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Markus V. Gut bacterial quorum sensing molecules and their association with inflammatory bowel disease: Advances and future perspectives. Biochem Biophys Res Commun 2024; 724:150243. [PMID: 38857558 DOI: 10.1016/j.bbrc.2024.150243] [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: 03/07/2024] [Revised: 05/15/2024] [Accepted: 06/06/2024] [Indexed: 06/12/2024]
Abstract
Inflammatory Bowel Disease (IBD) is an enduring inflammatory disease of the gastrointestinal tract (GIT). The complexity of IBD, its profound impact on patient's quality of life, and its burden on healthcare systems necessitate continuing studies to elucidate its etiology, refine care strategies, improve treatment outcomes, and identify potential targets for novel therapeutic interventions. The discovery of a connection between IBD and gut bacterial quorum sensing (QS) molecules has opened exciting opportunities for research into IBD pathophysiology. QS molecules are small chemical messengers synthesized and released by bacteria based on population density. These chemicals are sensed not only by the microbial species but also by host cells and are essential in gut homeostasis. QS molecules are now known to interact with inflammatory pathways, therefore rendering them potential therapeutic targets for IBD management. Given these intriguing developments, the most recent research findings in this area are herein reviewed. First, the global burden of IBD and the disruptions of the gut microbiota and intestinal barrier associated with the disease are assessed. Next, the general QS mechanism and signaling molecules in the gut are discussed. Then, the roles of QS molecules and their connection with IBD are elucidated. Lastly, the review proposes potential QS-based therapeutic targets for IBD, offering insights into the future research trajectory in this field.
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Affiliation(s)
- Victor Markus
- Near East University, Faculty of Medicine, Department of Medical Biochemistry, Nicosia, TRNC Mersin 10, Turkey.
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2
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Wang D, Zeng N, Li C, Li Z, Zhang N, Li B. Fungal biofilm formation and its regulatory mechanism. Heliyon 2024; 10:e32766. [PMID: 38988529 PMCID: PMC11233959 DOI: 10.1016/j.heliyon.2024.e32766] [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: 09/17/2023] [Revised: 06/07/2024] [Accepted: 06/08/2024] [Indexed: 07/12/2024] Open
Abstract
Fungal biofilm is a microbial community composed of fungal cells and extracellular polymeric substances (EPS). In recent years, fungal biofilms have played an increasingly important role in many fields. However, there are few studies on fungal biofilms and their related applications and development are still far from enough. Therefore, this review summarizes the composition and function of EPS in fungal biofilms, and improves and refines the formation process of fungal biofilms according to the latest viewpoints. Moreover, based on the study of Saccharomyces cerevisiae and Candida albicans, this review summarizes the gene regulation network of fungal biofilm synthesis, which is crucial for systematically understanding the molecular mechanism of fungal biofilm formation. It is of great significance to further develop effective methods at the molecular level to control harmful biofilms or enhance and regulate the formation of beneficial biofilms. Finally, the quorum sensing factors and mixed biofilms formed by fungi in the current research of fungal biofilms are summarized. These results will help to deepen the understanding of the formation process and internal regulation mechanism of fungal biofilm, provide reference for the study of EPS composition and structure, formation, regulation, group behavior and mixed biofilm formation of other fungal biofilms, and provide strategies and theoretical basis for the control, development and utilization of fungal biofilms.
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Affiliation(s)
- Dandan Wang
- College of Land and Environment, Shenyang Agricultural University, Shenyang, 110866, PR China
| | - Nan Zeng
- College of Land and Environment, Shenyang Agricultural University, Shenyang, 110866, PR China
| | - Chunji Li
- Innovative Institute for Plant Health, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, PR China
- Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China, Ministry of Agriculture and Rural Affairs, Guangzhou, 510225, PR China
- College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, PR China
| | - Zijing Li
- College of Food Science, Shenyang Agricultural University, Shenyang, 110866, PR China
| | - Ning Zhang
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, PR China
| | - Bingxue Li
- College of Land and Environment, Shenyang Agricultural University, Shenyang, 110866, PR China
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3
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Giallonardi G, Letizia M, Mellini M, Frangipani E, Halliday N, Heeb S, Cámara M, Visca P, Imperi F, Leoni L, Williams P, Rampioni G. Alkyl-quinolone-dependent quorum sensing controls prophage-mediated autolysis in Pseudomonas aeruginosa colony biofilms. Front Cell Infect Microbiol 2023; 13:1183681. [PMID: 37305419 PMCID: PMC10250642 DOI: 10.3389/fcimb.2023.1183681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/02/2023] [Indexed: 06/13/2023] Open
Abstract
Pseudomonas aeruginosa is a model quorum sensing (QS) pathogen with three interconnected QS circuits that control the production of virulence factors and antibiotic tolerant biofilms. The pqs QS system of P. aeruginosa is responsible for the biosynthesis of diverse 2-alkyl-4-quinolones (AQs), of which 2-heptyl-4-hydroxyquinoline (HHQ) and 2-heptyl-3-hydroxy-4(1H)-quinolone (PQS) function as QS signal molecules. Transcriptomic analyses revealed that HHQ and PQS influenced the expression of multiple genes via PqsR-dependent and -independent pathways whereas 2-heptyl-4-hydroxyquinoline N-oxide (HQNO) had no effect on P. aeruginosa transcriptome. HQNO is a cytochrome bc 1 inhibitor that causes P. aeruginosa programmed cell death and autolysis. However, P. aeruginosa pqsL mutants unable to synthesize HQNO undergo autolysis when grown as colony biofilms. The mechanism by which such autolysis occurs is not understood. Through the generation and phenotypic characterization of multiple P. aeruginosa PAO1 mutants producing altered levels of AQs in different combinations, we demonstrate that mutation of pqsL results in the accumulation of HHQ which in turn leads to Pf4 prophage activation and consequently autolysis. Notably, the effect of HHQ on Pf4 activation is not mediated via its cognate receptor PqsR. These data indicate that the synthesis of HQNO in PAO1 limits HHQ-induced autolysis mediated by Pf4 in colony biofilms. A similar phenomenon is shown to occur in P. aeruginosa cystic fibrosis (CF) isolates, in which the autolytic phenotype can be abrogated by ectopic expression of pqsL.
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Affiliation(s)
| | | | - Marta Mellini
- Department of Science, University Roma Tre, Rome, Italy
| | | | - Nigel Halliday
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Stephan Heeb
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Miguel Cámara
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Paolo Visca
- Department of Science, University Roma Tre, Rome, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
| | - Francesco Imperi
- Department of Science, University Roma Tre, Rome, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
| | - Livia Leoni
- Department of Science, University Roma Tre, Rome, Italy
| | - Paul Williams
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Giordano Rampioni
- Department of Science, University Roma Tre, Rome, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
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Markus V, Paul AA, Teralı K, Özer N, Marks RS, Golberg K, Kushmaro A. Conversations in the Gut: The Role of Quorum Sensing in Normobiosis. Int J Mol Sci 2023; 24:ijms24043722. [PMID: 36835135 PMCID: PMC9963693 DOI: 10.3390/ijms24043722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/03/2023] [Accepted: 02/11/2023] [Indexed: 02/15/2023] Open
Abstract
An imbalance in gut microbiota, termed dysbiosis, has been shown to affect host health. Several factors, including dietary changes, have been reported to cause dysbiosis with its associated pathologies that include inflammatory bowel disease, cancer, obesity, depression, and autism. We recently demonstrated the inhibitory effects of artificial sweeteners on bacterial quorum sensing (QS) and proposed that QS inhibition may be one mechanism behind such dysbiosis. QS is a complex network of cell-cell communication that is mediated by small diffusible molecules known as autoinducers (AIs). Using AIs, bacteria interact with one another and coordinate their gene expression based on their population density for the benefit of the whole community or one group over another. Bacteria that cannot synthesize their own AIs secretly "listen" to the signals produced by other bacteria, a phenomenon known as "eavesdropping". AIs impact gut microbiota equilibrium by mediating intra- and interspecies interactions as well as interkingdom communication. In this review, we discuss the role of QS in normobiosis (the normal balance of bacteria in the gut) and how interference in QS causes gut microbial imbalance. First, we present a review of QS discovery and then highlight the various QS signaling molecules used by bacteria in the gut. We also explore strategies that promote gut bacterial activity via QS activation and provide prospects for the future.
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Affiliation(s)
- Victor Markus
- Department of Medical Biochemistry, Faculty of Medicine, Near East University, Nicosia 99138, Cyprus
| | - Abraham Abbey Paul
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
| | - Kerem Teralı
- Department of Medical Biochemistry, Faculty of Medicine, Cyprus International University, Nicosia 99258, Cyprus
| | - Nazmi Özer
- Department of Biochemistry, Faculty of Pharmacy, Girne American University, Kyrenia 99428, Cyprus
| | - Robert S. Marks
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
- The Ilse Katz Center for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
| | - Karina Golberg
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
- Correspondence: (K.G.); (A.K.); Tel.: +972-74-7795293 (K.G.); +972-747795291 (A.K.)
| | - Ariel Kushmaro
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
- The Ilse Katz Center for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
- School of Sustainability and Climate Change, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
- Correspondence: (K.G.); (A.K.); Tel.: +972-74-7795293 (K.G.); +972-747795291 (A.K.)
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Bioengineering Approaches to Fight against Orthopedic Biomaterials Related-Infections. Int J Mol Sci 2022; 23:ijms231911658. [PMID: 36232956 PMCID: PMC9569980 DOI: 10.3390/ijms231911658] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/24/2022] [Accepted: 09/26/2022] [Indexed: 11/07/2022] Open
Abstract
One of the most serious complications following the implantation of orthopedic biomaterials is the development of infection. Orthopedic implant-related infections do not only entail clinical problems and patient suffering, but also cause a burden on healthcare care systems. Additionally, the ageing of the world population, in particular in developed countries, has led to an increase in the population above 60 years. This is a significantly vulnerable population segment insofar as biomaterials use is concerned. Implanted materials are highly susceptible to bacterial and fungal colonization and the consequent infection. These microorganisms are often opportunistic, taking advantage of the weakening of the body defenses at the implant surface–tissue interface to attach to tissues or implant surfaces, instigating biofilm formation and subsequent development of infection. The establishment of biofilm leads to tissue destruction, systemic dissemination of the pathogen, and dysfunction of the implant/bone joint, leading to implant failure. Moreover, the contaminated implant can be a reservoir for infection of the surrounding tissue where microorganisms are protected. Therefore, the biofilm increases the pathogenesis of infection since that structure offers protection against host defenses and antimicrobial therapies. Additionally, the rapid emergence of bacterial strains resistant to antibiotics prompted the development of new alternative approaches to prevent and control implant-related infections. Several concepts and approaches have been developed to obtain biomaterials endowed with anti-infective properties. In this review, several anti-infective strategies based on biomaterial engineering are described and discussed in terms of design and fabrication, mechanisms of action, benefits, and drawbacks for preventing and treating orthopaedic biomaterials-related infections.
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Phage Infection Restores PQS Signaling and Enhances Growth of a Pseudomonas aeruginosa lasI Quorum-Sensing Mutant. J Bacteriol 2022; 204:e0055721. [PMID: 35389255 PMCID: PMC9112912 DOI: 10.1128/jb.00557-21] [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] [Indexed: 11/28/2022] Open
Abstract
Chemical communication between bacteria and between bacteria and the bacteriophage (phage) viruses that prey on them can shape the outcomes of phage-bacterial encounters. Quorum sensing (QS) is a bacterial cell-to-cell communication process that promotes collective undertaking of group behaviors. QS relies on the production, release, accumulation, and detection of signal molecules called autoinducers. Phages can exploit QS-mediated communication to manipulate their hosts and maximize their own survival. In the opportunistic pathogen Pseudomonas aeruginosa, the LasI/R QS system induces the RhlI/R QS system, and in opposing manners, these two systems control the QS system that relies on the autoinducer called PQS. A P. aeruginosa ΔlasI mutant is impaired in PQS synthesis, leading to accumulation of the precursor molecule HHQ, and HHQ suppresses growth of the P. aeruginosa ΔlasI strain. We show that, in response to a phage infection, the P. aeruginosa ΔlasI mutant reactivates QS, which, in turn, restores pqsH expression, enabling conversion of HHQ into PQS. Moreover, downstream QS target genes encoding virulence factors are induced. Additionally, phage-infected P. aeruginosa ΔlasI cells transiently exhibit superior growth compared to uninfected cells. IMPORTANCE Clinical isolates of P. aeruginosa frequently harbor mutations in particular QS genes. Here, we show that infection by select temperate phages restores QS, a cell-to-cell communication mechanism in a P. aeruginosa QS mutant. Restoration of QS increases expression of genes encoding virulence factors. Thus, phage infection of select P. aeruginosa strains may increase bacterial pathogenicity, underscoring the importance of characterizing phage-host interactions in the context of bacterial mutants that are relevant in clinical settings.
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Inhibitory Effects of Artificial Sweeteners on Bacterial Quorum Sensing. Int J Mol Sci 2021; 22:ijms22189863. [PMID: 34576027 PMCID: PMC8472786 DOI: 10.3390/ijms22189863] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 09/09/2021] [Accepted: 09/10/2021] [Indexed: 12/19/2022] Open
Abstract
Despite having been tagged as safe and beneficial, recent evidence remains inconclusive regarding the status of artificial sweeteners and their putative effects on gut microbiota. Gut microorganisms are essential for the normal metabolic functions of their host. These microorganisms communicate within their community and regulate group behaviors via a molecular system termed quorum sensing (QS). In the present study, we aimed to study the effects of artificial sweeteners on this bacterial communication system. Using biosensor assays, biophysical protein characterization methods, microscale thermophoresis, swarming motility assays, growth assays, as well as molecular docking, we show that aspartame, sucralose, and saccharin have significant inhibitory actions on the Gram-negative bacteria N-acyl homoserine lactone-based (AHL) communication system. Our studies indicate that these three artificial sweeteners are not bactericidal. Protein-ligand docking and interaction profiling, using LasR as a representative participating receptor for AHL, suggest that the artificial sweeteners bind to the ligand-binding pocket of the protein, possibly interfering with the proper housing of the native ligand and thus impeding protein folding. Our findings suggest that these artificial sweeteners may affect the balance of the gut microbial community via QS-inhibition. We, therefore, infer an effect of these artificial sweeteners on numerous molecular events that are at the core of intestinal microbial function, and by extension on the host metabolism.
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8
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Jackson L, Waters V. Factors influencing the acquisition and eradication of early Pseudomonas aeruginosa infection in cystic fibrosis. J Cyst Fibros 2020; 20:8-16. [PMID: 33172756 DOI: 10.1016/j.jcf.2020.10.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 10/02/2020] [Accepted: 10/27/2020] [Indexed: 12/21/2022]
Abstract
In recent years considerable improvements have been made in increasing the life expectancy of patients with cystic fibrosis. New highly effective modulator therapies targeting the underlying defect in the cystic fibrosis transmembrane conductance regulator protein are expected to enhance lifespan even further. However, chronic Pseudomonas aeruginosa pulmonary infections continue to threaten CF patient lung health and mortality rates. Early and aggressive antibiotic eradication therapies targeting P. aeruginosa are standard practice, but these eradication therapies fail in 10-40% of patients. The reasons for P. aeruginosa eradication failure remain unclear. Thus, this review summarizes the evidence to date for pseudomonal acquisition and eradication failure in the cystic fibrosis lung. A complex combination of host and bacterial factors are responsible for initial establishment of P. aeruginosa pulmonary infections. Moreover, host and pseudomonal factors, polymicrobial interactions, and antimicrobial limitations in relation to P. aeruginosa eradication therapy failure are summarized.
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Affiliation(s)
- Lindsay Jackson
- Translational Medicine, Hospital for Sick Children, Toronto, Canada.
| | - Valerie Waters
- Translational Medicine, Hospital for Sick Children, Toronto, Canada; Infectious Diseases, Department of Pediatrics, Hospital for Sick Children, Toronto, Canada
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9
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Thapa SS, Grove A. Impaired purine homeostasis plays a primary role in trimethoprim-mediated induction of virulence genes in Burkholderia thailandensis. Mol Microbiol 2020; 115:610-622. [PMID: 33053234 DOI: 10.1111/mmi.14626] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 11/27/2022]
Abstract
One of the most commonly prescribed antibiotics against Burkholderia infections is co-trimoxazole, a cocktail of trimethoprim and sulfamethoxazole. Trimethoprim elicits an upregulation of the mal gene cluster, which encodes proteins involved in synthesis of the cytotoxic polyketide malleilactone; trimethoprim does so by increasing expression of the malR gene, which encodes the activator MalR. We report that B. thailandensis grown on trimethoprim exhibited increased virulence against Caenorhabditis elegans. This enhanced virulence correlated with an increase in expression of the mal gene cluster. Notably, inhibition of xanthine dehydrogenase by addition of allopurinol led to similar upregulation of malA and malR, with addition of trimethoprim or allopurinol also resulting in an equivalent intracellular accumulation of xanthine. Xanthine is a ligand for the transcription factor MftR that leads to attenuated DNA binding, and we show using chromatin immunoprecipitation that MftR binds directly to malR. Our gene expression data suggest that malR expression is repressed by both MftR and by a separate transcription factor, which also responds to a metabolite that accumulates on exposure to trimethoprim. Since allopurinol elicits a similar increase in malR/malA expression as trimethoprim, we suggest that impaired purine homeostasis plays a primary role in trimethoprim-mediated induction of malR and in turn malA.
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Affiliation(s)
- Sudarshan S Thapa
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - Anne Grove
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
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10
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Baker YR, Hodgkinson JT, Florea BI, Alza E, Galloway WRJD, Grimm L, Geddis SM, Overkleeft HS, Welch M, Spring DR. Identification of new quorum sensing autoinducer binding partners in Pseudomonas aeruginosa using photoaffinity probes. Chem Sci 2017; 8:7403-7411. [PMID: 29163891 PMCID: PMC5674140 DOI: 10.1039/c7sc01270e] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 08/26/2017] [Indexed: 12/20/2022] Open
Abstract
Many bacterial species, including the human pathogen Pseudomonas aeruginosa, employ a mechanism of intercellular communication known as quorum sensing (QS), which is mediated by signalling molecules termed autoinducers. The Pseudomonas Quinolone Signal (PQS) and 2-Heptyl-3H-4-Quinolone (HHQ) are autoinducers in P. aeruginosa, and they are considered important factors in the progress of infections by this clinically relevant organism. Herein, we report the development of HHQ and PQS photoaffinity-based probes for chemical proteomic studies. Application of these probes led to the identification of previously unsuspected putative HHQ and PQS binders, thereby providing new insights into QS at a proteomic level and revealing potential new small molecule targets for virulence attenuation strategies. Notably, we found evidence that PQS binds RhlR, the cognate receptor in the Rhl QS sub-system of P. aeruginosa. This is the first indication of interaction between the Rhl and PQS systems at the protein/ligand level, which suggests that RhlR should be considered a highly attractive target for antivirulence strategies.
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Affiliation(s)
- Y R Baker
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge , CB2 1EW , UK .
- Leiden Institute of Chemistry , Leiden University , Einsteinweg 55 , 2333 CC Leiden , The Netherlands
- Department of Biochemistry , University of Cambridge , 80 Tennis Court Road , Cambridge , CB2 1GA , UK .
| | - J T Hodgkinson
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge , CB2 1EW , UK .
- Department of Biochemistry , University of Cambridge , 80 Tennis Court Road , Cambridge , CB2 1GA , UK .
| | - B I Florea
- Leiden Institute of Chemistry , Leiden University , Einsteinweg 55 , 2333 CC Leiden , The Netherlands
| | - E Alza
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge , CB2 1EW , UK .
| | - W R J D Galloway
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge , CB2 1EW , UK .
| | - L Grimm
- Department of Biochemistry , University of Cambridge , 80 Tennis Court Road , Cambridge , CB2 1GA , UK .
| | - S M Geddis
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge , CB2 1EW , UK .
| | - H S Overkleeft
- Leiden Institute of Chemistry , Leiden University , Einsteinweg 55 , 2333 CC Leiden , The Netherlands
| | - M Welch
- Department of Biochemistry , University of Cambridge , 80 Tennis Court Road , Cambridge , CB2 1GA , UK .
| | - D R Spring
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge , CB2 1EW , UK .
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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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12
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Xu L, Venkataramani P, Ding Y, Liu Y, Deng Y, Yong GL, Xin L, Ye R, Zhang L, Yang L, Liang ZX. A Cyclic di-GMP-binding Adaptor Protein Interacts with Histidine Kinase to Regulate Two-component Signaling. J Biol Chem 2016; 291:16112-23. [PMID: 27231351 DOI: 10.1074/jbc.m116.730887] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Indexed: 11/06/2022] Open
Abstract
The bacterial messenger cyclic di-GMP (c-di-GMP) binds to a diverse range of effectors to exert its biological effect. Despite the fact that free-standing PilZ proteins are by far the most prevalent c-di-GMP effectors known to date, their physiological function and mechanism of action remain largely unknown. Here we report that the free-standing PilZ protein PA2799 from the opportunistic pathogen Pseudomonas aeruginosa interacts directly with the hybrid histidine kinase SagS. We show that PA2799 (named as HapZ: histidine kinase associated PilZ) binds directly to the phosphoreceiver (REC) domain of SagS, and that the SagS-HapZ interaction is further enhanced at elevated c-di-GMP concentration. We demonstrate that binding of HapZ to SagS inhibits the phosphotransfer between SagS and the downstream protein HptB in a c-di-GMP-dependent manner. In accordance with the role of SagS as a motile-sessile switch and biofilm growth factor, we show that HapZ impacts surface attachment and biofilm formation most likely by regulating the expression of a large number of genes. The observations suggest a previously unknown mechanism whereby c-di-GMP mediates two-component signaling through a PilZ adaptor protein.
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Affiliation(s)
- Linghui Xu
- From the School of Biological Sciences and Guangdong Innovative and Entrepreneurial Research Team of Sociomicrobiology Basic Science and Frontier Technology and
| | | | - Yichen Ding
- From the School of Biological Sciences and Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 and
| | - Yang Liu
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 and
| | - Yinyue Deng
- Guangdong Innovative and Entrepreneurial Research Team of Sociomicrobiology Basic Science and Frontier Technology and
| | | | - Lingyi Xin
- From the School of Biological Sciences and
| | - Ruijuan Ye
- From the School of Biological Sciences and
| | - Lianhui Zhang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, People's Republic of China
| | - Liang Yang
- From the School of Biological Sciences and Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 and
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Zhao J, Yu X, Zhu M, Kang H, Ma J, Wu M, Gan J, Deng X, Liang H. Structural and Molecular Mechanism of CdpR Involved in Quorum-Sensing and Bacterial Virulence in Pseudomonas aeruginosa. PLoS Biol 2016; 14:e1002449. [PMID: 27119725 PMCID: PMC4847859 DOI: 10.1371/journal.pbio.1002449] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 03/24/2016] [Indexed: 01/07/2023] Open
Abstract
Although quorum-sensing (QS) systems are important regulators of virulence gene expression in the opportunistic human pathogen Pseudomonas aeruginosa, their detailed regulatory mechanisms have not been fully characterized. Here, we show that deletion of PA2588 resulted in increased production of pyocyanin and biofilm, as well as enhanced pathogenicity in a mouse model. To gain insights into the function of PA2588, we performed a ChIP-seq assay and identified 28 targets of PA2588, including the intergenic region between PA2588 and pqsH, which encodes the key synthase of Pseudomonas quinolone signal (PQS). Though the C-terminal domain was similar to DNA-binding regions of other AraC family members, structural studies revealed that PA2588 has a novel fold at the N-terminal region (NTR), and its C-terminal HTH (helix-turn-helix) domain is also unique in DNA recognition. We also demonstrated that the adaptor protein ClpS, an essential regulator of ATP-dependent protease ClpAP, directly interacted with PA2588 before delivering CdpR to ClpAP for degradation. We named PA2588 as CdpR (ClpAP-degradation and pathogenicity Regulator). Moreover, deletion of clpP or clpS/clpA promotes bacterial survival in a mouse model of acute pneumonia infection. Taken together, this study uncovered that CdpR is an important QS regulator, which can interact with the ClpAS-P system to regulate the expression of virulence factors and pathogenicity.
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Affiliation(s)
- Jingru Zhao
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an, ShaanXi, China
| | - Xiang Yu
- Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai, China
- State Key Laboratory of Genetic Engineering, Innovative Collaborative Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai, China
| | - Miao Zhu
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an, ShaanXi, China
| | - Huaping Kang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an, ShaanXi, China
| | - Jinbiao Ma
- State Key Laboratory of Genetic Engineering, Innovative Collaborative Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai, China
| | - Min Wu
- Department of Basic Science, School of Medicine and Health Science, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Jianhua Gan
- Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai, China
- * E-mail: (JG); (XD); (HL)
| | - Xin Deng
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
- * E-mail: (JG); (XD); (HL)
| | - Haihua Liang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an, ShaanXi, China
- * E-mail: (JG); (XD); (HL)
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14
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Frydenlund Michelsen C, Hossein Khademi SM, Krogh Johansen H, Ingmer H, Dorrestein PC, Jelsbak L. Evolution of metabolic divergence in Pseudomonas aeruginosa during long-term infection facilitates a proto-cooperative interspecies interaction. ISME JOURNAL 2015; 10:1323-36. [PMID: 26684729 PMCID: PMC5029194 DOI: 10.1038/ismej.2015.220] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 10/20/2015] [Accepted: 10/25/2015] [Indexed: 02/08/2023]
Abstract
The effect of polymicrobial interactions on pathogen physiology and how it can act either to limit pathogen colonization or to potentiate pathogen expansion and virulence are not well understood. Pseudomonas aeruginosa and Staphylococcus aureus are opportunistic pathogens commonly found together in polymicrobial human infections. However, we have previously shown that the interactions between these two bacterial species are strain dependent. Whereas P. aeruginosa PAO1, a commonly used laboratory strain, effectively suppressed S. aureus growth, we observed a commensal-like interaction between the human host-adapted strain, DK2-P2M24-2003, and S. aureus. In this study, characterization by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) imaging mass spectrometry (IMS) and mass spectral (MS) molecular networking revealed a significant metabolic divergence between P. aeruginosa PAO1 and DK2-P2M24-2003, which comprised several virulence factors and signaling 4-hydroxy-2-alkylquinoline (HAQ) molecules. Strikingly, a further modulation of the HAQ profile was observed in DK2-P2M24-2003 during interaction with S. aureus, resulting in an area with thickened colony morphology at the P. aeruginosa–S. aureus interface. In addition, we found an HAQ-mediated protection of S. aureus by DK2-P2M24-2003 from the killing effect of tobramycin. Our findings suggest a model where the metabolic divergence manifested in human host-adapted P. aeruginosa is further modulated during interaction with S. aureus and facilitate a proto-cooperative P. aeruginosa–S. aureus relationship.
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Affiliation(s)
| | | | - Helle Krogh Johansen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark.,The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Hørsholm, Denmark
| | - Hanne Ingmer
- Department of Veterinary Disease Biology, Food Safety and Zoonoses, University of Copenhagen, Frederiksberg C, Denmark
| | - Pieter C Dorrestein
- Department of Pharmacology, University of California at San Diego, La Jolla, CA, USA.,Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, CA, USA.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA, USA
| | - Lars Jelsbak
- Department of Systems Biology, Technical University of Denmark, Lyngby, Denmark
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15
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Serra DO, Klauck G, Hengge R. Vertical stratification of matrix production is essential for physical integrity and architecture of macrocolony biofilms of Escherichia coli. Environ Microbiol 2015; 17:5073-88. [PMID: 26234179 PMCID: PMC5014196 DOI: 10.1111/1462-2920.12991] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 07/15/2015] [Indexed: 12/22/2022]
Abstract
Bacterial macrocolony biofilms grow into intricate three-dimensional structures that depend on self-produced extracellular polymers conferring protection, cohesion and elasticity to the biofilm. In Escherichia coli, synthesis of this matrix - consisting of amyloid curli fibres and cellulose - requires CsgD, a transcription factor regulated by the stationary phase sigma factor RpoS, and occurs in the nutrient-deprived cells of the upper layer of macrocolonies. Is this asymmetric matrix distribution functionally important or is it just a fortuitous by-product of an unavoidable nutrient gradient? In order to address this question, the RpoS-dependent csgD promoter was replaced by a vegetative promoter. This re-wiring of csgD led to CsgD and matrix production in both strata of macrocolonies, with the lower layer transforming into a rigid 'base plate' of growing yet curli-connected cells. As a result, the two strata broke apart followed by desiccation and exfoliation of the top layer. By contrast, matrix-free cells at the bottom of wild-type macrocolonies maintain colony contact with the humid agar support by flexibly filling the space that opens up under buckling areas of the macrocolony. Precisely regulated stratification in matrix-free and matrix-producing cell layers is thus essential for the physical integrity and architecture of E. coli macrocolony biofilms.
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Affiliation(s)
- Diego O Serra
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Berlin, 10115, Germany
| | - Gisela Klauck
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Berlin, 10115, Germany
| | - Regine Hengge
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Berlin, 10115, Germany
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16
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Mangwani N, Kumari S, Das S. Involvement of quorum sensing genes in biofilm development and degradation of polycyclic aromatic hydrocarbons by a marine bacterium Pseudomonas aeruginosa N6P6. Appl Microbiol Biotechnol 2015; 99:10283-97. [DOI: 10.1007/s00253-015-6868-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 07/20/2015] [Indexed: 12/16/2022]
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17
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Gannesen AV, Zhurina MV, Veselova MA, Khmel’ IA, Plakunov VK. Regulation of biofilm formation by Pseudomonas chlororaphis in an in vitro system. Microbiology (Reading) 2015. [DOI: 10.1134/s0026261715030042] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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18
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Sousa AM, Pereira MO, Lourenço A. MorphoCol: An ontology-based knowledgebase for the characterisation of clinically significant bacterial colony morphologies. J Biomed Inform 2015; 55:55-63. [DOI: 10.1016/j.jbi.2015.03.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 01/24/2015] [Accepted: 03/20/2015] [Indexed: 01/09/2023]
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Sankar Ganesh P, Rai Vittal R. In vitro antibiofilm activity of Murraya koenigii essential oil extracted using supercritical fluid CO2 method against Pseudomonas aeruginosa PAO1. Nat Prod Res 2015; 29:2295-8. [DOI: 10.1080/14786419.2015.1004673] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- P. Sankar Ganesh
- Department of Studies in Microbiology, University of Mysore, Manasagangotri, Mysore 570006, Karnataka, India
| | - Ravishankar Rai Vittal
- Department of Studies in Microbiology, University of Mysore, Manasagangotri, Mysore 570006, Karnataka, India
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20
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Waters V. Editorial commentary: how can understanding the phenotype of Pseudomonas aeruginosa lead to more successful eradication strategies in cystic fibrosis? Clin Infect Dis 2014; 59:632-4. [PMID: 24863402 DOI: 10.1093/cid/ciu388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Valerie Waters
- Division of Infectious Diseases, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada
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21
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Mayer-Hamblett N, Ramsey BW, Kulasekara HD, Wolter DJ, Houston LS, Pope CE, Kulasekara BR, Armbruster CR, Burns JL, Retsch-Bogart G, Rosenfeld M, Gibson RL, Miller SI, Khan U, Hoffman LR. Pseudomonas aeruginosa phenotypes associated with eradication failure in children with cystic fibrosis. Clin Infect Dis 2014; 59:624-31. [PMID: 24863401 DOI: 10.1093/cid/ciu385] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Pseudomonas aeruginosa is a key respiratory pathogen in people with cystic fibrosis (CF). Due to its association with lung disease progression, initial detection of P. aeruginosa in CF respiratory cultures usually results in antibiotic treatment with the goal of eradication. Pseudomonas aeruginosa exhibits many different phenotypes in vitro that could serve as useful prognostic markers, but the relative relationships between these phenotypes and failure to eradicate P. aeruginosa have not been well characterized. METHODS We measured 22 easily assayed in vitro phenotypes among the baseline P. aeruginosa isolates collected from 194 participants in the 18-month EPIC clinical trial, which assessed outcomes after antibiotic eradication therapy for newly identified P. aeruginosa. We then evaluated the associations between these baseline isolate phenotypes and subsequent outcomes during the trial, including failure to eradicate after antipseudomonal therapy, emergence of mucoidy, and occurrence of an exacerbation. RESULTS Baseline P. aeruginosa isolates frequently exhibited phenotypes thought to represent chronic adaptation, including mucoidy. Wrinkly colony surface and irregular colony edges were both associated with increased risk of eradication failure (hazard ratios [95% confidence intervals], 1.99 [1.03-3.83] and 2.14 [1.32-3.47], respectively). Phenotypes reflecting defective quorum sensing were significantly associated with subsequent mucoidy, but no phenotype was significantly associated with subsequent exacerbations during the trial. CONCLUSIONS Pseudomonas aeruginosa phenotypes commonly considered to reflect chronic adaptation were observed frequently among isolates at early detection. We found that 2 easily assayed colony phenotypes were associated with failure to eradicate after antipseudomonal therapy, both of which have been previously associated with altered biofilm formation and defective quorum sensing.
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Affiliation(s)
- Nicole Mayer-Hamblett
- Department of Pediatrics Department of Biostatistics Department of Seattle Children's Hospital, Washington
| | - Bonnie W Ramsey
- Department of Pediatrics Department of Seattle Children's Hospital, Washington
| | | | | | | | | | | | | | - Jane L Burns
- Department of Pediatrics Department of Seattle Children's Hospital, Washington
| | | | - Margaret Rosenfeld
- Department of Pediatrics Department of Seattle Children's Hospital, Washington
| | - Ronald L Gibson
- Department of Pediatrics Department of Seattle Children's Hospital, Washington
| | - Samuel I Miller
- Department of Microbiology Department of Genome Sciences Department of Medicine, University of Washington, Seattle
| | - Umer Khan
- Department of Seattle Children's Hospital, Washington
| | - Lucas R Hoffman
- Department of Pediatrics Department of Microbiology Department of Seattle Children's Hospital, Washington
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22
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The stringent response modulates 4-hydroxy-2-alkylquinoline biosynthesis and quorum-sensing hierarchy in Pseudomonas aeruginosa. J Bacteriol 2014; 196:1641-50. [PMID: 24509318 DOI: 10.1128/jb.01086-13] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
As a ubiquitous environmental organism and an important human pathogen, Pseudomonas aeruginosa readily adapts and responds to a wide range of conditions and habitats. The intricate regulatory networks that link quorum sensing and other global regulators allow P. aeruginosa to coordinate its gene expression and cell signaling in response to different growth conditions and stressors. Upon nutrient transitions and starvation, as well as other environmental stresses, the stringent response is activated, mediated by the signal (p)ppGpp. P. aeruginosa produces a family of molecules called HAQ (4-hydroxy-2-alkylquinolines), some of which exhibit antibacterial and quorum-sensing signaling functions and regulate virulence genes. In this study, we report that (p)ppGpp negatively regulates HAQ biosynthesis: in a (p)ppGpp-null (ΔSR) mutant, HHQ (4-hydroxyl-2-heptylquinoline) and PQS (3,4-dihydroxy-2-heptylquinoline) levels are increased due to upregulated pqsA and pqsR expression and reduced repression by the rhl system. We also found that (p)ppGpp is required for full expression of both rhl and las AHL (acyl-homoserine lactone) quorum-sensing systems, since the ΔSR mutant has reduced rhlI, rhlR, lasI, and lasR expression, butanoyl-homoserine lactone (C4-HSL) and 3-oxo-dodecanoyl-homoserine lactone (3-oxo-C12-HSL) levels, and rhamnolipid and elastase production. Furthermore, (p)ppGpp significantly modulates the AHL and PQS quorum-sensing hierarchy, as the las system no longer has a dominant effect on HAQ biosynthesis when the stringent response is inactivated.
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Chen YS, Shieh WJ, Goldsmith CS, Metcalfe MG, Greer PW, Zaki SR, Chang HH, Chan H, Chen YL. Alteration of the phenotypic and pathogenic patterns of Burkholderia pseudomallei that persist in a soil environment. Am J Trop Med Hyg 2014; 90:469-79. [PMID: 24445207 DOI: 10.4269/ajtmh.13-0051] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Melioidosis is caused by the soil-borne pathogen Burkholderia pseudomallei. To investigate whether the distinct phenotypic and virulent characteristics result from environmental adaptations in the soil or from the host body, two pairs of isogenic strains were generated by passages in soil or mice. After cultivation in soil, the levels of 3-hydroxytetradecanoic acid, biofilm formation, flagellar expression, and ultrastructure were altered in the bacteria. Uniformly fatal melioidosis developed as a result of infection with mouse-derived strains; however, the survival rates of mice infected with soil-derived strains prolonged. After primary infection or reinfection with soil-derived strains, the mice developed a low degree of bacterial hepatitis and bacterial colonization in the liver and bone marrow compared with mice that were infected with isogenic or heterogenic mouse-derived strains. We suggest that specific phenotypic and pathogenic patterns can be induced through infection with B. pseudomallei that has been cultured in different (soil versus mouse) environments.
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Affiliation(s)
- Yao-Shen Chen
- Division of Infectious Diseases, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan; Graduate Institute of Science Education and Environmental Education, National Kaohsiung Normal University, Kaohsiung; Taiwan/Department of Internal Medicine, National Yang-Ming University, Taipei, Taiwan; Infectious Diseases Pathology Branch, Centers for Disease Control and Prevention, Atlanta, Georgia; Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan; Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan; Department of Biotechnology, National Kaohsiung Normal University, Kaoshiung, Taiwan
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24
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Lysobacter enzymogenes uses two distinct cell-cell signaling systems for differential regulation of secondary-metabolite biosynthesis and colony morphology. Appl Environ Microbiol 2013; 79:6604-16. [PMID: 23974132 DOI: 10.1128/aem.01841-13] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lysobacter enzymogenes is a ubiquitous environmental bacterium that is emerging as a potentially novel biological control agent and a new source of bioactive secondary metabolites, such as the heat-stable antifungal factor (HSAF) and photoprotective polyene pigments. Thus far, the regulatory mechanism(s) for biosynthesis of these bioactive secondary metabolites remains largely unknown in L. enzymogenes. In the present study, the diffusible signal factor (DSF) and diffusible factor (DF)-mediated cell-cell signaling systems were identified for the first time from L. enzymogenes. The results show that both Rpf/DSF and DF signaling systems played critical roles in modulating HSAF biosynthesis in L. enzymogenes. Rpf/DSF signaling and DF signaling played negative and positive effects in polyene pigment production, respectively, with DF playing a more important role in regulating this phenotype. Interestingly, only Rpf/DSF, but not the DF signaling system, regulated colony morphology of L. enzymgenes. Both Rpf/DSF and DF signaling systems were involved in the modulation of expression of genes with diverse functions in L. enzymogenes, and their own regulons exhibited only a few loci that were regulated by both systems. These findings unveil for the first time new roles of the Rpf/DSF and DF signaling systems in secondary metabolite biosynthesis of L. enzymogenes.
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Usability application of multiplex polymerase chain reaction in the diagnosis of microorganisms isolated from urine of patients treated in cancer hospital. Radiol Oncol 2013; 47:296-303. [PMID: 24133395 PMCID: PMC3794886 DOI: 10.2478/raon-2013-0044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 05/11/2013] [Indexed: 11/21/2022] Open
Abstract
Background The objective of this study was: i) to compare the results of urine culture with polymerase chain reaction (PCR) -based detection of microorganisms using two commercially available kits, ii) to assess antimicrobial susceptibility of urine isolates from cancer patients to chosen antimicrobial drugs and, if necessary, to update the recommendation of empirical therapy. Materials and methods. A one-year hospital-based prospective study has been conducted in Greater Poland Cancer Centre and Genetic Medicine Laboratory CBDNA Research Centre in 2011. Urine cultures and urine PCR assay from 72 patients were examined Results Urine cultures and urine PCR assay from 72 patients were examined. Urine samples were positive for 128 strains from which 95 (74%) were identical in both tests. The most frequently isolated bacteria in both culture and PCR assay were coliform organisms and Enterococcus spp. The Gram negative bacilli were most resistant to cotrimoxazol. 77.2% of these bacilli and 100% of E. faecalis and S. agalactiae were sensitive to amoxicillin-clavulanic acid. 4.7% of Gram positive cocci were resistant to nitrofurantoin. Conclusions The PCR method quickly finds the causative agent of urinary tract infection (UTI) and, therefore, it can help with making the choice of the proper antimicrobial therapy at an early stage. It appears to be a viable alternative to the recommendations made in general treatment guidelines, in cases where diversified sensitivity patterns of microorganisms have been found.
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Chapalain A, Vial L, Laprade N, Dekimpe V, Perreault J, Déziel E. Identification of quorum sensing-controlled genes in Burkholderia ambifaria. Microbiologyopen 2013; 2:226-42. [PMID: 23382083 PMCID: PMC3633348 DOI: 10.1002/mbo3.67] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 12/18/2012] [Accepted: 12/26/2012] [Indexed: 01/23/2023] Open
Abstract
The Burkholderia cepacia complex (Bcc) comprises strains with a virulence potential toward immunocompromised patients as well as plant growth-promoting rhizobacteria (PGPR). Owing to the link between quorum sensing (QS) and virulence, most studies among Bcc species have been directed toward QS of pathogenic bacteria. We have investigated the QS of B. ambifaria, a PGPR only infrequently recovered from patients. The cepI gene, responsible for the synthesis of the main signaling molecule N-octanoylhomoserine lactone (C8 -HSL), was inactivated. Phenotypes of the B. ambifaria cepI mutant we observed, such as increased production of siderophores and decreased proteolytic and antifungal activities, are in agreement with those of other Bcc cepI mutants. The cepI mutant was then used as background strain for a whole-genome transposon-insertion mutagenesis strategy, allowing the identification of 20 QS-controlled genes, corresponding to 17 loci. The main functions identified are linked to antifungal and antimicrobial properties, as we have identified QS-controlled genes implicated in the production of pyrrolnitrin, burkholdines (occidiofungin-like molecules), and enacyloxins. This study provides insights in the QS-regulated functions of a PGPR, which could lead to beneficial potential biotechnological applications.
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Affiliation(s)
- Annelise Chapalain
- INRS-Institut Armand-Frappier, 531 bd des Prairies, Laval, Quebec H7V 1B7, Canada
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Lauenstein M, Kaufmann M, Persson GR. Clinical and microbiological results following nonsurgical periodontal therapy with or without local administration of piperacillin/tazobactam. Clin Oral Investig 2013; 17:1645-60. [DOI: 10.1007/s00784-012-0856-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 09/27/2012] [Indexed: 10/27/2022]
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