1
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Plotniece A, Sobolev A, Supuran CT, Carta F, Björkling F, Franzyk H, Yli-Kauhaluoma J, Augustyns K, Cos P, De Vooght L, Govaerts M, Aizawa J, Tammela P, Žalubovskis R. Selected strategies to fight pathogenic bacteria. J Enzyme Inhib Med Chem 2023; 38:2155816. [PMID: 36629427 PMCID: PMC9848314 DOI: 10.1080/14756366.2022.2155816] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/02/2022] [Accepted: 12/02/2022] [Indexed: 01/12/2023] Open
Abstract
Natural products and analogues are a source of antibacterial drug discovery. Considering drug resistance levels emerging for antibiotics, identification of bacterial metalloenzymes and the synthesis of selective inhibitors are interesting for antibacterial agent development. Peptide nucleic acids are attractive antisense and antigene agents representing a novel strategy to target pathogens due to their unique mechanism of action. Antisense inhibition and development of antisense peptide nucleic acids is a new approach to antibacterial agents. Due to the increased resistance of biofilms to antibiotics, alternative therapeutic options are necessary. To develop antimicrobial strategies, optimised in vitro and in vivo models are needed. In vivo models to study biofilm-related respiratory infections, device-related infections: ventilator-associated pneumonia, tissue-related infections: chronic infection models based on alginate or agar beads, methods to battle biofilm-related infections are discussed. Drug delivery in case of antibacterials often is a serious issue therefore this review includes overview of drug delivery nanosystems.
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Affiliation(s)
- Aiva Plotniece
- Latvian Institute of Organic Synthesis, Riga, Latvia
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Riga Stradiņš University, Riga, Latvia
| | | | - Claudiu T. Supuran
- Department of NEUROFARBA, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Firenze, Italy
| | - Fabrizio Carta
- Department of NEUROFARBA, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Firenze, Italy
| | - Fredrik Björkling
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, Center for Peptide-Based Antibiotics, University of Copenhagen, Copenhagen East, Denmark
| | - Henrik Franzyk
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, Center for Peptide-Based Antibiotics, University of Copenhagen, Copenhagen East, Denmark
| | - Jari Yli-Kauhaluoma
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, Drug Research Program, University of Helsinki, Helsinki, Finland
| | - Koen Augustyns
- Infla-Med, Centre of Excellence, University of Antwerp, Antwerp, Belgium
- Laboratory of Medicinal Chemistry, University of Antwerp, Antwerp, Belgium
| | - Paul Cos
- Department of Pharmaceutical Sciences, Laboratory for Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Antwerp, Belgium
| | - Linda De Vooght
- Department of Pharmaceutical Sciences, Laboratory for Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Antwerp, Belgium
| | - Matthias Govaerts
- Department of Pharmaceutical Sciences, Laboratory for Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Antwerp, Belgium
| | - Juliana Aizawa
- Department of Pharmaceutical Sciences, Laboratory for Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Antwerp, Belgium
| | - Päivi Tammela
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, Drug Research Program, University of Helsinki, Helsinki, Finland
| | - Raivis Žalubovskis
- Latvian Institute of Organic Synthesis, Riga, Latvia
- Faculty of Materials Science and Applied Chemistry, Institute of Technology of Organic Chemistry, Riga Technical University, Riga, Latvia
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2
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Verstraete L, Aizawa J, Govaerts M, De Vooght L, Lavigne R, Michiels J, Van den Bergh B, Cos P. In Vitro Persistence Level Reflects In Vivo Antibiotic Survival of Natural Pseudomonas aeruginosa Isolates in a Murine Lung Infection Model. Microbiol Spectr 2023; 11:e0497022. [PMID: 37140371 PMCID: PMC10269860 DOI: 10.1128/spectrum.04970-22] [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: 12/05/2022] [Accepted: 04/11/2023] [Indexed: 05/05/2023] Open
Abstract
Clinicians are increasingly confronted with the limitations of antibiotics to clear bacterial infections in patients. It has long been assumed that only antibiotic resistance plays a pivotal role in this phenomenon. Indeed, the worldwide emergence of antibiotic resistance is considered one of the major health threats of the 21st century. However, the presence of persister cells also has a significant influence on treatment outcomes. These antibiotic-tolerant cells are present in every bacterial population and are the result of the phenotypic switching of normal, antibiotic-sensitive cells. Persister cells complicate current antibiotic therapies and contribute to the development of resistance. In the past, extensive research has been performed to investigate persistence in laboratory settings; however, antibiotic tolerance under conditions that mimic the clinical setting remain poorly understood. In this study, we optimized a mouse model for lung infections with the opportunistic pathogen Pseudomonas aeruginosa. In this model, mice are intratracheally infected with P. aeruginosa embedded in seaweed alginate beads and subsequently treated with tobramycin via nasal droplets. A diverse panel of 18 P. aeruginosa strains originating from environmental, human, and animal clinical sources was selected to assess survival in the animal model. Survival levels were positively correlated with the survival levels determined via time-kill assays, a common method to study persistence in the laboratory. We showed that survival levels are comparable and thus that the classical persister assays are indicative of antibiotic tolerance in a clinical setting. The optimized animal model also enables us to test potential antipersister therapies and study persistence in relevant settings. IMPORTANCE The importance of targeting persister cells in antibiotic therapies is becoming more evident, as these antibiotic-tolerant cells underlie relapsing infections and resistance development. Here, we studied persistence in a clinically relevant pathogen, Pseudomonas aeruginosa. It is one of the six ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, P. aeruginosa, and Enterobacter spp.), which are considered major health threats. P. aeruginosa is mostly known to cause chronic lung infections in cystic fibrosis patients. We mimicked these lung infections in a mouse model to study persistence under more clinical conditions. It was shown that the survival levels of natural P. aeruginosa isolates in this model are positively correlated with the survival levels measured in classical persistence assays in vitro. These results not only validate the use of our current techniques to study persistence but also open opportunities to study new persistence mechanisms or evaluate new antipersister strategies in vivo.
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Affiliation(s)
- Laure Verstraete
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
- Center for Microbiology, Flanders Institute for Biotechnology, Leuven, Belgium
| | - Juliana Aizawa
- Laboratory for Microbiology, Parasitology and Hygiene, University of Antwerp, Antwerp, Belgium
| | - Matthias Govaerts
- Laboratory for Microbiology, Parasitology and Hygiene, University of Antwerp, Antwerp, Belgium
| | - Linda De Vooght
- Laboratory for Microbiology, Parasitology and Hygiene, University of Antwerp, Antwerp, Belgium
| | - Rob Lavigne
- Laboratory of Gene Technology, KU Leuven, Leuven, Belgium
| | - Jan Michiels
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
- Center for Microbiology, Flanders Institute for Biotechnology, Leuven, Belgium
| | - Bram Van den Bergh
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
- Center for Microbiology, Flanders Institute for Biotechnology, Leuven, Belgium
| | - Paul Cos
- Laboratory for Microbiology, Parasitology and Hygiene, University of Antwerp, Antwerp, Belgium
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3
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Azimi S, Lewin GR, Whiteley M. The biogeography of infection revisited. Nat Rev Microbiol 2022; 20:579-592. [PMID: 35136217 PMCID: PMC9357866 DOI: 10.1038/s41579-022-00683-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2022] [Indexed: 01/01/2023]
Abstract
Many microbial communities, including those involved in chronic human infections, are patterned at the micron scale. In this Review, we summarize recent work that has defined the spatial arrangement of microorganisms in infection and begun to demonstrate how changes in spatial patterning correlate with disease. Advances in microscopy have refined our understanding of microbial micron-scale biogeography in samples from humans. These findings then serve as a benchmark for studying the role of spatial patterning in preclinical models, which provide experimental versatility to investigate the interplay between biogeography and pathogenesis. Experimentation using preclinical models has begun to show how spatial patterning influences the interactions between cells, their ability to coexist, their virulence and their recalcitrance to treatment. Future work to study the role of biogeography in infection and the functional biogeography of microorganisms will further refine our understanding of the interplay of spatial patterning, pathogen virulence and disease outcomes.
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Affiliation(s)
- Sheyda Azimi
- School of Biological Sciences and Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA, USA
| | - Gina R Lewin
- Emory-Children's Cystic Fibrosis Center, Atlanta, GA, USA
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4
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Geitani R, Moubareck CA, Costes F, Marti L, Dupuis G, Sarkis DK, Touqui L. Bactericidal effects and stability of LL-37 and CAMA in the presence of human lung epithelial cells. Microbes Infect 2021; 24:104928. [PMID: 34954126 DOI: 10.1016/j.micinf.2021.104928] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 11/17/2022]
Abstract
Cationic antimicrobial peptides (CAMPs) are important actors in host innate immunity and represent a promising alternative to combat antibiotic resistance. Here, the bactericidal activity of two CAMPs (LL-37, and CAMA) was evaluated against Pseudomonas aeruginosa (PA) in the presence of IB3-1 cells, a cell line derived from patients with cystic fibrosis. The two CAMPs exerted different effects on PA survival depending on the timing of their administration. We observed a greater bactericidal effect when IB3-1 cells were pretreated with sub-minimum bactericidal concentrations (Sub-MBCs) of the CAMPs prior to infection. These findings suggest that CAMPs induce the production of factors by IB3-1 cells that improve their bactericidal action. However, we observed no bactericidal effect when supra-minimum bactericidal concentrations (Supra-MBCs) of the CAMPs were added to IB3-1 cells at the same time or after infection. Western-blot analysis showed a large decrease in LL-37 levels in supernatants of infected IB3-1 cells and an increase in LL-37 binding to these cells after LL-37 administration. LL-37 induced a weak inflammatory response in the cells without being toxic. In conclusion, our findings suggest a potential prophylactic action of CAMPs. The bactericidal effects were low when the CAMPs were added after cell infection, likely due to degradation of CAMPs by bacterial or epithelial cell proteases and/or due to adherence of CAMPs to cells becoming less available for direct bacterial killing.
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Affiliation(s)
- Regina Geitani
- Microbiology Laboratory, School of Pharmacy, Saint Joseph University, Beirut, Lebanon.
| | - Carole Ayoub Moubareck
- Microbiology Laboratory, School of Pharmacy, Saint Joseph University, Beirut, Lebanon; College of Natural and Health Sciences, Zayed University, Dubai, United Arab Emirates
| | - Floriane Costes
- "Sorbonne Université", INSERM UMR_S 938, "Centre de Recherche Saint-Antoine" (CRSA), Paris, France; "Mucoviscidose and Bronchopathies Chroniques", Department "Santé Globale", Pasteur Institute, Paris, France
| | - Léa Marti
- "Sorbonne Université", INSERM UMR_S 938, "Centre de Recherche Saint-Antoine" (CRSA), Paris, France; "Mucoviscidose and Bronchopathies Chroniques", Department "Santé Globale", Pasteur Institute, Paris, France
| | - Gabrielle Dupuis
- "Sorbonne Université", INSERM UMR_S 938, "Centre de Recherche Saint-Antoine" (CRSA), Paris, France; "Mucoviscidose and Bronchopathies Chroniques", Department "Santé Globale", Pasteur Institute, Paris, France
| | - Dolla Karam Sarkis
- Microbiology Laboratory, School of Pharmacy, Saint Joseph University, Beirut, Lebanon
| | - Lhousseine Touqui
- "Sorbonne Université", INSERM UMR_S 938, "Centre de Recherche Saint-Antoine" (CRSA), Paris, France; "Mucoviscidose and Bronchopathies Chroniques", Department "Santé Globale", Pasteur Institute, Paris, France.
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5
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Nolan C, Behrends V. Sub-Inhibitory Antibiotic Exposure and Virulence in Pseudomonas aeruginosa. Antibiotics (Basel) 2021; 10:antibiotics10111393. [PMID: 34827331 PMCID: PMC8615142 DOI: 10.3390/antibiotics10111393] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 12/20/2022] Open
Abstract
Pseudomonas aeruginosa is a prime opportunistic pathogen, one of the most important causes of hospital-acquired infections and the major cause of morbidity and mortality in cystic fibrosis lung infections. One reason for the bacterium's pathogenic success is the large array of virulence factors that it can employ. Another is its high degree of intrinsic and acquired resistance to antibiotics. In this review, we first summarise the current knowledge about the regulation of virulence factor expression and production. We then look at the impact of sub-MIC antibiotic exposure and find that the virulence-antibiotic interaction for P. aeruginosa is antibiotic-specific, multifaceted, and complex. Most studies undertaken to date have been in vitro assays in batch culture systems, involving short-term (<24 h) antibiotic exposure. Therefore, we discuss the importance of long-term, in vivo-mimicking models for future work, particularly highlighting the need to account for bacterial physiology, which by extension governs both virulence factor expression and antibiotic tolerance/resistance.
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6
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Rigauts C, Aizawa J, Taylor S, Rogers GB, Govaerts M, Cos P, Ostyn L, Sims S, Vandeplassche E, Sze M, Dondelinger Y, Vereecke L, Van Acker H, Simpson JL, Burr L, Willems A, Tunney MM, Cigana C, Bragonzi A, Coenye T, Crabbé A. Rothia mucilaginosa is an anti-inflammatory bacterium in the respiratory tract of patients with chronic lung disease. Eur Respir J 2021; 59:13993003.01293-2021. [PMID: 34588194 PMCID: PMC9068977 DOI: 10.1183/13993003.01293-2021] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/10/2021] [Indexed: 11/24/2022]
Abstract
Background Chronic airway inflammation is the main driver of pathogenesis in respiratory diseases such as severe asthma, chronic obstructive pulmonary disease, cystic fibrosis (CF) and bronchiectasis. While the role of common pathogens in airway inflammation is widely recognised, the influence of other microbiota members is still poorly understood. Methods We hypothesised that the lung microbiota contains bacteria with immunomodulatory activity which modulate net levels of immune activation by key respiratory pathogens. Therefore, we assessed the immunomodulatory effect of several members of the lung microbiota frequently reported as present in CF lower respiratory tract samples. Results We show that Rothia mucilaginosa, a common resident of the oral cavity that is also often detectable in the lower airways in chronic disease, has an inhibitory effect on pathogen- or lipopolysaccharide-induced pro-inflammatory responses, in vitro (three-dimensional cell culture model) and in vivo (mouse model). Furthermore, in a cohort of adults with bronchiectasis, the abundance of Rothia species was negatively correlated with pro-inflammatory markers (interleukin (IL)-8 and IL-1β) and matrix metalloproteinase (MMP)-1, MMP-8 and MMP-9 in sputum. Mechanistic studies revealed that R. mucilaginosa inhibits NF-κB pathway activation by reducing the phosphorylation of IκBα and consequently the expression of NF-κB target genes. Conclusions These findings indicate that the presence of R. mucilaginosa in the lower airways potentially mitigates inflammation, which could in turn influence the severity and progression of chronic respiratory disorders. A commensal bacterium of the lower airways, Rothia mucilaginosa, inhibits inflammation by NF-κB pathway inactivation. R. mucilaginosa abundance inversely correlates with sputum pro-inflammatory markers in chronic lung disease, indicating a beneficial role.https://bit.ly/3lNT9th
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Affiliation(s)
- Charlotte Rigauts
- Laboratory of Pharmaceutical Microbiology, Ghent University, Gent, Belgium
| | - Juliana Aizawa
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Wilrijk, Belgium
| | - Steven Taylor
- Microbiome and Host Health Programme, the South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia.,The SAHMRI Microbiome Research Laboratory, School of Medicine, Flinders University, Adelaide, South Australia, Australia
| | - Geraint B Rogers
- Microbiome and Host Health Programme, the South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia.,The SAHMRI Microbiome Research Laboratory, School of Medicine, Flinders University, Adelaide, South Australia, Australia
| | - Matthias Govaerts
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Wilrijk, Belgium
| | - Paul Cos
- Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Wilrijk, Belgium
| | - Lisa Ostyn
- Laboratory of Pharmaceutical Microbiology, Ghent University, Gent, Belgium
| | - Sarah Sims
- Microbiome and Host Health Programme, the South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia.,The SAHMRI Microbiome Research Laboratory, School of Medicine, Flinders University, Adelaide, South Australia, Australia
| | - Eva Vandeplassche
- Laboratory of Pharmaceutical Microbiology, Ghent University, Gent, Belgium
| | - Mozes Sze
- VIB Center for Inflammation Research, Ghent, Belgium
| | - Yves Dondelinger
- VIB Center for Inflammation Research, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Gent, Belgium
| | - Lars Vereecke
- VIB Center for Inflammation Research, Ghent, Belgium.,Department of Rheumatology, Ghent University, Gent, Belgium
| | - Heleen Van Acker
- Laboratory of Pharmaceutical Microbiology, Ghent University, Gent, Belgium
| | - Jodie L Simpson
- Faculty of Health and Medicine, Priority Research Centre for Healthy Lungs, University of Newcastle, Callaghan, New South Wales, Australia
| | - Lucy Burr
- Department of Respiratory Medicine, Mater Health Services, South Brisbane, QLD, Australia.,Mater Research - University of Queensland, Aubigny Place, South Brisbane, QLD, Australia
| | - Anne Willems
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Ghent University, Gent, Belgium
| | - Michael M Tunney
- School of Pharmacy, Queen's University Belfast, Belfast, United Kingdom
| | - Cristina Cigana
- Infections and Cystic Fibrosis Unit, Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Alessandra Bragonzi
- Infections and Cystic Fibrosis Unit, Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Gent, Belgium
| | - Aurélie Crabbé
- Laboratory of Pharmaceutical Microbiology, Ghent University, Gent, Belgium
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7
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O'Brien TJ, Hassan MM, Harrison F, Welch M. An in vitro model for the cultivation of polymicrobial biofilms under continuous-flow conditions. F1000Res 2021; 10:801. [PMID: 34557293 PMCID: PMC8442117 DOI: 10.12688/f1000research.55140.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/04/2021] [Indexed: 02/04/2023] Open
Abstract
The airways of people with cystic fibrosis (CF) are often chronically colonised with a diverse array of bacterial and fungal species. However, little is known about the relative partitioning of species between the planktonic and biofilm modes of growth in the airways. Existing in vivo and in vitro models of CF airway infection are ill-suited for the long-term recapitulation of mixed microbial communities. Here we describe a simple, in vitro continuous-flow model for the cultivation of polymicrobial biofilms and planktonic cultures on different substrata. Our data provide evidence for inter-species antagonism and synergism in biofilm ecology. We further show that the type of substratum on which the biofilms grow has a profound influence on their species composition. This happens without any major alteration in the composition of the surrounding steady-state planktonic community. Our experimentally-tractable model enables the systematic study of planktonic and biofilm communities under conditions that are nutritionally reminiscent of the CF airway microenvironment, something not possible using any existing in vivo models of CF airway infection.
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Affiliation(s)
| | | | - Freya Harrison
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Martin Welch
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QR, UK
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8
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Shaqour B, Aizawa J, Guarch-Pérez C, Górecka Ż, Christophersen L, Martinet W, Choińska E, Riool M, Verleije B, Beyers K, Moser C, Święszkowski W, Zaat SAJ, Cos P. Coupling Additive Manufacturing with Hot Melt Extrusion Technologies to Validate a Ventilator-Associated Pneumonia Mouse Model. Pharmaceutics 2021; 13:pharmaceutics13060772. [PMID: 34064276 PMCID: PMC8224298 DOI: 10.3390/pharmaceutics13060772] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/08/2021] [Accepted: 05/18/2021] [Indexed: 12/02/2022] Open
Abstract
Additive manufacturing is widely used to produce highly complex structures. Moreover, this technology has proven its superiority in producing tools which can be used in different applications. We designed and produced an extrusion nozzle that allowed us to hot melt extrude drug-loaded tubes. The tubes were an essential part of a new mouse ventilator-associated pneumonia (VAP) model. Ciprofloxacin (CPX) was selected for its expected activity against the pathogen Staphylococcus aureus and ease of incorporation into thermoplastic polyurethane (TPU). TPU was selected as the carrier polymer for its biocompatibility and use in a variety of medical devices such as tubing and catheters. The effect of loading CPX within the TPU polymeric matrix and the physicochemical properties of the produced tubes were investigated. CPX showed good thermal stability and in vitro activity in preventing S. aureus biofilm formation after loading within the tube’s polymeric matrix. Moreover, the produced tubes showed anti-infective efficacy in vivo. The produced tubes, which were extruded via our novel nozzle, were vital for the validation of our mouse VAP model. This model can be adopted to investigate other antibacterial and antibiofilm compounds incorporated in polymeric tubes using hot melt extrusion.
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Affiliation(s)
- Bahaa Shaqour
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1 S.7, 2610 Wilrijk, Belgium; (J.A.); (P.C.)
- Mechanical and Mechatronics Engineering Department, Faculty of Engineering & Information Technology, An-Najah National University, Nablus P.O. Box 7, Palestine
- Correspondence:
| | - Juliana Aizawa
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1 S.7, 2610 Wilrijk, Belgium; (J.A.); (P.C.)
| | - Clara Guarch-Pérez
- Department of Medical Microbiology and Infection Prevention, Amsterdam Institute for Infection and Immunity, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands; (C.G.-P.); (M.R.); (S.A.J.Z.)
| | - Żaneta Górecka
- Faculty of Materials Sciences and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw, Poland; (Ż.G.); (E.C.); (W.Ś.)
- Centre for Advanced Materials and Technologies CEZAMAT, Warsaw University of Technology, Poleczki 19, 02-822 Warsaw, Poland
| | - Lars Christophersen
- Department for Clinical Microbiology, Rigshospitalet, Henrik Harpestrengsvej 4A, Afsnit 93.01, 2100 Copenhagen, Denmark; (L.C.); (C.M.)
| | - Wim Martinet
- Laboratory of Physiopharmacology, University of Antwerp, Universiteitsplein 1 T.2, 2610 Wilrijk, Belgium;
| | - Emilia Choińska
- Faculty of Materials Sciences and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw, Poland; (Ż.G.); (E.C.); (W.Ś.)
| | - Martijn Riool
- Department of Medical Microbiology and Infection Prevention, Amsterdam Institute for Infection and Immunity, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands; (C.G.-P.); (M.R.); (S.A.J.Z.)
| | - Bart Verleije
- Voxdale bv, Bijkhoevelaan 32, 2110 Wijnegem, Belgium; (B.V.); (K.B.)
| | - Koen Beyers
- Voxdale bv, Bijkhoevelaan 32, 2110 Wijnegem, Belgium; (B.V.); (K.B.)
| | - Claus Moser
- Department for Clinical Microbiology, Rigshospitalet, Henrik Harpestrengsvej 4A, Afsnit 93.01, 2100 Copenhagen, Denmark; (L.C.); (C.M.)
| | - Wojciech Święszkowski
- Faculty of Materials Sciences and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw, Poland; (Ż.G.); (E.C.); (W.Ś.)
| | - Sebastian A. J. Zaat
- Department of Medical Microbiology and Infection Prevention, Amsterdam Institute for Infection and Immunity, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands; (C.G.-P.); (M.R.); (S.A.J.Z.)
| | - Paul Cos
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1 S.7, 2610 Wilrijk, Belgium; (J.A.); (P.C.)
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9
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Calum HP, Moser C, Jensen PO, Bjarnsholt T, Givskov M, Høiby N. Early IL-2 treatment of mice with Pseudomonas aeruginosa pneumonia induced PMN-dominating response and reduced lung pathology. APMIS 2020; 128:647-653. [PMID: 32794206 DOI: 10.1111/apm.13072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 08/03/2020] [Indexed: 11/27/2022]
Abstract
IL-2 is a pro-inflammatory and a Th1 inducing cytokine, which is important for activation of the cell-mediated immunity. IL-2 in serum and sputum has been observed to be reduced in cystic fibrosis (CF) patients. The present IL-2 treatment study of Pseudomonas aeruginosa (PA) lung infected mice was performed in order to evaluate the effect of IL-2 supplement. One hundred-and-twenty female BALB/c mice were divided into three groups: 1) IL-2 treatment/infection (TIG), 2) non-treatment/infection (NTIG), and 3) IL-2 treatment/non-infection (TNIG). The mice were challenged intra-tracheally with PA (PAO579) embedded in seaweed alginate to resemble the biofilm mode of growth. At day 0 and 1, the treatment groups received IL-2 s.c. Mice were killed on day 1 or 2, and cytokine production, lung pathology, and quantitative lung bacteriology were estimated. IL-2 treatment of infected mice reduced the number of mice with signs of macroscopic lung pathology at day 2 (p < 0.05). The reduced macroscopic pathology was paralleled by a reduced IL-1β and TNF-α. In contrast, an increased PMN response at day 2 was observed in the IL-2 treated mice (p < 0.01). This was preceded by a significantly higher degree of microscopic inflammation at day 1 (p < 0.02). The IL-12 levels decreased in both groups of infected mice at day 2 (p < 0.01), however, significantly more in the IL-2 treated mice (p < 0.02). In accordance, but surprisingly, IFN-γ was significantly reduced in the IL-2 treated PA infected group at day 2 (p < 0.05). The present results indicate that early IL-2 treatment prolongs the PMN response but also reduces pro-inflammatory IL-1β and TNF-α and macroscopic signs of pathology.
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Affiliation(s)
- Henrik Pierre Calum
- Department of Clinical Microbiology, Hvidovre Hospital, Hvidovre, Denmark.,Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
| | - Claus Moser
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
| | - Peter Ostrup Jensen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark.,Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Bjarnsholt
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark.,Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael Givskov
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Niels Høiby
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark.,Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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10
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Gao Y, Wang J, Chai M, Li X, Deng Y, Jin Q, Ji J. Size and Charge Adaptive Clustered Nanoparticles Targeting the Biofilm Microenvironment for Chronic Lung Infection Management. ACS NANO 2020; 14:5686-5699. [PMID: 32320228 DOI: 10.1021/acsnano.0c00269] [Citation(s) in RCA: 165] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Chronic lung infection caused by bacterial biofilms is an extremely serious clinical problem, which can lead to the failure of antibiotic therapy. Although nanoparticles have shown great potential in the treatment of biofilms, the efficient penetration and retention of nanoparticles in biofilms is still a big challenge. To address this issue, we herein fabricate size and charge adaptive azithromycin (AZM)-conjugated clustered nanoparticles (denoted as AZM-DA NPs) as therapeutic agents for treating biofilms. The AZM-DA NPs are prepared by electrostatic complexation between AZM conjugated amino-ended poly(amidoamine) dendrimer (PAMAM) and 2,3-dimethyl maleic anhydride (DA) modified poly(ethylene glycol)-block-polylysine (PEG-b-PLys). It is noteworthy that the AZM-DA NPs can disassemble in an acidic biofilm microenvironment (pH 6.0), leading to the release of secondary AZM-conjugated PAMAM nanoparticles (PAMAM-AZM NPs). PAMAM-AZM NPs with small size and positive charge are beneficial for improved penetration and retention inside biofilms, enhanced permeabilization of the bacterial membrane, and increased internalization of AZM, thus exhibiting excellent antibiofilm activities. AZM-DA NPs are also favorable as long-term antibacterial agents due to the reduced occurrence of drug resistance. In vivo therapeutic performance is confirmed by the reduced bacterial burden and the alleviated inflammation in the chronic lung infection model. This research not only develops an innovative strategy for antibiotic delivery in vivo but also provides an effective way for the management of biofilm-associated infections, including chronic lung infection.
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Affiliation(s)
- Yifan Gao
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China
| | - Jing Wang
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China
| | - Mengying Chai
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China
| | - Xu Li
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China
| | - Yongyan Deng
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China
| | - Qiao Jin
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China
| | - Jian Ji
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China
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11
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O'Brien TJ, Welch M. Recapitulation of polymicrobial communities associated with cystic fibrosis airway infections: a perspective. Future Microbiol 2019; 14:1437-1450. [PMID: 31778075 DOI: 10.2217/fmb-2019-0200] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The airways of persons with cystic fibrosis are prone to infection by a diverse and dynamic polymicrobial consortium. Currently, no models exist that permit recapitulation of this consortium within the laboratory. Such microbial ecosystems likely have a network of interspecies interactions, serving to modulate metabolic pathways and impact upon disease severity. The contribution of less abundant/fastidious microbial species on this cross-talk has often been neglected due to lack of experimental tractability. Here, we critically assess the existing models for studying polymicrobial infections. Particular attention is paid to 3Rs-compliant in vitro and in silico infection models, offering significant advantages over mammalian infection models. We outline why these models will likely become the 'go to' approaches when recapitulating polymicrobial cystic fibrosis infection.
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Affiliation(s)
- Thomas J O'Brien
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW, UK
| | - Martin Welch
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW, UK
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12
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Garge S, Azimi S, Diggle SP. A simple mung bean infection model for studying the virulence of Pseudomonas aeruginosa. MICROBIOLOGY-SGM 2018; 164:764-768. [PMID: 29629857 DOI: 10.1099/mic.0.000659] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Here we highlight the development of a simple and high-throughput mung bean model to study virulence in the opportunistic pathogen Pseudomonas aeruginosa. The model is easy to set up, and infection and virulence can be monitored for up to 10 days. In a first test of the model, we found that mung bean seedlings infected with PAO1 showed poor development of roots and high mortality rates compared to uninfected controls. We also found that a quorum-sensing (QS) mutant was significantly less virulent when compared with the PAO1 wild-type. Our work introduces a new tool for studying virulence in P. aeruginosa that will allow for high-throughput virulence studies of mutants and testing of the in vivo efficacy of new therapies at a time when new antimicrobial drugs are desperately needed.
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Affiliation(s)
- Sneha Garge
- Department of Microbiology and Biotechnology Center, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, India
| | - Sheyda Azimi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30032, USA
| | - Stephen P Diggle
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30032, USA
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13
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Moore JE, Mastoridis P. Clinical implications of Pseudomonas aeruginosa location in the lungs of patients with cystic fibrosis. J Clin Pharm Ther 2017; 42:259-267. [PMID: 28374433 DOI: 10.1111/jcpt.12521] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 03/05/2017] [Indexed: 12/18/2022]
Abstract
WHAT IS KNOWN AND OBJECTIVE Pseudomonas aeruginosa is the leading cause of lung infection in patients with cystic fibrosis (CF) and is associated with significant morbidity and mortality. Antibiotics are regarded as the foundational pharmacological treatment for the suppressive management of chronic P. aeruginosa infections and to eradicate the first infection by P. aeruginosa. Inhalation remains a preferred route for drug administration, providing direct access to the site of infection while minimizing systemic side effects. Effective suppressive management of P. aeruginosa infections, however, requires an understanding of the location of the bacteria in the lungs and consideration of the factors that could limit access of the inhaled antibiotic to the infected area. This review provides a systematic assessment of the scientific literature to gain insight into the location of P. aeruginosa in the lungs of patients with CF and its clinical implications. The characteristics of antibiotic inhalation systems are also discussed in this context. METHODS We reviewed evidence-based literature from both human and animal studies in which P. aeruginosa lung location was reported. Relevant publications were identified through a screening strategy and summarized by reported P. aeruginosa location. RESULTS AND DISCUSSION Most areas of the conductive and respiratory zones of the lungs are susceptible to P. aeruginosa colonization. Deposition of an inhaled antibiotic is dependent on the device and formulation characteristics, as well as the ability of the patient to generate sufficient inhaled volume. As patients with CF often experience a decline in lung function, the challenge is to ensure that the inhaled antibiotic can be delivered throughout the bronchial tree. WHAT IS NEW AND CONCLUSION An effective drug delivery system that can target P. aeruginosa in both the respiratory and conductive zones is required. The chosen inhalation device should also offer a drug formulation that can be quickly and effectively delivered to specific lung locations, with minimal inspiratory effort from the patient.
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Affiliation(s)
- J E Moore
- Northern Ireland Public Health Laboratory, Department of Bacteriology, Belfast City Hospital, Belfast, UK
| | - P Mastoridis
- Respiratory Department, Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA
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14
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New Mouse Model for Chronic Infections by Gram-Negative Bacteria Enabling the Study of Anti-Infective Efficacy and Host-Microbe Interactions. mBio 2017; 8:mBio.00140-17. [PMID: 28246361 PMCID: PMC5347345 DOI: 10.1128/mbio.00140-17] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Only a few, relatively cumbersome animal models enable long-term Gram-negative bacterial infections that mimic human situations, where untreated infections can last for weeks. Here, we describe a simple murine cutaneous abscess model that enables chronic or progressive infections, depending on the subcutaneously injected bacterial strain. In this model, Pseudomonas aeruginosa cystic fibrosis epidemic isolate LESB58 caused localized high-density skin and soft tissue infections and necrotic skin lesions for up to 10 days but did not disseminate in either CD-1 or C57BL/6 mice. The model was adapted for use with four major Gram-negative nosocomial pathogens, Acinetobacter baumannii, Klebsiella pneumoniae, Enterobacter cloacae, and Escherichia coli. This model enabled noninvasive imaging and tracking of lux-tagged bacteria, the influx of activated neutrophils, and production of reactive oxygen-nitrogen species at the infection site. Screening antimicrobials against high-density infections showed that local but not intravenous administration of gentamicin, ciprofloxacin, and meropenem significantly but incompletely reduced bacterial counts and superficial tissue dermonecrosis. Bacterial RNA isolated from the abscess tissue revealed that Pseudomonas genes involved in iron uptake, toxin production, surface lipopolysaccharide regulation, adherence, and lipase production were highly upregulated whereas phenazine production and expression of global activator gacA were downregulated. The model was validated for studying virulence using mutants of more-virulent P. aeruginosa strain PA14. Thus, mutants defective in flagella or motility, type III secretion, or siderophore biosynthesis were noninvasive and suppressed dermal necrosis in mice, while a strain with a mutation in the bfiS gene encoding a sensor kinase showed enhanced invasiveness and mortality in mice compared to controls infected with wild-type P. aeruginosa PA14. More than two-thirds of hospital infections are chronic or high-density biofilm infections and difficult to treat due to adaptive, multidrug resistance. Unfortunately, current models of chronic infection are technically challenging and difficult to track without sacrificing animals. Here we describe a model of chronic subcutaneous infection and abscess formation by medically important nosocomial Gram-negative pathogens that is simple and can be used for tracking infections by imaging, examining pathology and immune responses, testing antimicrobial treatments suitable for high-density bacterial infections, and studying virulence. We propose that this mouse model can be a game changer for modeling hard-to-treat Gram-negative bacterial chronic and skin infections.
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15
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The host genetic background defines diverse immune-reactivity and susceptibility to chronic Pseudomonas aeruginosa respiratory infection. Sci Rep 2016; 6:36924. [PMID: 27848994 PMCID: PMC5111113 DOI: 10.1038/srep36924] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 10/21/2016] [Indexed: 01/31/2023] Open
Abstract
Patients with P. aeruginosa airways infection show markedly variable clinical phenotypes likely influenced by genetic backgrounds. Here, we investigated the cellular events involved in resistance and susceptibility to P. aeruginosa chronic infection using genetically distinct inbred mouse strains. As for patients, different murine genotypes revealed variable susceptibility to infection. When directly compared, resistant C3H/HeOuJ and susceptible A/J strains revealed distinct immune responsiveness to the pathogen. In C3H/HeOuJ resistant mice, IL17-producing cells rapidly and transiently infiltrated the infected lung, and this was paralleled by the acute accumulation of alveolar macrophages, bacterial clearance and resolution of infection. In contrast, A/J susceptible mice revealed a more delayed and prolonged lung infiltration by IL17+ and IFNγ+ cells, persistence of innate inflammatory cells and establishment of chronic infection. We conclude that the host genetic background confers diverse immunoreactivity to P. aeruginosa and IL17-producing cells might contribute to the progress of chronic lung infection.
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16
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Zhao M, Lepak AJ, Andes DR. Animal models in the pharmacokinetic/pharmacodynamic evaluation of antimicrobial agents. Bioorg Med Chem 2016; 24:6390-6400. [PMID: 27887963 DOI: 10.1016/j.bmc.2016.11.008] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 11/02/2016] [Accepted: 11/03/2016] [Indexed: 12/28/2022]
Abstract
Animal infection models in the pharmacokinetic/pharmacodynamic (PK/PD) evaluation of antimicrobial therapy serve an important role in preclinical assessments of new antibiotics, dosing optimization for those that are clinically approved, and setting or confirming susceptibility breakpoints. The goal of animal model studies is to mimic the infectious diseases seen in humans to allow for robust PK/PD studies to find the optimal drug exposures that lead to therapeutic success. The PK/PD index and target drug exposures obtained in validated animal infection models are critical components in optimizing dosing regimen design in order to maximize efficacy while minimize the cost and duration of clinical trials. This review outlines the key components in animal infection models which have been used extensively in antibiotic discovery and development including PK/PD analyses.
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Affiliation(s)
- Miao Zhao
- Institute of Antibiotics Hua-shan Hospital, Fudan University & Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, China; Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Alexander J Lepak
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - David R Andes
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI, USA; William S. Middleton Memorial VA Hospital, Madison, WI, USA.
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17
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Abstract
Survival after lung transplantation is limited in large part due to the high incidence of chronic rejection, known as chronic lung allograft dysfunction (CLAD). Pulmonary infections are a frequent complication in lung transplant recipients, due both to immunosuppressive medications and constant exposure of the lung allograft to the external environment via the airways. Infection is a recognized risk factor for the development of CLAD, and both acute infection and chronic lung allograft colonization with microorganisms increase the risk for CLAD. Acute infection by community acquired respiratory viruses, and the bacteria Pseudomonas aeruginosa and Staphylococcus aureus are increasingly recognized as important risk factors for CLAD. Colonization by the fungus Aspergillus may also augment the risk of CLAD. Fostering this transition from healthy lung to CLAD in each of these infectious episodes is the persistence of an inflammatory lung allograft environment.
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Affiliation(s)
- Aric L Gregson
- Division of Infectious Diseases, Department of Medicine, University of California, Box 957119, Warren Hall 14-154, Los Angeles, CA, 90995-7119, USA.
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18
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Wagner S, Sommer R, Hinsberger S, Lu C, Hartmann RW, Empting M, Titz A. Novel Strategies for the Treatment of Pseudomonas aeruginosa Infections. J Med Chem 2016; 59:5929-69. [DOI: 10.1021/acs.jmedchem.5b01698] [Citation(s) in RCA: 176] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Stefanie Wagner
- Chemical
Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
| | - Roman Sommer
- Chemical
Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
| | - Stefan Hinsberger
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Cenbin Lu
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Rolf W. Hartmann
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Martin Empting
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Alexander Titz
- Chemical
Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
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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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20
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Dennis EA, Coats MT, Griffin SE, Hale JY, Novak L, Briles DE, Crain MJ. The Effects of CFTR and Mucoid Phenotype on Susceptibility and Innate Immune Responses in a Mouse Model of Pneumococcal Lung Disease. PLoS One 2015; 10:e0140335. [PMID: 26469863 PMCID: PMC4607445 DOI: 10.1371/journal.pone.0140335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 09/24/2015] [Indexed: 12/18/2022] Open
Abstract
Recent studies have reported the isolation of highly mucoid serotype 3 Streptococcus pneumoniae (Sp) from the respiratory tracts of children with cystic fibrosis (CF). Whether these highly mucoid Sp contribute to, or are associated with, respiratory failure among patients with CF remains unknown. Other mucoid bacteria, predominately Pseudomonas aeruginosa, are associated with CF respiratory decline. We used a mouse model of CF to study pneumococcal pneumonia with highly mucoid serotype 3 and non-mucoid serotype 19A Sp isolates. We investigated susceptibility to infection, survival, and bacterial counts from bronchoaviolar lavage samples and lung homogenates, as well as associated inflammatory cytokines at the site of infection, and lung pathology. Congenic CFTR-/- mice and wild-type (WT)-mice were infected intranasally with CHB756, CHB1126, and WU2 (highly mucoid capsular serotype 3, intermediately mucoid serotype 3, and less mucoid serotype 3, respectively), or CHB1058 (non-mucoid serotype 19A). BAL, lung homogenates, and blood were collected from mice 5 days post-infection. Higher CFU recovery and shorter survival were observed following infection of CFTR-/- mice with CHB756 compared to infection with CHB1126, WU2, or CHB1058 (P≤0.001). Additionally, CFTR-/- mice infected with CHB756 and CHB1126 were more susceptible to infection than WT-mice (P≤0.05). Between CFTR-/- mice and WT-mice, no significant differences in TNF-α, CXCL1/KC concentrations, or lung histopathology were observed. Our results indicate that highly mucoid type 3 Sp causes more severe lung disease than non-mucoid Sp, and does so more readily in the lungs of CFTR-/- than WT-mice.
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Affiliation(s)
- Evida A. Dennis
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Mamie T. Coats
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department of Biological Sciences, Alabama State University, Montgomery, Alabama, United States of America
| | - Sarah E. Griffin
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Joanetha Y. Hale
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Lea Novak
- Department of Anatomic Pathology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - David E. Briles
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Marilyn J. Crain
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
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Bacterial Adaptation during Chronic Respiratory Infections. Pathogens 2015; 4:66-89. [PMID: 25738646 PMCID: PMC4384073 DOI: 10.3390/pathogens4010066] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 02/15/2015] [Accepted: 02/25/2015] [Indexed: 01/22/2023] Open
Abstract
Chronic lung infections are associated with increased morbidity and mortality for individuals with underlying respiratory conditions such as cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD). The process of chronic colonisation allows pathogens to adapt over time to cope with changing selection pressures, co-infecting species and antimicrobial therapies. These adaptations can occur due to environmental pressures in the lung such as inflammatory responses, hypoxia, nutrient deficiency, osmolarity, low pH and antibiotic therapies. Phenotypic adaptations in bacterial pathogens from acute to chronic infection include, but are not limited to, antibiotic resistance, exopolysaccharide production (mucoidy), loss in motility, formation of small colony variants, increased mutation rate, quorum sensing and altered production of virulence factors associated with chronic infection. The evolution of Pseudomonas aeruginosa during chronic lung infection has been widely studied. More recently, the adaptations that other chronically colonising respiratory pathogens, including Staphylococcus aureus, Burkholderia cepacia complex and Haemophilus influenzae undergo during chronic infection have also been investigated. This review aims to examine the adaptations utilised by different bacterial pathogens to aid in their evolution from acute to chronic pathogens of the immunocompromised lung including CF and COPD.
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22
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Development of an ex vivo porcine lung model for studying growth, virulence, and signaling of Pseudomonas aeruginosa. Infect Immun 2014; 82:3312-23. [PMID: 24866798 PMCID: PMC4136229 DOI: 10.1128/iai.01554-14] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Research into chronic infection by bacterial pathogens, such as Pseudomonas aeruginosa, uses various in vitro and live host models. While these have increased our understanding of pathogen growth, virulence, and evolution, each model has certain limitations. In vitro models cannot recapitulate the complex spatial structure of host organs, while experiments on live hosts are limited in terms of sample size and infection duration for ethical reasons; live mammal models also require specialized facilities which are costly to run. To address this, we have developed an ex vivo pig lung (EVPL) model for quantifying Pseudomonas aeruginosa growth, quorum sensing (QS), virulence factor production, and tissue damage in an environment that mimics a chronically infected cystic fibrosis (CF) lung. In a first test of our model, we show that lasR mutants, which do not respond to 3-oxo-C12-homoserine lactone (HSL)-mediated QS, exhibit reduced virulence factor production in EVPL. We also show that lasR mutants grow as well as or better than a corresponding wild-type strain in EVPL. lasR mutants frequently and repeatedly arise during chronic CF lung infection, but the evolutionary forces governing their appearance and spread are not clear. Our data are not consistent with the hypothesis that lasR mutants act as social “cheats” in the lung; rather, our results support the hypothesis that lasR mutants are more adapted to the lung environment. More generally, this model will facilitate improved studies of microbial disease, especially studies of how cells of the same and different species interact in polymicrobial infections in a spatially structured environment.
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Thomsen K, Trøstrup H, Moser C. Animal models to evaluate bacterial biofilm development. Methods Mol Biol 2014; 1147:127-139. [PMID: 24664830 DOI: 10.1007/978-1-4939-0467-9_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Medical biofilms have attracted substantial attention especially in the past decade. Animal models are contributing significantly to understand the pathogenesis of medical biofilms. In addition, animal models are an essential tool in testing the hypothesis generated from clinical observations in patients and preclinical testing of agents showing in vitro antibiofilm effect. Here, we describe three animal models - two non-foreign body Pseudomonas aeruginosa biofilm models and a foreign body Staphylococcus aureus model.
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Affiliation(s)
- Kim Thomsen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
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Bjarnsholt T, Alhede M, Alhede M, Eickhardt-Sørensen SR, Moser C, Kühl M, Jensen PØ, Høiby N. The in vivo biofilm. Trends Microbiol 2013; 21:466-74. [PMID: 23827084 DOI: 10.1016/j.tim.2013.06.002] [Citation(s) in RCA: 501] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 05/26/2013] [Accepted: 06/05/2013] [Indexed: 11/15/2022]
Abstract
Bacteria can grow and proliferate either as single, independent cells or organized in aggregates commonly referred to as biofilms. When bacteria succeed in forming a biofilm within the human host, the infection often becomes very resistant to treatment and can develop into a chronic state. Biofilms have been studied for decades using various in vitro models, but it remains debatable whether such in vitro biofilms actually resemble in vivo biofilms in chronic infections. In vivo biofilms share several structural characteristics that differ from most in vitro biofilms. Additionally, the in vivo experimental time span and presence of host defenses differ from chronic infections and the chemical microenvironment of both in vivo and in vitro biofilms is seldom taken into account. In this review, we discuss why the current in vitro models of biofilms might be limited for describing infectious biofilms, and we suggest new strategies for improving this discrepancy.
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Affiliation(s)
- Thomas Bjarnsholt
- Department of International Health, Immunology, and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Clinical Microbiology 9301, Juliane Mariesvej 22, Copenhagen University Hospital, Copenhagen, Denmark.
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26
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Christophersen LJ, Trøstrup H, Malling Damlund DS, Bjarnsholt T, Thomsen K, Jensen PØ, Hougen HP, Høiby N, Moser C. Bead-size directed distribution of Pseudomonas aeruginosa results in distinct inflammatory response in a mouse model of chronic lung infection. Clin Exp Immunol 2013; 170:222-30. [PMID: 23039893 DOI: 10.1111/j.1365-2249.2012.04652.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Chronic Pseudomonas aeruginosa lung infection in cystic fibrosis (CF) patients is characterized by biofilms, tolerant to antibiotics and host responses. Instead, immune responses contribute to the tissue damage. However, this may depend on localization of infection in the upper conductive or in the peripheral respiratory zone. To study this we produced two distinct sizes of small alginate beads (SB) and large beads (LB) containing P. aeruginosa. In total, 175 BALB/c mice were infected with either SB or LB. At day 1 the quantitative bacteriology was higher in the SB group compared to the LB group (P < 0·003). For all time-points smaller biofilms were identified by Alcian blue staining in the SB group (P < 0·003). Similarly, the area of the airways in which biofilms were identified were smaller (P < 0·0001). A shift from exclusively endobronchial to both parenchymal and endobronchial localization of inflammation from day 1 to days 2/3 (P < 0·05), as well as a faster resolution of inflammation at days 5/6, was observed in the SB group (P < 0·03). Finally, both the polymorphonuclear neutrophil leucocyte (PMN) mobilizer granulocyte colony-stimulating factor (G-CSF) and chemoattractant macrophage inflammatory protein-2 (MIP-2) were increased at day 1 in the SB group (P < 0·0001). In conclusion, we have established a model enabling studies of host responses in different pulmonary zones. An effective recognition of and a more pronounced host response to infection in the peripheral zones, indicating that increased lung damage was demonstrated. Therefore, treatment of the chronic P. aeruginosa lung infection should be directed primarily at the peripheral lung zone by combined intravenous and inhalation antibiotic treatment.
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Affiliation(s)
- L J Christophersen
- Department of Clinical Microbiology 93.01, Copenhagen University Hospital, Rigshospitalet Department of Forensic Medicine, University of Copenhagen, Copenhagen, Denmark
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Ciofu O, Johansen HK, Aanaes K, Wassermann T, Alhede M, von Buchwald C, Høiby N. P. aeruginosa in the paranasal sinuses and transplanted lungs have similar adaptive mutations as isolates from chronically infected CF lungs. J Cyst Fibros 2013; 12:729-36. [PMID: 23478131 DOI: 10.1016/j.jcf.2013.02.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Revised: 02/06/2013] [Accepted: 02/11/2013] [Indexed: 01/02/2023]
Abstract
BACKGROUND Pseudomonas aeruginosa cells are present as biofilms in the paranasal sinuses and the lungs of chronically infected cystic fibrosis (CF) patients. Since different inflammatory responses and selective antibiotic pressures are acting in the sinuses compared with the lungs, we compared the adaptive profiles of mucoid and non-mucoid isolates from the two locations. METHODS We studied the genetic basis of phenotypic diversification and gene expression profiles in sequential lung and sinus P. aeruginosa isolates from four chronically infected CF patients, including pre- and post-lung transplantation isolates. RESULTS The same phenotypes caused by similar mutations and similar gene expression profiles were found in mucoid and non-mucoid isolates from the paranasal sinuses and from the lungs before and after transplantation. CONCLUSION Bilateral exchange of P. aeruginosa isolates between the paranasal sinuses and the lungs occurs in chronically infected patients and extensive sinus surgery before the lung transplantation might prevent infection of the new lung.
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Affiliation(s)
- Oana Ciofu
- Department of International Health, Immunology and Microbiology, Unit of Bacteriology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
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Trøstrup H, Thomsen K, Christophersen LJ, Hougen HP, Bjarnsholt T, Jensen PØ, Kirkby N, Calum H, Høiby N, Moser C. Pseudomonas aeruginosabiofilm aggravates skin inflammatory response in BALB/c mice in a novel chronic wound model. Wound Repair Regen 2013; 21:292-9. [DOI: 10.1111/wrr.12016] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Accepted: 11/20/2012] [Indexed: 02/01/2023]
Affiliation(s)
- Hannah Trøstrup
- Department of Clinical Microbiology; Copenhagen University Hospital, Rigshospitalet; Copenhagen; Denmark
| | - Kim Thomsen
- Department of Clinical Microbiology; Copenhagen University Hospital, Rigshospitalet; Copenhagen; Denmark
| | - Lars J. Christophersen
- Department of Clinical Microbiology; Copenhagen University Hospital, Rigshospitalet; Copenhagen; Denmark
| | - Hans P. Hougen
- Department of Forensic Medicine; University of Copenhagen; Copenhagen; Denmark
| | - Thomas Bjarnsholt
- Department of Clinical Microbiology; Copenhagen University Hospital, Rigshospitalet; Copenhagen; Denmark
| | - Peter Ø. Jensen
- Department of Clinical Microbiology; Copenhagen University Hospital, Rigshospitalet; Copenhagen; Denmark
| | - Nikolai Kirkby
- Department of Clinical Microbiology; Copenhagen University Hospital, Rigshospitalet; Copenhagen; Denmark
| | - Henrik Calum
- Department of Clinical Microbiology; Copenhagen University Hospital, Rigshospitalet; Copenhagen; Denmark
| | - Niels Høiby
- Department of Clinical Microbiology; Copenhagen University Hospital, Rigshospitalet; Copenhagen; Denmark
| | - Claus Moser
- Department of Clinical Microbiology; Copenhagen University Hospital, Rigshospitalet; Copenhagen; Denmark
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Bonfield TL, Hodges CA, Cotton CU, Drumm ML. Absence of the cystic fibrosis transmembrane regulator (Cftr) from myeloid-derived cells slows resolution of inflammation and infection. J Leukoc Biol 2012; 92:1111-22. [PMID: 22859830 DOI: 10.1189/jlb.0412188] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The absence or reduction of CFTR function causes CF and results in a pulmonary milieu characterized by bacterial colonization and unresolved inflammation. The ineffectiveness at controlling infection by species such as Pseudomonas aeruginosa suggests defects in innate immunity. Macrophages, neutrophils, and DCs have all been shown to express CFTR mRNA but at low levels, raising the question of whether CFTR has a functional role in these cells. Bone marrow transplants between CF and non-CF mice suggest that these cells are inherently different; we confirm this observation using conditional inactivation of Cftr in myeloid-derived cells. Mice lacking Cftr in myeloid cells overtly appear indistinguishable from non-CF mice until challenged with bacteria instilled into the lungs and airways, at which point, they display survival and inflammatory profiles intermediate in severity as compared with CF mice. These studies demonstrate that Cftr is involved directly in myeloid cell function and imply that these cells contribute to the pathophysiological phenotype of the CF lung.
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Affiliation(s)
- T L Bonfield
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH 44106-4948, USA.
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Rudkjøbing VB, Thomsen TR, Alhede M, Kragh KN, Nielsen PH, Johansen UR, Givskov M, Høiby N, Bjarnsholt T. The microorganisms in chronically infected end-stage and non-end-stage cystic fibrosis patients. ACTA ACUST UNITED AC 2012; 65:236-44. [DOI: 10.1111/j.1574-695x.2011.00925.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 12/12/2011] [Accepted: 12/13/2011] [Indexed: 12/31/2022]
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Ajoene, a sulfur-rich molecule from garlic, inhibits genes controlled by quorum sensing. Antimicrob Agents Chemother 2012; 56:2314-25. [PMID: 22314537 DOI: 10.1128/aac.05919-11] [Citation(s) in RCA: 271] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
In relation to emerging multiresistant bacteria, development of antimicrobials and new treatment strategies of infections should be expected to become a high-priority research area. Quorum sensing (QS), a communication system used by pathogenic bacteria like Pseudomonas aeruginosa to synchronize the expression of specific genes involved in pathogenicity, is a possible drug target. Previous in vitro and in vivo studies revealed a significant inhibition of P. aeruginosa QS by crude garlic extract. By bioassay-guided fractionation of garlic extracts, we determined the primary QS inhibitor present in garlic to be ajoene, a sulfur-containing compound with potential as an antipathogenic drug. By comprehensive in vitro and in vivo studies, the effect of synthetic ajoene toward P. aeruginosa was elucidated. DNA microarray studies of ajoene-treated P. aeruginosa cultures revealed a concentration-dependent attenuation of a few but central QS-controlled virulence factors, including rhamnolipid. Furthermore, ajoene treatment of in vitro biofilms demonstrated a clear synergistic, antimicrobial effect with tobramycin on biofilm killing and a cease in lytic necrosis of polymorphonuclear leukocytes. Furthermore, in a mouse model of pulmonary infection, a significant clearing of infecting P. aeruginosa was detected in ajoene-treated mice compared to a nontreated control group. This study adds to the list of examples demonstrating the potential of QS-interfering compounds in the treatment of bacterial infections.
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Alipour M, Dorval C, Suntres ZE, Omri A. Bismuth-ethanedithiol incorporated in a liposome-loaded tobramycin formulation modulates the alginate levels in mucoid Pseudomonas aeruginosa. ACTA ACUST UNITED AC 2011; 63:999-1007. [PMID: 21718282 DOI: 10.1111/j.2042-7158.2011.01304.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVES This study examined the antibacterial activity, alginate modulation, and deposition of a tobramycin bismuth-ethanedithiol (Tob-Bi) conventional (free) or vesicle-entrapped (lipo) formulation against two mucoid Pseudomonas aeruginosa clinical isolates. METHODS The inhibitory, bactericidal and biofilm eradication concentrations (in presence or absence of alginate lyase) were determined. The modulation of alginate was assessed by the carbazole assay and fluorescent-labelling of live alginate-producing biofilms by confocal microscopy. The deposition of the formulations was assessed using the immunogold-labelling technique, transmission electron microscopy, and energy dispersive X-ray spectroscopy (EDS). KEY FINDINGS The inhibitory and bactericidal concentrations for lipo Tob-Bi compared with free Tob-Bi were reduced in all strains by 2- to 8-fold, and 2- to 32-fold, respectively. The biofilm eradication concentrations for lipo Tob-Bi compared with free Tob-Bi were reduced by 4- to 32-fold in the mucoid strains. The addition of alginate lyase transiently enhanced eradication for one mucoid strain only. The alginate levels were attenuated by more than half, and free Tob-Bi fared better than lipo Tob-Bi determined by the carbazole assay. Under confocal microscopy, alginate lyase reduced alginate levels and detached mucoid biofilms. Free and lipo Tob-Bi did not detach the bacteria from the surface, but attenuated alginate levels. Tobramycin was detected by immunogold-labelling inside the bacterium, but EDS did not detect bismuth deposits. CONCLUSIONS These findings substantiate a role in which tobramycin, bismuth, and alginate lyase play in eradicating mucoid P. aeruginosa growth and modulate alginate levels.
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Affiliation(s)
- Misagh Alipour
- Department of Biomolecular Sciences, Laurentian University, Sudbury Medical Sciences Division, Sudbury, Ontario, Canada
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Mouse models of cystic fibrosis: Phenotypic analysis and research applications. J Cyst Fibros 2011; 10 Suppl 2:S152-71. [DOI: 10.1016/s1569-1993(11)60020-9] [Citation(s) in RCA: 167] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Høiby N, Ciofu O, Bjarnsholt T. Pseudomonas aeruginosa biofilms in cystic fibrosis. Future Microbiol 2011; 5:1663-74. [PMID: 21133688 DOI: 10.2217/fmb.10.125] [Citation(s) in RCA: 437] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The persistence of chronic Pseudomonas aeruginosa lung infections in cystic fibrosis (CF) patients is due to biofilm-growing mucoid (alginate-producing) strains. A biofilm is a structured consortium of bacteria, embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. In CF lungs, the polysaccharide alginate is the major part of the P. aeruginosa biofilm matrix. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and resist phagocytosis, as well as other components of the innate and the adaptive immune system. As a consequence, a pronounced antibody response develops, leading to immune complex-mediated chronic inflammation, dominated by polymorphonuclear leukocytes. The chronic inflammation is the major cause of the lung tissue damage in CF. Biofilm growth in CF lungs is associated with an increased frequency of mutations, slow growth and adaptation of the bacteria to the conditions in the lungs, and to antibiotic therapy. Low bacterial metabolic activity and increase of doubling times of the bacterial cells in CF lungs are responsible for some of the tolerance to antibiotics. Conventional resistance mechanisms, such as chromosomal β-lactamase, upregulated efflux pumps, and mutations of antibiotic target molecules in the bacteria, also contribute to the survival of P. aeruginosa biofilms. Biofilms can be prevented by early aggressive antibiotic prophylaxis or therapy, and they can be treated by chronic suppressive therapy.
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Affiliation(s)
- Niels Høiby
- Department of Clinical Microbiology 9301, Rigshospitalet, University of Copenhagen, Juliane Maries Vej 22, Copenhagen, Denmark.
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Lee B, Schjerling CK, Kirkby N, Hoffmann N, Borup R, Molin S, Høiby N, Ciofu O. Mucoid Pseudomonas aeruginosa isolates maintain the biofilm formation capacity and the gene expression profiles during the chronic lung infection of CF patients. APMIS 2011; 119:263-74. [PMID: 21492226 DOI: 10.1111/j.1600-0463.2011.02726.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Phenotypic and genotypic diversifications of Pseudomonas aeruginosa in the airways of patients with cystic fibrosis (CF) promote long-term survival of bacteria during chronic lung infection. Twelve clonally related, sequential mucoid and non-mucoid paired P. aeruginosa isolates obtained from three Danish CF patients were investigated. The in vitro biofilm formation capacity was studied under static and flow through conditions and the global gene expression profiles were investigated by Affymetrix GeneChip. Regulatory genes of alginate production and quorum sensing (QS) system were sequenced and measurements of the alginate production and the detection of the QS signal molecules were performed. Comparisons of mucoid and non-mucoid isolates from early and late stages of the infection showed that the mucoid phenotype maintained over a decade the capacity to form in vitro biofilm and showed an unaltered transcriptional profile, whereas substantial alterations in the transcriptional profiles and loss of the capacity to form in vitro biofilms were observed in corresponding isolates of the non-mucoid phenotype. The conserved gene expression pattern in the mucoid isolates vs the diversity of changes in non-mucoid isolates observed in this particular P. aeruginosa clone reflects different adaptation strategies used by these two phenotypes in the different niches of the CF lung environment.
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Affiliation(s)
- Baoleri Lee
- Department of International Health, Immunology and Microbiology, Panum Institute, University of Copenhagen, Denmark
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Bjarnsholt T, Jensen PØ, Jakobsen TH, Phipps R, Nielsen AK, Rybtke MT, Tolker-Nielsen T, Givskov M, Høiby N, Ciofu O. Quorum sensing and virulence of Pseudomonas aeruginosa during lung infection of cystic fibrosis patients. PLoS One 2010; 5:e10115. [PMID: 20404933 PMCID: PMC2853559 DOI: 10.1371/journal.pone.0010115] [Citation(s) in RCA: 187] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Accepted: 03/09/2010] [Indexed: 12/13/2022] Open
Abstract
Pseudomonas aeruginosa is the predominant microorganism in chronic lung infection of cystic fibrosis patients. The chronic lung infection is preceded by intermittent colonization. When the chronic infection becomes established, it is well accepted that the isolated strains differ phenotypically from the intermittent strains. Dominating changes are the switch to mucoidity (alginate overproduction) and loss of epigenetic regulation of virulence such as the Quorum Sensing (QS). To elucidate the dynamics of P. aeruginosa QS systems during long term infection of the CF lung, we have investigated 238 isolates obtained from 152 CF patients at different stages of infection ranging from intermittent to late chronic. Isolates were characterized with regard to QS signal molecules, alginate, rhamnolipid and elastase production and mutant frequency. The genetic basis for change in QS regulation were investigated and identified by sequence analysis of lasR, rhlR, lasI and rhlI. The first QS system to be lost was the one encoded by las system 12 years (median value) after the onset of the lung infection with subsequent loss of the rhl encoded system after 17 years (median value) shown as deficiencies in production of the 3-oxo-C12-HSL and C4-HSL QS signal molecules respectively. The concomitant development of QS malfunction significantly correlated with the reduced production of rhamnolipids and elastase and with the occurrence of mutations in the regulatory genes lasR and rhlR. Accumulation of mutations in both lasR and rhlR correlated with development of hypermutability. Interestingly, a higher number of mucoid isolates were found to produce C4-HSL signal molecules and rhamnolipids compared to the non-mucoid isolates. As seen from the present data, we can conclude that P. aeruginosa and particularly the mucoid strains do not lose the QS regulation or the ability to produce rhamnolipids until the late stage of the chronic infection.
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Affiliation(s)
- Thomas Bjarnsholt
- Institute for International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Peter Østrup Jensen
- Department of Clinical Microbiology, University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Tim Holm Jakobsen
- Institute for International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Richard Phipps
- BioSys, Technical University of Denmark, Lyngby, Denmark
| | - Anne Kirstine Nielsen
- Institute for International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Morten Theil Rybtke
- Institute for International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Institute for International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Michael Givskov
- Institute for International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Niels Høiby
- Institute for International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Microbiology, University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Oana Ciofu
- Institute for International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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Pseudomonas aeruginosa alginate promotes Burkholderia cenocepacia persistence in cystic fibrosis transmembrane conductance regulator knockout mice. Infect Immun 2010; 78:984-93. [PMID: 20048042 DOI: 10.1128/iai.01192-09] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa, a major respiratory pathogen in cystic fibrosis (CF) patients, facilitates infection by other opportunistic pathogens. Burkholderia cenocepacia, which normally infects adolescent patients, encounters alginate elaborated by mucoid P. aeruginosa. To determine whether P. aeruginosa alginate facilitates B. cenocepacia infection in mice, cystic fibrosis transmembrane conductance regulator knockout mice were infected with B. cenocepacia strain BC7 suspended in either phosphate-buffered saline (BC7/PBS) or P. aeruginosa alginate (BC7/alginate), and the pulmonary bacterial load and inflammation were monitored. Mice infected with BC7/PBS cleared all of the bacteria within 3 days, and inflammation was resolved by day 5. In contrast, mice infected with BC7/alginate showed persistence of bacteria and increased cytokine levels for up to 7 days. Histological examination of the lungs indicated that there was moderate to severe inflammation and pneumonic consolidation in isolated areas at 5 and 7 days postinfection in the BC7/alginate group. Further, alginate decreased phagocytosis of B. cenocepacia by professional phagocytes both in vivo and in vitro. P. aeruginosa alginate also reduced the proinflammatory responses of CF airway epithelial cells and alveolar macrophages to B. cenocepacia infection. The observed effects are specific to P. aeruginosa alginate, because enzymatically degraded alginate or other polyuronic acids did not facilitate bacterial persistence. These observations suggest that P. aeruginosa alginate may facilitate B. cenocepacia infection by interfering with host innate defense mechanisms.
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Current World Literature. Curr Opin Pulm Med 2009; 15:638-44. [DOI: 10.1097/mcp.0b013e3283328a80] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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van Gennip M, Moser C, Christensen LD, Bjarnsholt T, Calum H, Jensen PO, Christophersen L, Hougen HP, Ciofu O, Molin S, Givskov M, Hoiby N. Augmented effect of early antibiotic treatment in mice with experimental lung infections due to sequentially adapted mucoid strains of Pseudomonas aeruginosa. J Antimicrob Chemother 2009; 64:1241-50. [DOI: 10.1093/jac/dkp352] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Noreddin AM, Elkhatib WF. Novel in vitro pharmacodynamic model simulating ofloxacin pharmacokinetics in the treatment of Pseudomonas aeruginosa biofilm-associated infections. J Infect Public Health 2009; 2:120-8. [PMID: 20701871 DOI: 10.1016/j.jiph.2009.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Revised: 07/26/2009] [Accepted: 07/30/2009] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES The conventional in vitro models simulate pharmacodynamics of antibiotics in the treatment of planktonic Pseudomonas aeruginosa. In this study, we propose a novel pharmacodynamic model of ofloxacin activity in the treatment of P. aeruginosa biofilm. METHODS P. aeruginosa biofilm carrying coupons were suspended in a continuous flow central compartment bioreactor (CCB). In the CCB, the pharmacokinetics of different ofloxacin dosing regimens were simulated. Samples from the coupons and the CCB were assessed for viability of the biofilm and the shedding planktonic cells, respectively, over 24h. In addition, ofloxacin concentrations were assessed in each sample withdrawn for the CCB using bioassay method. RESULTS The microbiological outcomes on P. aeruginosa biofilm and the shedding planktonic cells in response to different ofloxacin dosing regimens were not parallel and this may explain the non-coincidence of microbiological and clinical outcomes with biofilm associated infections. CONCLUSION The current study has introduced unprecedented novel dynamic model for the assessment of the microbiological outcome on both biofilm and shedding planktonic cells of P. aeruginosa in response to different dosing regimens of ofloxacin which in turn can simulate the clinical outcomes in biofilm associated infections of P. aeruginosa, e.g. cystic fibrosis. Furthermore, different scenarios of antibiotic dosing regimens against biofilm related infections can be mimicked using such model.
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