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Cleaver L, Garnett JA. How to study biofilms: technological advancements in clinical biofilm research. Front Cell Infect Microbiol 2023; 13:1335389. [PMID: 38156318 PMCID: PMC10753778 DOI: 10.3389/fcimb.2023.1335389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 11/30/2023] [Indexed: 12/30/2023] Open
Abstract
Biofilm formation is an important survival strategy commonly used by bacteria and fungi, which are embedded in a protective extracellular matrix of organic polymers. They are ubiquitous in nature, including humans and other animals, and they can be surface- and non-surface-associated, making them capable of growing in and on many different parts of the body. Biofilms are also complex, forming polymicrobial communities that are difficult to eradicate due to their unique growth dynamics, and clinical infections associated with biofilms are a huge burden in the healthcare setting, as they are often difficult to diagnose and to treat. Our understanding of biofilm formation and development is a fast-paced and important research focus. This review aims to describe the advancements in clinical biofilm research, including both in vitro and in vivo biofilm models, imaging techniques and techniques to analyse the biological functions of the biofilm.
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Affiliation(s)
- Leanne Cleaver
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King’s College London, London, United Kingdom
| | - James A. Garnett
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King’s College London, London, United Kingdom
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2
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Rehman S, Antonovic AK, McIntire IE, Zheng H, Cleaver L, Adams CO, Portlock T, Richardson K, Shaw R, Oregioni A, Mastroianni G, Whittaker SBM, Kelly G, Fornili A, Cianciotto NP, Garnett JA. The Legionella collagen-like protein employs a unique binding mechanism for the recognition of host glycosaminoglycans. bioRxiv 2023:2023.12.10.570962. [PMID: 38106198 PMCID: PMC10723406 DOI: 10.1101/2023.12.10.570962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Bacterial adhesion is a fundamental process which enables colonisation of niche environments and is key for infection. However, in Legionella pneumophila, the causative agent of Legionnaires' disease, these processes are not well understood. The Legionella collagen-like protein (Lcl) is an extracellular peripheral membrane protein that recognises sulphated glycosaminoglycans (GAGs) on the surface of eukaryotic cells, but also stimulates bacterial aggregation in response to divalent cations. Here we report the crystal structure of the Lcl C-terminal domain (Lcl-CTD) and present a model for intact Lcl. Our data reveal that Lcl-CTD forms an unusual dynamic trimer arrangement with a positively charged external surface and a negatively charged solvent exposed internal cavity. Through Molecular Dynamics (MD) simulations, we show how the GAG chondroitin-4-sulphate associates with the Lcl-CTD surface via unique binding modes. Our findings show that Lcl homologs are present across both the Pseudomonadota and Fibrobacterota-Chlorobiota-Bacteroidota phyla and suggest that Lcl may represent a versatile carbohydrate binding mechanism.
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Affiliation(s)
- Saima Rehman
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King’s College London, London, UK
| | - Anna K. Antonovic
- School of Physical and Chemical Sciences, Queen Mary University of London, London, UK
| | - Ian E. McIntire
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Huaixin Zheng
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Leanne Cleaver
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King’s College London, London, UK
| | - Carlton O. Adams
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Theo Portlock
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King’s College London, London, UK
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Katherine Richardson
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Rosie Shaw
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Alain Oregioni
- The Medical Research Council Biomedical NMR Centre, the Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Giulia Mastroianni
- School of Physical and Chemical Sciences, Queen Mary University of London, London, UK
| | - Sara B-M. Whittaker
- School of Cancer Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Geoff Kelly
- The Medical Research Council Biomedical NMR Centre, the Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Arianna Fornili
- School of Physical and Chemical Sciences, Queen Mary University of London, London, UK
| | - Nicholas P. Cianciotto
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - James A. Garnett
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King’s College London, London, UK
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3
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Rofael S, Leboreiro Babe C, Davrandi M, Kondratiuk AL, Cleaver L, Ahmed N, Atkinson C, McHugh T, Lowe DM. Antibiotic resistance, bacterial transmission and improved prediction of bacterial infection in patients with antibody deficiency. JAC Antimicrob Resist 2023; 5:dlad135. [PMID: 38098890 PMCID: PMC10720947 DOI: 10.1093/jacamr/dlad135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 11/29/2023] [Indexed: 12/17/2023] Open
Abstract
Background Antibody-deficient patients are at high risk of respiratory tract infections. Many therefore receive antibiotic prophylaxis and have access to antibiotics for self-administration in the event of breakthrough infections, which may increase antimicrobial resistance (AMR). Objectives To understand AMR in the respiratory tract of patients with antibody deficiency. Methods Sputum samples were collected from antibody-deficient patients in a cross-sectional and prospective study; bacteriology culture, 16S rRNA profiling and PCR detecting macrolide resistance genes were performed. Bacterial isolates were identified using MALDI-TOF, antimicrobial susceptibility was determined by disc diffusion and WGS of selected isolates was done using Illumina NextSeq with analysis for resistome and potential cross-transmission. Neutrophil elastase was measured by a ProteaseTag immunoassay. Results Three hundred and forty-three bacterial isolates from sputum of 43 patients were tested. Macrolide and tetracycline resistance were common (82% and 35% of isolates). erm(B) and mef(A) were the most frequent determinants of macrolide resistance. WGS revealed viridans streptococci as the source of AMR genes, of which 23% also carried conjugative plasmids linked with AMR genes and other mobile genetic elements. Phylogenetic analysis of Haemophilus influenzae isolates suggested possible transmission between patients attending clinic.In the prospective study, a negative correlation between sputum neutrophil elastase concentration and Shannon entropy α-diversity (Spearman's ρ = -0.306, P = 0.005) and a positive relationship with Berger-Parker dominance index (ρ = 0.502, P < 0.001) were found. Similar relationships were noted for the change in elastase concentration between consecutive samples, increases in elastase associating with reduced α-diversity. Conclusions Measures to limit antibiotic usage and spread of AMR should be implemented in immunodeficiency clinics. Sputum neutrophil elastase may be a useful marker to guide use of antibiotics for respiratory infection.
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Affiliation(s)
- Sylvia Rofael
- Centre for Clinical Microbiology, University College London, Royal Free Campus, Pond Street, London, UK
- Faculty of Pharmacy, University of Alexandria, Alexandria, Egypt
| | - Clara Leboreiro Babe
- Centre for Clinical Microbiology, University College London, Royal Free Campus, Pond Street, London, UK
| | - Mehmet Davrandi
- Centre for Clinical Microbiology, University College London, Royal Free Campus, Pond Street, London, UK
| | - Alexandra L Kondratiuk
- Institute for Immunity and Transplantation, Division of Infection and Immunity, University College London, Pears Building, Rowland Hill Street, London, UK
| | - Leanne Cleaver
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, Guy’s Campus, King’s College London, London, UK
| | - Naseem Ahmed
- Centre for Clinical Microbiology, University College London, Royal Free Campus, Pond Street, London, UK
| | - Claire Atkinson
- Institute for Immunity and Transplantation, Division of Infection and Immunity, University College London, Pears Building, Rowland Hill Street, London, UK
- Cancer Biology and Therapy Research Group, Divisionof Human Sciences, School of Applied Sciences, London South Bank University, London, UK
| | - Timothy McHugh
- Centre for Clinical Microbiology, University College London, Royal Free Campus, Pond Street, London, UK
| | - David M Lowe
- Institute for Immunity and Transplantation, Division of Infection and Immunity, University College London, Pears Building, Rowland Hill Street, London, UK
- Department of Clinical Immunology, Royal Free London NHS Foundation Trust, Pond Street, London, UK
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Dixon A, Steinman HK, Kyrgidis A, Smith H, Sladden M, Zouboulis C, Argenziano G, Apalla Z, Lallas A, Longo C, Nirenberg A, Popescu C, Tzellos T, Cleaver L, Zachary C, Anderson S, Thomas JM. Online prediction tools for melanoma survival: A comparison. J Eur Acad Dermatol Venereol 2023; 37:1999-2003. [PMID: 37210649 DOI: 10.1111/jdv.19219] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 04/26/2023] [Indexed: 05/22/2023]
Abstract
BACKGROUND Breslow thickness, patient age and ulceration are the three most valuable clinical and pathological predictors of melanoma survival. A readily available reliable online tool that accurately considers these and other predictors could be valuable for clinicians managing melanoma patients. OBJECTIVE To compare online melanoma survival prediction tools that request user input on clinical and pathological features. METHODS Search engines were used to identify available predictive nomograms. For each, clinical and pathological predictors were compared. RESULTS Three tools were identified. The American Joint Committee on Cancer tool inappropriately rated thin tumours as higher risk than intermediate tumours. The University of Louisville tool was found to have six shortcomings: a requirement for sentinel node biopsy, unavailable input of thin melanoma or patients over 70 years of age and less reliable hazard ratio calculations for age, ulceration and tumour thickness. The LifeMath.net tool was found to appropriately consider tumour thickness, ulceration, age, sex, site and tumour subtype in predicting survival. LIMITATIONS The authors did not have access to the base data used to compile various prediction tools. CONCLUSION The LifeMath.net prediction tool is the most reliable for clinicians in counselling patients with newly diagnosed primary cutaneous melanoma regarding their survival prospects.
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Affiliation(s)
- A Dixon
- Australasian College of Cutaneous Oncology, Victoria, Melbourne, Australia
| | - H K Steinman
- Campbell University, Buies Creek, North Carolina, USA
| | - A Kyrgidis
- Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - H Smith
- Oxford Dermatology, Western Australia, Perth, Australia
| | - M Sladden
- University of Tasmania, Tasmania, Launceston, Australia
| | - C Zouboulis
- Staedtisches Klinikum Dessau, Brandenburg Medical School, Dessau, Germany
| | - G Argenziano
- Dermatology, University of Campania, Naples, Italy
| | - Z Apalla
- Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - A Lallas
- Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - C Longo
- University of Modena and Reggio Emilia, Modena, Italy
- Azienda Unita Sanitaria Locale, IRCCS di Reggio Emilia, Skin Cancer Center, Regio Emilia, Italy
| | - A Nirenberg
- Australasian College of Cutaneous Oncology, Victoria, Melbourne, Australia
| | - C Popescu
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - T Tzellos
- Arctic University of Norway, Tromsø, Norway
| | - L Cleaver
- AT Still University, Missouri, Kirksville, USA
| | - C Zachary
- University of California Irvine, California, Irvine, USA
| | - S Anderson
- Australasian College of Cutaneous Oncology, Victoria, Melbourne, Australia
| | - J M Thomas
- Formerly of Royal Marsden Hospital, Chelsea, London, UK
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Dixon AJ, Steinman HK, Kyrgidis A, Smith H, Sladden M, Zouboulis C, Argenziano G, Apalla Z, Lallas A, Longo C, Nirenberg A, Popescu C, Dixon JB, Tzellos T, Zachary C, Cleaver L, Anderson S, Zagarella S, Thomas JM. Improved methodology in determining melanoma mortality and selecting patients for immunotherapy. J Eur Acad Dermatol Venereol 2023. [PMID: 36785984 DOI: 10.1111/jdv.18951] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 02/08/2023] [Indexed: 02/15/2023]
Affiliation(s)
- A J Dixon
- Australasian College of Cutaneous Oncology, Melbourne, Victoria, Australia
| | - H K Steinman
- Campbell University, Buies Creek, North Carolina, USA
| | - A Kyrgidis
- Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - H Smith
- Oxford Dermatology, Perth, Western Australia, Australia
| | - M Sladden
- University of Tasmania, Launceston, Tasmania, Australia
| | - C Zouboulis
- Dessau Medical Center, Brandenburg Medical School, Dessau, Germany
| | | | - Z Apalla
- Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - A Lallas
- Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - C Longo
- University of Modena and Reggio Emilia, Modena, Italy
| | - A Nirenberg
- Australasian College of Cutaneous Oncology, Melbourne, Victoria, Australia
| | - C Popescu
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - J B Dixon
- Swinburne University of Technology, Melbourne, Victoria, Australia
| | - T Tzellos
- Arctic University of Norway, Tromsø, Norway
| | - C Zachary
- University of California, Irvine, California, USA
| | - L Cleaver
- A.T. Still University, Kirksville, Missouri, USA
| | - S Anderson
- Australasian College of Cutaneous Oncology, Melbourne, Victoria, Australia
| | - S Zagarella
- University of Sydney, Sydney, New South Wales, Australia
| | - J M Thomas
- Formerly of Royal Marsden Hospital, London, UK
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Foratori-Junior GA, Guennec AL, Fidalgo TKDS, Cleaver L, Buzalaf MAR, Carpenter GH, Sales-Peres SHDC. Metabolomic Profiles Associated with Obesity and Periodontitis during Pregnancy: Cross-Sectional Study with Proton Nuclear Magnetic Resonance ( 1H-NMR)-Based Analysis. Metabolites 2022; 12:metabo12111029. [PMID: 36355112 PMCID: PMC9694155 DOI: 10.3390/metabo12111029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/18/2022] [Accepted: 10/24/2022] [Indexed: 12/27/2022] Open
Abstract
This study aimed to elucidate the metabolomic signature associated with obesity and periodontitis during pregnancy in plasma and saliva biofluids. Ninety-eight pregnant women were divided into: with obesity and periodontitis (OP = 20), with obesity but without periodontitis (OWP = 27), with normal BMI but with periodontitis (NP = 21), with normal BMI and without periodontitis (NWP = 30). Saliva and plasma were analyzed by 1H-NMR for metabolites identification. Partial Least Squares-Discriminant Analysis (PLS-DA), Sparse PLS-DA (sPLS-DA), and Variable Importance of Projection (VIP) were performed. ANOVA and Pearson’s correlation were applied (p < 0.05). Plasmatic analysis indicated the levels of glucose (p = 0.041) and phenylalanine (p = 0.015) were positively correlated with periodontal parameters and BMI, respectively. In saliva, periodontitis was mainly associated with high levels of acetic acid (p = 0.024), isovaleric acid, butyric acid, leucine, valine, isoleucine, and propionic acid (p < 0.001). High salivary concentrations of glycine (p = 0.015), succinic acid (p = 0.015), and lactate (p = 0.026) were associated with obesity. Saliva demonstrated a more elucidative difference than plasma, indicating the glucose-alanine cycle, alanine metabolism, valine, leucine and isoleucine degradation, glutamate metabolism, and Warburg effect as the main metabolic pathways.
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Affiliation(s)
- Gerson Aparecido Foratori-Junior
- Department of Pediatric Dentistry, Orthodontics and Public Health, Bauru School of Dentistry, University of São Paulo, Bauru 17012-901, Brazil
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, Guy’s Campus, King’s College London, London SE1 1UL, UK
- Correspondence: (G.A.F.-J.); (S.H.d.C.S.-P.)
| | - Adrien Le Guennec
- Nuclear Magnetic Resonance Facility, Guy’s Campus, King’s College London, London SE1 1UL, UK
| | - Tatiana Kelly da Silva Fidalgo
- Department of Preventive and Community Dentistry, School of Dentistry, Rio de Janeiro State University, Rio de Janeiro 20551-030, Brazil
| | - Leanne Cleaver
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, Guy’s Campus, King’s College London, London SE1 1UL, UK
| | | | - Guy Howard Carpenter
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, Guy’s Campus, King’s College London, London SE1 1UL, UK
| | - Silvia Helena de Carvalho Sales-Peres
- Department of Pediatric Dentistry, Orthodontics and Public Health, Bauru School of Dentistry, University of São Paulo, Bauru 17012-901, Brazil
- Correspondence: (G.A.F.-J.); (S.H.d.C.S.-P.)
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Small E, Gardner L, Maharjan R, Starrs M, Cleaver L, Leamon A, Kunwar S, Joshi N, Votta K, Marvel J. 30 Current Understanding and Relevant Trends in Altitude Illness in Nepal (CURTAIN). Ann Emerg Med 2022. [DOI: 10.1016/j.annemergmed.2022.08.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Corsini P, Wang S, Rehman S, Fenn K, Sagar A, Sirovica S, Cleaver L, Edwards-Gayle C, Mastroianni G, Dorgan B, Sewell L, Lynham S, Iuga D, Franks T, Jarvis J, Carpenter G, Curtis M, Bernado P, Darbari V, Garnett J. Molecular and cellular insight into Escherichia coli SslE and its role during biofilm maturation. Access Microbiol 2022. [DOI: 10.1099/acmi.ac2021.po0191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Escherichia coli is a Gram-negative bacterium that colonizes the human intestine and virulent strains can cause severe diarrhoeal and extraintestinal diseases. The protein SslE is secreted by a range of pathogenic and some commensal E. colistrains. It can degrade mucins in the intestine, promotes biofilm maturation and in virulent strains, it is a major determinant of infection, although how it carries out these functions is not well understood. Here we examine SslE from the E. coli Waksman and H10407 strains and using electron microscopy (EM), small angle X-ray scattering (SAXS), nuclear magnetic resonance (NMR) spectroscopy and biochemical analyses we show that SslE has a highly dynamic structure in solution. We also directly observe acidification within mature biofilms, describe a mechanism where SslE forms unique functional fibres under these conditions and determine that these SslE aggregates can bind cellulose, a major exopolysaccharide of many E. coli biofilms. Our data indicates that the spatial organization of SslE polymers and local pH are critical for biofilm maturation and SslE is a key factor that drives persistence of SslE-secreting bacteria during acidic stress.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Dinu Iuga
- University of Warwick, United Kingdom
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Corsini PM, Wang S, Rehman S, Fenn K, Sagar A, Sirovica S, Cleaver L, Edwards-Gayle CJC, Mastroianni G, Dorgan B, Sewell LM, Lynham S, Iuga D, Franks WT, Jarvis J, Carpenter GH, Curtis MA, Bernadó P, Darbari VC, Garnett JA. Molecular and cellular insight into Escherichia coli SslE and its role during biofilm maturation. NPJ Biofilms Microbiomes 2022; 8:9. [PMID: 35217675 PMCID: PMC8881592 DOI: 10.1038/s41522-022-00272-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 01/31/2022] [Indexed: 11/10/2022] Open
Abstract
Escherichia coli is a Gram-negative bacterium that colonises the human intestine and virulent strains can cause severe diarrhoeal and extraintestinal diseases. The protein SslE is secreted by a range of pathogenic and commensal E. coli strains. It can degrade mucins in the intestine, promotes biofilm maturation and it is a major determinant of infection in virulent strains, although how it carries out these functions is not well understood. Here, we examine SslE from the commensal E. coli Waksman and BL21 (DE3) strains and the enterotoxigenic H10407 and enteropathogenic E2348/69 strains. We reveal that SslE has a unique and dynamic structure in solution and in response to acidification within mature biofilms it can form a unique aggregate with amyloid-like properties. Furthermore, we show that both SslE monomers and aggregates bind DNA in vitro and co-localise with extracellular DNA (eDNA) in mature biofilms, and SslE aggregates may also associate with cellulose under certain conditions. Our results suggest that interactions between SslE and eDNA are important for biofilm maturation in many E. coli strains and SslE may also be a factor that drives biofilm formation in other SslE-secreting bacteria.
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Affiliation(s)
- Paula M Corsini
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Sunjun Wang
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK
| | - Saima Rehman
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK
| | - Katherine Fenn
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Amin Sagar
- Centre de Biologie Structurale, Université de Montpellier, INSERM, CNRS, Montpellier, France
| | - Slobodan Sirovica
- Centre for Oral Bioengineering, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Leanne Cleaver
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK
| | | | - Giulia Mastroianni
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Ben Dorgan
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK
| | - Lee M Sewell
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK
| | - Steven Lynham
- Proteomics Facility, Centre of Excellence for Mass Spectrometry, King's College London, London, UK
| | - Dinu Iuga
- Department of Physics, University of Warwick, Coventry, UK
| | - W Trent Franks
- Department of Physics, University of Warwick, Coventry, UK
| | - James Jarvis
- Randall Division of Cell and Molecular Biophysics and Centre for Biomolecular Spectroscopy, King's College London, London, UK
| | - Guy H Carpenter
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK
| | - Michael A Curtis
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK
| | - Pau Bernadó
- Centre de Biologie Structurale, Université de Montpellier, INSERM, CNRS, Montpellier, France
| | - Vidya C Darbari
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK.
| | - James A Garnett
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK.
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK.
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10
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Carpenter G, Cleaver L, Blakeley M, Hasbullah N, Houghton J, Gardner A. Wine astringency reduces flavor intensity of Brussels sprouts. J Texture Stud 2018; 50:71-74. [PMID: 30387878 DOI: 10.1111/jtxs.12378] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 10/15/2018] [Accepted: 10/17/2018] [Indexed: 11/28/2022]
Abstract
The bitterness of vegetables is a leading reason why they are avoided by children and some adults. Bitterness is perceived via TAS2R receptors located on the tongue. In contrast, astringency is a mouthfeel rather than a taste, and is perceived as a dry, puckering sensation. To date few reports have suggested any interactions between the two processes even though they often occur simultaneously in many real foods. In this study, we have used Brussels sprouts as an exemplar bitter vegetable and examined the influence of a number of different interventions on perceived intensity. Subjects rated the intensity of Brussels sprouts before and after three interventions: gravy, red wine, and water. Only red wine caused a significant (p < .0001) decrease in VAS scale, from 5.5 to 3.5 on a 10-point labeled magnitude scale. The results suggest the astringency of the red wine affected the perception of bitter in the Brussels sprout. Some possible mechanisms are discussed. PRACTICAL APPLICATIONS: This report reveals a possible insight into how bitterness is perceived in humans. By using astringency to affect salivary proteins, we suggest they may play a role in the detection of bitterness. This may be by helping to transport bitterness compounds to the taste bud receptors or a separate mechanism. Potentially this also opens up new ways to block bitterness.
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Affiliation(s)
- Guy Carpenter
- Salivary Research, Mucosal and Salivary Biology Division, King's College London Dental Institute, Guy's Hospital, London, United Kingdom
| | - Leanne Cleaver
- Salivary Research, Mucosal and Salivary Biology Division, King's College London Dental Institute, Guy's Hospital, London, United Kingdom
| | - Matthew Blakeley
- Salivary Research, Mucosal and Salivary Biology Division, King's College London Dental Institute, Guy's Hospital, London, United Kingdom
| | - Nurulezah Hasbullah
- Salivary Research, Mucosal and Salivary Biology Division, King's College London Dental Institute, Guy's Hospital, London, United Kingdom
| | - Jack Houghton
- Salivary Research, Mucosal and Salivary Biology Division, King's College London Dental Institute, Guy's Hospital, London, United Kingdom
| | - Alex Gardner
- Salivary Research, Mucosal and Salivary Biology Division, King's College London Dental Institute, Guy's Hospital, London, United Kingdom
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Cleaver L, Croft JA, Ritchie E, Taylor WC. Chemical studies of the Proteaceae. IX. Synthesis of 5-alkylresorcinols from aliphatic precursors. Aust J Chem 1976. [DOI: 10.1071/ch9761989] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Methods for the
aromatization of ethyl 6-alkyl-2,4-dioxocyclohexanecarboxylates, available from
the base-catalysed condensation between α, β-unsaturated esters and acetoacetic ester, and related substances have been
explored. 5-Nonyl- and 5-tridecyl-resorcinol (grevillol)
have been synthesized by this route but it is not suitable for the synthesis of
5-alkenylresorcinols or substances of the striatol type.
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Cleaver L, Nimgirawath S, Ritchie E, Taylor WC. The alkaloids of Elmerrillia papuana (Magnoliaceae) : Structure and synthesis of elmerrillicine. Aust J Chem 1976. [DOI: 10.1071/ch9762003] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
From the bark of Elmerrillia papuana (Schltr.) Dandy (Magnoliaceae)
were isolated the known alkaloids liriodenine, norushinsunine (as its diacetyl
derivative) and N-methylushinsunine iodide, together
with a new alkaloid, elmerrillicine (as its monoacetyl and diacetyl
derivatives). By spectroscopic methods elmerrillicine
was deduced to be 3-methoxy-l,2-methylenedioxy-6-demethylaporphin-11-ol, This
structure was confirmed by a synthesis by the standard route involving a Pschorr reaction and by a photochemical synthesis in which
a dehydroaporphine was an intermediate.
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Bowden BF, Cleaver L, Ndalut PK, Ritchie E, Taylor WC. The chemical constituents of Australian Flindersia species. XX. An examination of F. pimenteliana. Aust J Chem 1975. [DOI: 10.1071/ch9751393] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The bark of F. pimenteliana F. Muell. yielded
seselin, xanthyletin, betulin, sitosterol and traces of dictamnine and
skimmianine. The leaves gave rutin, skimmianine,
betulin and sitosterol. From the wood only sitosterol could be isolated and a
trace of alkaloid detected.
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