201
|
Fukumoto A, Murakami C, Anzai Y, Kato F. Maniwamycins: new quorum-sensing inhibitors against Chromobacterium violaceum CV026 were isolated from Streptomyces sp. TOHO-M025. J Antibiot (Tokyo) 2015; 69:395-9. [PMID: 26648117 DOI: 10.1038/ja.2015.126] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 11/09/2015] [Accepted: 11/15/2015] [Indexed: 12/31/2022]
Abstract
Quorum sensing is an important microbial signaling system that controls the expression of many virulence genes. Maniwamycins C-F, new compounds and quorum-sensing inhibitors, were isolated from the culture broth of Streptomyces sp. TOHO-M025 using a silica gel column and preparative HPLC. The structures of maniwamycins were elucidated by spectroscopic analyses, including NMR. The compounds each have an azoxy moiety. All maniwamycins inhibited violacein synthesis, which is controlled by quorum sensing, in Chromobacterium violaceum CV026.
Collapse
Affiliation(s)
- Atsushi Fukumoto
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Toho University, Chiba, Japan
| | - Chikana Murakami
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Toho University, Chiba, Japan
| | - Yojiro Anzai
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Toho University, Chiba, Japan
| | - Fumio Kato
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Toho University, Chiba, Japan
| |
Collapse
|
202
|
Gölz G, Karadas G, Fischer A, Göbel UB, Alter T, Bereswill S, Heimesaat MM. Toll-Like Receptor-4 is Essential for Arcobacter Butzleri-Induced Colonic and Systemic Immune Responses in Gnotobiotic IL-10(-/-) Mice. Eur J Microbiol Immunol (Bp) 2015; 5:321-32. [PMID: 26716021 PMCID: PMC4681360 DOI: 10.1556/1886.2015.00043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 11/03/2015] [Indexed: 12/11/2022] Open
Abstract
Arcobacter butzleri causes sporadic cases of gastroenteritis, but the underlying immunopathological mechanisms of infection are unknown. We have recently demonstrated that A. butzleri-infected gnotobiotic IL-10–/– mice were clinically unaffected but exhibited intestinal and systemic inflammatory immune responses. For the first time, we here investigated the role of Toll-like receptor (TLR)-4, the main receptor for lipopolysaccharide and lipooligosaccharide of Gram-negative bacteria, in murine arcobacteriosis. Gnotobiotic TLR-4/IL-10-double deficient (TLR-4–/– IL-10–/–) and IL-10–/– control mice generated by broad-spectrum antibiotics were perorally infected with A. butzleri. Until day 16 postinfection, mice of either genotype were stably colonized with the pathogen, but fecal bacterial loads were approximately 0.5–2.0 log lower in TLR-4–/– IL-10–/– as compared to IL-10–/– mice. A. butzleri-infected TLR-4–/– IL-10–/– mice displayed less pronounced colonic apoptosis accompanied by lower numbers of macrophages and monocytes, T lymphocytes, regulatory T-cells, and B lymphocytes within the colonic mucosa and lamina propria as compared to IL-10–/– mice. Furthermore, colonic concentrations of nitric oxide, TNF, IL-6, MCP-1, and, remarkably, IFN-γ and IL-12p70 serum levels were lower in A. butzleri-infected TLR-4–/– IL-10–/– versus IL-10–/– mice. In conclusion, TLR-4 is involved in mediating murine A. butzleri infection. Further studies are needed to investigate the molecular mechanisms underlying Arcobacter–host interactions in more detail.
Collapse
Affiliation(s)
- Greta Gölz
- Institute of Food Hygiene, Freie Universität Berlin , Berlin, Germany
| | - Gül Karadas
- Institute of Food Hygiene, Freie Universität Berlin , Berlin, Germany
| | - André Fischer
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin , Berlin, Germany
| | - Ulf B Göbel
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin , Berlin, Germany
| | - Thomas Alter
- Institute of Food Hygiene, Freie Universität Berlin , Berlin, Germany
| | - Stefan Bereswill
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin , Berlin, Germany
| | - Markus M Heimesaat
- Department of Microbiology and Hygiene, Charité - University Medicine Berlin , Berlin, Germany
| |
Collapse
|
203
|
Yin H, Yin H, Deng Y, Wang H, Liu W, Zhuang X, Chu W. Tea polyphenols as an antivirulence compound Disrupt Quorum-Sensing Regulated Pathogenicity of Pseudomonas aeruginosa. Sci Rep 2015; 5:16158. [PMID: 26548447 PMCID: PMC4637895 DOI: 10.1038/srep16158] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 10/07/2015] [Indexed: 01/22/2023] Open
Abstract
Green tea, a water extract of non-fermented leaves of Camellia sinensis L., is one of the nonalcoholic beverages in China. It is becoming increasingly popular worldwide, because of its refreshing, mild stimulant and medicinal properties. Here we examined the quorum sensing inhibitory potentials of tea polyphenols (TP) as antivirulence compounds both in vitro and in vivo. Biosensor assay data suggested minimum inhibitory concentrations (MICs) of TP against selected pathogens were 6.25 ~ 12.5 mg/mL. At sub-MIC, TP can specifically inhibit the production of violacein in Chromobacterium violaceum 12472 with almost 98% reduction at 3.125 mg/mL without affecting its growth rate. Moreover, TP exhibited inhibitory effects on virulence phenotypes regulated by QS in Pseudomonas aeruginosa. The total proteolytic activity, elastase, swarming motility and biofilm formation were reduced in a concentration-dependent manner. In vivo, TP treatment resulted in the reduction of P. aeruginosa pathogenicity in Caenorhabditis elegans. When its concentration was 3.125 mg/mL, the survival rate reached 63.3%. In the excision wound infection model, the wound contraction percentage in treatment groups was relatively increased and the colony-forming units (CFU) in the wound area were significantly decreased. These results suggested that TP could be developed as a novel non-antibiotic QS inhibitor without killing the bacteria but as an antivirulence compound to control bacterial infection.
Collapse
Affiliation(s)
| | - Honging Yin
- Department of Microbiology, School of Life Science &Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Yifeng Deng
- Department of Veterinary Surgery, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Huafu Wang
- Lishui People's Hospital, the Sixth Affiliated Hospital of Wenzhou Medical University, Lishui 323000, China
| | - Wugao Liu
- Lishui People's Hospital, the Sixth Affiliated Hospital of Wenzhou Medical University, Lishui 323000, China
| | - Xiyi Zhuang
- Department of Microbiology, School of Life Science &Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Weihua Chu
- Department of Microbiology, School of Life Science &Technology, China Pharmaceutical University, Nanjing 210009, China
| |
Collapse
|
204
|
Chan KG, Liu YC, Chang CY. Inhibiting N-acyl-homoserine lactone synthesis and quenching Pseudomonas quinolone quorum sensing to attenuate virulence. Front Microbiol 2015; 6:1173. [PMID: 26539190 PMCID: PMC4609879 DOI: 10.3389/fmicb.2015.01173] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 10/09/2015] [Indexed: 01/27/2023] Open
Abstract
Bacteria sense their own population size, tune the expression of responding genes, and behave accordingly to environmental stimuli by secreting signaling molecules. This phenomenon is termed as quorum sensing (QS). By exogenously manipulating the signal transduction bacterial population behaviors could be controlled, which may be done through quorum quenching (QQ). QS related regulatory networks have been proven their involvement in regulating many virulence determinants in pathogenic bacteria in the course of infections. Interfering with QS signaling system could be a novel strategy against bacterial infections and therefore requires more understanding of their fundamental mechanisms. Here we review the development of studies specifically on the inhibition of production of N-acyl-homoserine lactone (AHL), a common proteobacterial QS signal. The opportunistic pathogen, Pseudomonas aeruginosa, equips the alkylquinolone (AQ)-mediated QS which also plays crucial roles in its pathogenicity. The studies in QQ targeting on AQ are also discussed.
Collapse
Affiliation(s)
- Kok-Gan Chan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya Kuala Lumpur, Malaysia
| | - Yi-Chia Liu
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee Dundee, UK
| | - Chien-Yi Chang
- Centre for Bacterial Cell Biology, Medical School, Newcastle University Newcastle upon Tyne, UK ; Interdisciplinary Computing and Complex BioSystems Research Group, School of Computing Science, Newcastle University Newcastle upon Tyne, UK
| |
Collapse
|
205
|
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: 48] [Impact Index Per Article: 4.8] [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.
Collapse
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.
| |
Collapse
|
206
|
Grandclément C, Tannières M, Moréra S, Dessaux Y, Faure D. Quorum quenching: role in nature and applied developments. FEMS Microbiol Rev 2015; 40:86-116. [PMID: 26432822 DOI: 10.1093/femsre/fuv038] [Citation(s) in RCA: 380] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2015] [Indexed: 12/11/2022] Open
Abstract
Quorum sensing (QS) refers to the capacity of bacteria to monitor their population density and regulate gene expression accordingly: the QS-regulated processes deal with multicellular behaviors (e.g. growth and development of biofilm), horizontal gene transfer and host-microbe (symbiosis and pathogenesis) and microbe-microbe interactions. QS signaling requires the synthesis, exchange and perception of bacterial compounds, called autoinducers or QS signals (e.g. N-acylhomoserine lactones). The disruption of QS signaling, also termed quorum quenching (QQ), encompasses very diverse phenomena and mechanisms which are presented and discussed in this review. First, we surveyed the QS-signal diversity and QS-associated responses for a better understanding of the targets of the QQ phenomena that organisms have naturally evolved and are currently actively investigated in applied perspectives. Next the mechanisms, targets and molecular actors associated with QS interference are presented, with a special emphasis on the description of natural QQ enzymes and chemicals acting as QS inhibitors. Selected QQ paradigms are detailed to exemplify the mechanisms and biological roles of QS inhibition in microbe-microbe and host-microbe interactions. Finally, some QQ strategies are presented as promising tools in different fields such as medicine, aquaculture, crop production and anti-biofouling area.
Collapse
Affiliation(s)
- Catherine Grandclément
- Institut for Integrative Biology of the Cell, Department of Microbiology, CNRS CEA Paris-Sud University, Saclay Plant Sciences, Avenue de la Terrasse, 91198 Gif-sur-Yvette cedex, France
| | - Mélanie Tannières
- Institut for Integrative Biology of the Cell, Department of Microbiology, CNRS CEA Paris-Sud University, Saclay Plant Sciences, Avenue de la Terrasse, 91198 Gif-sur-Yvette cedex, France
| | - Solange Moréra
- Institut for Integrative Biology of the Cell, Department of Structural Biology, CNRS CEA Paris-Sud University, Avenue de la Terrasse, 91198 Gif-sur-Yvette cedex, France
| | - Yves Dessaux
- Institut for Integrative Biology of the Cell, Department of Microbiology, CNRS CEA Paris-Sud University, Saclay Plant Sciences, Avenue de la Terrasse, 91198 Gif-sur-Yvette cedex, France
| | - Denis Faure
- Institut for Integrative Biology of the Cell, Department of Microbiology, CNRS CEA Paris-Sud University, Saclay Plant Sciences, Avenue de la Terrasse, 91198 Gif-sur-Yvette cedex, France
| |
Collapse
|
207
|
Wynendaele E, Gevaert B, Stalmans S, Verbeke F, De Spiegeleer B. Exploring the chemical space of quorum sensing peptides. Biopolymers 2015; 104:544-51. [DOI: 10.1002/bip.22649] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 03/12/2015] [Accepted: 03/30/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Evelien Wynendaele
- Drug Quality and Registration (DruQuaR) Group; Faculty of Pharmaceutical Sciences, Ghent University; Ottergemsesteenweg 460 Ghent 9000 Belgium
| | - Bert Gevaert
- Drug Quality and Registration (DruQuaR) Group; Faculty of Pharmaceutical Sciences, Ghent University; Ottergemsesteenweg 460 Ghent 9000 Belgium
| | - Sofie Stalmans
- Drug Quality and Registration (DruQuaR) Group; Faculty of Pharmaceutical Sciences, Ghent University; Ottergemsesteenweg 460 Ghent 9000 Belgium
| | - Frederick Verbeke
- Drug Quality and Registration (DruQuaR) Group; Faculty of Pharmaceutical Sciences, Ghent University; Ottergemsesteenweg 460 Ghent 9000 Belgium
| | - Bart De Spiegeleer
- Drug Quality and Registration (DruQuaR) Group; Faculty of Pharmaceutical Sciences, Ghent University; Ottergemsesteenweg 460 Ghent 9000 Belgium
| |
Collapse
|
208
|
Gill EE, Franco OL, Hancock REW. Antibiotic adjuvants: diverse strategies for controlling drug-resistant pathogens. Chem Biol Drug Des 2015; 85:56-78. [PMID: 25393203 PMCID: PMC4279029 DOI: 10.1111/cbdd.12478] [Citation(s) in RCA: 224] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 10/31/2014] [Accepted: 11/03/2014] [Indexed: 01/08/2023]
Abstract
The growing number of bacterial pathogens that are resistant to numerous antibiotics is a cause for concern around the globe. There have been no new broad-spectrum antibiotics developed in the last 40 years, and the drugs we have currently are quickly becoming ineffective. In this article, we explore a range of therapeutic strategies that could be employed in conjunction with antibiotics and may help to prolong the life span of these life-saving drugs. Discussed topics include antiresistance drugs, which are administered to potentiate the effects of current antimicrobials in bacteria where they are no longer (or never were) effective; antivirulence drugs, which are directed against bacterial virulence factors; host-directed therapies, which modulate the host's immune system to facilitate infection clearance; and alternative treatments, which include such therapies as oral rehydration for diarrhea, phage therapy, and probiotics. All of these avenues show promise for the treatment of bacterial infections and should be further investigated to explore their full potential in the face of a postantibiotic era.
Collapse
Affiliation(s)
- Erin E Gill
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | | | | |
Collapse
|
209
|
Rice AJ, Woo JK, Khan A, Szypulinski MZ, Johnson ME, Lee H, Lee H. Over-expression, purification, and confirmation of Bacillus anthracis transcriptional regulator NprR. Protein Expr Purif 2015; 125:83-9. [PMID: 26344899 DOI: 10.1016/j.pep.2015.08.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 08/28/2015] [Accepted: 08/31/2015] [Indexed: 12/21/2022]
Abstract
Quorum sensing (QS) has been recognized as an important biological phenomenon in which bacterial cells communicate and coordinate their gene expression and cellular processes with respect to population density. Bacillus anthracis is the etiological agent of fatal pulmonary anthrax infections, and the NprR/NprX QS system may be involved in its pathogenesis. NprR, renamed as aqsR for anthrax quorum sensing Regulator, is a transcriptional regulator that may control the expression of genes required for proliferation and survival. Currently, there is no protocol reported to over-express and purify B. anthracis AqsR. In this study, we describe cloning, purification, and confirmation of functional full-length B. anthracis AqsR protein. The AqsR gene was cloned into the pQE-30 vector with an HRV 3C protease recognition site between AqsR and the N-terminal His6-tag in order to yield near native AqsR after the His-tag cleavage, leaving only two additional amino acid residues at the N-terminus.
Collapse
Affiliation(s)
- Amy J Rice
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 S. Ashland, IL 60607, USA; Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, 900 S. Ashland, IL 60607, USA
| | - Jerry K Woo
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 S. Ashland, IL 60607, USA
| | - Attiya Khan
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 S. Ashland, IL 60607, USA
| | - Michael Z Szypulinski
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 S. Ashland, IL 60607, USA
| | - Michael E Johnson
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 S. Ashland, IL 60607, USA; Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, 900 S. Ashland, IL 60607, USA
| | - Hyunwoo Lee
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 S. Ashland, IL 60607, USA; Department of Biopharmaceutical Sciences, University of Illinois at Chicago, 900 S. Ashland, IL 60607, USA.
| | - Hyun Lee
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 S. Ashland, IL 60607, USA; Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, 900 S. Ashland, IL 60607, USA.
| |
Collapse
|
210
|
Affiliation(s)
- Mark S Thomas
- a Department of Infection and Immunity; Medical School ; University of Sheffield ; Sheffield , UK
| | | |
Collapse
|
211
|
Zhao J, Chen M, Quan CS, Fan SD. Mechanisms of quorum sensing and strategies for quorum sensing disruption in aquaculture pathogens. JOURNAL OF FISH DISEASES 2015; 38:771-786. [PMID: 25219871 DOI: 10.1111/jfd.12299] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 07/02/2014] [Accepted: 07/07/2014] [Indexed: 06/03/2023]
Abstract
In many countries, infectious diseases are a considerable threat to aquaculture. The pathogenicity of micro-organisms that infect aquaculture systems is closely related to the release of virulence factors and the formation of biofilms, both of which are regulated by quorum sensing (QS). Thus, QS disruption is a potential strategy for preventing disease in aquaculture systems. QS inhibitors (QSIs) not only inhibit the expression of virulence-associated genes but also attenuate the virulence of aquaculture pathogens. In this review, we discuss QS systems in important aquaculture pathogens and focus on the relationship between QS mechanisms and bacterial virulence in aquaculture. We further elucidate QS disruption strategies for targeting aquaculture pathogens. Four main types of QSIs that target aquaculture pathogens are discussed based on their mechanisms of action.
Collapse
Affiliation(s)
- J Zhao
- Key Laboratory of Biochemical Engineering State Ethnic Affairs Commission-Ministry of Education, Dalian Nationalities University, Dalian, China
- College of Life Science, Dalian Nationalities University, Dalian, China
| | - M Chen
- College of Bioengineering, Dalian Polytechnic University, Dalian, China
| | - C S Quan
- Key Laboratory of Biochemical Engineering State Ethnic Affairs Commission-Ministry of Education, Dalian Nationalities University, Dalian, China
- College of Life Science, Dalian Nationalities University, Dalian, China
| | - S D Fan
- Key Laboratory of Biochemical Engineering State Ethnic Affairs Commission-Ministry of Education, Dalian Nationalities University, Dalian, China
- College of Life Science, Dalian Nationalities University, Dalian, China
| |
Collapse
|
212
|
Wahman S, Emara M, Shawky RM, El-Domany RA, Aboulwafa MM. Inhibition of quorum sensing-mediated biofilm formation in Pseudomonas aeruginosa by a locally isolated Bacillus cereus. J Basic Microbiol 2015; 55:1406-16. [PMID: 26288125 DOI: 10.1002/jobm.201500268] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 07/24/2015] [Indexed: 11/06/2022]
Abstract
Quorum sensing has been shown to play a crucial role in Pseudomonas aeruginosa pathogenesis where it activates expression of myriad genes that regulate the production of important virulence factors such as biofilm formation. Antagonism of quorum sensing is an excellent target for antimicrobial therapy and represents a novel approach to combat drug resistance. In this study, Chromobacterium violaceum biosensor strain was employed as a fast, sensitive, reliable, and easy to use tool for rapid screening of soil samples for Quorum Sensing Inhibitors (QSI) and the optimal conditions for maximal QSI production were scrutinized. Screening of 127 soil isolates showed that 43 isolates were able to breakdown the HHL signal. Out of the 43 isolates, 38 isolates were able to inhibit the violet color of the biosensor and to form easily detectable zones of color inhibition around their growth. A confirmatory bioassay was carried out after concentrating the putative positive cell-free lysates. Three different isolates that belonged to Bacillus cereus group were shown to have QSI activities and their QSI activities were optimized by changing their culture conditions. Further experiments revealed that the cell-free lysates of these isolates were able to inhibit biofilm formation by P. aeruginosa clinical isolates.
Collapse
Affiliation(s)
- Shaimaa Wahman
- Department of Microbiology and Immunology, Faculty of Pharmacy, Helwan University, Cairo, Egypt
| | - Mohamed Emara
- Department of Microbiology and Immunology, Faculty of Pharmacy, Helwan University, Cairo, Egypt
| | - Riham M Shawky
- Department of Microbiology and Immunology, Faculty of Pharmacy, Helwan University, Cairo, Egypt
| | - Ramadan A El-Domany
- Department of Microbiology and Immunology, Faculty of Pharmacy, Kafr El Sheikh University, Egypt
| | | |
Collapse
|
213
|
Castillo-Juárez I, Maeda T, Mandujano-Tinoco EA, Tomás M, Pérez-Eretza B, García-Contreras SJ, Wood TK, García-Contreras R. Role of quorum sensing in bacterial infections. World J Clin Cases 2015; 3:575-598. [PMID: 26244150 PMCID: PMC4517333 DOI: 10.12998/wjcc.v3.i7.575] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 11/30/2014] [Accepted: 04/20/2015] [Indexed: 02/05/2023] Open
Abstract
Quorum sensing (QS) is cell communication that is widely used by bacterial pathogens to coordinate the expression of several collective traits, including the production of multiple virulence factors, biofilm formation, and swarming motility once a population threshold is reached. Several lines of evidence indicate that QS enhances virulence of bacterial pathogens in animal models as well as in human infections; however, its relative importance for bacterial pathogenesis is still incomplete. In this review, we discuss the present evidence from in vitro and in vivo experiments in animal models, as well as from clinical studies, that link QS systems with human infections. We focus on two major QS bacterial models, the opportunistic Gram negative bacteria Pseudomonas aeruginosa and the Gram positive Staphylococcus aureus, which are also two of the main agents responsible of nosocomial and wound infections. In addition, QS communication systems in other bacterial, eukaryotic pathogens, and even immune and cancer cells are also reviewed, and finally, the new approaches proposed to combat bacterial infections by the attenuation of their QS communication systems and virulence are also discussed.
Collapse
|
214
|
Smith K, Rajendran R, Kerr S, Lappin DF, Mackay WG, Williams C, Ramage G. Aspergillus fumigatus enhances elastase production in Pseudomonas aeruginosa co-cultures. Med Mycol 2015; 53:645-55. [PMID: 26162475 DOI: 10.1093/mmy/myv048] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 05/25/2015] [Indexed: 02/07/2023] Open
Abstract
In the cystic fibrosis (CF) lung the presence of bacteria and fungi in the airways promotes an inflammatory response causing progressive lung damage, ultimately leading to high rates of morbidity and mortality. We hypothesized that polymicrobial interactions play an important role in promoting airway pathogenesis. We therefore examined the interplay between the most commonly isolated bacterial CF pathogen, Pseudomonas aeruginosa, and the most prevalent filamentous fungi, Aspergillus fumigatus, to test this. Co-culture experiments showed that in the presence of A. fumigatus the production of P. aeruginosa elastase was enhanced. This was confirmed by the presence of zones of clearance on Elastin-Congo Red (ECR) agar, which was identified as elastase by mass spectrometry. When P. aeruginosa were grown in a co-culture model with mature A. fumigatus biofilms, 60% of isolates produced significantly more elastase in the presence of the filamentous fungi than in its absence (P < .05). The expression of lasB also increased when P. aeruginosa isolates PA01 and PA14 were grown in co-culture with A. fumigatus. Supernatants from co-culture experiments were also significantly toxic to a human lung epithelial cell line (19-38% cell cytotoxicity) in comparison to supernatants from P. aeruginosa only cultures (P < .0001). Here we report that P. aeruginosa cytotoxic elastase is enhanced in the presence of the filamentous fungi A. fumigatus, suggesting that this may have a role to play in the damaging pathology associated with the lung tissue in this disease. This indicates that patients who have a co-colonisation with these two organisms may have a poorer prognosis.
Collapse
Affiliation(s)
- Karen Smith
- Institute of Healthcare Associated Infection, School of Health, Nursing and Midwifery, University of the West of Scotland, United Kingdom
| | - Ranjith Rajendran
- Infection and Immunity Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Stephen Kerr
- Infection and Immunity Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - David F Lappin
- Infection and Immunity Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - William G Mackay
- Institute of Healthcare Associated Infection, School of Health, Nursing and Midwifery, University of the West of Scotland, United Kingdom
| | - Craig Williams
- Institute of Healthcare Associated Infection, School of Health, Nursing and Midwifery, University of the West of Scotland, United Kingdom
| | - Gordon Ramage
- Infection and Immunity Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| |
Collapse
|
215
|
García-Lara B, Saucedo-Mora M, Roldán-Sánchez J, Pérez-Eretza B, Ramasamy M, Lee J, Coria-Jimenez R, Tapia M, Varela-Guerrero V, García-Contreras R. Inhibition of quorum-sensing-dependent virulence factors and biofilm formation of clinical and environmental Pseudomonas aeruginosa
strains by ZnO nanoparticles. Lett Appl Microbiol 2015; 61:299-305. [DOI: 10.1111/lam.12456] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 05/22/2015] [Accepted: 06/07/2015] [Indexed: 11/27/2022]
Affiliation(s)
- B. García-Lara
- Department of Microbiology and Parasitology; Faculty of Medicine; UNAM; Mexico City Mexico
| | - M.Á. Saucedo-Mora
- Department of Microbiology and Parasitology; Faculty of Medicine; UNAM; Mexico City Mexico
| | - J.A. Roldán-Sánchez
- Department of Microbiology and Parasitology; Faculty of Medicine; UNAM; Mexico City Mexico
| | - B. Pérez-Eretza
- Department of Microbiology and Parasitology; Faculty of Medicine; UNAM; Mexico City Mexico
| | - M. Ramasamy
- School of Chemical Engineering; Yeungnam University; Gyeongsan Korea
| | - J. Lee
- School of Chemical Engineering; Yeungnam University; Gyeongsan Korea
| | - R. Coria-Jimenez
- Laboratory of Experimental Bacteriology; National Institute of Pediatrics; Mexico City Mexico
| | - M. Tapia
- Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM; Universidad Autónoma del Estado de México; Toluca Mexico
| | - V. Varela-Guerrero
- Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM; Universidad Autónoma del Estado de México; Toluca Mexico
| | - R. García-Contreras
- Department of Microbiology and Parasitology; Faculty of Medicine; UNAM; Mexico City Mexico
| |
Collapse
|
216
|
García-Contreras R, Peréz-Eretza B, Jasso-Chávez R, Lira-Silva E, Roldán-Sánchez JA, González-Valdez A, Soberón-Chávez G, Coria-Jiménez R, Martínez-Vázquez M, Alcaraz LD, Maeda T, Wood TK. High variability in quorum quenching and growth inhibition by furanone C-30 in Pseudomonas aeruginosa clinical isolates from cystic fibrosis patients. Pathog Dis 2015; 73:ftv040. [PMID: 26048733 DOI: 10.1093/femspd/ftv040] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2015] [Indexed: 11/13/2022] Open
Abstract
Pseudomonas aeruginosa colonizes the lungs of cystic fibrosis patients causing severe damage. This bacterium is intrinsically resistant to antibiotics and shows resistance against new antimicrobials and its virulence is controlled by the quorum-sensing response. Thus, attenuating its virulence by quorum quenching instead of inhibiting its growth has been proposed to minimize resistance; however, resistance against the canonical quorum quencher furanone C-30 can be achieved by mutations leading to increased efflux. In the present work, the effect of C-30 in the attenuation of the QS-controlled virulence factors elastase and pyocyanin was investigated in 50 isolates from cystic fibrosis patients. The results demonstrate that there is a high variability in the expression of both elastase and pyocyanin and that there are many naturally resistant C-30 strains. We report that the main mechanism of C-30 resistance in these strains was not due to enhanced efflux but a lack of permeability. Moreover, C-30 strongly inhibited the growth of several of the isolates studied, thus imposing high selective pressure for the generation of resistance.
Collapse
Affiliation(s)
- Rodolfo García-Contreras
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 México Departamento de Bioquímica, Instituto Nacional de Cardiología, Mexico City 14080, Mexico
| | - Berenice Peréz-Eretza
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 México
| | - Ricardo Jasso-Chávez
- Departamento de Bioquímica, Instituto Nacional de Cardiología, Mexico City 14080, Mexico
| | - Elizabeth Lira-Silva
- Departamento de Bioquímica, Instituto Nacional de Cardiología, Mexico City 14080, Mexico
| | - Jesús Alberto Roldán-Sánchez
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 México
| | - Abigail González-Valdez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510 México
| | - Gloria Soberón-Chávez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510 México
| | - Rafael Coria-Jiménez
- Laboratory of Experimental Bacteriology, National Institute of Pediatrics, Mexico City 04530, Mexico
| | | | - Luis David Alcaraz
- Departamento de Ecología de la Biodiversidad, Instituto de Ecología, Universidad Nacional Autónoma de México, 04510 México
| | - Toshinari Maeda
- Department of Biological Functions and Engineering, Kyushu Institute of Technology, Kitakyushu 808-0196, Japan
| | - Thomas K Wood
- Departments of Chemical Engineering and Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802-4400, USA
| |
Collapse
|
217
|
Arora DP, Hossain S, Xu Y, Boon EM. Nitric Oxide Regulation of Bacterial Biofilms. Biochemistry 2015; 54:3717-28. [PMID: 25996573 DOI: 10.1021/bi501476n] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Biofilms are surface-associated, multicellular communities of bacteria. Once established, they are extremely difficult to eradicate by antimicrobial treatment. It has been demonstrated in many species that biofilm formation may be regulated by the diatomic signaling molecule nitric oxide (NO). Although this is still a relatively new area of research, we review here the literature reporting an effect of NO on bacterial biofilm formation, emphasizing dose-dependent responses to NO concentrations when possible. Where it has been investigated, the underlying NO sensors or signaling pathways are also discussed. Most of the examples of NO-mediated biofilm regulation have been documented with exogenously applied NO, but we also survey possible natural sources of NO in biofilm regulation, including endogenously generated NO. Finally, because of the apparent broad-spectrum, antibiofilm effects of NO, NO-releasing materials and prodrugs have also been explored in this minireview.
Collapse
Affiliation(s)
- Dhruv P Arora
- †Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Sajjad Hossain
- §Graduate Program in Molecular and Cellular Biology, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Yueming Xu
- †Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Elizabeth M Boon
- †Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States.,§Graduate Program in Molecular and Cellular Biology, Stony Brook University, Stony Brook, New York 11794-3400, United States
| |
Collapse
|
218
|
Identification of Quorum-Sensing Inhibitors Disrupting Signaling between Rgg and Short Hydrophobic Peptides in Streptococci. mBio 2015; 6:e00393-15. [PMID: 25968646 PMCID: PMC4436074 DOI: 10.1128/mbio.00393-15] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Bacteria coordinate a variety of social behaviors, important for both environmental and pathogenic bacteria, through a process of intercellular chemical signaling known as quorum sensing (QS). As microbial resistance to antibiotics grows more common, a critical need has emerged to develop novel anti-infective therapies, such as an ability to attenuate bacterial pathogens by means of QS interference. Rgg quorum-sensing pathways, widespread in the phylum Firmicutes, employ cytoplasmic pheromone receptors (Rgg transcription factors) that directly bind and elicit gene expression responses to imported peptide signals. In the human-restricted pathogen Streptococcus pyogenes, the Rgg2/Rgg3 regulatory circuit controls biofilm development in response to the short hydrophobic peptides SHP2 and SHP3. Using Rgg-SHP as a model receptor-ligand target, we sought to identify chemical compounds that could specifically inhibit Rgg quorum-sensing circuits. Individual compounds from a diverse library of known drugs and drug-like molecules were screened for their ability to disrupt complexes of Rgg and FITC (fluorescein isothiocyanate)-conjugated SHP using a fluorescence polarization (FP) assay. The best hits were found to bind Rgg3 in vitro with submicromolar affinities, to specifically abolish transcription of Rgg2/3-controlled genes, and to prevent biofilm development in S. pyogenes without affecting bacterial growth. Furthermore, the top hit, cyclosporine A, as well as its nonimmunosuppressive analog, valspodar, inhibited Rgg-SHP pathways in multiple species of Streptococcus. The Rgg-FITC-peptide-based screen provides a platform to identify inhibitors specific for each Rgg type. Discovery of Rgg inhibitors constitutes a step toward the goal of manipulating bacterial behavior for purposes of improving health. The global emergence of antibiotic-resistant bacterial infections necessitates discovery not only of new antimicrobials but also of novel drug targets. Since antibiotics restrict microbial growth, strong selective pressures to develop resistance emerge quickly in bacteria. A new strategy to fight microbial infections has been proposed, namely, development of therapies that decrease pathogenicity of invading organisms while not directly inhibiting their growth, thus decreasing selective pressure to establish resistance. One possible means to this goal is to interfere with chemical communication networks used by bacteria to coordinate group behaviors, which can include the synchronized expression of genes that lead to disease. In this study, we identified chemical compounds that disrupt communication pathways regulated by Rgg proteins in species of Streptococcus. Treatment of cultures of S. pyogenes with the inhibitors diminished the development of biofilms, demonstrating an ability to control bacterial behavior with chemicals that do not inhibit growth.
Collapse
|
219
|
Abstract
UNLABELLED The protozoan parasite Trypanosoma brucei engages in surface-induced social behavior, termed social motility, characterized by single cells assembling into multicellular groups that coordinate their movements in response to extracellular signals. Social motility requires sensing and responding to extracellular signals, but the underlying mechanisms are unknown. Here we report that T. brucei social motility depends on cyclic AMP (cAMP) signaling systems in the parasite's flagellum (synonymous with cilium). Pharmacological inhibition of cAMP-specific phosphodiesterase (PDE) completely blocks social motility without impacting the viability or motility of individual cells. Using a fluorescence resonance energy transfer (FRET)-based sensor to monitor cAMP dynamics in live cells, we demonstrate that this block in social motility correlates with an increase in intracellular cAMP levels. RNA interference (RNAi) knockdown of the flagellar PDEB1 phenocopies pharmacological PDE inhibition, demonstrating that PDEB1 is required for social motility. Using parasites expressing distinct fluorescent proteins to monitor individuals in a genetically heterogeneous community, we found that the social motility defect of PDEB1 knockdowns is complemented by wild-type parasites in trans. Therefore, PDEB1 knockdown cells are competent for social motility but appear to lack a necessary factor that can be provided by wild-type cells. The combined data demonstrate that the role of cyclic nucleotides in regulating microbial social behavior extends to African trypanosomes and provide an example of transcomplementation in parasitic protozoa. IMPORTANCE In bacteria, studies of cell-cell communication and social behavior have profoundly influenced our understanding of microbial physiology, signaling, and pathogenesis. In contrast, mechanisms underlying social behavior in protozoan parasites are mostly unknown. Here we show that social behavior in the protozoan parasite Trypanosoma brucei is governed by cyclic-AMP signaling systems in the flagellum, with intriguing parallels to signaling systems that control bacterial social behavior. We also generated a T. brucei social behavior mutant and found that the mutant phenotype is complemented by wild-type cells grown in the same culture. Our findings open new avenues for dissecting social behavior and signaling in protozoan parasites and illustrate the capacity of these organisms to influence each other's behavior in mixed communities.
Collapse
|
220
|
Mantani Y, Ito E, Nishida M, Yuasa H, Masuda N, Qi WM, Kawano J, Yokoyama T, Hoshi N, Kitagawa H. Ultrastructural study on the morphological changes in indigenous bacteria of mucous layer and chyme throughout the rat intestine. J Vet Med Sci 2015; 77:1121-8. [PMID: 25890991 PMCID: PMC4591154 DOI: 10.1292/jvms.15-0139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Indigenous bacteria in the alimentary tract are exposed to various bactericidal
peptides and digestive enzymes, but the viability status and morphological changes of
indigenous bacteria are unclear. Therefore, the present study aimed to ultrastructurally
clarify the degeneration and viability status of indigenous bacteria in the rat intestine.
The majority of indigenous bacteria in the ileal mucous layer possessed intact cytoplasm,
but the cytoplasm of a few bacteria contained vacuoles. The vacuoles were more frequently
found in bacteria of ileal chyme than in those of ileal mucous layer and were found in a
large majority of bacteria in both the mucous layer and chyme throughout the large
intestine. In the dividing bacteria of the mucous layer and chyme throughout the
intestine, the ratio of area occupied by vacuoles was almost always less than 10%. Lysis
or detachment of the cell wall in the indigenous bacteria was more frequently found in the
large intestine than in the ileum, whereas bacterial remnants, such as cell walls, were
distributed almost evenly throughout the intestine. In an experimental control of
long-time-cultured Staphylococcus epidermidis on agar, similar vacuoles
were also found, but cell-wall degeneration was never observed. From these findings,
indigenous bacteria in the mucous layer were ultrastructurally confirmed to be the source
of indigenous bacteria in the chyme. Furthermore, the results suggested that indigenous
bacteria were more severely degenerated toward the large intestine and were probably
degraded in the intestine.
Collapse
Affiliation(s)
- Youhei Mantani
- Laboratory of Histophysiology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
221
|
Eng SA, Nathan S. Curcumin rescues Caenorhabditis elegans from a Burkholderia pseudomallei infection. Front Microbiol 2015; 6:290. [PMID: 25914690 PMCID: PMC4392299 DOI: 10.3389/fmicb.2015.00290] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 03/23/2015] [Indexed: 11/13/2022] Open
Abstract
The tropical pathogen Burkholderia pseudomallei requires long-term parenteral antimicrobial treatment to eradicate the pathogen from an infected patient. However, the development of antibiotic resistance is emerging as a threat to this form of treatment. To meet the need for alternative therapeutics, we proposed a screen of natural products for compounds that do not kill the pathogen, but in turn, abrogate bacterial virulence. We suggest that the use of molecules or compounds that are non-bactericidal (bacteriostatic) will reduce or abolish the development of resistance by the pathogen. In this study, we adopted the established Caenorhabditis elegans-B. pseudomallei infection model to screen a collection of natural products for any that are able to extend the survival of B. pseudomallei infected worms. Of the 42 natural products screened, only curcumin significantly improved worm survival following infection whilst not affecting bacterial growth. This suggested that curcumin promoted B. pseudomallei-infected worm survival independent of pathogen killing. To validate that the protective effect of curcumin was directed toward the pathogen, bacteria were treated with curcumin prior to infection. Worms fed with curcumin-treated bacteria survived with a significantly extended mean-time-to-death (p < 0.0001) compared to the untreated control. In in vitro assays, curcumin reduced the activity of known virulence factors (lipase and protease) and biofilm formation. To determine if other bacterial genes were also regulated in the presence of curcumin, a genome-wide transcriptome analysis was performed on curcumin-treated pathogen. A number of genes involved in iron acquisition and transport as well as genes encoding hypothetical proteins were induced in the presence of curcumin. Thus, we propose that curcumin may attenuate B. pseudomallei by modulating the expression of a number of bacterial proteins including lipase and protease as well as biofilm formation whilst concomitantly regulating iron transport and other proteins of unknown function.
Collapse
Affiliation(s)
- Su-Anne Eng
- Faculty of Science and Technology, School of Biosciences and Biotechnology, National University of Malaysia Bangi, Malaysia
| | - Sheila Nathan
- Faculty of Science and Technology, School of Biosciences and Biotechnology, National University of Malaysia Bangi, Malaysia
| |
Collapse
|
222
|
Rangel-Vega A, Bernstein LR, Mandujano-Tinoco EA, García-Contreras SJ, García-Contreras R. Drug repurposing as an alternative for the treatment of recalcitrant bacterial infections. Front Microbiol 2015; 6:282. [PMID: 25914685 PMCID: PMC4391038 DOI: 10.3389/fmicb.2015.00282] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 03/21/2015] [Indexed: 01/17/2023] Open
Abstract
Bacterial infection remains one of the leading causes of death worldwide, and the options for treating such infections are decreasing, due the rise of antibiotic-resistant bacteria. The pharmaceutical industry has produced few new types of antibiotics in more than a decade. Researchers are taking several approaches toward developing new classes of antibiotics, including (1) focusing on new targets and processes, such as bacterial cell–cell communication that upregulates virulence; (2) designing inhibitors of bacterial resistance, such as blockers of multidrug efflux pumps; and (3) using alternative antimicrobials such as bacteriophages. In addition, the strategy of finding new uses for existing drugs is beginning to produce results: antibacterial properties have been discovered for existing anticancer, antifungal, anthelmintic, and anti-inflammatory drugs. In this review, we discuss the antimicrobial properties of gallium compounds, 5-fluorouracil, ciclopirox, diflunisal, and some other FDA-approved drugs and argue that their repurposing for the treatment of bacterial infections, including those that are multidrug resistant, is a feasible strategy.
Collapse
Affiliation(s)
- Adrián Rangel-Vega
- Department of Microbiology and Parasitology, Faculty of Medicine, Universidad Nacional Autónoma de México Mexico City, Mexico
| | | | - Edna Ayerim Mandujano-Tinoco
- Epigenetics of Cancer Laboratory, Division of Basic Research, National Institute of Genomic Medicine Mexico City, Mexico
| | | | - Rodolfo García-Contreras
- Department of Microbiology and Parasitology, Faculty of Medicine, Universidad Nacional Autónoma de México Mexico City, Mexico
| |
Collapse
|
223
|
Detection of Pseudomonas aeruginosa by a triplex polymerase chain reaction assay based on lasI/R and gyrB genes. J Infect Public Health 2015; 8:314-22. [PMID: 25863575 DOI: 10.1016/j.jiph.2015.03.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 02/24/2015] [Accepted: 03/08/2015] [Indexed: 01/21/2023] Open
Abstract
Pseudomonas aeruginosa is a nosocomial pathogen, which, due to its inherent and acquired resistance to a wide range of antibiotics, causes high mortality rates. Therefore, rapid detection of the bacterium with high specificity and sensitivity plays a critical role in the control of the pathogenic bacterium. The aim of this study was to evaluate the accuracy and specificity of a prompt detection of the bacterium based on a triplex polymerase chain reaction that amplifies the lasI, lasR and gyrB genes. For this purpose, 30 clinical isolates of P. aeruginosa and 30 wound biopsy samples were retrieved from clinical diagnostic laboratories. After the extraction of the chromosomal DNA, the desired genes were amplified using uniplex and triplex PCR with appropriate primers. The specificity of the primers was evaluated by a comparison of the PCR results for P. aeruginosa clinical samples and non-Pseudomonas species control samples. The sensitivity of the primers was determined using a serial dilution of the genomic DNA template (100 ng to 100 fg) and by a comparison of the PCR and bacterial culture results. The results showed that the triplex PCR assay was positive for all of the samples (100%), while the PCR identifications were negative for non-Pseudomonas species. Additionally, at 10(-4) and 10(-5) diluted genomic DNA from P. aeruginosa (10 pg and 1 pg), the triplex PCR test was positive for the Las and gyrB genes in all of the samples, respectively. Based on these results, the designed primers can be used for the rapid, specific and sensitive diagnosis of P. aeruginosa in a triplex PCR assay.
Collapse
|
224
|
Antiabong JF, Ball AS, Brown MH. The effects of iron limitation and cell density on prokaryotic metabolism and gene expression: Excerpts from Fusobacterium necrophorum strain 774 (sheep isolate). Gene 2015; 563:94-102. [PMID: 25771225 DOI: 10.1016/j.gene.2015.03.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Revised: 01/18/2015] [Accepted: 03/07/2015] [Indexed: 11/24/2022]
Abstract
Fusobacterium necrophorum is a Gram-negative obligate anaerobe associated with several diseases in humans and animals. Despite its increasing clinical significance, there is little or no data on the relationship between its metabolism and virulence. Previous studies have shown that bacteria grown under iron-limitation express immunogenic antigens similar to those generated in vivo. Thus, this paper describes the relationship between F. necrophorum subsp. necrophorum (Fnn) metabolism and the expression of the encoded putative virulence factors under iron-restricted conditions. At the midlog phase, iron limitation reduced Fnn growth but the cell density was dependent on the size of the inoculum. Preferential utilization of glucose-1-phosphate, d-mannitol and l-phenylalanine; production of 2-hydroxycaproic acid and termination of dimethyl sulphide production were major Fnn response-factors to iron limitation. Ultimately, iron restriction resulted in an increased ability of Fnn to metabolize diverse carbon sources and in the expression of stress-specific virulence factors. Iron starvation in low Fnn cell density was associated with the up-regulation of haemagglutinin (HA) and leukotoxin (lktA) genes (2.49 and 3.72 fold change respectively). However, Fnn encoded Haemolysin (Hly), yebN homologue (febN) and tonB homologue, were down-regulated (0.15, 0.79 and 0.33, fold changes respectively). Interestingly, cell density appeared to play a regulatory role in the final bacteria cell biomass, induction of a metabolic gene expression and the expression pattern virulence factors in Fnn suggesting the role of a cell density-associated regulatory factor. This report suggest that future studies on differential expression of bacterial genes under altered environmental condition(s) should consider testing the effect of cell concentrations as this is often neglected in such studies. In conclusion, iron restriction induces preferential utilization of carbon sources and altered metabolism in Fnn with associated changes in the expression pattern of the virulence factors.
Collapse
Affiliation(s)
- John F Antiabong
- School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide 5001, Australia; School of Applied Sciences Royal Melbourne Institute of Technology University Melbourne, Bundoora 3083, Australia.
| | - Andrew S Ball
- School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide 5001, Australia; School of Applied Sciences Royal Melbourne Institute of Technology University Melbourne, Bundoora 3083, Australia
| | - Melissa H Brown
- School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide 5001, Australia
| |
Collapse
|
225
|
The dependence of quorum sensing in Serratia marcescens JG on the transcription of luxS gene. Arch Microbiol 2015; 197:715-21. [PMID: 25731898 DOI: 10.1007/s00203-015-1099-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 12/16/2014] [Accepted: 02/26/2015] [Indexed: 12/25/2022]
Abstract
Bacteria communicate with one another using chemical signal molecules. This phenomenon termed quorum sensing enables the bacteria to monitor the environment for other bacteria and to alter behavior on a population-wide scale in response to cell density. Serratia marcescens JG, a quorum sensing bacterium, can secrete a furanosyl borate diester autoinducer (AI-2) in the exponential phase of growth. In this study, to further investigate the regulation of AI-2 production in S. marcescens JG, the pfs and luxS promoter fusions to an operon luxCDABE reporter were constructed in a low-copy-number vector pBR322K, which allows an examination of transcription of the genes in the pathway for signal synthesis. The results show that the luxS expression is constitutive, and the transcription of luxS is tightly correlated with AI-2 production in S. marcescens JG because the peaks of AI-2 production and transcriptional level of luxS appear at the same time point. The close relation of the profiles of luxS transcription and AI-2 production was also confirmed with real-time PCR technology. These results support the hypothesis that the quorum sensing in S. marcescens JG is luxS dependent.
Collapse
|
226
|
Abstract
SUMMARY Autoinduction (AI), the response to self-produced chemical signals, is widespread in the bacterial world. This process controls vastly different target functions, such as luminescence, nutrient acquisition, and biofilm formation, in different ways and integrates additional environmental and physiological cues. This diversity raises questions about unifying principles that underlie all AI systems. Here, we suggest that such core principles exist. We argue that the general purpose of AI systems is the homeostatic control of costly cooperative behaviors, including, but not limited to, secreted public goods. First, costly behaviors require preassessment of their efficiency by cheaper AI signals, which we encapsulate in a hybrid "push-pull" model. The "push" factors cell density, diffusion, and spatial clustering determine when a behavior becomes effective. The relative importance of each factor depends on each species' individual ecological context and life history. In turn, "pull" factors, often stress cues that reduce the activation threshold, determine the cellular demand for the target behavior. Second, control is homeostatic because AI systems, either themselves or through accessory mechanisms, not only initiate but also maintain the efficiency of target behaviors. Third, AI-controlled behaviors, even seemingly noncooperative ones, are generally cooperative in nature, when interpreted in the appropriate ecological context. The escape of individual cells from biofilms, for example, may be viewed as an altruistic behavior that increases the fitness of the resident population by reducing starvation stress. The framework proposed here helps appropriately categorize AI-controlled behaviors and allows for a deeper understanding of their ecological and evolutionary functions.
Collapse
Affiliation(s)
- Burkhard A Hense
- Institute for Computational Biology, Helmholtz Zentrum München, Neuherberg/Munich, Germany
| | - Martin Schuster
- Department of Microbiology, Oregon State University, Corvallis, Oregon, USA
| |
Collapse
|
227
|
Cavaleiro E, Duarte AS, Esteves AC, Correia A, Whitcombe MJ, Piletska EV, Piletsky SA, Chianella I. Novel linear polymers able to inhibit bacterial quorum sensing. Macromol Biosci 2015; 15:647-56. [PMID: 25626858 DOI: 10.1002/mabi.201400447] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 12/05/2014] [Indexed: 11/11/2022]
Abstract
Bacterial phenotypes, such as biofilm formation, antibiotic resistance and virulence expression, are associated with quorum sensing. Quorum sensing is a density-dependent regulatory system of gene expression controlled by specific signal molecules, such as N-acyl homoserine lactones (AHLs), produced and released by bacteria. This study reports the development of linear polymers capable to attenuate quorum sensing by adsorption of AHLs. Linear polymers were synthesized using MMA as backbone monomer and methacrylic acid and itaconic acid as functional monomers. Two different quorum sensing-controlled phenotypes, Vibrio fischeri bioluminescence and Aeromonas hydrophila biofilm formation, were evaluated to test the polymers' efficiency. Results showed that both phenotypes were significantly affected by the polymers, with the itaconic acid-containing material being more effective than the methacrylic acid one. The polymer inhibitory effects were reverted by the addition of lactones, confirming attenuation of quorum sensing through sequestration of signal molecules. The polymers also showed no cytotoxicity when tested using a mammalian cell line.
Collapse
Affiliation(s)
- Eliana Cavaleiro
- Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal.,Centre for Biomedical Engineering, SATM, Cranfield University, Cranfield, Beds, UK
| | - Ana Sofia Duarte
- Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal.
| | | | - António Correia
- Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal
| | | | | | | | - Iva Chianella
- Centre for Biomedical Engineering, SATM, Cranfield University, Cranfield, Beds, UK
| |
Collapse
|
228
|
|
229
|
Modarresi F, Azizi O, Shakibaie MR, Motamedifar M, Mosadegh E, Mansouri S. Iron limitation enhances acyl homoserine lactone (AHL) production and biofilm formation in clinical isolates of Acinetobacter baumannii. Virulence 2015; 6:152-161. [PMID: 25622119 PMCID: PMC4601488 DOI: 10.1080/21505594.2014.1003001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 10/29/2014] [Accepted: 12/23/2014] [Indexed: 02/08/2023] Open
Abstract
Acinetobacter baumannii is an important source of infections in intensive care units (ICUs) of our hospitals in Kerman, Iran and the most frequently isolated strains produce biofilm. There is a little information about role of iron (Fe) levels on acyl homoserine lactone (AHL) production and biofilm formation in this microorganism. In the present study, we investigated the influence of iron-III limitation on AHL, siderophore, catechol and virulence factors in the biofilm forming clinical strains of A. baumannii. A total of 65 non-duplicated multidrug resistance (MDR) strains of A. baumannii were isolated from patients in ICUs of 2 hospitals in Kerman, Iran. Antibiotic susceptibility, siderophore and other iron chelators, hemolysis, cell twitching motility, capsule, gelatinase and DNase were studied. Presence of quorum sensing, LuxI and LuxR genes was detected by multiplex-PCR. AHL activity quantified by colorimetric method and the functional groups were determined by Fourier Transform Infra-Red Spectroscopy (FT-IR). Biofilm formation was detected by microtiter plate technique. All of the isolates were resistant to third generation of cephalosporins, ciprofloxacin, levofloxacin, tetracycline, whereas, 78% and 81% were resistant to amikacin and carbapenems, respectively. The siderophore activity was highest at 20 μM Fe(3+) (70%); however, it decreased to 45% as concentration of Fe(3+) increased to 80 μM. Furthermore, screening of the isolates for LuxI and LuxR genes showed that presence of both genes required in the isolates with high AHL activity. FT-IR analysis indicated C=O bond of the lactone ring and primary amides. Significantly, a higher amount of AHL (70%) was detected in the presence of low concentration of iron-III (20 μM); as iron concentration increased to 80 μM, the AHL activity was reduced to 40% (P ≤ 0.05). All the isolates exhibited twitching motility and had a capsule. No any gelatinase or DNase activity was detected. Quantification of the biofilm formation introduced 23 isolates with efficient attachment to microplate wells and strong biofilm. We found that both the AHL production and biofilm formation were regulated by iron concentration in a dose dependent manner. These findings provide evidence that iron limitation plays an important regulatory role in AHL and siderophore production resulting in strong or weak biofilm, thereby helping the organism to persist in less available micronutrient environment.
Collapse
Affiliation(s)
- Farzan Modarresi
- Department of Microbiology and Virology; Kerman University of Medical Sciences; Kerman, Iran
| | - Omid Azizi
- Department of Microbiology and Virology; Kerman University of Medical Sciences; Kerman, Iran
| | - Mohammad Reza Shakibaie
- Department of Microbiology and Virology; Kerman University of Medical Sciences; Kerman, Iran
- Research Center for Infectious Diseases and Tropical Medicine; Kerman University of Medical Sciences; Kerman, Iran
- Environmental Health Sciences and Engineering Research Center; Kerman University of Medical Sciences; Kerman, Iran
| | - Mohammad Motamedifar
- Departments of Bacteriology and Virology; Shiraz Medical School; Shiraz University of Medical Sciences, Shiraz, Iran
- Shiraz HIV/ AIDS Research Center (SHARC); Shiraz University of Medical Sciences; Shiraz, Iran
| | - Ellahe Mosadegh
- Department of Material Sciences and Engineering and Department of Environmental Sciences; International Center for Science; High-Technology and Environmental Sciences Center; Kerman, Iran
| | - Shahla Mansouri
- Department of Microbiology and Virology; Kerman University of Medical Sciences; Kerman, Iran
| |
Collapse
|
230
|
Chang CY, Krishnan T, Wang H, Chen Y, Yin WF, Chong YM, Tan LY, Chong TM, Chan KG. Non-antibiotic quorum sensing inhibitors acting against N-acyl homoserine lactone synthase as druggable target. Sci Rep 2014; 4:7245. [PMID: 25430794 PMCID: PMC4246208 DOI: 10.1038/srep07245] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 11/11/2014] [Indexed: 01/07/2023] Open
Abstract
N-acylhomoserine lactone (AHL)-based quorum sensing (QS) is important for the regulation of proteobacterial virulence determinants. Thus, the inhibition of AHL synthases offers non-antibiotics-based therapeutic potentials against QS-mediated bacterial infections. In this work, functional AHL synthases of Pseudomonas aeruginosa LasI and RhlI were heterologously expressed in an AHL-negative Escherichia coli followed by assessments on their AHLs production using AHL biosensors and high resolution liquid chromatography–mass spectrometry (LCMS). These AHL-producing E. coli served as tools for screening AHL synthase inhibitors. Based on a campaign of screening synthetic molecules and natural products using our approach, three strongest inhibitors namely are salicylic acid, tannic acid and trans-cinnamaldehyde have been identified. LCMS analysis further confirmed tannic acid and trans-cinnemaldehyde efficiently inhibited AHL production by RhlI. We further demonstrated the application of trans-cinnemaldehyde inhibiting Rhl QS system regulated pyocyanin production in P. aeruginosa up to 42.06%. Molecular docking analysis suggested that trans-cinnemaldehyde binds to the LasI and EsaI with known structures mainly interacting with their substrate binding sites. Our data suggested a new class of QS-inhibiting agents from natural products targeting AHL synthase and provided a potential approach for facilitating the discovery of anti-QS signal synthesis as basis of novel anti-infective approach.
Collapse
Affiliation(s)
- Chien-Yi Chang
- 1] Interdisciplinary Computing and Complex BioSystems (ICOS) research group, School of Computing Science, Claremont Tower, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK [2] The Centre for Bacterial Cell Biology, Medical School, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK
| | - Thiba Krishnan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Hao Wang
- School of Pharmacy, Ningxia Medical University, Yinchuan, P. R. China
| | - Ye Chen
- School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Wai-Fong Yin
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Yee-Meng Chong
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Li Ying Tan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Teik Min Chong
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Kok-Gan Chan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| |
Collapse
|
231
|
Kumar NV, Murthy PS, Manjunatha JR, Bettadaiah BK. Synthesis and quorum sensing inhibitory activity of key phenolic compounds of ginger and their derivatives. Food Chem 2014; 159:451-7. [PMID: 24767081 DOI: 10.1016/j.foodchem.2014.03.039] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 03/06/2014] [Accepted: 03/08/2014] [Indexed: 01/13/2023]
Abstract
Phenolic components of ginger (Zingiber officinale Roscoe) viz. [6]-gingerol, [6]-shogaol and zingerone exhibited quorum sensing inhibitory activity (QSI) against Chromobacterium violaceum and Pseudomonas aeruginosa. The inhibitory activity of all the compounds was studied by zone inhibition, pyocyanin, and violacein assay. All the compounds displayed good inhibition at 500ppm. [6]-Azashogaol, a new derivative of [6]-shogaol has been synthesized by Beckmann rearrangement of its oxime in the presence of ZnCl2. The structure elucidation of this new derivative was carried out by 1D ((1)H NMR and (13)C NMR) and 2D-NMR (COSY, HSQC and NOESY) spectral studies. This compound showed good QSI activity against P. aeruginosa. An isoxazoline derivative of [6]-gingerol was prepared and it exhibited good QSI activity. Present study illustrated that, the phenolic compounds of ginger and their derivatives form a class of compounds with promising QSI activity.
Collapse
Affiliation(s)
- N Vijendra Kumar
- Plantation Products, Spices and Flavour Technology Department, CSIR-Central Food Technological Research Institute, Mysore 570 020, India
| | - Pushpa S Murthy
- Plantation Products, Spices and Flavour Technology Department, CSIR-Central Food Technological Research Institute, Mysore 570 020, India
| | - J R Manjunatha
- Plantation Products, Spices and Flavour Technology Department, CSIR-Central Food Technological Research Institute, Mysore 570 020, India
| | - B K Bettadaiah
- Plantation Products, Spices and Flavour Technology Department, CSIR-Central Food Technological Research Institute, Mysore 570 020, India.
| |
Collapse
|
232
|
Nunoura T, Takaki Y, Kazama H, Kakuta J, Shimamura S, Makita H, Hirai M, Miyazaki M, Takai K. Physiological and genomic features of a novel sulfur-oxidizing gammaproteobacterium belonging to a previously uncultivated symbiotic lineage isolated from a hydrothermal vent. PLoS One 2014; 9:e104959. [PMID: 25133584 PMCID: PMC4136832 DOI: 10.1371/journal.pone.0104959] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 07/15/2014] [Indexed: 12/04/2022] Open
Abstract
Strain Hiromi 1, a sulfur-oxidizing gammaproteobacterium was isolated from a hydrothermal vent chimney in the Okinawa Trough and represents a novel genus that may include a phylogenetic group found as endosymbionts of deep-sea gastropods. The SSU rRNA gene sequence similarity between strain Hiromi 1 and the gastropod endosymbionts was approximately 97%. The strain was shown to grow both chemolithoautotrophically and chemolithoheterotrophically with an energy metabolism of sulfur oxidation and O2 or nitrate reduction. Under chemolithoheterotrophic growth conditions, the strain utilized organic acids and proteinaceous compounds as the carbon and/or nitrogen sources but not the energy source. Various sugars did not support growth as a sole carbon source. The observation of chemolithoheterotrophy in this strain is in line with metagenomic analyses of endosymbionts suggesting the occurrence of chemolithoheterotrophy in gammaproteobacterial symbionts. Chemolithoheterotrophy and the presence of homologous genes for virulence- and quorum sensing-related functions suggest that the sulfur-oxidizing chomolithotrophic microbes seek animal bodies and microbial biofilm formation to obtain supplemental organic carbons in hydrothermal ecosystems.
Collapse
Affiliation(s)
- Takuro Nunoura
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
- * E-mail:
| | - Yoshihiro Takaki
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| | - Hiromi Kazama
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| | - Jungo Kakuta
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| | - Shigeru Shimamura
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| | - Hiroko Makita
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| | - Miho Hirai
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| | - Masayuki Miyazaki
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| | - Ken Takai
- Subsurface Geobiology & Advanced Research (SUGAR) Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan
| |
Collapse
|
233
|
Mohamed GA, Ibrahim SRM, Shaaban MIA, Ross SA. Mangostanaxanthones I and II, new xanthones from the pericarp of Garcinia mangostana. Fitoterapia 2014; 98:215-21. [PMID: 25128900 DOI: 10.1016/j.fitote.2014.08.014] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 08/06/2014] [Accepted: 08/08/2014] [Indexed: 11/16/2022]
Abstract
Two new xanthones: mangostanaxanthones I (3) and II (5) were isolated from the pericarp of Garcinia mangostana, along with four known xanthones: 9-hydroxycalabaxanthone (1), parvifolixanthone C (2), α-mangostin (4), and rubraxanthone (6). Their structures were elucidated on the basis of IR, UV, 1D, 2D NMR, and MS spectroscopic data, in addition to comparison with literature data. The isolated compounds were evaluated for their antioxidant, antimicrobial, and quorum-sensing inhibitory activities. Compounds 3 and 5 displayed promising antioxidant activity with IC50 12.07 and 14.12 μM, respectively using DPPH assay. Compounds 4-6 had weak to moderate activity against Escherichia coli and Staphylococcus aureus, while demonstrated promising action against Bacillus cereus with MICs 0.25, 1.0, and 1.0mg/mL, respectively. The tested compounds were inactive against Candida albicans. However, they showed selective antifungal potential toward Aspergillus fumigatus. Compounds 3 and 4 possessed quorum-sensing inhibitory activity against Chromobacterium violaceum ATCC 12472.
Collapse
Affiliation(s)
- Gamal A Mohamed
- Department of Pharmacognosy, Faculty of Pharmacy, Al-Azhar University, Assiut Branch, Assiut 71524, Egypt
| | - Sabrin R M Ibrahim
- Department of Pharmacognosy and Pharmaceutical Chemistry, Faculty of Pharmacy, Taibah University, Al Madinah Al Munawarah 30078, Saudi Arabia; Department of Pharmacognosy, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt.
| | - Mona I A Shaaban
- Department of Microbiology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt; Department of Microbiology, Faculty of Pharmacy, Taibah University, Al Madinah Al Munawarah 30078, Saudi Arabia
| | - Samir A Ross
- National Center for Natural Products Research, The University of Mississippi, MS 38677, USA; Department of Pharmacognosy, School of Pharmacy, The University of Mississippi, MS 38677, USA
| |
Collapse
|
234
|
Kamaeva AA, Vasilchenko AS, Deryabin DG. Atomic force microscopy reveals a morphological differentiation of chromobacterium violaceum cells associated with biofilm development and directed by N-hexanoyl-L-homoserine lactone. PLoS One 2014; 9:e103741. [PMID: 25111599 PMCID: PMC4128650 DOI: 10.1371/journal.pone.0103741] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 07/01/2014] [Indexed: 12/17/2022] Open
Abstract
Chromobacterium violaceum abounds in soil and water ecosystems in tropical and subtropical regions and occasionally causes severe and often fatal human and animal infections. The quorum sensing (QS) system and biofilm formation are essential for C. violaceum's adaptability and pathogenicity, however, their interrelation is still unknown. C. violaceum's cell and biofilm morphology were examined by atomic force microscopy (AFM) in comparison with growth rates, QS-dependent violacein biosynthesis and biofilm biomass quantification. To evaluate QS regulation of these processes, the wild-type strain C. violaceum ATCC 31532 and its mini-Tn5 mutant C. violaceum NCTC 13274, cultivated with and without the QS autoinducer N-hexanoyl-L-homoserine lactone (C6-HSL), were used. We report for the first time the unusual morphological differentiation of C. violaceum cells, associated with biofilm development and directed by the QS autoinducer. AFM revealed numerous invaginations of the external cytoplasmic membrane of wild-type cells, which were repressed in the mutant strain and restored by exogenous C6-HSL. With increasing bacterial growth, polymer matrix extrusions formed in place of invaginations, whereas mutant cells were covered with a diffusely distributed extracellular substance. Thus, quorum sensing in C. violaceum involves a morphological differentiation that organises biofilm formation and leads to a highly differentiated matrix structure.
Collapse
Affiliation(s)
- Anara A. Kamaeva
- Department of Microbiology, Orenburg State University, Orenburg, Russia
- RSE «Republican Collection of Microorganisms», Astana, Republic of Kazakhstan
| | - Alexey S. Vasilchenko
- Department of Microbiology, Orenburg State University, Orenburg, Russia
- Laboratory of Disbiosis, Institute of Cellular and Intracellular Symbiosis, RAS, Orenburg, Russia
| | | |
Collapse
|
235
|
Abstract
The mammalian gut contains a complex assembly of commensal microbes termed microbiota. Although much has been learned about the role of these microbes in health, the mechanisms underlying these functions are ill defined. We have recently shown that the mammalian gut contains thousands of small molecules, most of which are currently unidentified. Therefore, we hypothesized that these molecules function as chemical cues used by hosts and microbes during their interactions in health and disease. Thus, a search was initiated to identify molecules produced by the microbiota that are sensed by pathogens. We found that a secreted molecule produced by clostridia acts as a strong repressor of Salmonella virulence, obliterating expression of the Salmonella pathogenicity island 1 as well as host cell invasion. It has been known for decades that the microbiota protects its hosts from invading pathogens, and these data suggest that chemical sensing may be involved in this phenomenon. Further investigations should reveal the exact biological role of this molecule as well as its therapeutic potential. Microbes can communicate through the production and sensing of small molecules. Within the complex ecosystem formed by commensal microbes living in and on the human body, it is likely that these molecular messages are used extensively during the interactions between different microbial species as well as with host cells. Deciphering such a molecular dialect will be fundamental to our understanding of host-microbe interactions in health and disease and may prove useful for the design of new therapeutic strategies that target these mechanisms of communication.
Collapse
|
236
|
Westerhoff HV, Brooks AN, Simeonidis E, García-Contreras R, He F, Boogerd FC, Jackson VJ, Goncharuk V, Kolodkin A. Macromolecular networks and intelligence in microorganisms. Front Microbiol 2014; 5:379. [PMID: 25101076 PMCID: PMC4106424 DOI: 10.3389/fmicb.2014.00379] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 07/05/2014] [Indexed: 11/13/2022] Open
Abstract
Living organisms persist by virtue of complex interactions among many components organized into dynamic, environment-responsive networks that span multiple scales and dimensions. Biological networks constitute a type of information and communication technology (ICT): they receive information from the outside and inside of cells, integrate and interpret this information, and then activate a response. Biological networks enable molecules within cells, and even cells themselves, to communicate with each other and their environment. We have become accustomed to associating brain activity - particularly activity of the human brain - with a phenomenon we call "intelligence." Yet, four billion years of evolution could have selected networks with topologies and dynamics that confer traits analogous to this intelligence, even though they were outside the intercellular networks of the brain. Here, we explore how macromolecular networks in microbes confer intelligent characteristics, such as memory, anticipation, adaptation and reflection and we review current understanding of how network organization reflects the type of intelligence required for the environments in which they were selected. We propose that, if we were to leave terms such as "human" and "brain" out of the defining features of "intelligence," all forms of life - from microbes to humans - exhibit some or all characteristics consistent with "intelligence." We then review advances in genome-wide data production and analysis, especially in microbes, that provide a lens into microbial intelligence and propose how the insights derived from quantitatively characterizing biomolecular networks may enable synthetic biologists to create intelligent molecular networks for biotechnology, possibly generating new forms of intelligence, first in silico and then in vivo.
Collapse
Affiliation(s)
- Hans V. Westerhoff
- Department of Molecular Cell Physiology, Vrije Universiteit AmsterdamAmsterdam, Netherlands
- Manchester Centre for Integrative Systems Biology, The University of ManchesterManchester, UK
- Synthetic Systems Biology, University of AmsterdamAmsterdam, Netherlands
| | - Aaron N. Brooks
- Institute for Systems BiologySeattle, WA, USA
- Molecular and Cellular Biology Program, University of WashingtonSeattle, WA, USA
| | - Evangelos Simeonidis
- Institute for Systems BiologySeattle, WA, USA
- Luxembourg Centre for Systems Biomedicine, University of LuxembourgEsch-sur-Alzette, Luxembourg
| | | | - Fei He
- Department of Automatic Control and Systems Engineering, The University of SheffieldSheffield, UK
| | - Fred C. Boogerd
- Department of Molecular Cell Physiology, Vrije Universiteit AmsterdamAmsterdam, Netherlands
| | | | - Valeri Goncharuk
- Netherlands Institute for NeuroscienceAmsterdam, Netherlands
- Russian Cardiology Research CenterMoscow, Russia
- Department of Medicine, Center for Alzheimer and Neurodegenerative Research, University of AlbertaEdmonton, AB, Canada
| | - Alexey Kolodkin
- Institute for Systems BiologySeattle, WA, USA
- Luxembourg Centre for Systems Biomedicine, University of LuxembourgEsch-sur-Alzette, Luxembourg
| |
Collapse
|
237
|
The Dynamic Interactions between Salmonella and the Microbiota, within the Challenging Niche of the Gastrointestinal Tract. INTERNATIONAL SCHOLARLY RESEARCH NOTICES 2014; 2014:846049. [PMID: 27437481 PMCID: PMC4897363 DOI: 10.1155/2014/846049] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 05/14/2014] [Indexed: 12/25/2022]
Abstract
Understanding how Salmonella species establish successful infections remains a foremost research priority. This gastrointestinal pathogen not only faces the hostile defenses of the host's immune system, but also faces fierce competition from the large and diverse community of microbiota for space and nutrients. Salmonella have solved these challenges ingeniously. To jump-start growth, Salmonella steal hydrogen produced by the gastrointestinal microbiota. Type 3 effector proteins are subsequently secreted by Salmonella to trigger potent inflammatory responses, which generate the alternative terminal electron acceptors tetrathionate and nitrate. Salmonella exclusively utilize these electron acceptors for anaerobic respiration, permitting metabolic access to abundant substrates such as ethanolamine to power growth blooms. Chemotaxis and flagella-mediated motility enable the identification of nutritionally beneficial niches. The resulting growth blooms also promote horizontal gene transfer amongst the resident microbes. Within the gastrointestinal tract there are opportunities for chemical signaling between host cells, the microbiota, and Salmonella. Host produced catecholamines and bacterial autoinducers form components of this chemical dialogue leading to dynamic interactions. Thus, Salmonella have developed remarkable strategies to initially shield against host defenses and to transiently compete against the intestinal microbiota leading to successful infections. However, the immunocompetent host is subsequently able to reestablish control and clear the infection.
Collapse
|
238
|
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: 102] [Impact Index Per Article: 9.3] [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.
Collapse
Affiliation(s)
- Vipin C Kalia
- Microbial Biotechnology and Genomics, CSIR-Institute of Genomics and Integrative Biology, Delhi University Campus, Mall Road, Delhi, 110007, India,
| | | | | |
Collapse
|
239
|
Genome of Staphylococcus xylosus and Comparison with S. aureus and S. epidermidis. J Genet Genomics 2014; 41:413-6. [DOI: 10.1016/j.jgg.2014.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 03/21/2014] [Accepted: 03/25/2014] [Indexed: 11/18/2022]
|
240
|
Aggarwal C, Jimenez JC, Nanavati D, Federle MJ. Multiple length peptide-pheromone variants produced by Streptococcus pyogenes directly bind Rgg proteins to confer transcriptional regulation. J Biol Chem 2014; 289:22427-36. [PMID: 24958729 DOI: 10.1074/jbc.m114.583989] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Streptococcus pyogenes, a human-restricted pathogen, accounts for substantial mortality related to infections worldwide. Recent studies indicate that streptococci produce and respond to several secreted peptide signaling molecules (pheromones), including those known as short hydrophobic peptides (SHPs), to regulate gene expression by a quorum-sensing mechanism. Upon transport into the bacterial cell, pheromones bind to and modulate activity of receptor proteins belonging to the Rgg family of transcription factors. Previously, we reported biofilm regulation by the Rgg2/3 quorum-sensing circuit in S. pyogenes. The aim of this study was to identify the composition of mature pheromones from cell-free culture supernatants that facilitate biofilm formation. Bioluminescent reporters were employed to detect active pheromones in culture supernatants fractionated by reverse-phase chromatography, and mass spectrometry was used to characterize their properties. Surprisingly, multiple SHPs that varied by length were detected. Synthetic peptides of each variant were tested individually using bioluminescence reporters and biofilm growth assays, and although activities differed widely among the group, peptides comprising the C-terminal eight amino acids of the full-length native peptide were most active. Direct Rgg/SHP interactions were determined using a fluorescence polarization assay that utilized FITC-labeled peptide ligands. Peptide receptor affinities were seen to be as low as 500 nm and their binding affinities directly correlated with observed bioactivity. Revelation of naturally produced pheromones along with determination of their affinity for cognate receptors are important steps forward in designing compounds whose purpose is positioned for future therapeutics aimed at treating infections through the interference of bacterial communication.
Collapse
Affiliation(s)
- Chaitanya Aggarwal
- From the Center for Pharmaceutical Biotechnology, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, and
| | - Juan Cristobal Jimenez
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois 60607 and
| | - Dhaval Nanavati
- the Chemistry of Life Processes Institute, Proteomics Core, Northwestern University, Evanston, Illinois 60208
| | - Michael J Federle
- From the Center for Pharmaceutical Biotechnology, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, and
| |
Collapse
|
241
|
García-Contreras R, Nuñez-López L, Jasso-Chávez R, Kwan BW, Belmont JA, Rangel-Vega A, Maeda T, Wood TK. Quorum sensing enhancement of the stress response promotes resistance to quorum quenching and prevents social cheating. ISME JOURNAL 2014; 9:115-25. [PMID: 24936763 DOI: 10.1038/ismej.2014.98] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 05/09/2014] [Accepted: 05/12/2014] [Indexed: 12/24/2022]
Abstract
Quorum sensing (QS) coordinates the expression of virulence factors and allows bacteria to counteract the immune response, partly by increasing their tolerance to the oxidative stress generated by immune cells. Despite the recognized role of QS in enhancing the oxidative stress response, the consequences of this relationship for the bacterial ecology remain unexplored. Here we demonstrate that QS increases resistance also to osmotic, thermal and heavy metal stress. Furthermore a QS-deficient lasR rhlR mutant is unable to exert a robust response against H2O2 as it has less induction of catalase and NADPH-producing dehydrogenases. Phenotypic microarrays revealed that the mutant is very sensitive to several toxic compounds. As the anti-oxidative enzymes are private goods not shared by the population, only the individuals that produce them benefit from their action. Based on this premise, we show that in mixed populations of wild-type and the mexR mutant (resistant to the QS inhibitor furanone C-30), treatment with C-30 and H2O2 increases the proportion of mexR mutants; hence, oxidative stress selects resistance to QS compounds. In addition, oxidative stress alone strongly selects for strains with active QS systems that are able to exert a robust anti oxidative response and thereby decreases the proportion of QS cheaters in cultures that are otherwise prone to invasion by cheats. As in natural environments stress is omnipresent, it is likely that this QS enhancement of stress tolerance allows cells to counteract QS inhibition and invasions by social cheaters, therefore having a broad impact in bacterial ecology.
Collapse
Affiliation(s)
| | - Leslie Nuñez-López
- Biochemistry Department, National Institute of Cardiology, Mexico City, Mexico
| | | | - Brian W Kwan
- Department of Chemical Engineeringy, Pennsylvania State University, University Park, PA, USA
| | - Javier A Belmont
- Biochemistry Department, National Institute of Cardiology, Mexico City, Mexico
| | - Adrián Rangel-Vega
- Internal Medicine Department, Speciality Hospital, National Medical Center 'Siglo XXI', IMSS, Mexico City, Mexico
| | - Toshinari Maeda
- Department of Biological Functions Engineering, Kyushu Institute of Technology, Kitakyushu, Japan
| | - Thomas K Wood
- 1] Department of Chemical Engineeringy, Pennsylvania State University, University Park, PA, USA [2] Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, USA
| |
Collapse
|
242
|
Quorum sensing-dependent metalloprotease VvpE is important in the virulence of Vibrio vulnificus to invertebrates. Microb Pathog 2014; 71-72:8-14. [DOI: 10.1016/j.micpath.2014.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 04/04/2014] [Accepted: 04/07/2014] [Indexed: 11/18/2022]
|
243
|
Yunos NYM, Tan WS, Mohamad NI, Tan PW, Adrian TGS, Yin WF, Chan KG. Quorum sensing activity of a Kluyvera sp. isolated from a Malaysian waterfall. SENSORS 2014; 14:8305-12. [PMID: 24815680 PMCID: PMC4063027 DOI: 10.3390/s140508305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 04/30/2014] [Accepted: 05/04/2014] [Indexed: 01/19/2023]
Abstract
In many species of bacteria, the quorum sensing mechanism is used as a unique communication system which allows them to regulate gene expression and behavior in accordance with their population density. N-Acylhomoserine lactones (AHLs) are known as diffusible autoinducer molecules involved in this communication network. This finding aimed to characterize the production of AHL of a bacterial strain ND04 isolated from a Malaysian waterfall. Strain ND04 was identified as Kluyvera sp. as confirmed by molecular analysis of its 16S ribosomal RNA gene sequence. Kluyvera sp. is closely related to the Enterobacteriaceae family. Chromobacterium violaceum CV026 was used as a biosensor to detect the production of AHL by strain ND04. High resolution triple quadrupole liquid chromatography-mass spectrometry analysis of strain ND04 showed our isolate produced two AHLs which are N-(3-oxohexanoyl)homoserine lactone (3-oxo-C6 HSL) and N-3-oxo-octanoyl-L-homoserine lactone (3-oxo-C8 HSL).
Collapse
Affiliation(s)
- Nina Yusrina Muhamad Yunos
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Wen-Si Tan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Nur Izzati Mohamad
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Pui-Wan Tan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Tan-Guan-Sheng Adrian
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Wai-Fong Yin
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Kok-Gan Chan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| |
Collapse
|
244
|
Microbial metabolism of quorum-sensing molecules acyl-homoserine lactones, γ-heptalactone and other lactones. Appl Microbiol Biotechnol 2014; 98:3401-12. [DOI: 10.1007/s00253-014-5518-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Revised: 12/30/2013] [Accepted: 01/03/2014] [Indexed: 10/25/2022]
|
245
|
Interspecific quorum sensing mediates the resuscitation of viable but nonculturable vibrios. Appl Environ Microbiol 2014; 80:2478-83. [PMID: 24509922 DOI: 10.1128/aem.00080-14] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Entry and exit from dormancy are essential survival mechanisms utilized by microorganisms to cope with harsh environments. Many bacteria, including the opportunistic human pathogen Vibrio vulnificus, enter a form of dormancy known as the viable but nonculturable (VBNC) state. VBNC cells can resuscitate when suitable conditions arise, yet the molecular mechanisms facilitating resuscitation in most bacteria are not well understood. We discovered that bacterial cell-free supernatants (CFS) can awaken preexisting dormant vibrio populations within oysters and seawater, while CFS from a quorum sensing mutant was unable to produce the same resuscitative effect. Furthermore, the quorum sensing autoinducer AI-2 could induce resuscitation of VBNC V. vulnificus in vitro, and VBNC cells of a mutant unable to produce AI-2 were unable to resuscitate unless the cultures were supplemented with exogenous AI-2. The quorum sensing inhibitor cinnamaldehyde delayed the resuscitation of wild-type VBNC cells, confirming the importance of quorum sensing in resuscitation. By monitoring AI-2 production by VBNC cultures over time, we found quorum sensing signaling to be critical for the natural resuscitation process. This study provides new insights into the molecular mechanisms stimulating VBNC cell exit from dormancy, which has significant implications for microbial ecology and public health.
Collapse
|
246
|
Witsø IL, Benneche T, Vestby LK, Nesse LL, Lönn-Stensrud J, Scheie AA. Thiophenone and furanone in control of Escherichia coli O103:H2 virulence. Pathog Dis 2014; 70:297-306. [PMID: 24391047 DOI: 10.1111/2049-632x.12128] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 12/20/2013] [Accepted: 12/23/2013] [Indexed: 01/11/2023] Open
Abstract
Escherichia coli are a mutual and foodborne pathogen, causing severe intestinal infections typically characterized by diarrhoea and vomiting. Biofilms are often a common source of pathogenic and nonpathogenic bacteria. Quorum sensing is a phenomenon where bacteria communicate and initiate the regulation of several virulence factors and biofilm formation. Thus, quorum sensing has been a new target in the fight against bacterial biofilms. In this study, we investigated the effect of two quorum-sensing inhibitors for preventing in vitro biofilm formation in wild-type E. coli O103:H2. Furanone F202 originates from the red algae Delisea pulchra, and thiophenone TF101 is a sulphur analogue of furanone. We also investigated the effect of thiophenone and furanone on virulence factors controlled by quorum sensing. Both TF101 and F202 interfered with biofilm formation, although TF101 was more effective. TF101 reduced motility presumably by interfering with flagella production, visualized by microscopic techniques. The expressions of flhd, which are involved in flagella synthesis, were affected by thiophenone. This is the first study exploring the effect of thiophenone on E. coli biofilm formation and virulence factors.
Collapse
Affiliation(s)
- Ingun L Witsø
- Department of Oral Biology, University of Oslo, Norway
| | | | | | | | | | | |
Collapse
|
247
|
Reducing virulence of the human pathogen Burkholderia by altering the substrate specificity of the quorum-quenching acylase PvdQ. Proc Natl Acad Sci U S A 2014; 111:1568-73. [PMID: 24474783 DOI: 10.1073/pnas.1311263111] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The use of enzymes to interfere with quorum sensing represents an attractive strategy to fight bacterial infections. We used PvdQ, an effective quorum-quenching enzyme from Pseudomonas aeruginosa, as a template to generate an acylase able to effectively hydrolyze C8-HSL, the major communication molecule produced by the Burkholderia species. We discovered that the combination of two single mutations leading to variant PvdQ(Lα146W,Fβ24Y) conferred high activity toward C8-HSL. Exogenous addition of PvdQ(Lα146W,Fβ24Y) dramatically decreased the amount of C8-HSL present in Burkholderia cenocepacia cultures and inhibited a quorum sensing-associated phenotype. The efficacy of this PvdQ variant to combat infections in vivo was further confirmed by its ability to rescue Galleria mellonella larvae upon infection, demonstrating its potential as an effective agent toward Burkholderia infections. Kinetic analysis of the enzymatic activities toward 3-oxo-C12-L-HSL and C8-L-HSL corroborated a substrate switch. This work demonstrates the effectiveness of quorum-quenching acylases as potential novel antimicrobial drugs. In addition, we demonstrate that their substrate range can be easily switched, thereby paving the way to selectively target only specific bacterial species inside a complex microbial community.
Collapse
|
248
|
Bertucci MA, Lee SJ, Gagné MR. Selective transamidation of 3-oxo-N-acyl homoserine lactones by hydrazine derivatives. Org Biomol Chem 2014; 12:7197-200. [DOI: 10.1039/c4ob01156b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrazine derivatives are employed for selective amide cleavage of 3-oxo-N-acyl homoserine lactones under physiologically relevant conditions.
Collapse
Affiliation(s)
- Michael A. Bertucci
- Department of Chemistry
- University of North Carolina at Chapel Hill
- Chapel Hill, USA
| | | | - Michel R. Gagné
- Department of Chemistry
- University of North Carolina at Chapel Hill
- Chapel Hill, USA
| |
Collapse
|
249
|
Storz MP, Allegretta G, Kirsch B, Empting M, Hartmann RW. From in vitro to in cellulo: structure–activity relationship of (2-nitrophenyl)methanol derivatives as inhibitors of PqsD in Pseudomonas aeruginosa. Org Biomol Chem 2014; 12:6094-104. [DOI: 10.1039/c4ob00707g] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
More than 60 derivatives of (2-nitrophenyl)methanol were synthesized and evaluated regarding their potency to inhibit PqsD. In vitro and in cellulo structure–activity relationships were derived.
Collapse
Affiliation(s)
- Michael P. Storz
- Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS)
- 66123 Saarbrücken, Germany
| | - Giuseppe Allegretta
- Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS)
- 66123 Saarbrücken, Germany
| | - Benjamin Kirsch
- Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS)
- 66123 Saarbrücken, Germany
| | - Martin Empting
- Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS)
- 66123 Saarbrücken, Germany
| | - Rolf W. Hartmann
- Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS)
- 66123 Saarbrücken, Germany
- Pharmaceutical and Medicinal Chemistry
- Saarland University
- 66123 Saarbrücken, Germany
| |
Collapse
|
250
|
Erriu M, Blus C, Szmukler-Moncler S, Buogo S, Levi R, Barbato G, Madonnaripa D, Denotti G, Piras V, Orrù G. Microbial biofilm modulation by ultrasound: current concepts and controversies. ULTRASONICS SONOCHEMISTRY 2014; 21:15-22. [PMID: 23751458 DOI: 10.1016/j.ultsonch.2013.05.011] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Revised: 05/08/2013] [Accepted: 05/18/2013] [Indexed: 05/05/2023]
Abstract
Biofilm elimination is often necessary during antimicrobial therapy or industrial medical manufacturing decontamination. In this context, ultrasound treatment has been frequently described in the literature for its antibiofilm effectiveness, but at the same time, various authors have described ultrasound as a formidable enhancer of bacterial viability. This discrepancy has found no solution in the current literature for around 9 years; some works have shown that every time bacteria are exposed to an ultrasonic field, both destruction and stimulation phenomena co-exist. This co-existence proves to have different final effects based on various factors such as: ultrasound frequency and intensity, the bacterial species involved, the material used for ultrasound diffusion, the presence of cavitation effects and the forms of bacterial planktonic or biofilm. The aim of this work is to analyze current concepts regarding ultrasound effect on prokaryotic cells, and in particular ultrasound activity on bacterial biofilm.
Collapse
Affiliation(s)
- Matteo Erriu
- Oral Biotechnology Laboratory (OBL), Università degli Studi di Cagliari, Cagliari, Italy.
| | | | | | | | | | | | | | | | | | | |
Collapse
|