracts moderately arrested biofilm formation and cell viability. Further, real-time quantitative PCR (RT-qPCR) analysis revealed that expressions of genes associated with virulence factors, flhD, fimA, fimC, bsmA, bsmB, pigA, pigC, and shlA, were significantly down-regulated compared with control. In addition, the extracts combined with imipenem inhibited the QS system of S. marcescens NJ01, disrupted its preformed biofilm, released the intra-biofilm bacteria and killed the bacteria gradually. Therefore, the extracts combined with imipenem can partially restore bacterial drug sensitivity. These results suggest that the extracts from SCSGAF0054 effectively interfere with the QS system to treat S. marcescens infection alone or combining with classical antimicrobial drugs.
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Affiliation(s)
- Dan-Rui Liu
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou, 570228, China
| | - Qing-Xiang Yan
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Xiamen, 361005, China
| | - Zheng-Biao Zou
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Xiamen, 361005, China
| | - Chun-Lan Xie
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Xiamen, 361005, China
| | - Xian-Wen Yang
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, Xiamen, 361005, China
| | - Ai-Qun Jia
- The Central Lab, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, 570311, China
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Yehuda A, Malach E, Vanunu Ofri S, Slamti L, Kuo SH, Lau JZ, Oh MW, Adeoye J, Shlezinger N, Lereclus D, Lau GW, Hayouka Z. The quorum-sensing peptidic inhibitor rescues host immune system eradication: A novel infectivity mechanism. Proc Natl Acad Sci U S A 2023; 120:e2301045120. [PMID: 37607229 PMCID: PMC10469338 DOI: 10.1073/pnas.2301045120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 06/23/2023] [Indexed: 08/24/2023] Open
Abstract
Subverting the host immune system is a major task for any given pathogen to assure its survival and proliferation. For the opportunistic human pathogen Bacillus cereus (Bc), immune evasion enables the establishment of potent infections. In various species of the Bc group, the pleiotropic regulator PlcR and its cognate cell-cell signaling peptide PapR7 regulate virulence gene expression in response to fluctuations in population density, i.e., a quorum-sensing (QS) system. However, how QS exerts its effects during infections and whether PlcR confers the immune evading ability remain unclear. Herein, we report how interception of the QS communication in Bc obliterates the ability to affect the host immune system. Here, we designed a peptide-based QS inhibitor that suppresses PlcR-dependent virulence factor expression and attenuates Bc infectivity in mouse models. We demonstrate that the QS peptidic inhibitor blocks host immune system-mediated eradication by reducing the expression of PlcR-regulated major toxins similarly to the profile that was observed for isogenic strains. Our findings provide evidence that Bc infectivity is regulated by QS circuit-mediated destruction of host immunity, thus reveal a interesting strategy to limit Bc virulence and enhance host defense. This peptidic quorum-quenching agent constitutes a readily accessible chemical tool for studying how other pathogen QS systems modulate host immunity and forms a basis for development of anti-infective therapeutics.
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Affiliation(s)
- Avishag Yehuda
- Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agricultural, Food & Environment, The Hebrew University of Jerusalem, Rehovot76100, Israel
| | - Einav Malach
- Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agricultural, Food & Environment, The Hebrew University of Jerusalem, Rehovot76100, Israel
| | - Shahar Vanunu Ofri
- Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agricultural, Food & Environment, The Hebrew University of Jerusalem, Rehovot76100, Israel
| | - Leyla Slamti
- Unité Micalis, Domaine de La Minière, Unité Mixte de Recherche 1319, Institut National de la Recherche Agronomique, 78280Guyancourt, France
| | - Shanny Hsuan Kuo
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL61802
| | - Jonathan Z. Lau
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL61802
| | - Myung Whan Oh
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL61802
| | - John Adeoye
- Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agricultural, Food & Environment, The Hebrew University of Jerusalem, Rehovot76100, Israel
| | - Neta Shlezinger
- Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agricultural, Food & Environment, The Hebrew University of Jerusalem, Rehovot76100, Israel
| | - Didier Lereclus
- Unité Micalis, Domaine de La Minière, Unité Mixte de Recherche 1319, Institut National de la Recherche Agronomique, 78280Guyancourt, France
| | - Gee W. Lau
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL61802
| | - Zvi Hayouka
- Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agricultural, Food & Environment, The Hebrew University of Jerusalem, Rehovot76100, Israel
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Favero F, Tolentino TA, Fernandes V, Treptow W, Pereira AL, Lira Machado AH. α-Alkylidene δ-lactones inhibit quorum sensing phenotypes in Chromobacterium strain CV026 showing interaction with the CviR receptor. RSC Adv 2023; 13:18045-18057. [PMID: 37323447 PMCID: PMC10267776 DOI: 10.1039/d3ra01975f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 06/07/2023] [Indexed: 06/17/2023] Open
Abstract
Disruption of bacterial quorum sensing (QS) is presented as a promising strategy to overcome clinically relevant and phytopathogenic bacteria. This work presents α-alkylidene δ-lactones as new chemical scaffolds that inhibit the biosynthesis of violacein in the biosensor strain Chromobacterium CV026. Three molecules displayed higher than 50% violacein reduction when tested at concentrations lower than 625 µM. The most active α-alkylidene δ-lactone inhibited the hydrolysis of chitin concomitantly with the inhibition of violacein production in CV026, suggesting the disruption of its QS machinery. Further, RT-qPCR and competition experiments showed this molecule to be a transcriptional inhibitor of the QS-regulated operon vioABCDE. Docking calculations suggested a good correlation between binding affinity energies and inhibition effects, with all molecules positioned within the CviR autoinducer-binding domain (AIBD). The most active lactone yielded the best binding affinity energy, most probably due to its unprecedented binding with the AIBD. Our results show α-alkylidene δ-lactones as promising chemical scaffolds for the development of new QS inhibitors affecting LuxR/LuxI-systems.
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Affiliation(s)
- Fernanda Favero
- Instituto de Química, Universidade de Brasília, Campus Universitário Darcy Ribeiro Asa Norte Brasília DF 70910-900 Brazil
- Campus of Ceilândia, University of Brasília, Centro Metropolitano Conjunto A, Ceilândia Sul Brasília DF 72220-275 Brazil
| | - Terezinha Alves Tolentino
- Instituto de Química, Universidade de Brasília, Campus Universitário Darcy Ribeiro Asa Norte Brasília DF 70910-900 Brazil
| | - Vinicius Fernandes
- Laboratório de Biologia Teórica e Computacional, Departamento de Biologia Celular, Universidade de Brasília, Campus Universitário Darcy Ribeiro Asa Norte Brasília DF 70910-900 Brazil
| | - Werner Treptow
- Laboratório de Biologia Teórica e Computacional, Departamento de Biologia Celular, Universidade de Brasília, Campus Universitário Darcy Ribeiro Asa Norte Brasília DF 70910-900 Brazil
| | - Alex Leite Pereira
- Campus of Ceilândia, University of Brasília, Centro Metropolitano Conjunto A, Ceilândia Sul Brasília DF 72220-275 Brazil
| | - Angelo Henrique Lira Machado
- Instituto de Química, Universidade de Brasília, Campus Universitário Darcy Ribeiro Asa Norte Brasília DF 70910-900 Brazil
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Ahmed AA, A. Salih F, Yousef M. Rhus coriaria extracts inhibit quorum sensing-related virulence and biofilm production in drug-resistant Pseudomonas aeruginosa recovered from burn wounds. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2022; 25:1349-1356. [PMID: 36474566 PMCID: PMC9699946 DOI: 10.22038/ijbms.2022.66085.14527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/20/2022] [Indexed: 01/25/2023]
Abstract
OBJECTIVES Numerous studies have confirmed sumac's ability to inhibit pathogens and even eradicate chronic drug-resistant infections. Current research was conducted to demonstrate the action of various sumac extracts at sub-inhibitory concentrations in modulating pathogen-related characteristics instead of killing them. MATERIALS AND METHODS The influence of sumac extracts on the quorum sensing dependent virulence of multidrug-resistant isolates of Pseudomonas aeruginosa recovered from burn wounds was considered by detecting the effect on biofilm development, various virulence factors, and expression of bacterial exotoxin A and quorum sensing related genes. RESULTS Experiments to characterize and measure sumac extract's impact on the P. aeruginosa growth, biofilm, exoproteases, pyocyanin, motility, and the quorum sensing networks revealed that all studied characteristics were reduced by concentrations below inhibition without affecting bacterial growth. Furthermore, the expression of exotoxin A, rhl, and las glucons was declined or even inhibited by lower levels of sumac fruit fractions. CONCLUSION The findings revealed that sumac fights infections either by its inhibitory effect on the bacterial cells or by reducing bacterial signaling and virulence by disruption of the bacterial signal system.
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Affiliation(s)
- Akhter A Ahmed
- Department of Biology, Salahaddin University Erbil, Erbil, Iraq,Corresponding author: Akhter A Ahmed. Department of Biology, Salahaddin University- Erbil, Erbil, Iraq.
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Cavalu S, Elbaramawi SS, Eissa AG, Radwan MF, S. Ibrahim T, Khafagy ES, Lopes BS, Ali MAM, Hegazy WAH, Elfaky MA. Characterization of the Anti-Biofilm and Anti-Quorum Sensing Activities of the β-Adrenoreceptor Antagonist Atenolol against Gram-Negative Bacterial Pathogens. Int J Mol Sci 2022; 23:13088. [PMID: 36361877 PMCID: PMC9656717 DOI: 10.3390/ijms232113088] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 10/18/2022] [Accepted: 10/25/2022] [Indexed: 08/10/2023] Open
Abstract
The development of bacterial resistance to antibiotics is an increasing public health issue that worsens with the formation of biofilms. Quorum sensing (QS) orchestrates the bacterial virulence and controls the formation of biofilm. Targeting bacterial virulence is promising approach to overcome the resistance increment to antibiotics. In a previous detailed in silico study, the anti-QS activities of twenty-two β-adrenoreceptor blockers were screened supposing atenolol as a promising candidate. The current study aims to evaluate the anti-QS, anti-biofilm and anti-virulence activities of the β-adrenoreceptor blocker atenolol against Gram-negative bacteria Serratia marcescens, Pseudomonas aeruginosa, and Proteus mirabilis. An in silico study was conducted to evaluate the binding affinity of atenolol to S. marcescens SmaR QS receptor, P. aeruginosa QscR QS receptor, and P. mirabilis MrpH adhesin. The atenolol anti-virulence activity was evaluated against the tested strains in vitro and in vivo. The present finding shows considerable ability of atenolol to compete with QS proteins and significantly downregulated the expression of QS- and virulence-encoding genes. Atenolol showed significant reduction in the tested bacterial biofilm formation, virulence enzyme production, and motility. Furthermore, atenolol significantly diminished the bacterial capacity for killing and protected mice. In conclusion, atenolol has potential anti-QS and anti-virulence activities against S. marcescens, P. aeruginosa, and P. mirabilis and can be used as an adjuvant in treatment of aggressive bacterial infections.
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Affiliation(s)
- Simona Cavalu
- Faculty of Medicine and Pharmacy, University of Oradea, P-ta 1 Decembrie 10, 410087 Oradea, Romania
| | - Samar S. Elbaramawi
- Medicinal Chemistry Department, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
| | - Ahmed G. Eissa
- Medicinal Chemistry Department, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
| | - Mohamed F. Radwan
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Tarek S. Ibrahim
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - El-Sayed Khafagy
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-kharj 11942, Saudi Arabia
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt
| | - Bruno Silvester Lopes
- School of Health and Life Sciences, Teesside University, Middlesbrough TS1 3BA, UK
- National Horizons Centre, Teesside University, Darlington DL1 1HG, UK
| | - Mohamed A. M. Ali
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University, Riyadh 11432, Saudi Arabia
- Department of Biochemistry, Faculty of Science, Ain Shams University, Abbassia, Cairo 11566, Egypt
| | - Wael A. H. Hegazy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
- Pharmacy Program, Department of Pharmaceutical Sciences, Oman College of Health Sciences, Muscat 113, Oman
| | - Mahmoud A. Elfaky
- Department of Natural Products, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Centre for Artificial Intelligence in Precision Medicines, King Abdulaziz University, Jeddah 21589, Saudi Arabia
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6
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Recent Advance in Small Molecules Targeting RhlR of Pseudomonas aeruginosa. Antibiotics (Basel) 2022; 11:antibiotics11020274. [PMID: 35203876 PMCID: PMC8868144 DOI: 10.3390/antibiotics11020274] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 12/02/2022] Open
Abstract
Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic gram-negative pathogen that can cause various infections, particularly in patients with compromised host defenses. P. aeruginosa forms biofilms and produces virulence factors through quorum sensing (QS) network, resulting in resistance to antibiotics. RhlI/RhlR, one of key QS systems in P. aeruginosa, is considered an attractive target for inhibiting biofilm formation and attenuating virulence factors. Several recent studies examined small molecules targeting the RhlI/RhlR system and their in vitro and in vivo biological activities. In this review, RhlR-targeted modulators, including agonists and antagonists, are discussed with particular focus on structure-activity relationship studies and outlook for next-generation anti-biofilm agents.
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Aflakian F, Rad M, Hashemitabar G, Lagzian M, Ramezani M. Design and assessment of novel synthetic peptides to inhibit quorum sensing-dependent biofilm formation in Pseudomonas aeruginosa. BIOFOULING 2022; 38:131-146. [PMID: 35067121 DOI: 10.1080/08927014.2022.2028280] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 01/01/2022] [Accepted: 01/07/2022] [Indexed: 06/14/2023]
Abstract
Pseudomonas aeruginosa is one of the most common biofilm-producing bacteria, often leading to long-term and chronic infections. The LasR regulator protein acts as the central regulator of the quorum sensing (QS) system and coordinates the expression of some virulence and biofilm genes. In this study, novel peptides (WSF, FASK, YDVD) were designed for binding to the domain of the transcriptional activator of the LasR protein and interfere with LasR in the QS system of P. aeruginosa. The effects of these peptides on biofilm production, expression of biofilm-related genes (AlgC, PslA, PelA), and growth of planktonic P. aeruginosa were investigated. All three peptides inhibited the growth of P. aeruginosa planktonic cells at 1600 µg ml-1 and exhibited anti-biofilm effects at sub-inhibitory concentrations (800 µg ml-1). Measurements of the mRNA levels of biofilm-related genes at sub-inhibitory concentrations of the designed peptides showed a significant decrease.
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Affiliation(s)
- Fatemeh Aflakian
- Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Mehrnaz Rad
- Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Gholamreza Hashemitabar
- Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Milad Lagzian
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran
| | - Mohammad Ramezani
- Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
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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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Vetrivel A, Natchimuthu S, Subramanian V, Murugesan R. High-Throughput Virtual Screening for a New Class of Antagonist Targeting LasR of Pseudomonas aeruginosa. ACS OMEGA 2021; 6:18314-18324. [PMID: 34308062 PMCID: PMC8296597 DOI: 10.1021/acsomega.1c02191] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 06/16/2021] [Indexed: 05/28/2023]
Abstract
Pseudomonas aeruginosa, an opportunistic human pathogen, causes fatal effects in patients with cystic fibrosis and immunocompromised individuals and leads to around 1000 deaths annually. The quorum sensing mechanism of P. aeruginosa plays a major role in promoting biofilm formation and expression of virulent genes. Hence, quorum sensing inhibition is a promising novel approach to treat these bacterial infections as these organisms show a wide range of antibiotic resistance. Among the interconnected quorum sensing network of P. aeruginosa, targeting the las system is of increased interest as its principal receptor protein LasR is the earliest activated gene. It is also shown to be involved in the regulation of other virulence-associated genes. In this study, we have applied high-throughput virtual screening, an in silico computational method to identify a new class of LasR inhibitors that could serve as potent antagonists to treat P. aeruginosa-associated infections. Three-tire structure-based virtual screening was performed on the Schrödinger small molecule database, which resulted in 12 top hit compounds with docking scores lesser than -11.0 kcal/mol. Three of these best-scored compounds CACPD2011a-0001928786 (C1), CACPD2011a-0001927437 (C2), and CACPD2011a-0000896051 (C3) were further analyzed. The binding free energies of these compounds in complex with the target protein LasR (3IX4) were evaluated, and the pharmacokinetic properties were determined. The stability of the docked complexes was assessed by running a molecular dynamics simulation for 100 ns. Molecular dynamics simulation analysis revealed that all three compounds were found to be in stable contact with the protein over the entire simulation period. The antagonistic effect of these compounds was validated using the LasR reporter gene assay in the presence of acyl homoserine lactone. Significant reduction in the β-galactosidase enzyme activity was achieved at 100 nM concentration for all three compounds pursued. Hence, the present study provides strong evidence that these three compounds could serve as quorum sensing inhibitors of P. aeruginosa LasR protein and can be a probable candidate to treat Pseudomonas-associated infections.
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Affiliation(s)
- Aishwarya Vetrivel
- Department
of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for
Women, Coimbatore 641043, Tamil Nadu, India
| | - Santhi Natchimuthu
- Department
of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for
Women, Coimbatore 641043, Tamil Nadu, India
| | | | - Rajeswari Murugesan
- Department
of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for
Women, Coimbatore 641043, Tamil Nadu, India
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10
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Aldawsari MF, Khafagy ES, Saqr AA, Alalaiwe A, Abbas HA, Shaldam MA, Hegazy WAH, Goda RM. Tackling Virulence of Pseudomonas aeruginosa by the Natural Furanone Sotolon. Antibiotics (Basel) 2021; 10:antibiotics10070871. [PMID: 34356792 PMCID: PMC8300740 DOI: 10.3390/antibiotics10070871] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 07/13/2021] [Accepted: 07/15/2021] [Indexed: 02/07/2023] Open
Abstract
The bacterial resistance development due to the incessant administration of antibiotics has led to difficulty in their treatment. Natural adjuvant compounds can be co-administered to hinder the pathogenesis of resistant bacteria. Sotolon is the prevailing aromatic compound that gives fenugreek its typical smell. In the current work, the anti-virulence activities of sotolon on Pseudomonas aeruginosa have been evaluated. P. aeruginosa has been treated with sotolon at sub-minimum inhibitory concentration (MIC), and production of biofilm and other virulence factors were assessed. Moreover, the anti-quorum sensing (QS) activity of sotolon was in-silico evaluated by evaluating the affinity of sotolon to bind to QS receptors, and the expression of QS genes was measured in the presence of sotolon sub-MIC. Furthermore, the sotolon in-vivo capability to protect mice against P. aeruginosa was assessed. Significantly, sotolon decreased the production of bacterial biofilm and virulence factors, the expression of QS genes, and protected mice from P. aeruginosa. Conclusively, the plant natural substance sotolon attenuated the pathogenicity of P. aeruginosa, locating it as a plausible potential therapeutic agent for the treatment of its infections. Sotolon can be used in the treatment of bacterial infections as an alternative or adjuvant to antibiotics to combat their high resistance to antibiotics.
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Affiliation(s)
- Mohammed F. Aldawsari
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-kharj 11942, Saudi Arabia; (M.F.A.); (A.A.S.); (A.A.)
| | - El-Sayed Khafagy
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-kharj 11942, Saudi Arabia; (M.F.A.); (A.A.S.); (A.A.)
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt
- Correspondence: ; Tel.: +966-533-564-286
| | - Ahmed Al Saqr
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-kharj 11942, Saudi Arabia; (M.F.A.); (A.A.S.); (A.A.)
| | - Ahmed Alalaiwe
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-kharj 11942, Saudi Arabia; (M.F.A.); (A.A.S.); (A.A.)
| | - Hisham A. Abbas
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt; (H.A.A.); (W.A.H.H.)
| | - Moataz A. Shaldam
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kafrelsheikh University, Kafr El-Sheikh 33511, Egypt;
| | - Wael A. H. Hegazy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt; (H.A.A.); (W.A.H.H.)
| | - Reham M. Goda
- Department of Microbiology and Biotechnology, Faculty of Pharmacy, Delta University for Science and Biotechnology, Gamasa 35712, Egypt;
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Stevendaal MHME, Hest JCM, Mason AF. Functional Interactions Between Bottom‐Up Synthetic Cells and Living Matter for Biomedical Applications. CHEMSYSTEMSCHEM 2021. [DOI: 10.1002/syst.202100009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Marleen H. M. E. Stevendaal
- Institute for Complex Molecular Systems Eindhoven University of Technology P.O. Box 513 (STO 3.41) 5600MB Eindhoven (The Netherlands
| | - Jan C. M. Hest
- Institute for Complex Molecular Systems Eindhoven University of Technology P.O. Box 513 (STO 3.41) 5600MB Eindhoven (The Netherlands
| | - Alexander F. Mason
- Institute for Complex Molecular Systems Eindhoven University of Technology P.O. Box 513 (STO 3.41) 5600MB Eindhoven (The Netherlands
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12
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Wullich SC, Wijma HJ, Janssen DB, Fetzner S. Stabilizing AqdC, a Pseudomonas Quinolone Signal-Cleaving Dioxygenase from Mycobacteria, by FRESCO-Based Protein Engineering. Chembiochem 2021; 22:733-742. [PMID: 33058333 PMCID: PMC7894191 DOI: 10.1002/cbic.202000641] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/13/2020] [Indexed: 12/11/2022]
Abstract
The mycobacterial PQS dioxygenase AqdC, a cofactor-less protein with an α/β-hydrolase fold, inactivates the virulence-associated quorum-sensing signal molecule 2-heptyl-3-hydroxy-4(1H)-quinolone (PQS) produced by the opportunistic pathogen Pseudomonas aeruginosa and is therefore a potential anti-virulence tool. We have used computational library design to predict stabilizing amino acid replacements in AqdC. While 57 out of 91 tested single substitutions throughout the protein led to stabilization, as judged by increases in T app m of >2 °C, they all impaired catalytic activity. Combining substitutions, the proteins AqdC-G40K-A134L-G220D-Y238W and AqdC-G40K-G220D-Y238W showed extended half-lives and the best trade-off between stability and activity, with increases in T app m of 11.8 and 6.1 °C and relative activities of 22 and 72 %, respectively, compared to AqdC. Molecular dynamics simulations and principal component analysis suggested that stabilized proteins are less flexible than AqdC, and the loss of catalytic activity likely correlates with an inability to effectively open the entrance to the active site.
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Affiliation(s)
- Sandra C. Wullich
- Institut für Molekulare Mikrobiologie und BiotechnologieWWU MünsterCorrensstraße 348149 MünsterGermany
| | - Hein J. Wijma
- Department of Biochemistry Groningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenNijenborgh 49747 AGGroningen (TheNetherlands
| | - Dick B. Janssen
- Department of Biochemistry Groningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenNijenborgh 49747 AGGroningen (TheNetherlands
| | - Susanne Fetzner
- Institut für Molekulare Mikrobiologie und BiotechnologieWWU MünsterCorrensstraße 348149 MünsterGermany
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13
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van Galen C, Barnard DT, Stanley RJ. Stark Spectroscopy of Lumichrome: A Possible Candidate for Stand-Off Detection of Bacterial Quorum Sensing. J Phys Chem B 2020; 124:11835-11842. [PMID: 33325706 PMCID: PMC8714027 DOI: 10.1021/acs.jpcb.0c09498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Lumichrome (7,8-dimethylalloxazine, LC) is a natural photodegradation product and catabolite of flavin coenzymes. Although not a coenzyme itself, LC is used for biosignaling in plants and single-celled organisms, including quorum sensing in the formation of biofilms. The noninvasive detection of in vivo lumichrome would be useful for monitoring this signaling event. For molecules that undergo significant charge redistribution upon light excitation (e.g., intramolecular charge transfer), there are optical detection methods (e.g., second-harmonic generation) that would be well suited to this task. Here, we have used Stark spectroscopy to measure the extent and direction of charge redistribution in photoexcited LC. Stark and low-temperature absorption spectra were obtained at 77 K on LC in ethanol glasses and analyzed using the Liptay analysis to obtain the difference dipole moments and polarizabilities. These data were complemented by a computational analysis of the excited states using density functional theory (DFT) at the TD-B3LYP/6-311+G(2d,p) level of theory.
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Affiliation(s)
- Cornelius van Galen
- Department of Chemistry, Temple University, 250B Beury Hall, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - David T Barnard
- Department of Chemistry, Temple University, 250B Beury Hall, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Robert J Stanley
- Department of Chemistry, Temple University, 250B Beury Hall, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
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14
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Ziegler EW, Brown AB, Nesnas N, Chouinard CD, Mehta AK, Palmer AG. β-Cyclodextrin Encapsulation of Synthetic AHLs: Drug Delivery Implications and Quorum-Quenching Exploits. Chembiochem 2020; 22:1292-1301. [PMID: 33238068 DOI: 10.1002/cbic.202000773] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 11/23/2020] [Indexed: 12/22/2022]
Abstract
Many bacteria, such as Pseudomonas aeruginosa, regulate phenotypic switching in a population density-dependent manner through a phenomenon known as quorum sensing (QS). For Gram-negative bacteria, QS relies on the synthesis, transmission, and perception of low-molecular-weight signal molecules that are predominantly N-acyl-l-homoserine lactones (AHLs). Efforts to disrupt AHL-mediated QS have largely focused on the development of synthetic AHL analogues (SAHLAs) that are structurally similar to native AHLs. However, like AHLs, these molecules tend to be hydrophobic and are poorly soluble under aqueous conditions. Water-soluble macrocycles, such as cyclodextrins (CDs), that encapsulate hydrophobic guests have long been used by both the agricultural and pharmaceutical industries to overcome the solubility issues associated with hydrophobic compounds of interest. Conveniently, CDs have also demonstrated anti-AHL-mediated QS effects. Here, using fluorescence spectroscopy, NMR spectrometry, and mass spectrometry, we evaluate the affinity of SAHLAs, as well as their hydrolysis products, for β-CD inclusion. We also evaluated the ability of these complexes to inhibit wild-type P. aeruginosa virulence in a Caenorhabditis elegans host infection study, for the first time. Our efforts confirm the potential of β-CDs for the improved delivery of SAHLAs at the host/microbial interface, expanding the utility of this approach as a strategy for probing and controlling QS.
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Affiliation(s)
- Eric W Ziegler
- Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, 150W. University Boulevard, Melbourne, FL 32901, USA
| | - Alan B Brown
- Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, 150W. University Boulevard, Melbourne, FL 32901, USA
| | - Nasri Nesnas
- Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, 150W. University Boulevard, Melbourne, FL 32901, USA
| | - Christopher D Chouinard
- Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, 150W. University Boulevard, Melbourne, FL 32901, USA
| | - Anil K Mehta
- National High Magnetic Field Laboratory, McKnight Brain Institute, University of Florida, 1149 Newell Drive, Gainesville, FL 32610, USA
| | - Andrew G Palmer
- Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, 150W. University Boulevard, Melbourne, FL 32901, USA.,Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology, 150W. University Boulevard, Melbourne, FL 32901, USA
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15
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Shannon B, Zamora-Chimal CG, Postiglione L, Salzano D, Grierson CS, Marucci L, Savery NJ, di Bernardo M. In Vivo Feedback Control of an Antithetic Molecular-Titration Motif in Escherichia coli Using Microfluidics. ACS Synth Biol 2020; 9:2617-2624. [PMID: 32966743 DOI: 10.1021/acssynbio.0c00105] [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: 11/28/2022]
Abstract
We study both in silico and in vivo the real-time feedback control of a molecular titration motif that has been earmarked as a fundamental component of antithetic and multicellular feedback control schemes in E. coli. We show that an external feedback control strategy can successfully regulate the average fluorescence output of a bacterial cell population to a desired constant level in real-time. We also provide in silico evidence that the same strategy can be used to track a time-varying reference signal where the set-point is switched to a different value halfway through the experiment. We use the experimental data to refine and parametrize an in silico model of the motif that can be used as an error computation module in future embedded or multicellular control experiments.
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Affiliation(s)
- Barbara Shannon
- DNA-Protein Interactions Unit, School of Biochemistry, University of Bristol, Bristol BS8 1TD, U.K
- BrisSynBio, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, U.K
| | - Criseida G. Zamora-Chimal
- Department of Engineering Mathematics, University of Bristol, Bristol BS8 1UB, U.K
- BrisSynBio, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, U.K
| | - Lorena Postiglione
- Department of Engineering Mathematics, University of Bristol, Bristol BS8 1UB, U.K
| | - Davide Salzano
- Department of Electrical Engineering and Information Technology, University of Naples Federico II, 80125 Naples, Italy
| | - Claire S. Grierson
- School of Biological Sciences, University of Bristol, Bristol BS8 1UH, U.K
- BrisSynBio, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, U.K
| | - Lucia Marucci
- Department of Engineering Mathematics, University of Bristol, Bristol BS8 1UB, U.K
- BrisSynBio, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, U.K
| | - Nigel J. Savery
- DNA-Protein Interactions Unit, School of Biochemistry, University of Bristol, Bristol BS8 1TD, U.K
- BrisSynBio, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, U.K
| | - Mario di Bernardo
- Department of Engineering Mathematics, University of Bristol, Bristol BS8 1UB, U.K
- Department of Electrical Engineering and Information Technology, University of Naples Federico II, 80125 Naples, Italy
- BrisSynBio, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, U.K
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Abdel-Rhman SH, Rizk DE, Abdelmegeed ES. Effect of Sub-Minimum Inhibitory Concentrations of Tyrosol and EDTA on Quorum Sensing and Virulence of Pseudomonas aeruginosa. Infect Drug Resist 2020; 13:3501-3511. [PMID: 33116669 PMCID: PMC7550211 DOI: 10.2147/idr.s264805] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 09/11/2020] [Indexed: 02/06/2023] Open
Abstract
Introduction Pseudomonas aeruginosa is considered a dangerous pathogen, as it causes many human diseases, besides that it is resistant to almost all types of antibacterial agents. So, new strategies to overcome P. aeruginosa infection have evolved to attenuate its virulence factors and inhibit its quorum-sensing (QS) activity. Purpose This study investigated the effect of tyrosol and EDTA as anti-quorum-sensing and antivirulence agents against P. aeruginosa PAO1. Methods Anti-quorum activity of sub-minimum inhibitory concentrations (sub-MICs) of tyrosol and EDTA was tested using Chromobacterium violaceum (CV 12,472) biosensor bioassay. Miller assay was used to assess the inhibition of QS signal molecules by β-galactosidase activity determination. Also, their effects on the production of protease, lipase, lecithinase, and motility were tested. The inhibitory effects of these molecules on QS regulatory genes and exotoxins genes expression were evaluated by real-time PCR. Results Tyrosol and EDTA at sub-MICs inhibited the production of violacein pigment. Both compounds inhibited QS molecules production and their associated virulence factors (protease, lipase, lecithinase, and motility) (P≤ 0.05). Besides, the expression levels of QS regulatory genes (lasI, lasR, rhƖI, rhIR, pqsA, and pqsR) and exotoxins genes (exoS and exoY) were significantly reduced (P≤ 0.05). Conclusion Both tyrosol and EDTA can be used to fight P. aeruginosa infection as anti-quorum-sensing and antivirulence agents at their sub-MICs.
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Affiliation(s)
- Shaymaa H Abdel-Rhman
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt.,Department of Pharmaceutics and Pharmaceutical Biotechnology, Faculty of Pharmacy, Taibah University, AlMadinah Al Munawwarah, Saudi Arabia
| | - Dina E Rizk
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Eman S Abdelmegeed
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
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17
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Chbib C. Impact of the structure-activity relationship of AHL analogues on quorum sensing in Gram-negative bacteria. Bioorg Med Chem 2019; 28:115282. [PMID: 31918952 DOI: 10.1016/j.bmc.2019.115282] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/05/2019] [Accepted: 12/18/2019] [Indexed: 01/12/2023]
Abstract
With the emergence of microbial resistance pathogens, recent research aims at studying new mechanisms of action of antibiotics. This review discusses the mechanisms and types of quorum sensing (QS) inhibitors in Gram negative bacteria. It illustrates all published data available in literature pertaining to novel compounds that showed activity against different targets in the quorum sensing pathways in Gram negative bacteria. A systemic overview has been conducted by searching PubMed, Medline, and the Cochrane Library and data extraction of all quorum sensing inhibitors with their mechanisms of action have been collected. This review will focus on signaling autoinducer AI-1 in Gram negative bacteria. The biological activity of the antagonists is mainly reported as IC50 (the concentration of an inhibitor where the response is reduced by half).
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Affiliation(s)
- Christiane Chbib
- College of Pharmacy, Larkin University, 18301 North Miami Ave, Miami, FL 33169, United States.
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18
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Potent modulation of the CepR quorum sensing receptor and virulence in a Burkholderia cepacia complex member using non-native lactone ligands. Sci Rep 2019; 9:13449. [PMID: 31530834 PMCID: PMC6748986 DOI: 10.1038/s41598-019-49693-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 08/29/2019] [Indexed: 12/13/2022] Open
Abstract
The Burkholderia cepacia complex (Bcc) is a family of closely related bacterial pathogens that are the causative agent of deadly human infections. Virulence in Bcc species has been shown to be controlled by the CepI/CepR quorum sensing (QS) system, which is mediated by an N-acyl L-homoserine lactone (AHL) signal (C8-AHL) and its cognate LuxR-type receptor (CepR). Chemical strategies to block QS in Bcc members would represent an approach to intercept this bacterial communication process and further delineate its role in infection. In the current study, we sought to identify non-native AHLs capable of agonizing or antagonizing CepR, and thereby QS, in a Bcc member. We screened a library of AHL analogs in cell-based reporters for CepR, and identified numerous highly potent CepR agonists and antagonists. These compounds remain active in a Bcc member, B. multivorans, with one agonist 250-fold more potent than the native ligand C8-AHL, and can affect QS-controlled motility. Further, the CepR antagonists prolong C. elegans survival in an infection model. These AHL analogs are the first reported non-native molecules that both directly modulate CepR and impact QS-controlled phenotypes in a Bcc member, and represent valuable chemical tools to assess the role of QS in Bcc infections.
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19
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Srinivasarao S, Nandikolla A, Nizalapur S, Yu TT, Pulya S, Ghosh B, Murugesan S, Kumar N, Chandra Sekhar KVG. Design, synthesis and biological evaluation of 1,2,3-triazole based 2-aminobenzimidazoles as novel inhibitors of LasR dependent quorum sensing in Pseudomonas aeruginosa. RSC Adv 2019; 9:29273-29292. [PMID: 35528444 PMCID: PMC9071802 DOI: 10.1039/c9ra05059k] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 09/06/2019] [Indexed: 11/26/2022] Open
Abstract
Bacteria regulate their phenotype, growth and population via a signalling pathway known as quorum sensing. In this process, bacteria produce signalling molecules (autoinducers) to recognize their population density. Inhibiting this quorum sensing signalling pathway is one of the potential methods to treat bacterial infection. 2-Aminobenimdazoles are reported to be the strongest inhibitors of quorum sensing against wild-type P. aeruginosa. 1,2,3-Triazole based acyl homoserine lactones are found to be good inhibitors of the quorum sensing LasR receptor. Hence, in our current study, forty 1,2,3-triazole based 2-aminobenzimdazoles were synthesized and characterized using IR, NMR, MS and elemental analysis. A single crystal was developed for N-(1H-benzo[d]imidazol-2-yl)-2-(4-nonyl-1H-1,2,3-triazol-1-yl)acetamide (6d). All final compounds were screened for in vitro quorum sensing inhibitory activity against Pseudomonas aeruginosa. The quorum sensing inhibitory activity was determined in the LasR expressing P. aeruginosa MH602 reporter strain by measuring green fluorescent protein production. Among the title compounds, N-(1H-benzo[d]imidazol-2-yl)-2-(4-(4-chlorophenyl)-1H-1,2,3-triazol-1-yl)acetamide (6i) exhibited good quorum sensing inhibitory activity of 64.99% at 250 μM. N-(1H-Benzo[d]imidazol-2-yl)-2-(4-(4-nitrophenyl)-1H-1,2,3-triazol-1-yl)acetamide (6p) exhibited the most promising quorum sensing inhibitory activity with 68.23, 67.10 and 63.67% inhibition at 250, 125 and 62.5 μM, respectively. N-(1H-Benzo[d]imidazol-2-yl)-2-(4-(4-(trifluoromethyl)phenyl)-1H-1,2,3-triazol-1-yl)acetamide (6o) and N-(5,6-dimethyl-1H-benzo[d]imidazol-2-yl)-2-(4-(4-(trifluoromethyl)phenyl)-1H-1,2,3-triazol-1-yl)acetamide (7l) also exhibited 64.25% and 65.80% quorum sensing inhibition at 250 μM. Compound 6p, the most active quorum sensing inhibitor, also displayed low cytotoxicity at the tested concentrations (25, 50 and 100 μM) against normal human embryonic kidney cell lines. Finally, a docking study using Schrodinger Glide elucidated the possible putative binding mode of the significantly active compound 6p at the active site of the target LasR receptor (PDB ID: 2UV0).
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Affiliation(s)
- Singireddi Srinivasarao
- Department of Chemistry, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Jawahar Nagar, Kapra Mandal Hyderabad - 500078 Telangana India +91 40 66303527
| | - Adinarayana Nandikolla
- Department of Chemistry, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Jawahar Nagar, Kapra Mandal Hyderabad - 500078 Telangana India +91 40 66303527
| | | | - Tsz Tin Yu
- School of Chemistry, UNSW Sydney NSW 2052 Australia
| | - Sravani Pulya
- Department of Pharmacy, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Jawahar Nagar, Kapra Mandal Hyderabad-500078 Telangana India
| | - Balaram Ghosh
- Department of Pharmacy, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Jawahar Nagar, Kapra Mandal Hyderabad-500078 Telangana India
| | - Sankaranarayanan Murugesan
- Medicinal Chemistry Research Laboratory, Department of Pharmacy, Birla Institute of Technology and Science Pilani 333031 India
| | - Naresh Kumar
- School of Chemistry, UNSW Sydney NSW 2052 Australia
| | - Kondapalli Venkata Gowri Chandra Sekhar
- Department of Chemistry, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Jawahar Nagar, Kapra Mandal Hyderabad - 500078 Telangana India +91 40 66303527
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20
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Ahmed AA, Salih FA. Quercus infectoria gall extracts reduce quorum sensing-controlled virulence factors production and biofilm formation in Pseudomonas aeruginosa recovered from burn wounds. Altern Ther Health Med 2019; 19:177. [PMID: 31319827 PMCID: PMC6639949 DOI: 10.1186/s12906-019-2594-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 07/04/2019] [Indexed: 01/05/2023]
Abstract
Background Quercus gall extracts’ ability to kill pathogens in vitro and even removal of chronic drug-resistant infections has been reported by several studies. The current investigation is focused on the action of extracts of Quercus infectoria gall in their sub-inhibitory concentrations on the corresponding bacterial behaviours instead of killing them. Methods The effect of gall extracts on the quorum sensing (QS) associated virulence of multiple drug resistant Pseudomonas aeruginosa recovered from burns wounds was studied. The influence of different extracts on the production of bacterial virulence and biofilm, and expression of the genes encoding quorum sensing and exotoxin A were investigated. Quorum sensing is a crucial regulator of virulence and biofilm development in Pseudomonas aeruginosa and other medical related microbes. Results Experiments to characterise and quantify Q. infectoria gall extracts impact on the quorum sensing networks of P.aeruginosa revealed that the expression of las, rhl, and exotoxin A (ETA) genes levels including the associated virulence were reduced by the extracts at their subinhibitory concentrations. Conclusions The obtained results indicated that extracts of Q. infectoria galls fight infections either by their inhibitory constituents, which vigorously eradicate cells or by disruption of the pathogens quorum sensing system through weakening the virulence and bacterial coordination.
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21
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Flockton TR, Schnorbus L, Araujo A, Adams J, Hammel M, Perez LJ. Inhibition of Pseudomonas aeruginosa Biofilm Formation with Surface Modified Polymeric Nanoparticles. Pathogens 2019; 8:pathogens8020055. [PMID: 31022836 PMCID: PMC6631850 DOI: 10.3390/pathogens8020055] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/09/2019] [Accepted: 04/17/2019] [Indexed: 01/02/2023] Open
Abstract
The gram-negative bacterial pathogen Pseudomonas aeruginosa represents a prominent clinical concern. Due to the observed high levels of antibiotic resistance, copious biofilm formation, and wide array of virulence factors produced by these bacteria, new treatment technologies are required. Here, we present the development of a series of P. aeruginosa LecA-targeted polymeric nanoparticles and demonstrate the anti-adhesion and biofilm inhibitory properties of these constructs.
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Affiliation(s)
- Tyler R Flockton
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, USA.
| | - Logan Schnorbus
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, USA.
| | - Agustin Araujo
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, USA.
| | - Jill Adams
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, USA.
| | - Maryjane Hammel
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, USA.
| | - Lark J Perez
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, USA.
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22
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Schmucker DJ, Dunbar SR, Shepherd TD, Bertucci MA. n → π* Interactions in N-Acyl Homoserine Lactone Derivatives and Their Effects on Hydrolysis Rates. J Phys Chem A 2019; 123:2537-2543. [DOI: 10.1021/acs.jpca.8b12266] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Daniel J. Schmucker
- Department of Chemistry, Moravian College, 1200 Main Street, Bethlehem, Pennsylvania 18018, United States
| | - Sydney R. Dunbar
- Department of Chemistry, Hartwick College, 1 Hartwick Drive, Oneonta, New York 13820, United States
| | - Tricia D. Shepherd
- Department of Chemistry, Moravian College, 1200 Main Street, Bethlehem, Pennsylvania 18018, United States
| | - Michael A. Bertucci
- Department of Chemistry, Moravian College, 1200 Main Street, Bethlehem, Pennsylvania 18018, United States
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23
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Synthetic small molecules as anti-biofilm agents in the struggle against antibiotic resistance. Eur J Med Chem 2018; 161:154-178. [PMID: 30347328 DOI: 10.1016/j.ejmech.2018.10.036] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/10/2018] [Accepted: 10/15/2018] [Indexed: 01/24/2023]
Abstract
Biofilm formation significantly contributes to microbial survival in hostile environments and it is currently considered a key virulence factor for pathogens responsible for serious chronic infections. In the last decade many efforts have been made to identify new agents able to modulate bacterial biofilm life cycle, and many compounds have shown interesting activities in inhibiting biofilm formation or in dispersing pre-formed biofilms. However, only a few of these compounds were tested using in vivo models for their clinical significance. Contrary to conventional antibiotics, most of the anti-biofilm compounds act as anti-virulence agents as they do not affect bacterial growth. In this review we selected the most relevant literature of the last decade, focusing on the development of synthetic small molecules able to prevent bacterial biofilm formation or to eradicate pre-existing biofilms of clinically relevant Gram-positive and Gram-negative pathogens. In addition, we provide a comprehensive list of the possible targets to counteract biofilm formation and development, as well as a detailed discussion the advantages and disadvantages of the different current biofilm-targeting strategies.
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24
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Srinivasarao S, Nizalapur S, Yu TT, Wenholz DS, Trivedi P, Ghosh B, Rangan K, Kumar N, Gowri Chandra Sekhar K. Design, Synthesis and Biological Evaluation of Triazole-Containing 2-Phenylindole and Salicylic Acid as Quorum Sensing Inhibitors Against Pseudomonas aeruginosa. ChemistrySelect 2018. [DOI: 10.1002/slct.201801622] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Singireddi Srinivasarao
- Department of Chemistry; Birla Institute of Technology and Science, Pilani; Hyderabad Campus, Jawahar Nagar, Kapra Mandal; Hyderabad - 500078, Telangana India
| | | | - Tsz Tin Yu
- School of Chemistry; UNSW Sydney; NSW 2052, Australia
| | | | - Prakruti Trivedi
- Department of Pharmacy; Birla Institute of Technology and Science-Pilani; Hyderabad Campus, Jawahar Nagar, Kapra Mandal; Hyderabad-500 078, Telangana India
| | - Balaram Ghosh
- Department of Pharmacy; Birla Institute of Technology and Science-Pilani; Hyderabad Campus, Jawahar Nagar, Kapra Mandal; Hyderabad-500 078, Telangana India
| | - Krishnan Rangan
- Department of Chemistry; Birla Institute of Technology and Science, Pilani; Hyderabad Campus, Jawahar Nagar, Kapra Mandal; Hyderabad - 500078, Telangana India
| | - Naresh Kumar
- School of Chemistry; UNSW Sydney; NSW 2052, Australia
| | - Kondapalli Venkata Gowri Chandra Sekhar
- Department of Chemistry; Birla Institute of Technology and Science, Pilani; Hyderabad Campus, Jawahar Nagar, Kapra Mandal; Hyderabad - 500078, Telangana India
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25
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Boursier ME, Manson DE, Combs JB, Blackwell HE. A comparative study of non-native N-acyl l-homoserine lactone analogs in two Pseudomonas aeruginosa quorum sensing receptors that share a common native ligand yet inversely regulate virulence. Bioorg Med Chem 2018; 26:5336-5342. [PMID: 29793752 DOI: 10.1016/j.bmc.2018.05.018] [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: 03/14/2018] [Revised: 05/07/2018] [Accepted: 05/13/2018] [Indexed: 10/16/2022]
Abstract
Certain bacteria can coordinate group behaviors via a chemical communication system known as quorum sensing (QS). Gram-negative bacteria typically use N-acyl l-homoserine lactone (AHL) signals and their cognate intracellular LuxR-type receptors for QS. The opportunistic pathogen Pseudomonas aeruginosa has a relatively complex QS circuit in which two of its LuxR-type receptors, LasR and QscR, are activated by the same natural signal, N-(3-oxo)-dodecanoyl l-homoserine lactone. Intriguingly, once active, LasR activates virulence pathways in P. aeruginosa, while activated QscR can inactivate LasR and thus repress virulence. We have a limited understanding of the structural features of AHLs that engender either agonistic activity in both receptors or receptor-selective activity. Compounds with the latter activity profile could prove especially useful tools to tease out the roles of these two receptors in virulence regulation. A small collection of AHL analogs was assembled and screened in cell-based reporter assays for activity in both LasR and QscR. We identified several structural motifs that bias ligand activation towards each of the two receptors. These findings will inform the development of new synthetic ligands for LasR and QscR with improved potencies and selectivities.
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Affiliation(s)
- Michelle E Boursier
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA
| | - Daniel E Manson
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA
| | - Joshua B Combs
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA
| | - Helen E Blackwell
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA.
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26
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Wysoczynski-Horita CL, Boursier ME, Hill R, Hansen K, Blackwell HE, Churchill MEA. Mechanism of agonism and antagonism of the Pseudomonas aeruginosa quorum sensing regulator QscR with non-native ligands. Mol Microbiol 2018; 108:240-257. [PMID: 29437248 DOI: 10.1111/mmi.13930] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2018] [Indexed: 12/25/2022]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that uses the process of quorum sensing (QS) to coordinate the expression of many virulence genes. During quorum sensing, N-acyl-homoserine lactone (AHL) signaling molecules regulate the activity of three LuxR-type transcription factors, LasR, RhlR and QscR. To better understand P. aeruginosa QS signal reception, we examined the mechanism underlying the response of QscR to synthetic agonists and antagonists using biophysical and structural approaches. The structure of QscR bound to a synthetic agonist reveals a novel mode of ligand binding supporting a general mechanism for agonist activity. In turn, antagonists of QscR with partial agonist activity were found to destabilize and greatly impair QscR dimerization and DNA binding. These results highlight the diversity of LuxR-type receptor responses to small molecule agonists and antagonists and demonstrate the potential for chemical strategies for the selective targeting of individual QS systems.
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Affiliation(s)
- Christina L Wysoczynski-Horita
- Department of Pharmacology and Program in Structural Biology and Biochemistry, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | | | - Ryan Hill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Kirk Hansen
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Helen E Blackwell
- Department of Chemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Mair E A Churchill
- Department of Pharmacology and Program in Structural Biology and Biochemistry, University of Colorado School of Medicine, Aurora, CO 80045, USA
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27
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Virtual screening and biological evaluation of biofilm inhibitors on dual targets in quorum sensing system. Future Med Chem 2017; 9:1983-1994. [PMID: 29076756 DOI: 10.4155/fmc-2017-0127] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
AIM Resistance to conventional antibiotics has spurred interest in exploring new antimicrobial strategies. Suppressing quorum sensing within biofilm is a promising antimicrobial strategy. LasR in quorum sensing system of the Gram-negative bacteria, Pseudomonas aeruginosa, directly enhances virulence and antibiotic resistance, with QscR as its indirect suppressor, so targeting both of them can synergistically take the effect. METHODOLOGY/RESULTS An in silico protocol combining pharmacophores with molecular docking was applied. Pharmacophores of QscR agonists and LasR antagonists were prepared for preliminary screening, followed by counter-screen using a pharmacophore model of LasR agonists and molecular docking of LasR. Four compounds with novel scaffolds were confirmed as potential biofilm inhibitors with preliminary experimental data. CONCLUSION Novel biofilm inhibitors can be found with the method.
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28
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Niu K, Kuk M, Jung H, Chan K, Kim S. Leaf Extracts of Selected Gardening Trees Can Attenuate Quorum Sensing and Pathogenicity of Pseudomonas aeruginosa PAO1. Indian J Microbiol 2017; 57:329-338. [PMID: 28904418 DOI: 10.1007/s12088-017-0660-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 07/03/2017] [Indexed: 11/29/2022] Open
Abstract
An increasing concern on resistance to multiple-antibiotics has led to the discovery of novel agents and the establishment of new precaution strategy. Numerous plant sources have been widely studied to reduce virulence of pathogenic bacteria by interfering cell-to-cell based communication called quorum sensing (QS). Leaf extracts of 17 gardening trees were collected and investigated for their anti-QS effects using a sensor strain Chromobacterium violaceum CV026. Methanolic extracts of K4 (Acer palmatum), K9 (Acer pseudosieboldianum) and K13 (Cercis chinensis) leaves were selected for further experiments based on their antagonism effect on QS without inhibiting C. violaceum CV026 growth. Subsequently, the leaf extracts on QS-mediated virulence of Pseudomonas aeruginosa PAO1 involved in biofilm formation, motility, bioluminescence, pyocyanin production, QS molecules production, and Caenorhabditis elegans killing activity were evaluated. The biofilm formation ability and swarming motility of P. aeruginosa PAO1 were decreased approximately 50% in the presence of these leaf extracts at a concentration of 1 mg/mL. The expression level of lecA::lux of P. aeruginosa PAO1 and pyocyanin production were also reduced. The three leaf extracts also decreased autoinducer (AI) production in P. aeruginosa PAO1 without direct degradation, suggesting that AI synthesis might have been suppressed by these extracts. The three leaf extracts also showed anti-infection activity in C. elegans model. Taken together, these results suggest that methanolic leaf extracts of K4, K9 and K13 have the potential to attenuate the virulence of P. aeruginosa PAO1.
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Affiliation(s)
- Kaimin Niu
- Department of Animal Science and Technology, Konkuk University, Seoul, South Korea
| | - Min Kuk
- Department of Animal Science and Technology, Konkuk University, Seoul, South Korea
| | - Haein Jung
- Department of Animal Science and Technology, Konkuk University, Seoul, South Korea
| | - Kokgan Chan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Sooki Kim
- Department of Animal Science and Technology, Konkuk University, Seoul, South Korea
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29
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Jakobsen TH, Tolker-Nielsen T, Givskov M. Bacterial Biofilm Control by Perturbation of Bacterial Signaling Processes. Int J Mol Sci 2017; 18:ijms18091970. [PMID: 28902153 PMCID: PMC5618619 DOI: 10.3390/ijms18091970] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 09/06/2017] [Accepted: 09/07/2017] [Indexed: 01/20/2023] Open
Abstract
The development of effective strategies to combat biofilm infections by means of either mechanical or chemical approaches could dramatically change today’s treatment procedures for the benefit of thousands of patients. Remarkably, considering the increased focus on biofilms in general, there has still not been invented and/or developed any simple, efficient and reliable methods with which to “chemically” eradicate biofilm infections. This underlines the resilience of infective agents present as biofilms and it further emphasizes the insufficiency of today’s approaches used to combat chronic infections. A potential method for biofilm dismantling is chemical interception of regulatory processes that are specifically involved in the biofilm mode of life. In particular, bacterial cell to cell signaling called “Quorum Sensing” together with intracellular signaling by bis-(3′-5′)-cyclic-dimeric guanosine monophosphate (cyclic-di-GMP) have gained a lot of attention over the last two decades. More recently, regulatory processes governed by two component regulatory systems and small non-coding RNAs have been increasingly investigated. Here, we review novel findings and potentials of using small molecules to target and modulate these regulatory processes in the bacterium Pseudomonas aeruginosa to decrease its pathogenic potential.
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Affiliation(s)
- Tim Holm Jakobsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark.
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark.
| | - Michael Givskov
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark.
- Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore.
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30
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Hossain MA, Lee SJ, Park NH, Mechesso AF, Birhanu BT, Kang J, Reza MA, Suh JW, Park SC. Impact of phenolic compounds in the acyl homoserine lactone-mediated quorum sensing regulatory pathways. Sci Rep 2017; 7:10618. [PMID: 28878346 PMCID: PMC5587592 DOI: 10.1038/s41598-017-10997-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 08/17/2017] [Indexed: 01/10/2023] Open
Abstract
Quorum sensing (QS) is a cell density-dependent regulation of virulent bacterial gene expression by autoinducers that potentially pertains in the epidemic of bacterial virulence. This study was initially designed to evaluate the effect of 5 phenolic compounds in the modulation of QS and virulence factors of Chromobacterium violaceum and Pseudomonas aeruginosa, and to determine the mechanisms of their effects. Biosensor strains were used to assess antibacterial and anti-QS effect of these compounds. Only methyl gallate (MG) among these compounds demonstrated profound anti-QS effect in the preliminary study, and thus only MG was utilized further to evaluate the effects on the synthesis and activity of acyl homoserine lactone (AHL) in C. violaceum and on the modulation of biofilm, motility, proteolytic, elastase, pyocyanin, and rhamnolipid activity in P. aeruginosa. Finally, the effect of MG on the expression of QS-regulated genes of P. aeruginosa was verified. MG suppressed both the synthesis and activity of AHL in C. violaceum. It also restricted the biofilm formation and other QS-associated virulence factor of P. aeruginosa. MG concentration-dependently suppressed the expression of lasI/R, rhlI/R, and pqsA of P. aeruginosa and was non-toxic in in vitro study. This is the first report of the anti-QS mechanism of MG.
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Affiliation(s)
- Md Akil Hossain
- Laboratory of Clinical Pharmacokinetics and Pharmacodynamics, College of Veterinary Medicine, Kyungpook National University, Daegu, 702-701, Republic of Korea.,Veterinary drugs & Biologics Division, Animal and Plant Quarantine Agency (QIA), 177, Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Republic of Korea
| | - Seung-Jin Lee
- Laboratory of Clinical Pharmacokinetics and Pharmacodynamics, College of Veterinary Medicine, Kyungpook National University, Daegu, 702-701, Republic of Korea
| | - Na-Hye Park
- Laboratory of Clinical Pharmacokinetics and Pharmacodynamics, College of Veterinary Medicine, Kyungpook National University, Daegu, 702-701, Republic of Korea
| | - Abraham Fikru Mechesso
- Laboratory of Clinical Pharmacokinetics and Pharmacodynamics, College of Veterinary Medicine, Kyungpook National University, Daegu, 702-701, Republic of Korea
| | - Biruk Tesfaye Birhanu
- Laboratory of Clinical Pharmacokinetics and Pharmacodynamics, College of Veterinary Medicine, Kyungpook National University, Daegu, 702-701, Republic of Korea
| | - JeongWoo Kang
- Veterinary drugs & Biologics Division, Animal and Plant Quarantine Agency (QIA), 177, Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Republic of Korea
| | - Md Ahsanur Reza
- Faculty of Animal Science and Veterinary Medicine, Patuakhali Science and Technology University (Outer Campus), Babugonj, Barisal, 8210, Bangladesh
| | - Joo-Won Suh
- Center for Nutraceutical and Pharmaceutical Materials, Division of Bioscience and Bioinformatics, Science campus, Myongji University, 449-728, Yongin, Gyeonggi, Republic of Korea.
| | - Seung-Chun Park
- Laboratory of Clinical Pharmacokinetics and Pharmacodynamics, College of Veterinary Medicine, Kyungpook National University, Daegu, 702-701, Republic of Korea.
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31
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Suneby EG, Herndon LR, Schneider TL. Pseudomonas aeruginosa LasR·DNA Binding Is Directly Inhibited by Quorum Sensing Antagonists. ACS Infect Dis 2017; 3:183-189. [PMID: 28075113 DOI: 10.1021/acsinfecdis.6b00163] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Inhibition of quorum sensing in Pseudomonas aeruginosa is of interest as a possible antivirulence strategy for this pathogenic bacterium. The LasR regulator protein is important in coordinating gene expression in response to quorum sensing signaling molecules. One predominant strategy for LasR inhibition is the development of small-molecule antagonists that mimic the native autoinducer, though the mechanism by which they inactivate LasR is not known. This work reveals that multiple antagonists function by binding to and stabilizing LasR in a conformation that renders it unable to bind DNA. Further analysis of purified LasR complexed with known antagonists indicates that DNA binding can be recovered with the addition of native autoinducer, providing insights into the reversibility of ligand binding for this transcription factor. This in vitro assay could be used to assess future promising antagonists and complements existing cell-based reporter assays.
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Affiliation(s)
- Emma G. Suneby
- Department of Chemistry, Connecticut College, New London, Connecticut 06320, United States
| | - Leslie R. Herndon
- Department
of Chemistry, Smith College, Northampton, Massachusetts 01063, United States
| | - Tanya L. Schneider
- Department of Chemistry, Connecticut College, New London, Connecticut 06320, United States
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32
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Capilato JN, Philippi SV, Reardon T, McConnell A, Oliver DC, Warren A, Adams JS, Wu C, Perez LJ. Development of a novel series of non-natural triaryl agonists and antagonists of the Pseudomonas aeruginosa LasR quorum sensing receptor. Bioorg Med Chem 2016; 25:153-165. [PMID: 27825554 DOI: 10.1016/j.bmc.2016.10.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 10/13/2016] [Accepted: 10/17/2016] [Indexed: 10/20/2022]
Abstract
Bacterial chemical communication, through a process called quorum sensing (QS), plays a central role in infection in numerous bacterial pathogens. Quorum sensing in Pseudomonas aeruginosa employs a series of small molecule receptors including the master QS regulator, LasR. In this study we investigate a non-natural triaryl series of LasR ligands using a combination of structure activity relationship studies and computational modeling. These studies have enabled the identification of key structural requirements for ligand binding and have revealed a new strategy for inducing the therapeutically relevant antagonism of LasR.
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Affiliation(s)
- Joseph N Capilato
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Shane V Philippi
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Thomas Reardon
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Ashleigh McConnell
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Dylan C Oliver
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Amy Warren
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Jill S Adams
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Chun Wu
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
| | - Lark J Perez
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, United States
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33
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Palmer AG, Mukherjee A, Stacy DM, Lazar S, Ané JM, Blackwell HE. Interkingdom Responses to Bacterial Quorum Sensing Signals Regulate Frequency and Rate of Nodulation in Legume-Rhizobia Symbiosis. Chembiochem 2016; 17:2199-2205. [DOI: 10.1002/cbic.201600373] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Indexed: 12/26/2022]
Affiliation(s)
- Andrew G. Palmer
- Department of Biological Sciences; Florida Institute of Technology; 150 West University Melbourne FL 32904 USA
| | - Arijit Mukherjee
- Department of Biology; University of Central Arkansas; 201 Donaghey Conway AK 72035 USA
| | - Danielle M. Stacy
- Department of Chemistry; University of Wisconsin-Madison; 1101 University Avenue Madison WI 53706 USA
| | - Stephen Lazar
- Department of Biological Sciences; Florida Institute of Technology; 150 West University Melbourne FL 32904 USA
| | - Jean-Michel Ané
- Department of Agronomy; University of Wisconsin-Madison; 1575 Linden Drive Madison WI 53706 USA
- Department of Bacteriology; University of Wisconsin-Madison; 1550 Linden Drive Madison WI 53706 USA
| | - Helen E. Blackwell
- Department of Chemistry; University of Wisconsin-Madison; 1101 University Avenue Madison WI 53706 USA
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34
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Hawver LA, Jung SA, Ng WL. Specificity and complexity in bacterial quorum-sensing systems. FEMS Microbiol Rev 2016; 40:738-52. [PMID: 27354348 PMCID: PMC5007282 DOI: 10.1093/femsre/fuw014] [Citation(s) in RCA: 162] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/18/2016] [Indexed: 12/15/2022] Open
Abstract
Quorum sensing (QS) is a microbial cell-to-cell communication process that relies on the production and detection of chemical signals called autoinducers (AIs) to monitor cell density and species complexity in the population. QS allows bacteria to behave as a cohesive group and coordinate collective behaviors. While most QS receptors display high specificity to their AI ligands, others are quite promiscuous in signal detection. How do specific QS receptors respond to their cognate signals with high fidelity? Why do some receptors maintain low signal recognition specificity? In addition, many QS systems are composed of multiple intersecting signaling pathways: what are the benefits of preserving such a complex signaling network when a simple linear ‘one-to-one’ regulatory pathway seems sufficient to monitor cell density? Here, we will discuss different molecular mechanisms employed by various QS systems that ensure productive and specific QS responses. Moreover, the network architectures of some well-characterized QS circuits will be reviewed to understand how the wiring of different regulatory components achieves different biological goals. This review focuses on the specificity and complexity of quorum-sensing circuits in both Gram-negative and Gram-positive bacterial species.
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Affiliation(s)
- Lisa A Hawver
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Sarah A Jung
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA Program in Molecular Microbiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Wai-Leung Ng
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA Program in Molecular Microbiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111, USA
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35
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Welsh MA, Blackwell HE. Chemical probes of quorum sensing: from compound development to biological discovery. FEMS Microbiol Rev 2016; 40:774-94. [PMID: 27268906 DOI: 10.1093/femsre/fuw009] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2016] [Indexed: 01/20/2023] Open
Abstract
Bacteria can utilize chemical signals to coordinate the expression of group-beneficial behaviors in a method of cell-cell communication called quorum sensing (QS). The discovery that QS controls the production of virulence factors and biofilm formation in many common pathogens has driven an explosion of research aimed at both deepening our fundamental understanding of these regulatory networks and developing chemical agents that can attenuate QS signaling. The inherently chemical nature of QS makes studying these pathways with small molecule tools a complementary approach to traditional microbiology techniques. Indeed, chemical tools are beginning to yield new insights into QS regulation and provide novel strategies to inhibit QS. Here, we review the most recent advances in the development of chemical probes of QS systems in Gram-negative bacteria, with an emphasis on the opportunistic pathogen Pseudomonas aeruginosa We first describe reports of novel small molecule modulators of QS receptors and QS signal synthases. Next, in several case studies, we showcase how chemical tools have been deployed to reveal new knowledge of QS biology and outline lessons for how researchers might best target QS to combat bacterial virulence. To close, we detail the outstanding challenges in the field and suggest strategies to overcome these issues.
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Affiliation(s)
- Michael A Welsh
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA
| | - Helen E Blackwell
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706, USA
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36
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Kafle P, Amoh AN, Reaves JM, Suneby EG, Tutunjian KA, Tyson RL, Schneider TL. Molecular Insights into the Impact of Oxidative Stress on the Quorum-Sensing Regulator Protein LasR. J Biol Chem 2016; 291:11776-86. [PMID: 27053110 DOI: 10.1074/jbc.m116.719351] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Indexed: 01/05/2023] Open
Abstract
The LasR regulator protein functions at the top of the Pseudomonas aeruginosa quorum-sensing hierarchy and is implicated in promoting bacterial virulence. Of note is recent evidence that this transcription factor may also respond to oxidative stress. Here, all cysteines in LasR were inspected to deduce their redox sensitivity and to probe the connection between stress response and LasR activity using purified LasR and individual LasR domains. Cys(79) in the ligand binding domain of LasR appears to be important for ligand recognition and folding of this domain to potentiate DNA binding but does not seem to be sensitive to oxidative stress when bound to its native ligand. Two cysteines in the DNA binding domain of LasR do form a disulfide bond when treated with hydrogen peroxide, and formation of this Cys(201)-Cys(203) disulfide bond appears to disrupt the DNA binding activity of the transcription factor. Mutagenesis of either of these cysteines leads to expression of a protein that no longer binds DNA. A cell-based reporter assay linking LasR function with β-galactosidase activity gave results consistent with those obtained with purified LasR. This work provides a possible mechanism for oxidative stress response by LasR and indicates that multiple cysteines within the protein may prove to be useful targets for disabling its activity.
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Affiliation(s)
- Prapti Kafle
- From the Department of Chemistry, Connecticut College, New London, Connecticut 06320
| | - Amanda N Amoh
- From the Department of Chemistry, Connecticut College, New London, Connecticut 06320
| | - Jocelyn M Reaves
- From the Department of Chemistry, Connecticut College, New London, Connecticut 06320
| | - Emma G Suneby
- From the Department of Chemistry, Connecticut College, New London, Connecticut 06320
| | - Kathryn A Tutunjian
- From the Department of Chemistry, Connecticut College, New London, Connecticut 06320
| | - Reed L Tyson
- From the Department of Chemistry, Connecticut College, New London, Connecticut 06320
| | - Tanya L Schneider
- From the Department of Chemistry, Connecticut College, New London, Connecticut 06320
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37
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Chbib C, Sobczak AJ, Mudgal M, Gonzalez C, Lumpuy D, Nagaj J, Stokowa-Soltys K, Wnuk SF. S-Ribosylhomocysteine Analogues Modified at the Ribosyl C-4 Position. J Sulphur Chem 2016; 37:307-327. [PMID: 27516805 DOI: 10.1080/17415993.2015.1137921] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
4-C-Alkyl/aryl-S-ribosylhomocysteine (SRH) analogues were prepared by coupling of homocysteine with 4-substituted ribofuranose derivatives. The diastereoselective incorporation of the methyl substituent into the 4 position of the ribose ring was accomplished by addition of methylmagnesium bromide to the protected ribitol-4-ulose yielding the 4-C-methylribitol in 85% yield as single 4R diastereomer. The 4-C hexyl, octyl, vinyl, and aryl ribitols were prepared analogously. Chelation controlled addition of a carbanion to ketones from the (Si-face) was responsible for the observed stereochemical outcome. Oxidation of the primary alcohol of the 4-C ribitols with the catalytic amount of tetrapropylammonium perruthenate in the presence of N-methylmorpholine N-oxide produced 4-C-alkylribono-1,4-lactones in high yields. Mesylation of the latter compounds at the 5-hydroxyl position and treatment with a protected homocysteine thiolate afforded protected 4-C-alkyl/aryl-SRH analogues as the lactones. Reduction with lithium triethylborohydride and successive global deprotections with TFA afforded 4-C-alkyl/aryl SRH analogues. These analogues might impede the S-ribosylhomocysteinase(LuxS)-catalyzed reaction by preventing β-elimination of a homocysteine molecule, and thus depleting the production of quorum sensing signaling molecule AI-2.
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Affiliation(s)
- Christiane Chbib
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Adam J Sobczak
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Mukesh Mudgal
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Cesar Gonzalez
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Daniel Lumpuy
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Justyna Nagaj
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Kamila Stokowa-Soltys
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Stanislaw F Wnuk
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA
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38
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O’Reilly MC, Blackwell HE. Structure-Based Design and Biological Evaluation of Triphenyl Scaffold-Based Hybrid Compounds as Hydrolytically Stable Modulators of a LuxR-Type Quorum Sensing Receptor. ACS Infect Dis 2016; 2:32-38. [PMID: 26807436 PMCID: PMC4709822 DOI: 10.1021/acsinfecdis.5b00112] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Indexed: 12/28/2022]
Abstract
![]()
Many
common bacterial pathogens utilize quorum sensing to coordinate group
behaviors and initiate virulence at high cell densities. The use of
small molecules to block quorum sensing provides a means of abrogating
pathogenic phenotypes, but many known quorum sensing modulators have
limitations, including hydrolytic instability and displaying non-monotonic
dose curves (indicative of additional targets and/or modes of action).
To address these issues, we undertook a structure-based scaffold-hopping
approach to develop new chemical modulators of the LasR quorum sensing
receptor in Pseudomonas aeruginosa.
We combined components from a triphenyl derivative known to strongly
agonize LasR with chemical moieties known for LasR antagonism and
generated potent LasR antagonists that are hydrolytically stable across
a range of pH values. Additionally, many of these antagonists do not
exhibit non-monotonic dose effects, delivering probes that inhibit
LasR across a wider range of assay conditions relative to known lactone-based
ligands.
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Affiliation(s)
- Matthew C. O’Reilly
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Helen E. Blackwell
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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Moore JD, Rossi FM, Welsh MA, Nyffeler KE, Blackwell HE. A Comparative Analysis of Synthetic Quorum Sensing Modulators in Pseudomonas aeruginosa: New Insights into Mechanism, Active Efflux Susceptibility, Phenotypic Response, and Next-Generation Ligand Design. J Am Chem Soc 2015; 137:14626-39. [PMID: 26491787 PMCID: PMC4665086 DOI: 10.1021/jacs.5b06728] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Quorum sensing (QS) is a chemical signaling mechanism that allows bacterial populations to coordinate gene expression in response to social and environmental cues. Many bacterial pathogens use QS to initiate infection at high cell densities. Over the past two decades, chemical antagonists of QS in pathogenic bacteria have attracted substantial interest for use both as tools to further elucidate QS mechanisms and, with further development, potential anti-infective agents. Considerable recent research has been devoted to the design of small molecules capable of modulating the LasR QS receptor in the opportunistic pathogen Pseudomonas aeruginosa. These molecules hold significant promise in a range of contexts; however, as most compounds have been developed independently, comparative activity data for these compounds are scarce. Moreover, the mechanisms by which the bulk of these compounds act are largely unknown. This paucity of data has stalled the choice of an optimal chemical scaffold for further advancement. Herein, we submit the best-characterized LasR modulators to standardized cell-based reporter and QS phenotypic assays in P. aeruginosa, and we report the first comprehensive set of comparative LasR activity data for these compounds. Our experiments uncovered multiple interesting mechanistic phenomena (including a potential alternative QS-modulatory ligand binding site/partner) that provide new, and unexpected, insights into the modes by which many of these LasR ligands act. The lead compounds, data trends, and mechanistic insights reported here will significantly aid the design of new small molecule QS inhibitors and activators in P. aeruginosa, and in other bacteria, with enhanced potencies and defined modes of action.
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Affiliation(s)
- Joseph D Moore
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Francis M Rossi
- Department of Chemistry, SUNY Cortland , Cortland, New York 13045, United States
| | - Michael A Welsh
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Kayleigh E Nyffeler
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Helen E Blackwell
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
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40
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Eibergen NR, Moore JD, Mattmann ME, Blackwell HE. Potent and Selective Modulation of the RhlR Quorum Sensing Receptor by Using Non-native Ligands: An Emerging Target for Virulence Control in Pseudomonas aeruginosa. Chembiochem 2015; 16:2348-56. [PMID: 26460240 DOI: 10.1002/cbic.201500357] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Indexed: 11/10/2022]
Abstract
Pseudomonas aeruginosa uses N-acylated L-homoserine lactone signals and a triumvirate of LuxR-type receptor proteins--LasR, RhlR, and QscR--for quorum sensing (QS). Each of these receptors can contribute to QS activation or repression and, thereby, the control of myriad virulence phenotypes in this pathogen. LasR has traditionally been considered to be at the top of the QS receptor hierarchy in P. aeruginosa; however, recent reports suggest that RhlR plays a more prominent role in infection than originally predicted, in some circumstances superseding that of LasR. Herein, we report the characterization of a set of synthetic, small-molecule agonists and antagonists of RhlR. Using E. coli reporter strains, we demonstrated that many of these compounds can selectively activate or inhibit RhlR instead of LasR and QscR. Moreover, several molecules maintain their activities in P. aeruginosa at concentrations analogous to native RhlR signal levels. These compounds represent useful chemical probes to study the role of RhlR in the complex QS circuitry of P. aeruginosa, its direct (and indirect) effects on virulence, and its overall merit as a target for anti-infective therapy.
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Affiliation(s)
- Nora R Eibergen
- Dow Microbial Control, The Dow Chemical Company, 400 Arcola Road, Collegeville, PA, 19426, USA
| | - Joseph D Moore
- Dow Microbial Control, The Dow Chemical Company, 400 Arcola Road, Collegeville, PA, 19426, USA
| | | | - Helen E Blackwell
- Department of Chemistry, The University of Wisconsin-Madison, 1101 University Avenue, Madison, WI, 53706, USA.
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41
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Gerdt JP, McInnis CE, Schell TL, Blackwell HE. Unraveling the contributions of hydrogen-bonding interactions to the activity of native and non-native ligands in the quorum-sensing receptor LasR. Org Biomol Chem 2015; 13:1453-62. [PMID: 25474181 DOI: 10.1039/c4ob02252a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Quorum sensing (QS) via the synthesis and detection of N-acyl L-homoserine lactone (AHL) signals regulates important pathogenic and mutualistic phenotypes in many bacteria. Over the past two decades, the development of non-native molecules that modulate this cell-cell signaling process has become an active area of research. The majority of these compounds were designed to block binding of the native AHL signal to its cognate LuxR-type receptor, and much effort has focused on LasR in the opportunistic pathogen Pseudomonas aeruginosa. Despite a small set of reported LasR structural data, it remains unclear which polar interactions are most important for either (i) activation of the LasR receptor by its native AHL signal, N-(3-oxo)-dodecanoyl L-homoserine lactone (OdDHL), or (ii) activation or inhibition of LasR by related AHL analogs. Herein, we report our investigations into the activity of OdDHL and five synthetic analogs in wild-type LasR and in nine LasR mutants with modifications to key polar residues in their ligand binding sites. Our results allowed us to rank, for the first time, the relative importance of each LasR:OdDHL hydrogen bond for LasR activation and provide strong evidence for the five synthetic ligands binding LasR in a very similar orientation as OdDHL. By delineating the specific molecular interactions that are important for LasR modulation by AHLs, these findings should aid in the design of new synthetic modulators of LasR (and homologous LuxR-type receptors) with improved potencies and selectivities.
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Affiliation(s)
- Joseph P Gerdt
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706-1322, USA.
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42
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Sobczak AJ, Chbib C, Wnuk SF. S-Ribosylhomocysteine analogs containing a [4-thio]ribose ring. Carbohydr Res 2015; 415:39-47. [PMID: 26279525 DOI: 10.1016/j.carres.2015.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 07/04/2015] [Accepted: 07/07/2015] [Indexed: 01/16/2023]
Abstract
The [4-thio]-S-ribosylhomocysteine (SRH) analogs containing substitution of a sulfur atom for the endocyclic oxygen were synthesized by coupling of the 4-thioribose substrates with a thiolate generated from the protected homocysteine. Coupling of the protected 1-deoxy-5-O-mesyl-S-oxo-4-thio-D-ribofuranose with homocysteinate salt gave the C4 epimers of [4-thio]-SRH at the sulfoxide oxidation level lacking a hydroxyl group at anomeric carbon. Treatment of these sulfoxides with BF3⋅Et2O/NaI affected simultaneous reduction to sulfide and global deprotection affording 1-deoxy-4-thio-SRH analog. Treatment of the protected 1-deoxy-S-oxo-4-thio-D-ribofuranose sulfoxide with DAST/SbCl3 resulted in the fluoro-Pummerer rearrangement to give 4-thio-β-D-ribofuranosyl fluoride. Mesylation of the latter at 5-hydroxyl position followed by coupling with homocysteinate salt and subsequent global deprotection with trifluoroacetic acid afforded [4-thio]-SRH thiohemiacetal.
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Affiliation(s)
- Adam J Sobczak
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Christiane Chbib
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Stanislaw F Wnuk
- Department of Chemistry & Biochemistry, Florida International University, Miami, FL 33199, USA.
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43
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Hansen MR, Jakobsen TH, Bang CG, Cohrt AE, Hansen CL, Clausen JW, Le Quement ST, Tolker-Nielsen T, Givskov M, Nielsen TE. Triazole-containing N-acyl homoserine lactones targeting the quorum sensing system in Pseudomonas aeruginosa. Bioorg Med Chem 2015; 23:1638-50. [DOI: 10.1016/j.bmc.2015.01.038] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 01/21/2015] [Accepted: 01/22/2015] [Indexed: 12/14/2022]
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O’Brien K, Noto JG, Nichols-O’Neill L, Perez LJ. Potent Irreversible Inhibitors of LasR Quorum Sensing in Pseudomonas aeruginosa. ACS Med Chem Lett 2015; 6:162-7. [PMID: 25699144 PMCID: PMC4329587 DOI: 10.1021/ml500459f] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 12/27/2014] [Indexed: 01/21/2023] Open
Abstract
Antagonism of quorum sensing represents a promising new antivirulence approach for the treatment of bacterial infection. The development of a novel series of non-natural irreversible antagonists of P. aeruginosa LasR is described. The lead compounds identified (25 and 28) display potent LasR antagonist activity and inhibit expression of the P. aeruginosa virulence factors pyocyanin and biofilm formation in PAO1 and PA14.
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Affiliation(s)
| | | | - Luke Nichols-O’Neill
- Department of Chemistry and
Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, New Jersey 08028, United States
| | - Lark J. Perez
- Department of Chemistry and
Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, New Jersey 08028, United States
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45
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El-Mowafy SA, Shaaban MI, Abd El Galil KH. Sodium ascorbate as a quorum sensing inhibitor of Pseudomonas aeruginosa. J Appl Microbiol 2014; 117:1388-99. [PMID: 25175797 DOI: 10.1111/jam.12631] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 08/02/2014] [Accepted: 08/22/2014] [Indexed: 11/28/2022]
Abstract
AIMS Quorum sensing circuits regulate virulence factors in Pseudomonas aeruginosa and coordinate bacterial pathogenicity. We are interested in exploring available medications for their antiquorum sensing activity. METHODS AND RESULTS First, we determined the MIC of ascorbate against Ps. aeruginosa strain PAO1, and all further experiments used concentrations below the MIC so that results could not be caused by reduced viability. Tests of subinhibitory concentrations of sodium ascorbate on cell signals were performed using a reporter strain assay. Sub-MICs of sodium ascorbate resulted in significant reduction of the signalling molecules C4-HSL and 3-oxo-C12-HSL (P < 0·01). The influence of sub-MIC of sodium ascorbate on virulence factors was also determined and ascorbate treatment led to significant depression of elastase, protease and haemolysin activities. In addition, inhibition of pyocyanin production, attenuation of biofilm formation and alteration of Pseudomonas motility was observed. Analysis by RT-PCR tested the effect of ascorbate on the expression of QS regulatory genes. Expression of QS regulatory genes, lasI, lasR, rhlI, rhlR, pqsR and pqsA, was repressed compared to untreated Ps. aeruginosa PAO1, confirming that ascorbate QS inhibition works on gene expression at the molecular level. CONCLUSION Sodium ascorbate, even at low concentrations, inhibited QS and related virulence factors of Ps. aeruginosa PAO1. SIGNIFICANCE AND IMPACT OF THE STUDY This study demonstrated that sodium ascorbate could function as signal modulator and virulence inhibitor in Ps. aeruginosa.
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Affiliation(s)
- S A El-Mowafy
- Microbiology Department, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
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46
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The hierarchy quorum sensing network in Pseudomonas aeruginosa. Protein Cell 2014; 6:26-41. [PMID: 25249263 PMCID: PMC4286720 DOI: 10.1007/s13238-014-0100-x] [Citation(s) in RCA: 761] [Impact Index Per Article: 76.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 08/28/2014] [Indexed: 12/13/2022] Open
Abstract
Pseudomonas aeruginosa causes severe and persistent infections in immune compromised individuals and cystic fibrosis sufferers. The infection is hard to eradicate as P. aeruginosa has developed strong resistance to most conventional antibiotics. The problem is further compounded by the ability of the pathogen to form biofilm matrix, which provides bacterial cells a protected environment withstanding various stresses including antibiotics. Quorum sensing (QS), a cell density-based intercellular communication system, which plays a key role in regulation of the bacterial virulence and biofilm formation, could be a promising target for developing new strategies against P. aeruginosa infection. The QS network of P. aeruginosa is organized in a multi-layered hierarchy consisting of at least four interconnected signaling mechanisms. Evidence is accumulating that the QS regulatory network not only responds to bacterial population changes but also could react to environmental stress cues. This plasticity should be taken into consideration during exploration and development of anti-QS therapeutics.
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47
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Montebello AN, Brecht RM, Turner RD, Ghali M, Pu X, Nagarajan R. Acyl-ACP substrate recognition in Burkholderia mallei BmaI1 acyl-homoserine lactone synthase. Biochemistry 2014; 53:6231-42. [PMID: 25215658 PMCID: PMC4188261 DOI: 10.1021/bi5009529] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The acyl-homoserine lactone (AHL) autoinducer mediated quorum sensing regulates virulence in several pathogenic bacteria. The hallmark of an efficient quorum sensing system relies on the tight specificity in the signal generated by each bacterium. Since AHL signal specificity is derived from the acyl-chain of the acyl-ACP (ACP = acyl carrier protein) substrate, AHL synthase enzymes must recognize and react with the native acyl-ACP with high catalytic efficiency while keeping reaction rates with non-native acyl-ACPs low. The mechanism of acyl-ACP substrate recognition in these enzymes, however, remains elusive. In this study, we investigated differences in catalytic efficiencies for shorter and longer chain acyl-ACP substrates reacting with an octanoyl-homoserine lactone synthase Burkholderia mallei BmaI1. With the exception of two-carbon shorter hexanoyl-ACP, the catalytic efficiencies of butyryl-ACP, decanoyl-ACP, and octanoyl-CoA reacting with BmaI1 decreased by greater than 20-fold compared to the native octanoyl-ACP substrate. Furthermore, we also noticed kinetic cooperativity when BmaI1 reacted with non-native acyl-donor substrates. Our kinetic data suggest that non-native acyl-ACP substrates are unable to form a stable and productive BmaI1·acyl-ACP·SAM ternary complex and are thus effectively discriminated by the enzyme. These results offer insights into the molecular basis of substrate recognition for the BmaI1 enzyme.
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Affiliation(s)
- Aubrey N Montebello
- Department of Chemistry and Biochemistry, Boise State University , 1910 University Drive, Boise, Idaho 83725, United States
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48
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Gerdt JP, McInnis CE, Schell TL, Rossi FM, Blackwell HE. Mutational analysis of the quorum-sensing receptor LasR reveals interactions that govern activation and inhibition by nonlactone ligands. ACTA ACUST UNITED AC 2014; 21:1361-1369. [PMID: 25242287 DOI: 10.1016/j.chembiol.2014.08.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 08/05/2014] [Accepted: 08/18/2014] [Indexed: 01/03/2023]
Abstract
Gram-negative bacteria use N-acyl L-homoserine lactone (AHL) quorum-sensing (QS) signals to regulate the expression of myriad phenotypes. Non-native AHL analogs can strongly attenuate QS receptor activity and thereby QS signaling; however, we currently lack a molecular understanding of the mechanisms by which most of these compounds elicit their agonistic or antagonistic profiles. In this study, we investigated the origins of striking activity profile switches (i.e., receptor activator to inhibitor, and vice versa) observed upon alteration of the lactone head group in certain AHL analogs. Reporter gene assays of mutant versions of the Pseudomonas aeruginosa QS receptor LasR revealed that interactions between the ligands and Trp60, Tyr56, and Ser129 govern whether these ligands behave as LasR activators or inhibitors. Using this knowledge, we propose a model for the modulation of LasR by AHL analogs-encompassing a subtly different interaction with the binding pocket to a global change in LasR conformation.
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Affiliation(s)
- Joseph P Gerdt
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Christine E McInnis
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Trevor L Schell
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Francis M Rossi
- Department of Chemistry, SUNY Cortland, Cortland, NY 13045, USA
| | - Helen E Blackwell
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
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49
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Kalia VC, Wood TK, Kumar P. Evolution of resistance to quorum-sensing inhibitors. MICROBIAL ECOLOGY 2014; 68:13-23. [PMID: 24194099 PMCID: PMC4012018 DOI: 10.1007/s00248-013-0316-y] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 10/14/2013] [Indexed: 05/23/2023]
Abstract
The major cause of mortality and morbidity in human beings is bacterial infection. Bacteria have developed resistance to most of the antibiotics primarily due to large-scale and "indiscriminate" usage. The need is to develop novel mechanisms to treat bacterial infections. The expression of pathogenicity during bacterial infections is mediated by a cell density-dependent phenomenon known as quorum sensing (QS). A wide array of QS systems (QSS) is operative in expressing the virulent behavior of bacterial pathogens. Each QSS may be mediated largely by a few major signals along with others produced in minuscule quantities. Efforts to target signal molecules and their receptors have proved effective in alleviating the virulent behavior of such pathogenic bacteria. These QS inhibitors (QSIs) have been reported to be effective in influencing the pathogenicity without affecting bacterial growth. However, evidence is accumulating that bacteria may develop resistance to QSIs. The big question is whether QSIs will meet the same fate as antibiotics.
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Affiliation(s)
- Vipin C Kalia
- Microbial Biotechnology and Genomics, CSIR-Institute of Genomics and Integrative Biology, Delhi University Campus, Mall Road, Delhi, 110007, India,
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50
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Thomanek H, Schenk ST, Stein E, Kogel KH, Schikora A, Maison W. Modified N-acyl-homoserine lactones as chemical probes for the elucidation of plant-microbe interactions. Org Biomol Chem 2014; 11:6994-7003. [PMID: 24057134 DOI: 10.1039/c3ob41215f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Gram-negative bacteria often use N-acyl-homoserine lactones (AHLs) as signal molecules to monitor their local population densities and to regulate gene-expression in a process called "Quorum Sensing" (QS). This cell-to-cell communication allows bacteria to adapt to environmental changes and to behave as multicellular communities. QS plays a key role in both bacterial virulence towards the host and symbiotic interactions with other organisms. Plants also perceive AHLs and respond to them with changes in gene expression or modifications in development. Herein, we report the synthesis of new AHL-derivatives for the investigation and identification of AHL-interacting proteins. We show that our new compounds are still recognised by different bacteria and that a novel biotin-tagged-AHL derivative interacts with a bacterial AHL receptor.
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Affiliation(s)
- Heike Thomanek
- Pharmaceutical and Medicinal Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany.
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