1
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Kabir RB, Ahsan T, Rahman MF, Jobayer M, Shamsuzzaman SM. Biofilm-producing and specific antibiotic resistance genes in Pseudomonas aeruginosa isolated from patients admitted to a tertiary care hospital, Bangladesh. IJID REGIONS 2024; 11:100369. [PMID: 38799795 PMCID: PMC11126856 DOI: 10.1016/j.ijregi.2024.100369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 04/21/2024] [Accepted: 04/22/2024] [Indexed: 05/29/2024]
Abstract
Objectives Biofilms are responsible for persistent infections and antimicrobial resistance. Pseudomonas aeruginosa was investigated with its ability to form biofilm by detecting genes responsible for producing biofilms and biofilm-specific antimicrobial resistance. The association between antibiotic resistance and biofilm was investigated. Methods This cross-sectional study was conducted from July 2017 to December 2018. A total of 446 samples (infected burn, surgical wounds, and endotracheal aspirate) were collected from admitted patients of Dhaka Medical College and Hospital, Bangladesh. P. aeruginosa was isolated and identified by biochemical tests and polymerase chain reaction. Biofilm production by tissue culture plate method followed by detection of biofilm-producing genes (pqsA, pslA, pslD, pslH, pelA, lasR) and biofilm-specific antibiotic resistance genes (ndvB, PA1874, PA1876, PA1877) by polymerase chain reaction were done. Antibiotic susceptibility test was carried out by disk diffusion method; for colistin agar dilution method of minimal inhibitory concentration was followed. Results Among 232 (52.02%) positive strains of P. aeruginosa, 24 (10.30%) produced biofilms in tissue culture plate. Among biofilm-producing genes, pqsA was the highest (79.17%). pslA and pelA were 70.83%, pslD 45.83%, pslH and lasR 37.5%. Among biofilm-specific antibiotic resistance genes, 16.67% were ndvB, and 8.33% were PA1874 and PA1877. Biofilm-forming strains were significantly resistant to colistin. Conclusions Detection of biofilm-forming genes may be a good tool for the evaluation of biofilm production, which will help in prompt and better management of chronic or device-associated infections.
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Affiliation(s)
| | - Tasnim Ahsan
- Department of Microbiology, Ibn Sina Medical College, Dhaka, Bangladesh
| | - Md. Faizur Rahman
- Department of Microbiology, Dhaka Medical College, Dhaka, Bangladesh
| | - Mohammad Jobayer
- Department of Microbiology, Dhaka Medical College, Dhaka, Bangladesh
| | - SM Shamsuzzaman
- Department of Microbiology, Dhaka Medical College, Dhaka, Bangladesh
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2
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Amyx-Sherer K, Reichhardt C. Challenges and opportunities in elucidating the structures of biofilm exopolysaccharides: A case study of the Pseudomonas aeruginosa exopolysaccharide called Pel. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2024; 62:361-369. [PMID: 37919227 DOI: 10.1002/mrc.5405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 10/09/2023] [Accepted: 10/17/2023] [Indexed: 11/04/2023]
Abstract
Biofilm formation protects bacteria from antibiotic treatment and host immune responses, making biofilm infections difficult to treat. Within biofilms, bacterial cells are entangled in a self-produced extracellular matrix that typically includes exopolysaccharides. Molecular-level descriptions of biofilm matrix components, especially exopolysaccharides, have been challenging to attain due to their complex nature and lack of solubility and crystallinity. Solid-state nuclear magnetic resonance (NMR) has emerged as a key tool to determine the structure of biofilm matrix exopolysaccharides without degradative sample preparation. In this review, we discuss challenges of studying biofilm matrix exopolysaccharides and opportunities to develop solid-state NMR approaches to study these generally intractable materials. We specifically highlight investigations of the exopolysaccharide called Pel made by the opportunistic pathogen, Pseudomonas aeruginosa. We provide a roadmap for determining exopolysaccharide structure and discuss future opportunities to study such systems using solid-state NMR. The strategies discussed for elucidating biofilm exopolysaccharide structure should be broadly applicable to studying the structures of other glycans.
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Affiliation(s)
- Kristen Amyx-Sherer
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Courtney Reichhardt
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, USA
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3
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Elfadadny A, Ragab RF, AlHarbi M, Badshah F, Ibáñez-Arancibia E, Farag A, Hendawy AO, De los Ríos-Escalante PR, Aboubakr M, Zakai SA, Nageeb WM. Antimicrobial resistance of Pseudomonas aeruginosa: navigating clinical impacts, current resistance trends, and innovations in breaking therapies. Front Microbiol 2024; 15:1374466. [PMID: 38646632 PMCID: PMC11026690 DOI: 10.3389/fmicb.2024.1374466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 03/05/2024] [Indexed: 04/23/2024] Open
Abstract
Pseudomonas aeruginosa, a Gram-negative bacterium, is recognized for its adaptability and opportunistic nature. It poses a substantial challenge in clinical settings due to its complicated antibiotic resistance mechanisms, biofilm formation, and capacity for persistent infections in both animal and human hosts. Recent studies revealed a potential zoonotic transmission of P. aeruginosa between animals, the environment, and human populations which highlights awareness of this microbe. Implementation of the One Health approach, which underscores the connection between human, animal, and environmental health, we aim to offer a comprehensive perspective on the current landscape of P. aeruginosa management. This review presents innovative strategies designed to counteract P. aeruginosa infections. Traditional antibiotics, while effective in many cases, are increasingly compromised by the development of multidrug-resistant strains. Non-antibiotic avenues, such as quorum sensing inhibition, phage therapy, and nanoparticle-based treatments, are emerging as promising alternatives. However, their clinical application encounters obstacles like cost, side effects, and safety concerns. Effectively addressing P. aeruginosa infections necessitates persistent research efforts, advancements in clinical development, and a comprehension of host-pathogen interactions to deal with this resilient pathogen.
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Affiliation(s)
- Ahmed Elfadadny
- Laboratory of Internal Medicine, Cooperative Division of Veterinary Sciences, Tokyo University of Agriculture and Technology, Fuchu, Japan
- Department of Internal Medicine, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt
| | - Rokaia F. Ragab
- Laboratory of Internal Medicine, Cooperative Division of Veterinary Sciences, Tokyo University of Agriculture and Technology, Fuchu, Japan
- Department of Biochemistry, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt
| | - Maha AlHarbi
- Department of Biology, College of Science, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Farhad Badshah
- State Key Laboratory of Animal Biotech Breeding, Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, China
| | - Eliana Ibáñez-Arancibia
- PhD Program in Sciences Mentioning Applied Molecular and Cell Biology, La Frontera University, Temuco, Chile
- Laboratory of Engineering, Biotechnology and Applied Biochemistry – LIBBA, Department of Chemical Engineering, Faculty of Engineering and Science, La Frontera University, Temuco, Chile
- Department of Biological and Chemical Sciences, Faculty of Natural Resources, Catholic University of Temuco, Temuco, Chile
| | - Ahmed Farag
- Department of Surgery, Anesthesiology, and Radiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Amin Omar Hendawy
- Department of Animal and Poultry Production, Faculty of Agriculture, Damanhour University, Damanhour, Egypt
| | - Patricio R. De los Ríos-Escalante
- Department of Biological and Chemical Sciences, Faculty of Natural Resources, Catholic University of Temuco, Temuco, Chile
- Nucleus of Environmental Sciences, Faculty of Natural Resources, Catholic University of Temuco, Temuco, Chile
| | - Mohamed Aboubakr
- Department of Pharmacology, Faculty of Veterinary Medicine, Benha University, Moshtohor, Toukh, Qaliobiya, Egypt
| | - Shadi A. Zakai
- Department of Clinical Microbiology and Immunology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Wedad M. Nageeb
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
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4
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Sedzicki J, Ni D, Lehmann F, Stahlberg H, Dehio C. Structure-function analysis of the cyclic β-1,2-glucan synthase from Agrobacterium tumefaciens. Nat Commun 2024; 15:1844. [PMID: 38418509 PMCID: PMC10901819 DOI: 10.1038/s41467-024-45415-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 01/22/2024] [Indexed: 03/01/2024] Open
Abstract
The synthesis of complex sugars is a key aspect of microbial biology. Cyclic β-1,2-glucan (CβG) is a circular polysaccharide critical for host interactions of many bacteria, including major pathogens of humans (Brucella) and plants (Agrobacterium). CβG is produced by the cyclic glucan synthase (Cgs), a multi-domain membrane protein. So far, its structure as well as the mechanism underlining the synthesis have not been clarified. Here we use cryo-electron microscopy (cryo-EM) and functional approaches to study Cgs from A. tumefaciens. We determine the structure of this complex protein machinery and clarify key aspects of CβG synthesis, revealing a distinct mechanism that uses a tyrosine-linked oligosaccharide intermediate in cycles of polymerization and processing of the glucan chain. Our research opens possibilities for combating pathogens that rely on polysaccharide virulence factors and may lead to synthetic biology approaches for producing complex cyclic sugars.
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Affiliation(s)
| | - Dongchun Ni
- Laboratory of Biological Electron Microscopy (LBEM), IPHYS, SB, EPFL, and Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, CH-1015, Switzerland
| | - Frank Lehmann
- Biozentrum, University of Basel, Basel, CH-4056, Switzerland
| | - Henning Stahlberg
- Laboratory of Biological Electron Microscopy (LBEM), IPHYS, SB, EPFL, and Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, CH-1015, Switzerland.
| | - Christoph Dehio
- Biozentrum, University of Basel, Basel, CH-4056, Switzerland.
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5
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Schniete JK, Brüser T, Horn MA, Tschowri N. Specialized biopolymers: versatile tools for microbial resilience. Curr Opin Microbiol 2024; 77:102405. [PMID: 38070462 DOI: 10.1016/j.mib.2023.102405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/07/2023] [Accepted: 11/09/2023] [Indexed: 02/12/2024]
Abstract
Bacteria produce a wide range of specialized biopolymers that can be classified into polysaccharides, polyamides, and polyesters and are considered to fulfill storage functions. In this review, we highlight recent developments in the field linking metabolism of biopolymers to stress and signaling physiology of the producers and demonstrating that biopolymers contribute to bacterial stress resistance and shape structure and composition of microenvironments. While specialized biopolymers are currently the focus of much attention in biotechnology as innovative and biodegradable materials, our understanding about the regulation and functions of these valuable compounds for the producers, microbial communities, and our environment is still very limited. Addressing open questions about signals, mechanisms, and functions in the area of biopolymers harbors potential for exciting discoveries with high relevance for biotechnology and fundamental research.
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Affiliation(s)
- Jana K Schniete
- Institute of Microbiology, Leibniz Universität Hannover, 30419 Hannover, Germany.
| | - Thomas Brüser
- Institute of Microbiology, Leibniz Universität Hannover, 30419 Hannover, Germany
| | - Marcus A Horn
- Institute of Microbiology, Leibniz Universität Hannover, 30419 Hannover, Germany
| | - Natalia Tschowri
- Institute of Microbiology, Leibniz Universität Hannover, 30419 Hannover, Germany
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6
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Otun SO, Graca R, Achilonu I. Combating Aminoglycoside Resistance: From Structural and Functional Characterisation to Therapeutic Challenges with RKAAT. Curr Protein Pept Sci 2024; 25:454-468. [PMID: 38314602 DOI: 10.2174/0113892037278814231226104509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/04/2023] [Accepted: 12/07/2023] [Indexed: 02/06/2024]
Abstract
A comprehensive knowledge of aminoglycoside-modifying enzymes (AMEs) and their role in bacterial resistance mechanisms is urgently required due to the rising incidence of antibiotic resistance, particularly in Klebsiella pneumoniae infections. This study explores the essential features of AMEs, including their structural and functional properties, the processes by which they contribute to antibiotic resistance, and the therapeutic importance of aminoglycosides. The study primarily examines the Recombinant Klebsiella pneumoniae Aminoglycoside Adenylyl Transferase (RKAAT), particularly emphasizing its biophysical characteristics and the sorts of resistance it imparts. Furthermore, this study examines the challenges presented by RKAAT-mediated resistance, an evaluation of treatment methods and constraints, and options for controlling infection. The analysis provides a prospective outlook on strategies to address and reduce antibiotic resistance. This extensive investigation seeks to provide vital insights into the continuing fight against bacterial resistance, directing future research efforts and medicinal approaches.
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Affiliation(s)
- Sarah Oluwatobi Otun
- Department of Molecular and Cell Biology, Protein Structure-function Unit, University of Witwatersrand, Johannesburg, South Africa
| | - Richard Graca
- Department of Molecular and Cell Biology, Protein Structure-function Unit, University of Witwatersrand, Johannesburg, South Africa
| | - Ikechukwu Achilonu
- Department of Molecular and Cell Biology, Protein Structure-function Unit, University of Witwatersrand, Johannesburg, South Africa
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7
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Fernández-Billón M, Llambías-Cabot AE, Jordana-Lluch E, Oliver A, Macià MD. Mechanisms of antibiotic resistance in Pseudomonas aeruginosa biofilms. Biofilm 2023; 5:100129. [PMID: 37205903 PMCID: PMC10189392 DOI: 10.1016/j.bioflm.2023.100129] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 04/29/2023] [Accepted: 05/02/2023] [Indexed: 05/21/2023] Open
Abstract
Pseudomonas aeruginosa is a major cause of life-threatening acute infections and life-long lasting chronic infections. The characteristic biofilm mode of life in P. aeruginosa chronic infections severely limits the efficacy of antimicrobial therapies, as it leads to intrinsic tolerance, involving physical and physiological factors in addition to biofilm-specific genes that can confer a transient protection against antibiotics promoting the development of resistance. Indeed, a striking feature of this pathogen is the extraordinary capacity to develop resistance to nearly all available antibiotics through the selection of chromosomal mutations, evidenced by its outstanding and versatile mutational resistome. This threat is dramatically amplified in chronic infections, driven by the frequent emergence of mutator variants with enhanced spontaneous mutation rates. Thus, this mini review is focused on describing the complex interplay of antibiotic resistance mechanisms in P. aeruginosa biofilms, to provide potentially useful information for the design of effective therapeutic strategies.
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Affiliation(s)
- María Fernández-Billón
- Department of Microbiology, Hospital Universitario Son Espases, Health Research Institute of the Balearic Islands (IdISBa), 07120, Palma de Mallorca, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Infecciosas, Instituto de Salud Carlos III (CIBERINFEC), 28029, Madrid, Spain
| | - Aina E. Llambías-Cabot
- Department of Microbiology, Hospital Universitario Son Espases, Health Research Institute of the Balearic Islands (IdISBa), 07120, Palma de Mallorca, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Infecciosas, Instituto de Salud Carlos III (CIBERINFEC), 28029, Madrid, Spain
| | - Elena Jordana-Lluch
- Department of Microbiology, Hospital Universitario Son Espases, Health Research Institute of the Balearic Islands (IdISBa), 07120, Palma de Mallorca, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Infecciosas, Instituto de Salud Carlos III (CIBERINFEC), 28029, Madrid, Spain
| | - Antonio Oliver
- Department of Microbiology, Hospital Universitario Son Espases, Health Research Institute of the Balearic Islands (IdISBa), 07120, Palma de Mallorca, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Infecciosas, Instituto de Salud Carlos III (CIBERINFEC), 28029, Madrid, Spain
| | - María D. Macià
- Department of Microbiology, Hospital Universitario Son Espases, Health Research Institute of the Balearic Islands (IdISBa), 07120, Palma de Mallorca, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Infecciosas, Instituto de Salud Carlos III (CIBERINFEC), 28029, Madrid, Spain
- Corresponding author. Department of Microbiology, Hospital Universitario Son Espases, Crta. Vallemossa 79, 07120, Palma de Mallorca, Spain.
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8
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Maddela NR, Abiodun AS, Zhang S, Prasad R. Biofouling in Membrane Bioreactors-Mitigation and Current Status: a Review. Appl Biochem Biotechnol 2023; 195:5643-5668. [PMID: 36418712 DOI: 10.1007/s12010-022-04262-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2022] [Indexed: 11/27/2022]
Abstract
Biological fouling as termed biofouling is caused by varied living organisms and is difficult to eliminate from the environment thus becoming a major issue during membrane bioreactors. Biofouling in membrane bioreactors (MBRs) is a crucial problem in increasing liquid pressure due to reduced pore diameter, clogging of the membrane pores, and alteration of the chemical composition of the water which greatly limits the growth of MBRs. Thus, membrane biofouling and/or microbial biofilms is a hot research topic to improve the market competitiveness of the MBR technology. Though several antibiofouling strategies (addition of bioflocculant or sponge into MBRs) came to light, biological approaches are sustainable and more practicable. Among the biological approaches, quorum sensing-based biofouling control (so-called quorum quenching) is an interesting and promising tool in combating biofouling issues in the MBRs. Several review articles have been published in the area of membrane biofouling and mitigation approaches. However, there is no single source of information about biofouling and/or biofilm formation in different environmental settings and respective problems, antibiofilm strategies and current status, quorum quenching, and its futurity. Thus, the objectives of the present review were to provide latest insights on mechanism of membrane biofouling, quorum sensing molecules, biofilm-associated problems in different environmental setting and antibiofilm strategies, special emphasis on quorum quenching, and its futurity in the biofilm/biofouling control. We believe that these insights greatly help in the better understanding of biofouling and aid in the development of sustainable antibiofouling strategies.
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Affiliation(s)
- Naga Raju Maddela
- Departmento de Ciencias Biológicas, Facultad de Ciencias de la Salud, Universidad Técnica de Manabí, Portoviejo, Ecuador
- Instituto de Investigación, Universidad Técnica de Manabí, Portoviejo, Ecuador
| | - Aransiola Sesan Abiodun
- Bioresources Development Centre, National Biotechnology Development Agency (NABDA), Ogbomoso, Nigeria
| | - Shaoqing Zhang
- School of Civil Engineering, Guangzhou University, Guangzhou, 510006, People's Republic of China
| | - Ram Prasad
- Department of Botany, Mahatma Gandhi Central University, Motihari, Bihar, India.
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9
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Spiers AJ, Dorfmueller HC, Jerdan R, McGregor J, Nicoll A, Steel K, Cameron S. Bioinformatics characterization of BcsA-like orphan proteins suggest they form a novel family of pseudomonad cyclic-β-glucan synthases. PLoS One 2023; 18:e0286540. [PMID: 37267309 PMCID: PMC10237404 DOI: 10.1371/journal.pone.0286540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 05/18/2023] [Indexed: 06/04/2023] Open
Abstract
Bacteria produce a variety of polysaccharides with functional roles in cell surface coating, surface and host interactions, and biofilms. We have identified an 'Orphan' bacterial cellulose synthase catalytic subunit (BcsA)-like protein found in four model pseudomonads, P. aeruginosa PA01, P. fluorescens SBW25, P. putida KT2440 and P. syringae pv. tomato DC3000. Pairwise alignments indicated that the Orphan and BcsA proteins shared less than 41% sequence identity suggesting they may not have the same structural folds or function. We identified 112 Orphans among soil and plant-associated pseudomonads as well as in phytopathogenic and human opportunistic pathogenic strains. The wide distribution of these highly conserved proteins suggest they form a novel family of synthases producing a different polysaccharide. In silico analysis, including sequence comparisons, secondary structure and topology predictions, and protein structural modelling, revealed a two-domain transmembrane ovoid-like structure for the Orphan protein with a periplasmic glycosyl hydrolase family GH17 domain linked via a transmembrane region to a cytoplasmic glycosyltransferase family GT2 domain. We suggest the GT2 domain synthesises β-(1,3)-glucan that is transferred to the GH17 domain where it is cleaved and cyclised to produce cyclic-β-(1,3)-glucan (CβG). Our structural models are consistent with enzymatic characterisation and recent molecular simulations of the PaPA01 and PpKT2440 GH17 domains. It also provides a functional explanation linking PaPAK and PaPA14 Orphan (also known as NdvB) transposon mutants with CβG production and biofilm-associated antibiotic resistance. Importantly, cyclic glucans are also involved in osmoregulation, plant infection and induced systemic suppression, and our findings suggest this novel family of CβG synthases may provide similar range of adaptive responses for pseudomonads.
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Affiliation(s)
- Andrew J. Spiers
- School of Applied Sciences, Abertay University, Dundee, United Kingdom
| | - Helge C. Dorfmueller
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Robyn Jerdan
- School of Applied Sciences, Abertay University, Dundee, United Kingdom
| | - Jessica McGregor
- Nuffield Research Placement Students, School of Applied Sciences, Abertay University, Dundee, United Kingdom
| | - Abbie Nicoll
- Nuffield Research Placement Students, School of Applied Sciences, Abertay University, Dundee, United Kingdom
| | - Kenzie Steel
- Nuffield Research Placement Students, School of Applied Sciences, Abertay University, Dundee, United Kingdom
| | - Scott Cameron
- School of Applied Sciences, Abertay University, Dundee, United Kingdom
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10
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Iminated aminoglycosides in self-emulsifying drug delivery systems: Dual approach to break down the microbial defense. J Colloid Interface Sci 2023; 630:164-178. [DOI: 10.1016/j.jcis.2022.10.077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/21/2022] [Accepted: 10/16/2022] [Indexed: 11/07/2022]
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11
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Guillaume O, Butnarasu C, Visentin S, Reimhult E. Interplay between biofilm microenvironment and pathogenicity of Pseudomonas aeruginosa in cystic fibrosis lung chronic infection. Biofilm 2022; 4:100089. [PMID: 36324525 PMCID: PMC9618985 DOI: 10.1016/j.bioflm.2022.100089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 10/14/2022] [Accepted: 10/17/2022] [Indexed: 11/07/2022] Open
Abstract
Pseudomonas aeruginosa (PA) is a highly, if not the most, versatile microorganism capable of colonizing diverse environments. One of the niches in which PA is able to thrive is the lung of cystic fibrosis (CF) patients. Due to a genetic aberration, the lungs of CF-affected patients exhibit impaired functions, rendering them highly susceptible to bacterial colonization. Once PA attaches to the epithelial surface and transitions to a mucoid phenotype, the infection becomes chronic, and antibiotic treatments become inefficient. Due to the high number of affected people and the severity of this infection, CF-chronic infection is a well-documented disease. Still, numerous aspects of PA CF infection remain unclear. The scientific reports published over the last decades have stressed how PA can adapt to CF microenvironmental conditions and how its surrounding matrix of extracellular polymeric substances (EPS) plays a key role in its pathogenicity. In this context, it is of paramount interest to present the nature of the EPS together with the local CF-biofilm microenvironment. We review how the PA biofilm microenvironment interacts with drugs to contribute to the pathogenicity of CF-lung infection. Understanding why so many drugs are inefficient in treating CF chronic infection while effectively treating planktonic PA is essential to devising better therapeutic targets and drug formulations.
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Affiliation(s)
- Olivier Guillaume
- 3D Printing and Biofabrication Group, Institute of Materials Science and Technology, TU Wien (Technische Universität Wien), Getreidemarkt 9/308, 1060, Vienna, Austria,Austrian Cluster for Tissue Regeneration, Austria,Corresponding author. 3D Printing and Biofabrication Group, Institute of Materials Science and Technology, TU Wien (Technische Universität Wien), Getreidemarkt 9/308, 1060, Vienna, Austria.
| | - Cosmin Butnarasu
- Department of Molecular Biotechnology and Health Science, University of Turin, Turin, 10135, Italy
| | - Sonja Visentin
- Department of Molecular Biotechnology and Health Science, University of Turin, Turin, 10135, Italy
| | - Erik Reimhult
- Institute of Biologically Inspired Materials, Department of Nanobiotechnology, University of Natural Resources and Life Sciences Vienna, Muthgasse 11, 1190, Vienna, Austria
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12
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Cairns CM, Michael FS, Jamshidi M, van Faassen H, Yang Q, Henry KA, Hussack G, Sauvageau J, Vinogradov EV, Cox AD. Structural Characterization and Evaluation of an Epitope at the Tip of the A-Band Rhamnan Polysaccharide of Pseudomonas aeruginosa. ACS Infect Dis 2022; 8:1336-1346. [PMID: 35653593 DOI: 10.1021/acsinfecdis.2c00183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pseudomonas aeruginosa produces a variety of cell surface glycans. Previous studies identified a common polysaccharide (PS) antigen often termed A-band PS that was composed of a neutral d-rhamnan trisaccharide repeating unit as a relatively conserved cell surface carbohydrate. However, nuclear magnetic resonance (NMR) spectra and chemical analysis of A-PS preparations showed the presence of several additional components. Here, we report the characterization of the carbohydrate component responsible for these signals. The carbohydrate antigen consists of an immunogenic methylated rhamnan oligosaccharide at the nonreducing end of the A-band PS. Initial studies performed with the isolated antigen permitted the production of conjugates that were used to immunize mice and rabbits and generate monoclonal and polyclonal antibodies. The polyclonal antibodies were able to recognize the majority of P. aeruginosa strains in our collection, and three monoclonal antibodies were generated, one of which was able to recognize and facilitate opsonophagocytic killing of a majority of P. aeruginosa strains. This monoclonal antibody was able to recognize all P. aeruginosa strains in our collection that includes clinical and serotype strains. Synthetic oligosaccharides (mono- to pentasaccharides) representing the terminal 3-O-methyl d-rhamnan were prepared, and the trisaccharide was identified as the antigenic determinant required to effectively mimic the natural antigen recognized by the broadly cross-reactive monoclonal antibody. These data suggest that there is considerable promise in this antigen as a vaccine or therapeutic target.
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Affiliation(s)
- Chantelle M. Cairns
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Frank St. Michael
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Mohammad Jamshidi
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Henk van Faassen
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Qingling Yang
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Kevin A. Henry
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Greg Hussack
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Janelle Sauvageau
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Evgeny V. Vinogradov
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Andrew D. Cox
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
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Kumagai Y, Kishimura H, Lang W, Tagami T, Okuyama M, Kimura A. Characterization of an Unknown Region Linked to the Glycoside Hydrolase Family 17 β-1,3-Glucanase of Vibrio vulnificus Reveals a Novel Glucan-Binding Domain. Mar Drugs 2022; 20:md20040250. [PMID: 35447923 PMCID: PMC9026390 DOI: 10.3390/md20040250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 01/27/2023] Open
Abstract
The glycoside hydrolase family 17 β-1,3-glucanase of Vibrio vulnificus (VvGH17) has two unknown regions in the N- and C-termini. Here, we characterized these domains by preparing mutant enzymes. VvGH17 demonstrated hydrolytic activity of β-(1→3)-glucan, mainly producing laminaribiose, but not of β-(1→3)/β-(1→4)-glucan. The C-terminal-truncated mutants (ΔC466 and ΔC441) showed decreased activity, approximately one-third of that of the WT, and ΔC415 lost almost all activity. An analysis using affinity gel containing laminarin or barley β-glucan revealed a shift in the mobility of the ΔC466, ΔC441, and ΔC415 mutants compared to the WT. Tryptophan residues showed a strong affinity for carbohydrates. Three of four point-mutations of the tryptophan in the C-terminus (W472A, W499A, and W542A) showed a reduction in binding ability to laminarin and barley β-glucan. The C-terminus was predicted to have a β-sandwich structure, and three tryptophan residues (Trp472, Trp499, and Trp542) constituted a putative substrate-binding cave. Linker and substrate-binding functions were assigned to the C-terminus. The N-terminal-truncated mutants also showed decreased activity. The WT formed a trimer, while the N-terminal truncations formed monomers, indicating that the N-terminus contributed to the multimeric form of VvGH17. The results of this study are useful for understanding the structure and the function of GH17 β-1,3-glucanases.
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Affiliation(s)
- Yuya Kumagai
- Faculty of Fisheries Sciences, Hokkaido University, Hakodate 041-8611, Japan;
- Correspondence: (Y.K.); (A.K.)
| | - Hideki Kishimura
- Faculty of Fisheries Sciences, Hokkaido University, Hakodate 041-8611, Japan;
| | - Weeranuch Lang
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; (W.L.); (T.T.); (M.O.)
| | - Takayoshi Tagami
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; (W.L.); (T.T.); (M.O.)
| | - Masayuki Okuyama
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; (W.L.); (T.T.); (M.O.)
| | - Atsuo Kimura
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; (W.L.); (T.T.); (M.O.)
- Correspondence: (Y.K.); (A.K.)
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14
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Tong Q, Li T, Jiang L, Wang Z, Qian Y. Nanoparticle, a promising therapeutic strategy for the treatment of infective endocarditis. Anatol J Cardiol 2022; 26:90-99. [PMID: 35190356 PMCID: PMC8878918 DOI: 10.5152/anatoljcardiol.2021.867] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2021] [Indexed: 07/30/2023] Open
Abstract
Infective endocarditis (IE) has been recognized as a biofilm-related disease caused by pathogenic microorganisms, such as bacteria and fungi that invade and damage the heart valves and endocardium. There are many difficulties and challenges in the antimicrobial treatment of IE, including multi-drug resistant pathogens, large dose of drug administration with following side effects, and poor prognosis. For the past few years, the development of nanotechnology has promoted the use of nanoparticles as antimicrobial nano-pharmaceuticals or novel drug delivery systems (NDDS) in antimicrobial therapy for chronic infections and biofilm-related infectious disease as these molecules exhibit several advantages. Therefore, nanoparticles have a potential role to play in solving problems in the treatment of IE, including improving antimicrobial activity, increasing drug bioavailability, minimizing frequency of drug administration, and preventing side effects. In this article, we review the latest advances in nanoparticles against drug-resistant bacteria in biofilm and recommends nanoparticles as an alternative strategy to the antibiotic treatment of IE.
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Affiliation(s)
- Qi Tong
- Department of Cardiovascular Surgery, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University; Chengdu-China
| | - Tao Li
- Department of Cardiovascular Surgery, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University; Chengdu-China
| | - Lu Jiang
- Department of Cardiovascular Surgery, Sichuan Provincial People's University of Electronic Science and Technology of China; Chengdu-China
| | - Zhengjie Wang
- Department of Cardiovascular Surgery, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University; Chengdu-China
| | - Yongjun Qian
- Department of Cardiovascular Surgery, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University; Chengdu-China
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15
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Laborda P, Hernando-Amado S, Martínez JL, Sanz-García F. Antibiotic Resistance in Pseudomonas. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:117-143. [DOI: 10.1007/978-3-031-08491-1_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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16
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Matern WM, Parker H, Danchik C, Hoover L, Bader JS, Karakousis PC. Genetic Determinants of Intrinsic Antibiotic Tolerance in Mycobacterium avium. Microbiol Spectr 2021; 9:e0024621. [PMID: 34523947 PMCID: PMC8557931 DOI: 10.1128/spectrum.00246-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 08/06/2021] [Indexed: 11/20/2022] Open
Abstract
The Mycobacterium avium complex (MAC) is one of the most prevalent causes of nontuberculous mycobacteria pulmonary infection in the United States, and yet it remains understudied. Current MAC treatment requires more than a year of intermittent to daily combination antibiotic therapy, depending on disease severity. In order to shorten and simplify curative regimens, it is important to identify the innate bacterial factors contributing to reduced antibiotic susceptibility, namely, antibiotic tolerance genes. In this study, we performed a genome-wide transposon screen to elucidate M. avium genes that play a role in the bacterium's tolerance to first- and second-line antibiotics. We identified a total of 193 unique M. avium mutants with significantly altered susceptibility to at least one of the four clinically used antibiotics we tested, including two mutants (in DFS55_00905 and DFS55_12730) with panhypersusceptibility. The products of the antibiotic tolerance genes we have identified may represent novel targets for future drug development studies aimed at shortening the duration of therapy for MAC infections. IMPORTANCE The prolonged treatment required to eradicate Mycobacterium avium complex (MAC) infection is likely due to the presence of subpopulations of antibiotic-tolerant bacteria with reduced susceptibility to currently available drugs. However, little is known about the genes and pathways responsible for antibiotic tolerance in MAC. In this study, we performed a forward genetic screen to identify M. avium antibiotic tolerance genes, whose products may represent attractive targets for the development of novel adjunctive drugs capable of shortening the curative treatment for MAC infections.
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Affiliation(s)
- William M. Matern
- High-Throughput Biology Center, Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Center for Systems Approaches to Infectious Diseases (C-SAID), Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Center for Tuberculosis Research, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Harley Parker
- Center for Systems Approaches to Infectious Diseases (C-SAID), Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Center for Tuberculosis Research, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Carina Danchik
- Center for Systems Approaches to Infectious Diseases (C-SAID), Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Center for Tuberculosis Research, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Leah Hoover
- Center for Systems Approaches to Infectious Diseases (C-SAID), Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Center for Tuberculosis Research, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Joel S. Bader
- High-Throughput Biology Center, Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Center for Systems Approaches to Infectious Diseases (C-SAID), Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Petros C. Karakousis
- Center for Systems Approaches to Infectious Diseases (C-SAID), Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Center for Tuberculosis Research, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
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17
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Ma J, Hou S, Chan-Park MB, Duan H. Antibiofilm Activity of Gallium(III) Complexed Anionic Polymers in Combination with Antibiotics. Macromol Rapid Commun 2021; 42:e2100255. [PMID: 34418208 DOI: 10.1002/marc.202100255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 07/05/2021] [Indexed: 11/11/2022]
Abstract
Pseudomonas aeruginosa (P. aeruginosa) is a life-threatening pathogen associated with multiantibiotic resistance, which is largely caused by its strong ability to form biofilms. Recent research has revealed that gallium (III) shows an activity against the biofilm of P. aeruginosa by interfering with Fe metabolism. The antibacterial activity of the combination of Ga3+ ion and antibiotic rifampicin (RMP) against P. aeruginosa PAO1 is investigated. An anionic polymer poly{{2-[(2-methylprop-2-enoyl)oxy]ethyl}phosphonic acid} (PDMPOH) is exploited to form complexes (GaPD) with Ga3+ . The GaPD complexes act as a carrier of Ga3+ and release Ga3+ via enzymatic degradation by bacterial lipases. GaPD is found to damage the outer membrane, leading to enhanced cellular uptake of RMP and Ga3+ due to increased outer membrane permeability, which inhibits the RNA polymerase and interferes with Fe metabolism. The antibiofilm activity and biocompatibility of the GaPD system offer a promising treatment option for P. aeruginosa biofilm-related infections.
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Affiliation(s)
- Jielin Ma
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457, Singapore
| | - Shuai Hou
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457, Singapore
| | - Mary B Chan-Park
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457, Singapore
| | - Hongwei Duan
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457, Singapore
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18
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Sanz-García F, Gil-Gil T, Laborda P, Ochoa-Sánchez LE, Martínez JL, Hernando-Amado S. Coming from the Wild: Multidrug Resistant Opportunistic Pathogens Presenting a Primary, Not Human-Linked, Environmental Habitat. Int J Mol Sci 2021; 22:8080. [PMID: 34360847 PMCID: PMC8347278 DOI: 10.3390/ijms22158080] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/22/2021] [Accepted: 07/24/2021] [Indexed: 12/24/2022] Open
Abstract
The use and misuse of antibiotics have made antibiotic-resistant bacteria widespread nowadays, constituting one of the most relevant challenges for human health at present. Among these bacteria, opportunistic pathogens with an environmental, non-clinical, primary habitat stand as an increasing matter of concern at hospitals. These organisms usually present low susceptibility to antibiotics currently used for therapy. They are also proficient in acquiring increased resistance levels, a situation that limits the therapeutic options for treating the infections they cause. In this article, we analyse the most predominant opportunistic pathogens with an environmental origin, focusing on the mechanisms of antibiotic resistance they present. Further, we discuss the functions, beyond antibiotic resistance, that these determinants may have in the natural ecosystems that these bacteria usually colonize. Given the capacity of these organisms for colonizing different habitats, from clinical settings to natural environments, and for infecting different hosts, from plants to humans, deciphering their population structure, their mechanisms of resistance and the role that these mechanisms may play in natural ecosystems is of relevance for understanding the dissemination of antibiotic resistance under a One-Health point of view.
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Affiliation(s)
| | | | | | | | - José L. Martínez
- Centro Nacional de Biotecnología, CSIC, 28049 Madrid, Spain; (F.S.-G.); (T.G.-G.); (P.L.); (L.E.O.-S.); (S.H.-A.)
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19
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Xu Q, Hu X, Wang Y. Alternatives to Conventional Antibiotic Therapy: Potential Therapeutic Strategies of Combating Antimicrobial-Resistance and Biofilm-Related Infections. Mol Biotechnol 2021; 63:1103-1124. [PMID: 34309796 DOI: 10.1007/s12033-021-00371-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 07/08/2021] [Indexed: 12/14/2022]
Abstract
Antibiotics have been denoted as the orthodox therapeutic agents for fighting bacteria-related infections in clinical practices for decades. Nevertheless, overuse of antibiotics has led to the upsurge of species with antimicrobial resistance (AMR) or multi-drug resistance. Bacteria can also grow into the biofilm, which accounts for at least two-thirds of infections. Distinct gene expression and self-produced heterogeneous hydrated extracellular polymeric substance matrix architecture of biofilm contribute to their tolerance and externally manifest as antibiotic resistance. In this review, the difficulties in combating biofilm formation and AMR are introduced, and novel alternatives to antibiotics such as metal nanoparticles and quaternary ammonium compounds, chitosan and its derivatives, antimicrobial peptides, stimuli-responsive materials, phage therapy and other therapeutic strategies, from compounds to hydrogel, from inorganic to biological, are discussed. We expect to provide useful information for the readers who are seeking for solutions to the problem of AMR and biofilm-related infections.
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Affiliation(s)
- Qian Xu
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, 610065, Sichuan, People's Republic of China
| | - Xuefeng Hu
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, 610065, Sichuan, People's Republic of China.
| | - Yunbing Wang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, 610065, Sichuan, People's Republic of China.
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20
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Lundgren BR, Shoytush JM, Scheel RA, Sain S, Sarwar Z, Nomura CT. Utilization of L-glutamate as a preferred or sole nutrient in Pseudomonas aeruginosa PAO1 depends on genes encoding for the enhancer-binding protein AauR, the sigma factor RpoN and the transporter complex AatJQMP. BMC Microbiol 2021; 21:83. [PMID: 33722201 PMCID: PMC7962211 DOI: 10.1186/s12866-021-02145-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/04/2021] [Indexed: 11/10/2022] Open
Abstract
Background Glutamate and aspartate are preferred nutrients for a variety of microorganisms. In the case for many Pseudomonas spp., utilization of these amino acids is believed to be dependent on a transporter complex comprised of a periplasmic-solute binding protein (AatJ), two permease domains (AatQM) and an ATP-binding component (AatP). Notably, expression of this transporter complex is hypothesized to be regulated at the transcriptional level by the enhancer-binding protein AauR and the alternative sigma factor RpoN. The purpose of the current study was to determine the biological significance of the putative aatJ-aatQMP operon and its regulatory aauR and rpoN genes in the utilization of L-glutamate, L-glutamine, L-aspartate and L-asparagine in Pseudomonas aeruginosa PAO1. Results Deletion of the aatJ-aatQMP, aauR or rpoN genes did not affect the growth of P. aeruginosa PAO1 on L-glutamate, L-glutamine, L-aspartate and L-asparagine equally. Instead, only growth on L-glutamate as the sole carbon source was abolished with the deletion of any one of these genes. Interestingly, growth of the aauR mutant on L-glutamate was readily restored via plasmid-based expression of the aatQMP genes, suggesting that it is the function of AatQMP (and not AatJ) that is limiting in the absence of the aauR gene. Subsequent analysis of beta-galactosidase reporters revealed that both aatJ and aatQ were induced in response to L-glutamate, L-glutamine, L-aspartate or L-asparagine in a manner dependent on the aauR and rpoN genes. In addition, both aatJ and aatQ were expressed at reduced levels in the absence of the inducing-amino acids and the regulatory aauR and rpoN genes. The expression of the aatJ-aatQMP genes is, therefore, multifaceted. Lastly, the expression levels of aatJ were significantly higher (> 5 fold) than that of aatQ under all tested conditions. Conclusions The primary function of AauR in P. aeruginosa PAO1 is to activate expression of the aatJ-aatQMP genes in response to exogenous acidic amino acids and their amide derivatives. Importantly, it is the AauR-RpoN mediated induction of the aatQMP genes that is the pivotal factor enabling P. aeruginosa PAO1 to effectively utilize or consume L-glutamate as a sole or preferred nutrient.
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Affiliation(s)
- Benjamin R Lundgren
- Department of Chemistry, State University of New York - College of Environmental Science and Forestry, Syracuse, 1 Forestry Drive, Syracuse, New York, 13210, USA.
| | - Joseph M Shoytush
- Department of Chemistry, State University of New York - College of Environmental Science and Forestry, Syracuse, 1 Forestry Drive, Syracuse, New York, 13210, USA
| | - Ryan A Scheel
- Department of Chemistry, State University of New York - College of Environmental Science and Forestry, Syracuse, 1 Forestry Drive, Syracuse, New York, 13210, USA
| | - Safreen Sain
- Department of Biology, The College of New Jersey, 2000 Pennington Road, Ewing, NJ, 08628, USA
| | - Zaara Sarwar
- Department of Biology, The College of New Jersey, 2000 Pennington Road, Ewing, NJ, 08628, USA
| | - Christopher T Nomura
- Department of Biological Sciences, University of Idaho, 875 Perimeter Drive, Moscow, ID, 83844, USA
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21
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Hosseinkhan N, Allahverdi A, Abdolmaleki F. The novel potential multidrug-resistance biomarkers for Pseudomonas aeruginosa lung infections using transcriptomics data analysis. INFORMATICS IN MEDICINE UNLOCKED 2021. [DOI: 10.1016/j.imu.2020.100509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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22
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Biofilms as Promoters of Bacterial Antibiotic Resistance and Tolerance. Antibiotics (Basel) 2020; 10:antibiotics10010003. [PMID: 33374551 PMCID: PMC7822488 DOI: 10.3390/antibiotics10010003] [Citation(s) in RCA: 166] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/15/2020] [Accepted: 12/19/2020] [Indexed: 12/12/2022] Open
Abstract
Multidrug resistant bacteria are a global threat for human and animal health. However, they are only part of the problem of antibiotic failure. Another bacterial strategy that contributes to their capacity to withstand antimicrobials is the formation of biofilms. Biofilms are associations of microorganisms embedded a self-produced extracellular matrix. They create particular environments that confer bacterial tolerance and resistance to antibiotics by different mechanisms that depend upon factors such as biofilm composition, architecture, the stage of biofilm development, and growth conditions. The biofilm structure hinders the penetration of antibiotics and may prevent the accumulation of bactericidal concentrations throughout the entire biofilm. In addition, gradients of dispersion of nutrients and oxygen within the biofilm generate different metabolic states of individual cells and favor the development of antibiotic tolerance and bacterial persistence. Furthermore, antimicrobial resistance may develop within biofilms through a variety of mechanisms. The expression of efflux pumps may be induced in various parts of the biofilm and the mutation frequency is induced, while the presence of extracellular DNA and the close contact between cells favor horizontal gene transfer. A deep understanding of the mechanisms by which biofilms cause tolerance/resistance to antibiotics helps to develop novel strategies to fight these infections.
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23
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A bacteriocin-based antimicrobial formulation to effectively disrupt the cell viability of methicillin-resistant Staphylococcus aureus (MRSA) biofilms. NPJ Biofilms Microbiomes 2020; 6:58. [PMID: 33268776 PMCID: PMC7710749 DOI: 10.1038/s41522-020-00166-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 10/20/2020] [Indexed: 12/15/2022] Open
Abstract
Antibiotic-resistant and biofilm-associated infections brought about by methicillin-resistant Staphylococcus aureus (MRSA) strains is a pressing issue both inside as well as outside nosocomial environments worldwide. Here, we show that a combination of two bacteriocins with distinct structural and functional characteristics, garvicin KS, and micrococcin P1, showed a synergetic antibacterial activity against biofilms produced in vitro by S. aureus, including several MRSA strains. In addition, this bacteriocin-based antimicrobial combination showed the ability to restore the sensitivity of the highly resilient MRSA strain ATCC 33591 to the β-lactam antibiotic penicillin G. By using a combination of bacterial cell metabolic assays, confocal and scanning electron microscopy, we show that the combination between garvicin KS, micrococcin P1, and penicillin G potently inhibit cell viability within S. aureus biofilms by causing severe cell damage. Together these data indicate that bacteriocins can be valuable therapeutic tools in the fight against biofilm-associated MRSA infections.
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24
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Parker H, Lorenc R, Ruelas Castillo J, Karakousis PC. Mechanisms of Antibiotic Tolerance in Mycobacterium avium Complex: Lessons From Related Mycobacteria. Front Microbiol 2020; 11:573983. [PMID: 33101247 PMCID: PMC7554310 DOI: 10.3389/fmicb.2020.573983] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 09/01/2020] [Indexed: 11/13/2022] Open
Abstract
Mycobacterium avium complex (MAC) species are the most commonly isolated nontuberculous mycobacteria to cause pulmonary infections worldwide. The lengthy and complicated therapy required to cure lung disease due to MAC is at least in part due to the phenomenon of antibiotic tolerance. In this review, we will define antibiotic tolerance and contrast it with persistence and antibiotic resistance. We will discuss physiologically relevant stress conditions that induce altered metabolism and antibiotic tolerance in mycobacteria. Next, we will review general molecular mechanisms underlying bacterial antibiotic tolerance, particularly those described for MAC and related mycobacteria, including Mycobacterium tuberculosis, with a focus on genes containing significant sequence homology in MAC. An improved understanding of antibiotic tolerance mechanisms can lay the foundation for novel approaches to target antibiotic-tolerant mycobacteria, with the goal of shortening the duration of curative treatment and improving survival in patients with MAC.
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Affiliation(s)
- Harley Parker
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Rachel Lorenc
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Jennie Ruelas Castillo
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Petros C Karakousis
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States.,Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
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25
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Ultrastructure imaging of Pseudomonas aeruginosa lawn biofilms and eradication of the tobramycin-resistant variants under in vitro electroceutical treatment. Sci Rep 2020; 10:9879. [PMID: 32555250 PMCID: PMC7303171 DOI: 10.1038/s41598-020-66823-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 05/22/2020] [Indexed: 12/12/2022] Open
Abstract
Electrochemically generated bactericidal compounds have been shown to eradicate bacterial lawn biofilms through electroceutical treatment. However, the ultrastructure of biofilms exposed to these species has not been studied. Moreover, it is unknown if the efficacy of electroceutical treatment extends to antibiotic-resistant variants that emerge in lawn biofilms after antibiotic treatment. In this report, the efficacy of the in vitro electroceutical treatment of Pseudomonas aeruginosa biofilms is demonstrated both at room temperature and in an incubator, with a ~4 log decrease (p < 0.01) in the biofilm viability observed over the anode at both conditions. The ultrastructure changes in the lawn biofilms imaged using transmission electron microscopy demonstrate significant bacterial cell damage over the anode after 24 h of electroceutical treatment. A mix of both damaged and undamaged cells was observed over the cathode. Finally, both eradication and prevention of the emergence of tobramycin-resistant variants were demonstrated by combining antibiotic treatment with electroceutical treatment on the lawn biofilms.
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26
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The race between drug introduction and appearance of microbial resistance. Current balance and alternative approaches. Curr Opin Pharmacol 2019; 48:48-56. [DOI: 10.1016/j.coph.2019.04.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 04/23/2019] [Accepted: 04/23/2019] [Indexed: 11/13/2022]
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Pang Z, Raudonis R, Glick BR, Lin TJ, Cheng Z. Antibiotic resistance in Pseudomonas aeruginosa: mechanisms and alternative therapeutic strategies. Biotechnol Adv 2018; 37:177-192. [PMID: 30500353 DOI: 10.1016/j.biotechadv.2018.11.013] [Citation(s) in RCA: 923] [Impact Index Per Article: 153.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 11/21/2018] [Accepted: 11/24/2018] [Indexed: 01/09/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that is a leading cause of morbidity and mortality in cystic fibrosis patients and immunocompromised individuals. Eradication of P. aeruginosa has become increasingly difficult due to its remarkable capacity to resist antibiotics. Strains of Pseudomonas aeruginosa are known to utilize their high levels of intrinsic and acquired resistance mechanisms to counter most antibiotics. In addition, adaptive antibiotic resistance of P. aeruginosa is a recently characterized mechanism, which includes biofilm-mediated resistance and formation of multidrug-tolerant persister cells, and is responsible for recalcitrance and relapse of infections. The discovery and development of alternative therapeutic strategies that present novel avenues against P. aeruginosa infections are increasingly demanded and gaining more and more attention. Although mostly at the preclinical stages, many recent studies have reported several innovative therapeutic technologies that have demonstrated pronounced effectiveness in fighting against drug-resistant P. aeruginosa strains. This review highlights the mechanisms of antibiotic resistance in P. aeruginosa and discusses the current state of some novel therapeutic approaches for treatment of P. aeruginosa infections that can be further explored in clinical practice.
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Affiliation(s)
- Zheng Pang
- Department of Pathology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Renee Raudonis
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Bernard R Glick
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Tong-Jun Lin
- Department of Pathology, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Pediatrics, IWK Health Centre, Halifax, NS B3K 6R8, Canada
| | - Zhenyu Cheng
- Department of Pathology, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
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Pse-T2, an Antimicrobial Peptide with High-Level, Broad-Spectrum Antimicrobial Potency and Skin Biocompatibility against Multidrug-Resistant Pseudomonas aeruginosa Infection. Antimicrob Agents Chemother 2018; 62:AAC.01493-18. [PMID: 30323036 DOI: 10.1128/aac.01493-18] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 09/30/2018] [Indexed: 02/06/2023] Open
Abstract
Pseudin-2, isolated from the frog Pseudis paradoxa, exhibits potent antibacterial activity but also cytotoxicity. In an effort to develop clinically applicable antimicrobial peptides (AMPs), we designed pseudin-2 analogs with Lys substitutions, resulting in elevated amphipathic α-helical structure and cationicity. In addition, truncated analogs of pseudin-2 and Lys-substituted peptides were synthesized to produce linear 18-residue amphipathic α-helices, which were further investigated for their mechanism and functions. These truncated analogs exhibited higher antimicrobial activity and lower cytotoxicity than pseudin-2. In particular, Pse-T2 showed marked pore formation, permeabilization of the outer/inner bacterial membranes, and DNA binding. Fluorescence spectroscopy and scanning electron microscopy showed that Pse-T2 kills bacterial cells by disrupting membrane integrity. In vivo, wounds infected with multidrug-resistant (MDR) Pseudomonas aeruginosa healed significantly faster when treated with Pse-T2 than did untreated wounds or wounds treated with ciprofloxacin. Moreover, Pse-T2 facilitated infected-wound closure by reducing inflammation through suppression of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α). These data suggest that the small antimicrobial peptide Pse-T2 could be useful for future development of therapeutic agents effective against MDR bacterial strains.
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Mechanisms of Bacterial Tolerance and Persistence in the Gastrointestinal and Respiratory Environments. Clin Microbiol Rev 2018; 31:31/4/e00023-18. [PMID: 30068737 DOI: 10.1128/cmr.00023-18] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Pathogens that infect the gastrointestinal and respiratory tracts are subjected to intense pressure due to the environmental conditions of the surroundings. This pressure has led to the development of mechanisms of bacterial tolerance or persistence which enable microorganisms to survive in these locations. In this review, we analyze the general stress response (RpoS mediated), reactive oxygen species (ROS) tolerance, energy metabolism, drug efflux pumps, SOS response, quorum sensing (QS) bacterial communication, (p)ppGpp signaling, and toxin-antitoxin (TA) systems of pathogens, such as Escherichia coli, Salmonella spp., Vibrio spp., Helicobacter spp., Campylobacter jejuni, Enterococcus spp., Shigella spp., Yersinia spp., and Clostridium difficile, all of which inhabit the gastrointestinal tract. The following respiratory tract pathogens are also considered: Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Burkholderia cenocepacia, and Mycobacterium tuberculosis Knowledge of the molecular mechanisms regulating the bacterial tolerance and persistence phenotypes is essential in the fight against multiresistant pathogens, as it will enable the identification of new targets for developing innovative anti-infective treatments.
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Pseudomonas aeruginosa Biofilm Antibiotic Resistance Gene ndvB Expression Requires the RpoS Stationary-Phase Sigma Factor. Appl Environ Microbiol 2018; 84:AEM.02762-17. [PMID: 29352081 DOI: 10.1128/aem.02762-17] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 01/11/2018] [Indexed: 01/21/2023] Open
Abstract
Chronic, biofilm-based bacterial infections are exceptionally difficult to eradicate due to the high degree of antibiotic recalcitrance exhibited by cells in biofilm communities. In the opportunistic pathogen Pseudomonas aeruginosa, biofilm recalcitrance is multifactorial and arises in part from the preferential expression of resistance genes in biofilms compared to exponential-phase planktonic cells. One such mechanism involves ndvB, which we have previously shown to be expressed specifically in biofilms. In this study, we investigated the regulatory basis of this lifestyle-specific expression by developing an unstable green fluorescent protein (GFP) transcriptional reporter to observe the expression pattern of ndvB We found that in addition to its expression in biofilms, ndvB was upregulated in planktonic cells as they enter stationary phase. The transcription of ndvB in both growth phases was shown to be dependent on the stationary-phase sigma factor RpoS, and mutation of a putative RpoS binding site in the ndvB promoter abolished the activity of the promoter in stationary-phase cells. Overall, we have expanded our understanding of the temporal expression of ndvB in P. aeruginosa and have uncovered a regulatory basis for its growth phase-dependent expression.IMPORTANCE Bacterial biofilms are more resistant to antibiotics than free-living planktonic cells, and understanding the mechanistic basis of this resistance can inform treatments of biofilm-based infections. In addition to chemical and structural barriers that can inhibit antibiotic entry, the upregulation of specific genes in biofilms contributes to the resistance. We investigated this biofilm-specific gene induction by examining expression patterns of ndvB, a gene involved in biofilm resistance of the opportunistic pathogen Pseudomonas aeruginosa We characterized ndvB expression in planktonic and biofilm growth conditions with an unstable green fluorescent protein (GFP) reporter and found that the expression of ndvB in biofilms is dependent on the stationary-phase sigma factor RpoS. Overall, our results support the physiological similarity between biofilms and stationary-phase cells and suggest that the induction of some stationary-phase genes in biofilms may contribute to their increased antibiotic resistance.
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Hall CW, Mah TF. Molecular mechanisms of biofilm-based antibiotic resistance and tolerance in pathogenic bacteria. FEMS Microbiol Rev 2018; 41:276-301. [PMID: 28369412 DOI: 10.1093/femsre/fux010] [Citation(s) in RCA: 845] [Impact Index Per Article: 140.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 02/22/2017] [Indexed: 02/06/2023] Open
Abstract
Biofilms are surface-attached groups of microbial cells encased in an extracellular matrix that are significantly less susceptible to antimicrobial agents than non-adherent, planktonic cells. Biofilm-based infections are, as a result, extremely difficult to cure. A wide range of molecular mechanisms contribute to the high degree of recalcitrance that is characteristic of biofilm communities. These mechanisms include, among others, interaction of antimicrobials with biofilm matrix components, reduced growth rates and the various actions of specific genetic determinants of antibiotic resistance and tolerance. Alone, each of these mechanisms only partially accounts for the increased antimicrobial recalcitrance observed in biofilms. Acting in concert, however, these defences help to ensure the survival of biofilm cells in the face of even the most aggressive antimicrobial treatment regimens. This review summarises both historical and recent scientific data in support of the known biofilm resistance and tolerance mechanisms. Additionally, suggestions for future work in the field are provided.
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Jin N, Paraskevaidi M, Semple KT, Martin FL, Zhang D. Infrared Spectroscopy Coupled with a Dispersion Model for Quantifying the Real-Time Dynamics of Kanamycin Resistance in Artificial Microbiota. Anal Chem 2017; 89:9814-9821. [DOI: 10.1021/acs.analchem.7b01765] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Naifu Jin
- Lancaster
Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Maria Paraskevaidi
- School
of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston PR1 2HE, United Kingdom
| | - Kirk T. Semple
- Lancaster
Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Francis L. Martin
- School
of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston PR1 2HE, United Kingdom
| | - Dayi Zhang
- Lancaster
Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
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Saffari M, Karami S, Firoozeh F, Sehat M. Evaluation of biofilm-specific antimicrobial resistance genes in Pseudomonas aeruginosa isolates in Farabi Hospital. J Med Microbiol 2017; 66:905-909. [DOI: 10.1099/jmm.0.000521] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Mahmood Saffari
- Department of Microbiology, School of Medicine‚ Kashan University of Medical Sciences, Kashan, Iran
| | - Shabnam Karami
- Department of Microbiology, School of Medicine‚ Kashan University of Medical Sciences, Kashan, Iran
| | - Farzaneh Firoozeh
- Department of Microbiology, School of Medicine‚ Kashan University of Medical Sciences, Kashan, Iran
| | - Mojtaba Sehat
- Trauma Research Center, Kashan University of Medical Sciences, Kashan, Iran
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DdaR (PA1196) Regulates Expression of Dimethylarginine Dimethylaminohydrolase for the Metabolism of Methylarginines in Pseudomonas aeruginosa PAO1. J Bacteriol 2017; 199:JB.00001-17. [PMID: 28167521 DOI: 10.1128/jb.00001-17] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 01/31/2017] [Indexed: 11/20/2022] Open
Abstract
Dimethylarginine dimethylaminohydrolases (DDAHs) catalyze the hydrolysis of methylarginines to yield l-citrulline and methylamines as products. DDAHs and their central roles in methylarginine metabolism have been characterized for eukaryotic cells. While DDAHs are known to exist in some bacteria, including Streptomyces coelicolor and Pseudomonas aeruginosa, the physiological importance and genetic regulation of bacterial DDAHs remain poorly understood. To provide some insight into bacterial methylarginine metabolism, this study focused on identifying the key elements or factors regulating DDAH expression in P. aeruginosa PAO1. First, results revealed that P. aeruginosa can utilize NG ,NG -dimethyl-l-arginine (ADMA) as a sole source of nitrogen but not carbon. Second, expression of the ddaH gene was observed to be induced in the presence of methylarginines, including NG -monomethyl-l-arginine (l-NMMA) and ADMA. Third, induction of the ddaH gene was shown to be achieved through a mechanism consisting of the putative enhancer-binding protein PA1196 and the alternative sigma factor RpoN. Both PA1196 and RpoN were essential for the expression of the ddaH gene in response to methylarginines. On the basis of the results of this study, PA1196 was given the name DdaR, for dimethylarginine dimethylaminohydrolase regulator. Interestingly, DdaR and its target ddaH gene are conserved only among P. aeruginosa strains, suggesting that this particular Pseudomonas species has evolved to utilize methylarginines from its environment.IMPORTANCE Methylated arginine residues are common constituents of eukaryotic proteins. During proteolysis, methylarginines are released in their free forms and become accessible nutrients for bacteria to utilize as growth substrates. In order to have a clearer and better understanding of this process, we explored methylarginine utilization in the metabolically versatile bacterium Pseudomonas aeruginosa PAO1. Our results show that the transcriptional regulator DdaR (PA1196) and the sigma factor RpoN positively regulate expression of dimethylarginine dimethylaminohydrolases (DDAHs) in response to exogenous methylarginines. DDAH is the central enzyme of methylarginine degradation, and its transcriptional regulation by DdaR-RpoN is expected to be conserved among P. aeruginosa strains.
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The naringenin-induced exoproteome of Rhizobium etli CE3. Arch Microbiol 2017; 199:737-755. [PMID: 28255691 DOI: 10.1007/s00203-017-1351-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 01/25/2017] [Accepted: 02/01/2017] [Indexed: 01/29/2023]
Abstract
Flavonoids excreted by legume roots induce the expression of symbiotically essential nodulation (nod) genes in rhizobia, as well as that of specific protein export systems. In the bean microsymbiont Rhizobium etli CE3, nod genes are induced by the flavonoid naringenin. In this study, we identified 693 proteins in the exoproteome of strain CE3 grown in minimal medium with or without naringenin, with 101 and 100 exoproteins being exclusive to these conditions, respectively. Four hundred ninety-two (71%) of the extracellular proteins were found in both cultures. Of the total exoproteins identified, nearly 35% were also present in the intracellular proteome of R. etli bacteroids, 27% had N-terminal signal sequences and a significant number had previously demonstrated or possible novel roles in symbiosis, including bacterial cell surface modification, adhesins, proteins classified as MAMPs (microbe-associated molecular patterns), such as flagellin and EF-Tu, and several normally cytoplasmic proteins as Ndk and glycolytic enzymes, which are known to have extracellular "moonlighting" roles in bacteria that interact with eukaryotic cells. It is noteworthy that the transmembrane ß (1,2) glucan biosynthesis protein NdvB, an essential symbiotic protein in rhizobia, was found in the R. etli naringenin-induced exoproteome. In addition, potential binding sites for two nod-gene transcriptional regulators (NodD) occurred somewhat more frequently in the promoters of genes encoding naringenin-induced exoproteins in comparison to those ofexoproteins found in the control condition.
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Dobruchowska JM, Jonsson JO, Fridjonsson OH, Aevarsson A, Kristjansson JK, Altenbuchner J, Watzlawick H, Gerwig GJ, Dijkhuizen L, Kamerling JP, Hreggvidsson GO. Modification of linear (β1→3)-linked gluco-oligosaccharides with a novel recombinant β-glucosyltransferase (trans-β-glucosidase) enzyme from Bradyrhizobium diazoefficiens. Glycobiology 2016; 26:1157-1170. [PMID: 27550196 DOI: 10.1093/glycob/cww074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 07/14/2016] [Accepted: 07/18/2016] [Indexed: 11/13/2022] Open
Abstract
Recently, we have shown that glycoside hydrolases enzymes of family GH17 from proteobacteria (genera Pseudomonas, Azotobacter) catalyze elongation transfer reactions with laminari-oligosaccharides generating (β1→3) linkages preferably and to a lesser extent (β1→6) or (β1→4) linkages. In the present study, the cloning and characterization of the gene encoding the structurally very similar GH17 domain of the NdvB enzyme from Bradyrhizobium diazoefficiens, designated Glt20, as well as its catalytic properties are described. The Glt20 enzyme was strikingly different from the previously investigated bacterial GH17 enzymes, both regarding substrate specificity and product formation. The Azotobacter and Pseudomonas enzymes cleaved the donor laminari-oligosaccharide substrates three or four moieties from the non-reducing end, generating linear oligosaccharides. In contrast, the Glt20 enzyme cleaved donor laminari-oligosaccharide substrates two glucose moieties from the reducing end, releasing laminaribiose and transferring the remainder to laminari-oligosaccharide acceptor substrates creating only (β1→3)(β1→6) branching points. This enables Glt20 to transfer larger oligosaccharide chains than the other type of bacterial enzymes previously described, and helps explain the biologically significant formation of cyclic β-glucans in B. diazoefficiens.
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Affiliation(s)
- Justyna M Dobruchowska
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | | | | | | | | | - Josef Altenbuchner
- Institut für Industrielle Genetik, Universität Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
| | - Hildegard Watzlawick
- Institut für Industrielle Genetik, Universität Stuttgart, Allmandring 31, 70569 Stuttgart, Germany
| | - Gerrit J Gerwig
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.,NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Lubbert Dijkhuizen
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Johannis P Kamerling
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.,NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Gudmundur O Hreggvidsson
- Matís, Vínlandsleid 12, 113 Reykjavík, Iceland .,Department of Biology, University of Iceland, Sturlugata 7, 101 Reykjavík, Iceland
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Abstract
Biofilm infections are exceptionally recalcitrant to antimicrobial treatment or clearance by host immune responses. Within biofilms, microbes form adherent multicellular communities that are embedded in an extracellular matrix. Many prescribed antifungal drugs are not effective against biofilm infections owing to several protective factors including poor diffusion of drugs through biofilms as well as specific drug-matrix interactions. Despite the key roles that biofilms play in infections, there is little quantitative information about their composition and structural complexity because of the analytical challenge of studying these dense networks using traditional techniques. Within this review, recent work to elucidate fungal biofilm composition is discussed, with particular attention given to the challenges of annotation and quantification of matrix composition.
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Park MH, Kim SY, Roh EY, Lee HS. Difference of Type 3 secretion system (T3SS) effector gene genotypes (exoU and exoS) and its implication to antibiotics resistances in isolates of Pseudomonas aeruginosa from chronic otitis media. Auris Nasus Larynx 2016; 44:258-265. [PMID: 27461174 DOI: 10.1016/j.anl.2016.07.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 06/30/2016] [Accepted: 07/05/2016] [Indexed: 01/15/2023]
Abstract
OBJECTIVE Type 3 secretion system (T3SS) is the most important virulence factor in Pseudomonas aeruginosa infection. Of the various T3SS effector genes, exoS and exoU showed mutually exclusive distributions, and these two genes showed varied virulence. In many pseudomonal infections, the distribution of these genes showed different pattern and it influenced severity of infection. This study was aimed to evaluate differences of virulence factors and antibiotics resistance between chronic otitis media and other body infection caused by P. aeruginosa. METHODS To estimate the prevalence of effector genes of T3SS, especially the distributions of exoS and exoU genes and their association with antibiotic resistance in COM, we compared the prevalence of T3SS genes in isolates from COM with those from lower respiratory infection and bacteremia. Other virulence genes, including groEL, pilA, ndvB, lasB, rhlI, and apr, were also studied to evaluate prevalence. These isolates were tested for antibiotic susceptibility, and we examined the association between antibiotic susceptibility and the prevalence of T3SS effector genes. RESULTS The COM group showed a significantly higher exoU-positive rate than the control group (70.6% vs. 6.7%; P<0.01). Furthermore, COM patients with exoU showed significant antibiotic resistance to ciprofloxacin and tobramycin (P=0.035), whereas there was no significant difference in the control group. CONCLUSIONS The high incidence of exoU-positive P. aeruginosa and ciprofloxacin resistance can explain the chronicity and intractability of infection in COM. Elucidation of this pathogenicity will facilitate the development of new treatment options for COM patients.
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Affiliation(s)
- Min-Hyun Park
- Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul Metropolitan Government-Seoul National University, Seoul, Republic of Korea
| | - So Young Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea.
| | - Eun Yun Roh
- Department of Clinical Laboratory Medicine, Boramae Medical Center, Seoul Metropolitan Government-Seoul National University, Seoul, Republic of Korea
| | - Ho Sun Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul Metropolitan Government-Seoul National University, Seoul, Republic of Korea
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Reyes-Pérez A, Vargas MDC, Hernández M, Aguirre-von-Wobeser E, Pérez-Rueda E, Encarnacion S. Transcriptomic analysis of the process of biofilm formation in Rhizobium etli CFN42. Arch Microbiol 2016; 198:847-60. [PMID: 27226009 DOI: 10.1007/s00203-016-1241-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 03/17/2016] [Accepted: 05/06/2016] [Indexed: 12/19/2022]
Abstract
Organisms belonging to the genus Rhizobium colonize leguminous plant roots and establish a mutually beneficial symbiosis. Biofilms are structured ecosystems in which microbes are embedded in a matrix of extracellular polymeric substances, and their development is a multistep process. The biofilm formation processes of R. etli CFN42 were analyzed at an early (24-h incubation) and mature stage (72 h), comparing cells in the biofilm with cells remaining in the planktonic stage. A genome-wide microarray analysis identified 498 differentially regulated genes, implying that expression of ~8.3 % of the total R. etli gene content was altered during biofilm formation. In biofilms-attached cells, genes encoding proteins with diverse functions were overexpressed including genes involved in membrane synthesis, transport and chemotaxis, repression of flagellin synthesis, as well as surface components (particularly exopolysaccharides and lipopolysaccharides), in combination with the presence of activators or stimulators of N-acyl-homoserine lactone synthesis This suggests that R. etli is able to sense surrounding environmental conditions and accordingly regulate the transition from planktonic and biofilm growth. In contrast, planktonic cells differentially expressed genes associated with transport, motility (flagellar and twitching) and inhibition of exopolysaccharide synthesis. To our knowledge, this is the first report of nodulation and nitrogen assimilation-related genes being involved in biofilm formation in R. etli. These results contribute to the understanding of the physiological changes involved in biofilm formation by bacteria.
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Affiliation(s)
- Agustín Reyes-Pérez
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Apartado Postal 565-A, Cuernavaca, Morelos, Mexico.,Facultad de Ciencias, Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Apartado Postal 70-153, C.P. 0415, Cuernavaca, D.F., Mexico.,Centro de Investigación en Dinámica Celular, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos, 62209, Mexico
| | - María Del Carmen Vargas
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Apartado Postal 565-A, Cuernavaca, Morelos, Mexico
| | - Magdalena Hernández
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Apartado Postal 565-A, Cuernavaca, Morelos, Mexico
| | - Eneas Aguirre-von-Wobeser
- Red de Estudios Moleculares Avanzados, Instituto de Ecología, A. C. Coatepec 351, El Haya, Xalapa, Veracruz, Mexico
| | - Ernesto Pérez-Rueda
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, UNAM, Av. Universidad s/n, Col. Chamilpa, Cuernavaca, Morelos, Mexico
| | - Sergio Encarnacion
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Apartado Postal 565-A, Cuernavaca, Morelos, Mexico.
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Sheppard DC, Howell PL. Biofilm Exopolysaccharides of Pathogenic Fungi: Lessons from Bacteria. J Biol Chem 2016; 291:12529-12537. [PMID: 27129222 DOI: 10.1074/jbc.r116.720995] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Exopolysaccharides play an important structural and functional role in the development and maintenance of microbial biofilms. Although the majority of research to date has focused on the exopolysaccharide systems of biofilm-forming bacteria, recent studies have demonstrated that medically relevant fungi such as Candida albicans and Aspergillus fumigatus also form biofilms during infection. These fungal biofilms share many similarities with those of bacteria, including the presence of secreted exopolysaccharides as core components of the extracellular matrix. This review will highlight our current understanding of fungal biofilm exopolysaccharides, as well as the parallels that can be drawn with those of their bacterial counterparts.
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Affiliation(s)
- Donald C Sheppard
- Departments of Medicine, Microbiology and Immunology, Research Institute of the McGill University Health Centre, McGill University, Montréal, Québec H4A 3J1; Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, McGill University, Montréal, Québec H4A 3J1.
| | - P Lynne Howell
- Program in Molecular Structure & Function, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
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Lee K, Lee KM, Go J, Ryu JC, Ryu JH, Yoon SS. The ferrichrome receptor A as a new target for Pseudomonas aeruginosa virulence attenuation. FEMS Microbiol Lett 2016; 363:fnw104. [PMID: 27190289 DOI: 10.1093/femsle/fnw104] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2016] [Indexed: 01/02/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen, known to develop robust biofilms. Its biofilm development increases when antibiotics are presented at subminimal inhibitory concentrations (MICs) for reasons that remain unclear. In order to identify genes that affect biofilm development under such a sublethal antibiotic stress condition, we screened a transposon (Tn) mutant library of PAO1, a prototype P. aeruginosa strain. Among ∼5000 mutants, a fiuA gene mutant was verified to form very defective biofilms in the presence of sub-MIC carbenicillin. The fiuA gene encodes ferrichrome receptor A, involved in the iron acquisition process. Of note, biofilm formation was not decreased in the ΔpchΔpvd mutant defective in the production of pyochelin and pyoverdine, two well-characterized P. aeruginosa siderophore molecules. Moreover, ΔfiuA, a non-polar fiuA deletion mutant, produced a significantly decreased level of elastase, a major virulence determinant. Mouse airway infection experiments revealed that the mutant expressed significantly less pathogenicity. Our results suggest that the fiuA gene has pleiotropic functions that affect P. aeruginosa biofilm development and virulence. The targeting of FiuA could enable the attenuation of P. aeruginosa virulence and may be suitable for the development of a drug that specifically controls the virulence of this important pathogen.
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Affiliation(s)
- Keehoon Lee
- Department of Microbiology and Immunology, Yonsei University College of Medicine, Seoul, 120-752, Korea Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 120-752, Korea
| | - Kang-Mu Lee
- Department of Microbiology and Immunology, Yonsei University College of Medicine, Seoul, 120-752, Korea
| | - Junhyeok Go
- Department of Microbiology and Immunology, Yonsei University College of Medicine, Seoul, 120-752, Korea Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 120-752, Korea
| | - Jae-Chan Ryu
- Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 120-752, Korea The Research Center for Human Natural Defense System, Yonsei University College of Medicine, Seoul, 120-752, Korea
| | - Ji-Hwan Ryu
- Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 120-752, Korea The Research Center for Human Natural Defense System, Yonsei University College of Medicine, Seoul, 120-752, Korea
| | - Sang Sun Yoon
- Department of Microbiology and Immunology, Yonsei University College of Medicine, Seoul, 120-752, Korea Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul, 120-752, Korea Institute for Immunology and Immunological Diseases, Yonsei University College of Medicine, Seoul, 120-752, Korea
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43
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Rybtke M, Hultqvist LD, Givskov M, Tolker-Nielsen T. Pseudomonas aeruginosa Biofilm Infections: Community Structure, Antimicrobial Tolerance and Immune Response. J Mol Biol 2015; 427:3628-45. [DOI: 10.1016/j.jmb.2015.08.016] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/18/2015] [Accepted: 08/20/2015] [Indexed: 02/07/2023]
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Bontemps-Gallo S, Lacroix JM. New insights into the biological role of the osmoregulated periplasmic glucans in pathogenic and symbiotic bacteria. ENVIRONMENTAL MICROBIOLOGY REPORTS 2015; 7:690-7. [PMID: 26265506 PMCID: PMC4618058 DOI: 10.1111/1758-2229.12325] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 07/24/2015] [Accepted: 07/31/2015] [Indexed: 05/06/2023]
Abstract
This review emphasizes the biological roles of the osmoregulated periplasmic glucans (OPGs). Osmoregulated periplasmic glucans occur in almost all α-, β- and γ-Proteobacteria. This polymer of glucose is required for full virulence. The roles of the OPGs are complex and vary depending on the species. Here, we outline the four major roles of the OPGs through four different pathogenic and one symbiotic bacterial models (Dickeya dadantii, Salmonella enterica, Pseudomonas aeruginosa, Brucella abortus and Sinorhizobium meliloti). When periplasmic, the OPGs are a part of the signal transduction pathway and indirectly regulate genes involved in virulence. The OPGs can also be secreted. When outside of the cell, they interact directly with antibiotics to protect the bacterial cell or interact with the host cell to facilitate the invasion process. When OPGs are not found, as in the ε-Proteobacteria, OPG-like oligosaccharides are present. Their presence strengthens the evidence that OPGs play an important role in virulence.
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Affiliation(s)
- Sébastien Bontemps-Gallo
- Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South 4th Street, Hamilton, MT, 59840, USA. Phone: +1 (406) 363-9259.
| | - Jean-Marie Lacroix
- Structural and Functional Glycobiology Unit, UMR CNRS-Lille1 8576, University of Lille, 59655 Villeneuve d’Ascq cedex, France. Phone: +33 3 20 43 65 92.
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Garneau-Tsodikova S, Labby KJ. Mechanisms of Resistance to Aminoglycoside Antibiotics: Overview and Perspectives. MEDCHEMCOMM 2015; 7:11-27. [PMID: 26877861 DOI: 10.1039/c5md00344j] [Citation(s) in RCA: 267] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Aminoglycoside (AG) antibiotics are used to treat many Gram-negative and some Gram-positive infections and, importantly, multidrug-resistant tuberculosis. Among various bacterial species, resistance to AGs arises through a variety of intrinsic and acquired mechanisms. The bacterial cell wall serves as a natural barrier for small molecules such as AGs and may be further fortified via acquired mutations. Efflux pumps work to expel AGs from bacterial cells, and modifications here too may cause further resistance to AGs. Mutations in the ribosomal target of AGs, while rare, also contribute to resistance. Of growing clinical prominence is resistance caused by ribosome methyltransferases. By far the most widespread mechanism of resistance to AGs is the inactivation of these antibiotics by AG-modifying enzymes. We provide here an overview of these mechanisms by which bacteria become resistant to AGs and discuss their prevalence and potential for clinical relevance.
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Affiliation(s)
- Sylvie Garneau-Tsodikova
- University of Kentucky, Department of Pharmaceutical Sciences, 789 South Limestone Street, Lexington, KY, USA. ; Tel: 859-218-1686
| | - Kristin J Labby
- Beloit College, Department of Chemistry, 700 College Street, Beloit, WI, USA. ; Tel: 608-363-2273
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Jennings LK, Storek KM, Ledvina HE, Coulon C, Marmont LS, Sadovskaya I, Secor PR, Tseng BS, Scian M, Filloux A, Wozniak DJ, Howell PL, Parsek MR. Pel is a cationic exopolysaccharide that cross-links extracellular DNA in the Pseudomonas aeruginosa biofilm matrix. Proc Natl Acad Sci U S A 2015; 112:11353-8. [PMID: 26311845 PMCID: PMC4568648 DOI: 10.1073/pnas.1503058112] [Citation(s) in RCA: 376] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Biofilm formation is a complex, ordered process. In the opportunistic pathogen Pseudomonas aeruginosa, Psl and Pel exopolysaccharides and extracellular DNA (eDNA) serve as structural components of the biofilm matrix. Despite intensive study, Pel's chemical structure and spatial localization within mature biofilms remain unknown. Using specialized carbohydrate chemical analyses, we unexpectedly found that Pel is a positively charged exopolysaccharide composed of partially acetylated 1→4 glycosidic linkages of N-acetylgalactosamine and N-acetylglucosamine. Guided by the knowledge of Pel's sugar composition, we developed a tool for the direct visualization of Pel in biofilms by combining Pel-specific Wisteria floribunda lectin staining with confocal microscopy. The results indicate that Pel cross-links eDNA in the biofilm stalk via ionic interactions. Our data demonstrate that the cationic charge of Pel is distinct from that of other known P. aeruginosa exopolysaccharides and is instrumental in its ability to interact with other key biofilm matrix components.
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Affiliation(s)
- Laura K Jennings
- Department of Microbiology, University of Washington, Seattle, WA 98195
| | - Kelly M Storek
- Department of Microbiology, University of Washington, Seattle, WA 98195
| | - Hannah E Ledvina
- Department of Microbiology, University of Washington, Seattle, WA 98195
| | - Charlène Coulon
- Equipe Biochimie des Produits Aquatiques, Université du Littoral-Côte d'Opale, 62327 Boulogne-sur-mer, France
| | - Lindsey S Marmont
- Program in Molecular Structure and Function, The Hospital for Sick Children, Toronto, ON, Canada M5G 0A1; Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, ON, Canada M5S 1A8
| | - Irina Sadovskaya
- Equipe Biochimie des Produits Aquatiques, Université du Littoral-Côte d'Opale, 62327 Boulogne-sur-mer, France
| | - Patrick R Secor
- Department of Microbiology, University of Washington, Seattle, WA 98195
| | - Boo Shan Tseng
- Department of Microbiology, University of Washington, Seattle, WA 98195
| | - Michele Scian
- School of Pharmacy, University of Washington, Seattle, WA, 98195
| | - Alain Filloux
- Division of Cell and Molecular Biology, Faculty of Natural Science, Center for Molecular Microbiology and Infection, Imperial College London, London SW7 2AZ, United Kingdom
| | - Daniel J Wozniak
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210; Department of Microbiology, The Ohio State University, Columbus, OH 43210; Center for Microbial Interface Biology, The Ohio State University, Columbus, OH 43210
| | - P Lynne Howell
- Program in Molecular Structure and Function, The Hospital for Sick Children, Toronto, ON, Canada M5G 0A1; Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, ON, Canada M5S 1A8
| | - Matthew R Parsek
- Department of Microbiology, University of Washington, Seattle, WA 98195;
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Biofilm-related infections: bridging the gap between clinical management and fundamental aspects of recalcitrance toward antibiotics. Microbiol Mol Biol Rev 2015; 78:510-43. [PMID: 25184564 DOI: 10.1128/mmbr.00013-14] [Citation(s) in RCA: 751] [Impact Index Per Article: 83.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Surface-associated microbial communities, called biofilms, are present in all environments. Although biofilms play an important positive role in a variety of ecosystems, they also have many negative effects, including biofilm-related infections in medical settings. The ability of pathogenic biofilms to survive in the presence of high concentrations of antibiotics is called "recalcitrance" and is a characteristic property of the biofilm lifestyle, leading to treatment failure and infection recurrence. This review presents our current understanding of the molecular mechanisms of biofilm recalcitrance toward antibiotics and describes how recent progress has improved our capacity to design original and efficient strategies to prevent or eradicate biofilm-related infections.
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Rafii F, Hart ME. Antimicrobial resistance in clinically important biofilms. World J Pharmacol 2015; 4:31-46. [DOI: 10.5497/wjp.v4.i1.31] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/22/2014] [Accepted: 12/17/2014] [Indexed: 02/06/2023] Open
Abstract
A biofilm contains a consortium of cohesive bacterial cells forming a complex structure that is a sedentary, but dynamic, community. Biofilms adhere on biotic and abiotic surfaces, including the surfaces of practically all medical devices. Biofilms are reported to be responsible for approximately 60% of nosocomial infections due to implanted medical devices, such as intravenous catheters, and they also cause other foreign-body infections and chronic infections. The presence of biofilm on a medical device may result in the infection of surrounding tissues and failure of the device, necessitating the removal and replacement of the device. Bacteria from biofilms formed on medical devices may be released and disperse, with the potential for the formation of new biofilms in other locations and the development of a systemic infection. Regardless of their location, bacteria in biofilms are tolerant of the activities of the immune system, antimicrobial agents, and antiseptics. Concentrations of antimicrobial agents sufficient to eradicate planktonic cells have no effect on the same microorganism in a biofilm. Depending on the microbial consortium or component of the biofilm that is involved, various combinations of factors have been suggested to explain the recalcitrant nature of biofilms toward killing by antibiotics. In this mini-review, some of the factors contributing to antimicrobial resistance in biofilms are discussed.
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Fungal β-1,3-glucan increases ofloxacin tolerance of Escherichia coli in a polymicrobial E. coli/Candida albicans biofilm. Antimicrob Agents Chemother 2015; 59:3052-8. [PMID: 25753645 DOI: 10.1128/aac.04650-14] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 03/04/2015] [Indexed: 12/19/2022] Open
Abstract
In the past, biofilm-related research has focused mainly on axenic biofilms. However, in nature, biofilms are often composed of multiple species, and the resulting polymicrobial interactions influence industrially and clinically relevant outcomes such as performance and drug resistance. In this study, we show that Escherichia coli does not affect Candida albicans tolerance to amphotericin or caspofungin in an E. coli/C. albicans biofilm. In contrast, ofloxacin tolerance of E. coli is significantly increased in a polymicrobial E. coli/C. albicans biofilm compared to its tolerance in an axenic E. coli biofilm. The increased ofloxacin tolerance of E. coli is mainly biofilm specific, as ofloxacin tolerance of E. coli is less pronounced in polymicrobial E. coli/C. albicans planktonic cultures. Moreover, we found that ofloxacin tolerance of E. coli decreased significantly when E. coli/C. albicans biofilms were treated with matrix-degrading enzymes such as the β-1,3-glucan-degrading enzyme lyticase. In line with a role for β-1,3-glucan in mediating ofloxacin tolerance of E. coli in a biofilm, we found that ofloxacin tolerance of E. coli increased even more in E. coli/C. albicans biofilms consisting of a high-β-1,3-glucan-producing C. albicans mutant. In addition, exogenous addition of laminarin, a polysaccharide composed mainly of poly-β-1,3-glucan, to an E. coli biofilm also resulted in increased ofloxacin tolerance. All these data indicate that β-1,3-glucan from C. albicans increases ofloxacin tolerance of E. coli in an E. coli/C. albicans biofilm.
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Jolivet-Gougeon A, Bonnaure-Mallet M. Biofilms as a mechanism of bacterial resistance. DRUG DISCOVERY TODAY. TECHNOLOGIES 2015; 11:49-56. [PMID: 24847653 DOI: 10.1016/j.ddtec.2014.02.003] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Inside the biofilm, antimicrobial agents must overcome high cell density, an increased number of resistant mutants, substance delivery, molecular exchanges, such as high levels of beta-lactamases or inducers of efflux pump expression, and specific adaptive cells, so-called persisters. The environment within the biofilm modulates the response to antibiotics, especially when the SOS response or DNA repair systems are involved. Exposure to subinhibitory concentrations of antibiotics can enhance biofilm formation and mutagenesis. Thus, a global response to cell stress seems to be responsible for antibiotic-induced biofilm formation.
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