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Kaur M, Mozaheb N, Paiva TO, Herent MF, Goormaghtigh F, Paquot A, Terrasi R, Mignolet E, Décout JL, Lorent JH, Larondelle Y, Muccioli GG, Quetin-Leclercq J, Dufrêne YF, Mingeot-Leclercq MP. Insight into the outer membrane asymmetry of P. aeruginosa and the role of MlaA in modulating the lipidic composition, mechanical, biophysical, and functional membrane properties of the cell envelope. Microbiol Spectr 2024; 12:e0148424. [PMID: 39373473 PMCID: PMC11537012 DOI: 10.1128/spectrum.01484-24] [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: 07/10/2024] [Accepted: 08/14/2024] [Indexed: 10/08/2024] Open
Abstract
In Gram-negative bacteria, the outer membrane (OM) is asymmetric, with lipopolysaccharides (LPS) in the outer leaflet and glycerophospholipids (GPLs) in the inner leaflet. The asymmetry is maintained by the Mla system (MlaA-MlaBCDEF), which contributes to lipid homeostasis by removing mislocalized GPLs from the outer leaflet of the OM. Here, we ascribed how Pseudomonas aeruginosa ATCC 27853 coordinately regulates pathways to provide defense against the threats posed by the deletion of mlaA. Especially, we explored (i) the effects on membrane lipid composition including LPS, GPLs, and lysophospholipids, (ii) the biophysical properties of the OM such as stiffness and fluidity, and (iii) the impact of these changes on permeability, antibiotic susceptibility, and membrane vesicles (MVs) generation. Deletion of mlaA induced an increase in total GPLs and a decrease in LPS level while also triggering alterations in lipid A structures (arabinosylation and palmitoylation), likely to be induced by a two-component system (PhoPQ-PmrAB). Altered lipid composition may serve a physiological purpose in regulating the mechanobiological and functional properties of P. aeruginosa. We demonstrated an increase in cell stiffness without alteration of turgor pressure and inner membrane (IM) fluidity in ∆mlaA. In addition, membrane vesiculation increased without any change in OM/IM permeability. An amphiphilic aminoglycoside derivative (3',6-dinonyl neamine) that targets P. aeruginosa membranes induced an opposite effect on ∆mlaA strain with a trend toward a return to the situation observed for the WT strain. Efforts dedicated to understanding the crosstalk between the OM lipid composition, and the mechanical behavior of bacterial envelope, is one needed step for designing new targets or new drugs to fight P. aeruginosa infections.IMPORTANCEPseudomonas aeruginosa is a Gram-negative bacterium responsible for severe hospital-acquired infections. The outer membrane (OM) of Gram-negative bacteria acts as an effective barrier against toxic compounds, and therefore, compromising this structure could increase sensitivity to antibiotics. The OM is asymmetric with the highly packed lipopolysaccharide monolayer at the outer leaflet and glycerophospholipids at the inner leaflet. OM asymmetry is maintained by the Mla pathway resulting in the retrograde transport of glycerophospholipids from the OM to the inner membrane. In this study, we show that deleting mlaA, the membrane component of Mla system located at the OM, affects the mechanical and functional properties of P. aeruginosa cell envelope. Our results provide insights into the role of MlaA, involved in the Mla transport pathway in P. aeruginosa.
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Affiliation(s)
- M. Kaur
- UCLouvain, Louvain Drug Research Institute, Cellular & Molecular Pharmacology, Brussels, Belgium
| | - N. Mozaheb
- UCLouvain, Louvain Drug Research Institute, Cellular & Molecular Pharmacology, Brussels, Belgium
| | - T. O. Paiva
- UCLouvain, Louvain Institute of Biomolecular Science and Technology, nanoBiophysics, Louvain-la-Neuve, Belgium
| | - M.-F. Herent
- UCLouvain, Louvain Drug Research Institute, Pharmacognosy, Brussels, Belgium
| | - F. Goormaghtigh
- UCLouvain, Louvain Drug Research Institute, Cellular & Molecular Pharmacology, Brussels, Belgium
| | - A. Paquot
- UCLouvain, Louvain Drug Research Institute, Bioanalysis and Pharmacology of Bioactive Lipids, Brussels, Belgium
| | - R. Terrasi
- UCLouvain, Louvain Drug Research Institute, Bioanalysis and Pharmacology of Bioactive Lipids, Brussels, Belgium
| | - E. Mignolet
- UCLouvain, Louvain Institute of Biomolecular Science and Technology, Biochemistry of Nutrition and Environmental Toxicology Louvain-la-Neuve, Brussels, Belgium
| | - J.-L. Décout
- Université Grenoble Alpes, CNRS, DPM, Grenoble, France
| | - J. H. Lorent
- UCLouvain, Louvain Drug Research Institute, Cellular & Molecular Pharmacology, Brussels, Belgium
| | - Y. Larondelle
- UCLouvain, Louvain Institute of Biomolecular Science and Technology, Biochemistry of Nutrition and Environmental Toxicology Louvain-la-Neuve, Brussels, Belgium
| | - G. G. Muccioli
- UCLouvain, Louvain Drug Research Institute, Bioanalysis and Pharmacology of Bioactive Lipids, Brussels, Belgium
| | - J. Quetin-Leclercq
- UCLouvain, Louvain Drug Research Institute, Pharmacognosy, Brussels, Belgium
| | - Y. F. Dufrêne
- UCLouvain, Louvain Institute of Biomolecular Science and Technology, nanoBiophysics, Louvain-la-Neuve, Belgium
| | - M.-P. Mingeot-Leclercq
- UCLouvain, Louvain Drug Research Institute, Cellular & Molecular Pharmacology, Brussels, Belgium
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Wang Z, Vanbever R, Lorent JH, Solis J, Knoop C, Van Bambeke F. Repurposing DNase I and alginate lyase to degrade the biofilm matrix of dual-species biofilms of Staphylococcus aureus and Pseudomonas aeruginosa grown in artificial sputum medium: In-vitro assessment of their activity in combination with broad-spectrum antibiotics. J Cyst Fibros 2024; 23:1146-1152. [PMID: 38402083 DOI: 10.1016/j.jcf.2024.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/16/2024] [Accepted: 02/20/2024] [Indexed: 02/26/2024]
Abstract
BACKGROUND Biofilm-associated pulmonary infections pose therapeutic challenges in cystic fibrosis patients, especially when involving multiple bacterial species. Enzymatic degradation of the biofilm matrix may offer a potential solution to enhance antibiotic efficacy. This study investigated the repurposing of DNase I, commonly used for its mucolytic activity in cystic fibrosis, to target extracellular DNA within biofilms, as well as potential synergies with alginate lyase and broad-spectrum antibiotics in dual-species biofilms of Pseudomonas aeruginosa and Staphylococcus aureus. METHODS Dual-species biofilms were grown in artificial sputum medium using S. aureus and P. aeruginosa isolated by pairs from the same patients and exposed to various combinations of enzymes, meropenem, or tobramycin. Activity was assessed by measuring biofilm biomass and viable counts. Matrix degradation and decrease in bacterial load were visualized using confocal microscopy. Biofilm viscoelasticity was estimated by rheology. RESULTS Nearly complete destruction of the biofilms was achieved only if combining the enzymatic cocktail with the two antibiotics, and if using supratherapeutic levels of DNase I and high concentrations of alginate lyase. Biofilms containing non-pigmented mucoid P. aeruginosa required higher antibiotic concentrations, despite low viscoelasticity. In contrast, for biofilms with pigmented mucoid P. aeruginosa, a correlation was observed between the efficacy of different treatments and the reduction they caused in elasticity and viscosity of the biofilm. CONCLUSIONS In this complex, highly drug-tolerant biofilm model, enzymes prove useful adjuvants to enhance antibiotic activity. However, the necessity for high enzyme concentrations emphasizes the need for thorough concentration-response evaluations and safety assessments before considering clinical applications.
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Affiliation(s)
- Zhifen Wang
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Rita Vanbever
- Advanced Drug Delivery and Biomaterials, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Joseph H Lorent
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Jessica Solis
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Christiane Knoop
- Erasme Hospital, Université libre de Bruxelles, Brussels, Belgium
| | - Françoise Van Bambeke
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
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3
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Wang Z, De Soir S, Glorieux A, Merabishvili M, Knoop C, De Vos D, Pirnay JP, Van Bambeke F. Bacteriophages as potential antibiotic potentiators in cystic fibrosis: A new model to study the combination of antibiotics with a bacteriophage cocktail targeting dual species biofilms of Staphylococcus aureus and Pseudomonas aeruginosa. Int J Antimicrob Agents 2024; 64:107276. [PMID: 39009289 DOI: 10.1016/j.ijantimicag.2024.107276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 06/17/2024] [Accepted: 07/10/2024] [Indexed: 07/17/2024]
Abstract
OBJECTIVES Staphylococcus aureus and Pseudomonas aeruginosa co-infections in patients with cystic fibrosis (CF) are associated with disease severity. Their treatment is complicated by biofilm formation in the sticky mucus obstructing the airways. We investigated the activity of phages-antibiotics combinations using a dual species biofilm (P. aeruginosa/S. aureus) formed in artificial sputum medium. METHODS Biofilmswere incubated with broad-spectrum antibiotics (meropenem, ceftazidime, ciprofloxacin, tobramycin) combined with a cocktail of two (bacterio)phages (PSP3 and ISP) proven active via spot tests and double agar on P. aeruginosa PAO1 and S. aureus ATCC 25923. RESULTS At the highest tested concentrations (100 x MIC), antibiotics alone caused a 20-50% reduction in biomass and reduced S. aureus and P. aeruginosa CFU of 2.3 to 2.8 and 2.1 to 3.6 log10, respectively. Phages alone reduced biofilm biomass by 23% and reduced P. aeruginosa CFU of 2.1 log10, but did not affect S. aureus viability. Phages enhanced antibiotic effects on biomass and exhibited additive effects with antibiotics against P. aeruginosa, but not against S. aureus. Following inhibition of bacterial respiration by phages in planktonic cultures rationalised these observations by demonstrating that PSP3 was effective at multiplicities of infection (MOI) as low as 10-4 plaque forming units (PFU)/CFU on P. aeruginosa, but ISP, at higher MOI (> 0.1) against S. aureus. CONCLUSION Pre-screening inhibition of bacterial respiration by phages may assist in selecting those showing activity at sufficiently low titers to showcase anti-biofilm activity in this complex but clinically-relevant in vitro model of biofilm.
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Affiliation(s)
- Zhifen Wang
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Steven De Soir
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium; Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Neder-over-Heembeek, Belgium
| | - Antoine Glorieux
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium; Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Neder-over-Heembeek, Belgium
| | - Maya Merabishvili
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Neder-over-Heembeek, Belgium
| | - Christiane Knoop
- Erasme Hospital, Université libre de Bruxelles, Brussels, Belgium
| | - Daniel De Vos
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Neder-over-Heembeek, Belgium
| | - Jean-Paul Pirnay
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Neder-over-Heembeek, Belgium
| | - Françoise Van Bambeke
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
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Trognon J, Rima M, Lajoie B, Roques C, El Garah F. NaCl-induced modulation of species distribution in a mixed P. aeruginosa / S. aureus / B.cepacia biofilm. Biofilm 2023; 6:100153. [PMID: 37711514 PMCID: PMC10497989 DOI: 10.1016/j.bioflm.2023.100153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/16/2023] Open
Abstract
Pseudomonas aeruginosa, Staphylococcus aureus, and Burkholderia cepacia are notorious pathogens known for their ability to form resilient biofilms, particularly within the lung environment of cystic fibrosis (CF) patients. The heightened concentration of NaCl, prevalent in the airway liquid of CF patients' lungs, has been identified as a factor that promotes the growth of osmotolerant bacteria like S. aureus and dampens host antibacterial defenses, thereby fostering favorable conditions for infections. In this study, we aimed to investigate how increased NaCl concentrations impact the development of multi-species biofilms in vitro, using both laboratory strains and clinical isolates of P. aeruginosa, S. aureus, and B. cepacia co-cultures. Employing a low-nutrient culture medium that fosters biofilm growth of the selected species, we quantified biofilm formation through a combination of adherent CFU counts, qPCR analysis, and confocal microscopy observations. Our findings reaffirmed the challenges faced by S. aureus in establishing growth within 1:1 mixed biofilms with P. aeruginosa when cultivated in a minimal medium. Intriguingly, at an elevated NaCl concentration of 145 mM, a symbiotic relationship emerged between S. aureus and P. aeruginosa, enabling their co-existence. Notably, this hyperosmotic environment also exerted an influence on the interplay of these two bacteria with B. cepacia. We demonstrated that elevated NaCl concentrations play a pivotal role in orchestrating the distribution of these three species within the biofilm matrix. Furthermore, our study unveiled the beneficial impact of NaCl on the biofilm growth of clinically relevant mucoid P. aeruginosa strains, as well as two strains of methicillin-sensitive and methicillin-resistant S. aureus. This underscores the crucial role of the microenvironment during the colonization and infection processes. The results suggest that hyperosmotic conditions could hold the key to unlocking a deeper understanding of the genesis and behavior of CF multi-species biofilms.
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Affiliation(s)
- Jeanne Trognon
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | - Maya Rima
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | - Barbora Lajoie
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| | - Christine Roques
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
- CHU Toulouse, Hôpital Purpan, Service de Bactériologie Hygiène, Toulouse, France
| | - Fatima El Garah
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
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Youf R, Ghanem R, Nasir A, Lemercier G, Montier T, Le Gall T. Impact of mucus and biofilm on antimicrobial photodynamic therapy: Evaluation using Ruthenium(II) complexes. Biofilm 2023; 5:100113. [PMID: 37396462 PMCID: PMC10313506 DOI: 10.1016/j.bioflm.2023.100113] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/17/2023] [Accepted: 03/19/2023] [Indexed: 07/04/2023] Open
Abstract
The biofilm lifestyle of bacterial pathogens is a hallmark of chronic lung infections such as in cystic fibrosis (CF) patients. Bacterial adaptation to the complex conditions in CF-affected lungs and repeated antibiotherapies lead to increasingly tolerant and hard-to-treat biofilms. In the context of growing antimicrobial resistance and restricted therapeutic options, antimicrobial photodynamic therapy (aPDT) shows great promise as an alternative to conventional antimicrobial modalities. Typically, aPDT consists in irradiating a non-toxic photosensitizer (PS) to generate reactive oxygen species (ROS), which kill pathogens in the surrounding environment. In a previous study, we reported that some ruthenium (II) complexes ([Ru(II)]) can mediate potent photodynamic inactivation (PDI) against planktonic cultures of Pseudomonas aeruginosa and Staphylococcus aureus clinical isolates. In the present work, [Ru(II)] were further assayed to evaluate their ability to photo-inactivate such bacteria under more complex experimental conditions better recapitulating the microenvironment in lung infected airways. Bacterial PDI was tentatively correlated with the properties of [Ru(II)] in biofilms, in mucus, and following diffusion across the latter. Altogether, the results obtained demonstrate the negative impacting role of mucus and biofilm components on [Ru(II)]-mediated PDT, following different possible mechanisms of action. Technical limitations were also identified that may be overcome, making this report a pilot for other similar studies. In conclusion, [Ru(II)] may be subjected to specific chemical engineering and/or drug formulation to adapt their properties to the harsh micro-environmental conditions of the infected respiratory tract.
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Affiliation(s)
- Raphaëlle Youf
- Inserm, Univ Brest, EFS, UMR 1078, GGB, F-29200, Brest, France
| | - Rosy Ghanem
- Inserm, Univ Brest, EFS, UMR 1078, GGB, F-29200, Brest, France
- CHU de Brest, Service de Génétique Médicale et de Biologie de la Reproduction, 29200, Brest, France
| | - Adeel Nasir
- Inserm, Univ Brest, EFS, UMR 1078, GGB, F-29200, Brest, France
| | - Gilles Lemercier
- Université de Reims Champagne-Ardenne, UMR CNRS 7312, BP 1039, CEDEX 2, 51687, Reims, France
| | - Tristan Montier
- Inserm, Univ Brest, EFS, UMR 1078, GGB, F-29200, Brest, France
- CHU de Brest, Service de Génétique Médicale et de Biologie de la Reproduction, 29200, Brest, France
- CHU de Brest, Centre de Référence des Maladies Rares Maladies Neuromusculaires, 29200, Brest, France
| | - Tony Le Gall
- Inserm, Univ Brest, EFS, UMR 1078, GGB, F-29200, Brest, France
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Di Bonaventura G, Lupetti V, Di Giulio A, Muzzi M, Piccirilli A, Cariani L, Pompilio A. Repurposing High-Throughput Screening Identifies Unconventional Drugs with Antibacterial and Antibiofilm Activities against Pseudomonas aeruginosa under Experimental Conditions Relevant to Cystic Fibrosis. Microbiol Spectr 2023; 11:e0035223. [PMID: 37306577 PMCID: PMC10433973 DOI: 10.1128/spectrum.00352-23] [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: 01/22/2023] [Accepted: 05/13/2023] [Indexed: 06/13/2023] Open
Abstract
Pseudomonas aeruginosa is the most common pathogen infecting cystic fibrosis (CF) lungs, causing acute and chronic infections. Intrinsic and acquired antibiotic resistance allow P. aeruginosa to colonize and persist despite antibiotic treatment, making new therapeutic approaches necessary. Combining high-throughput screening and drug repurposing is an effective way to develop new therapeutic uses for drugs. This study screened a drug library of 3,386 drugs, mostly FDA approved, to identify antimicrobials against P. aeruginosa under physicochemical conditions relevant to CF-infected lungs. Based on the antibacterial activity, assessed spectrophotometrically against the prototype RP73 strain and 10 other CF virulent strains, and the toxic potential evaluated toward CF IB3-1 bronchial epithelial cells, five potential hits were selected for further analysis: the anti-inflammatory and antioxidant ebselen, the anticancer drugs tirapazamine, carmofur, and 5-fluorouracil, and the antifungal tavaborole. A time-kill assay showed that ebselen has the potential to cause rapid and dose-dependent bactericidal activity. The antibiofilm activity was evaluated by viable cell count and crystal violet assays, revealing carmofur and 5-fluorouracil as the most active drugs in preventing biofilm formation regardless of the concentration. In contrast, tirapazamine and tavaborole were the only drugs actively dispersing preformed biofilms. Tavaborole was the most active drug against CF pathogens other than P. aeruginosa, especially against Burkholderia cepacia and Acinetobacter baumannii, while carmofur, ebselen, and tirapazamine were particularly active against Staphylococcus aureus and B. cepacia. Electron microscopy and propidium iodide uptake assay revealed that ebselen, carmofur, and tirapazamine significantly damage cell membranes, with leakage and cytoplasm loss, by increasing membrane permeability. IMPORTANCE Antibiotic resistance makes it urgent to design new strategies for treating pulmonary infections in CF patients. The repurposing approach accelerates drug discovery and development, as the drugs' general pharmacological, pharmacokinetic, and toxicological properties are already well known. In the present study, for the first time, a high-throughput compound library screening was performed under experimental conditions relevant to CF-infected lungs. Among 3,386 drugs screened, the clinically used drugs from outside infection treatment ebselen, tirapazamine, carmofur, 5-fluorouracil, and tavaborole showed, although to different extents, anti-P. aeruginosa activity against planktonic and biofilm cells and broad-spectrum activity against other CF pathogens at concentrations not toxic to bronchial epithelial cells. The mode-of-action studies revealed ebselen, carmofur, and tirapazamine targeted the cell membrane, increasing its permeability with subsequent cell lysis. These drugs are strong candidates for repurposing for treating CF lung P. aeruginosa infections.
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Affiliation(s)
- Giovanni Di Bonaventura
- Department of Medical, Oral, and Biotechnological Sciences, G. d’Annunzio University of Chieti-Pescara, Chieti, Italy
- Center for Advanced Studies and Technology, G. d’Annunzio University of Chieti-Pescara, Chieti, Italy
| | - Veronica Lupetti
- Department of Medical, Oral, and Biotechnological Sciences, G. d’Annunzio University of Chieti-Pescara, Chieti, Italy
- Center for Advanced Studies and Technology, G. d’Annunzio University of Chieti-Pescara, Chieti, Italy
| | | | | | - Alessandra Piccirilli
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L’Aquila, Italy
| | - Lisa Cariani
- Microbiology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Arianna Pompilio
- Department of Medical, Oral, and Biotechnological Sciences, G. d’Annunzio University of Chieti-Pescara, Chieti, Italy
- Center for Advanced Studies and Technology, G. d’Annunzio University of Chieti-Pescara, Chieti, Italy
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7
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De Bleeckere A, Van den Bossche S, De Sutter PJ, Beirens T, Crabbé A, Coenye T. High throughput determination of the biofilm prevention concentration for Pseudomonas aeruginosa biofilms using a synthetic cystic fibrosis sputum medium. Biofilm 2023; 5:100106. [PMID: 36845825 PMCID: PMC9945637 DOI: 10.1016/j.bioflm.2023.100106] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 01/17/2023] [Accepted: 02/04/2023] [Indexed: 02/09/2023] Open
Abstract
The presence of Pseudomonas aeruginosa biofilms in cystic fibrosis (CF) patients suffering from chronic lung infections contributes to the failure of antimicrobial therapy. Conventionally, the minimal inhibitory concentration (MIC) is determined to assess the antimicrobial susceptibility of a pathogen, however this parameter fails to predict success in treating biofilm-associated infections. In the present study we developed a high throughput method to determine the antimicrobial concentration required to prevent P. aeruginosa biofilm formation, using a synthetic cystic fibrosis sputum medium (SCFM2). Biofilms were grown in SCFM2 for 24 h in the presence of antibiotics (tobramycin, ciprofloxacin or colistin), whereafter biofilms were disrupted and a resazurin staining was used to quantify the number of surviving metabolically active cells. In parallel, the content of all wells was plated to determine the number of colony forming units (CFU). Biofilm preventing concentrations (BPCs) were compared to MICs and minimal bactericidal concentrations (MBCs) determined according to EUCAST guidelines. Correlations between the resazurin-derived fluorescence and CFU counts were assessed with Kendall's Tau Rank tests. A significant correlation between fluorescence and CFU counts was observed for 9 out of 10 strains investigated, suggesting the fluorometric assay is a reliable alternative to plating for most P. aeruginosa isolates to determine biofilm susceptibility in relevant conditions. For all isolates a clear difference between MICs and BPCs of all three antibiotics was observed, with the BPCs being consistently higher than the MICs. Additionally, the extent of this difference appeared to be antibiotic-dependent. Our findings suggest that this high throughput assay could be a valuable addition to evaluate the antimicrobial susceptibility in P. aeruginosa biofilms in the context of CF.
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Affiliation(s)
- Amber De Bleeckere
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | | | - Pieter-Jan De Sutter
- Laboratory of Medical Biochemistry and Clinical Analysis, Ghent University, Ghent, Belgium
| | - Tine Beirens
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Aurélie Crabbé
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium,Corresponding author.
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8
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Lethongkam S, Sunghan J, Wangdee C, Durongphongtorn S, Siri R, Wunnoo S, Paosen S, Voravuthikunchai SP, Dejyong K, Daengngam C. Biogenic nanosilver-fabricated endotracheal tube to prevent microbial colonization in a veterinary hospital. Appl Microbiol Biotechnol 2023; 107:623-638. [PMID: 36562803 PMCID: PMC9780629 DOI: 10.1007/s00253-022-12327-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 10/29/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022]
Abstract
COVID-19 patients have often required prolonged endotracheal intubation, increasing the risk of developing ventilator-associated pneumonia (VAP). A preventive strategy is proposed based on an endotracheal tube (ETT) modified by the in situ deposition of eucalyptus-mediated synthesized silver nanoparticles (AgNPs). The surfaces of the modified ETT were embedded with AgNPs of approximately 28 nm and presented a nanoscale roughness. Energy dispersive X-ray spectroscopy confirmed the presence of silver on and inside the coated ETT, which exhibited excellent antimicrobial activity against Gram-positive and Gram-negative bacteria, and fungi, including multidrug-resistant clinical isolates. Inhibition of planktonic growth and microbial adhesion ranged from 99 to 99.999% without cytotoxic effects on mammalian cells. Kinetic studies showed that microbial adhesion to the coated surface was inhibited within 2 h. Cell viability in biofilms supplemented with human tracheal mucus was reduced by up to 95%. In a porcine VAP model, the AgNPs-coated ETT prevented adhesion of Pseudomonas aeruginosa and completely inhibited bacterial invasion of lung tissue. The potential antimicrobial efficacy and safety of the coated ETT were established in a randomized control trial involving 47 veterinary patients. The microbial burden was significantly lower on the surface of the AgNPs-coated ETT than on the uncoated ETT (p < 0.05). KEY POINTS: • Endotracheal tube surfaces were modified by coating with green-synthesized AgNPs • P. aeruginosa burden of endotracheal tube and lung was reduced in a porcine model • Effective antimicrobial activity and safety was demonstrated in a clinical trial.
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Affiliation(s)
- Sakkarin Lethongkam
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
- Natural Product Research Center of Excellence, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
- Center of Antimicrobial Biomaterial Innovation-Southeast Asia, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Jutapoln Sunghan
- Faculty of Veterinary Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Chalika Wangdee
- Department of Veterinary Surgery, Faculty of Veterinary Science, Chulalongkorn University, Henri-dunant, Bangkok, 10330, Thailand
| | - Sumit Durongphongtorn
- Department of Veterinary Surgery, Faculty of Veterinary Science, Chulalongkorn University, Henri-dunant, Bangkok, 10330, Thailand
| | - Ratchaneewan Siri
- Division of Physical Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Suttiwan Wunnoo
- Center of Antimicrobial Biomaterial Innovation-Southeast Asia, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Supakit Paosen
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
- Natural Product Research Center of Excellence, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
- Center of Antimicrobial Biomaterial Innovation-Southeast Asia, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Supayang P Voravuthikunchai
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
- Natural Product Research Center of Excellence, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
- Center of Antimicrobial Biomaterial Innovation-Southeast Asia, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Krittee Dejyong
- Faculty of Veterinary Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand.
| | - Chalongrat Daengngam
- Division of Physical Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand.
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9
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Valzano F, Boncompagni SR, Micieli M, Di Maggio T, Di Pilato V, Colombini L, Santoro F, Pozzi G, Rossolini GM, Pallecchi L. Activity of N-Acetylcysteine Alone and in Combination with Colistin against Pseudomonas aeruginosa Biofilms and Transcriptomic Response to N-Acetylcysteine Exposure. Microbiol Spectr 2022; 10:e0100622. [PMID: 35735984 PMCID: PMC9431628 DOI: 10.1128/spectrum.01006-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 06/03/2022] [Indexed: 11/25/2022] Open
Abstract
Chronic colonization by Pseudomonas aeruginosa is critical in cystic fibrosis (CF) and other chronic lung diseases, contributing to disease progression. Biofilm growth and a propensity to evolve multidrug resistance phenotypes drastically limit the available therapeutic options. In this perspective, there has been growing interest in evaluating combination therapies, especially for drugs that can be administered by nebulization, which allows high drug concentrations to be reached at the site of infections while limiting systemic toxicity. Here, we investigated the potential antibiofilm activity of N-acetylcysteine (NAC) alone and in combination with colistin against a panel of P. aeruginosa strains (most of which are from CF patients) and the transcriptomic response of a P. aeruginosa CF strain to NAC exposure. NAC alone (8,000 mg/L) showed a limited and strain-dependent antibiofilm activity. Nonetheless, a relevant antibiofilm synergism of NAC-colistin combinations (NAC at 8,000 mg/L plus colistin at 2 to 32 mg/L) was observed with all strains. Synergism was also confirmed with the artificial sputum medium model. RNA sequencing of NAC-exposed planktonic cultures revealed that NAC (8,000 mg/L) mainly induced (i) a Zn2+ starvation response (known to induce attenuation of P. aeruginosa virulence), (ii) downregulation of genes of the denitrification apparatus, and (iii) downregulation of flagellar biosynthesis pathway. NAC-mediated inhibition of P. aeruginosa denitrification pathway and flagellum-mediated motility were confirmed experimentally. These findings suggested that NAC-colistin combinations might contribute to the management of biofilm-associated P. aeruginosa lung infections. NAC might also have a role in reducing P. aeruginosa virulence, which could be relevant in the very early stages of lung colonization. IMPORTANCE Pseudomonas aeruginosa biofilm-related chronic lung colonization contributes to cystic fibrosis (CF) disease progression. Colistin is often a last-resort antibiotic for the treatment of such P. aeruginosa infections, and it has been increasingly used in CF, especially by nebulization. N-acetylcysteine (NAC) is a mucolytic agent with antioxidant activity, commonly administered with antibiotics for the treatment of lower respiratory tract infections. Here, we show that NAC potentiated colistin activity against in vitro biofilms models of P. aeruginosa strains, with both drugs tested at the high concentrations achievable after nebulization. In addition, we report the first transcriptomic data on the P. aeruginosa response to NAC exposure.
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Affiliation(s)
- Felice Valzano
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | | | - Maria Micieli
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Tiziana Di Maggio
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Vincenzo Di Pilato
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy
| | - Lorenzo Colombini
- Laboratory of Molecular Microbiology and Biotechnology, Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Francesco Santoro
- Laboratory of Molecular Microbiology and Biotechnology, Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Gianni Pozzi
- Laboratory of Molecular Microbiology and Biotechnology, Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Gian Maria Rossolini
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
- Clinical Microbiology and Virology Unit, Careggi University Hospital, Florence, Italy
| | - Lucia Pallecchi
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
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10
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Wang G, Brunel JM, Preusse M, Mozaheb N, Willger SD, Larrouy-Maumus G, Baatsen P, Häussler S, Bolla JM, Van Bambeke F. The membrane-active polyaminoisoprenyl compound NV716 re-sensitizes Pseudomonas aeruginosa to antibiotics and reduces bacterial virulence. Commun Biol 2022; 5:871. [PMID: 36008485 PMCID: PMC9411590 DOI: 10.1038/s42003-022-03836-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 08/11/2022] [Indexed: 11/09/2022] Open
Abstract
Pseudomonas aeruginosa is intrinsically resistant to many antibiotics due to the impermeability of its outer membrane and to the constitutive expression of efflux pumps. Here, we show that the polyaminoisoprenyl compound NV716 at sub-MIC concentrations re-sensitizes P. aeruginosa to abandoned antibiotics by binding to the lipopolysaccharides (LPS) of the outer membrane, permeabilizing this membrane and increasing antibiotic accumulation inside the bacteria. It also prevents selection of resistance to antibiotics and increases their activity against biofilms. No stable resistance could be selected to NV716-itself after serial passages with subinhibitory concentrations, but the transcriptome of the resulting daughter cells shows an upregulation of genes involved in the synthesis of lipid A and LPS, and a downregulation of quorum sensing-related genes. Accordingly, NV716 also reduces motility, virulence factors production, and biofilm formation. NV716 shows a unique and highly promising profile of activity when used alone or in combination with antibiotics against P. aeruginosa, combining in a single molecule anti-virulence and potentiator effects. Additional work is required to more thoroughly understand the various functions of NV716. The polyaminoisoprenyl compound NV716 re-sensitizes Pseudomonas aeruginosa to antibiotics through permeabilizing the outer membrane and increases the activity of antibiotics on biofilms.
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Affiliation(s)
- Gang Wang
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Jean-Michel Brunel
- Aix Marseille Université, INSERM, SSA, Membranes et Cibles thérapeutiques (MCT), Marseille, France
| | - Matthias Preusse
- Department of Molecular Bacteriology, Helmoltz Centre for Infection Research, Braunschweig, Germany
| | - Negar Mozaheb
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Sven D Willger
- Department of Molecular Bacteriology, Helmoltz Centre for Infection Research, Braunschweig, Germany.,Department of Molecular Bacteriology, Twincore, Hannover, Germany.,Institute for Medical Biometry and Bioinformatics, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Gerald Larrouy-Maumus
- Department of Life Sciences, Faculty of Natural Sciences, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Pieter Baatsen
- Electron Microscopy Platform & Bio Imaging Core, VIB & KULeuven Center for Brain & Disease Research, KULeuven, Leuven, Belgium
| | - Susanne Häussler
- Department of Molecular Bacteriology, Helmoltz Centre for Infection Research, Braunschweig, Germany.,Department of Molecular Bacteriology, Twincore, Hannover, Germany.,Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark.,Cluster of Excellence RESIST, Hannover Medical School, Hannover, Germany
| | - Jean-Michel Bolla
- Aix Marseille Université, INSERM, SSA, Membranes et Cibles thérapeutiques (MCT), Marseille, France
| | - Françoise Van Bambeke
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
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11
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Canton R, Doi Y, Simner PJ. Treatment of carbapenem-resistant Pseudomonas aeruginosa infections: a case for cefiderocol. Expert Rev Anti Infect Ther 2022; 20:1077-1094. [PMID: 35502603 DOI: 10.1080/14787210.2022.2071701] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 04/26/2022] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Carbapenem-resistant (CR) Pseudomonas aeruginosa infections constitute a serious clinical threat globally. Patients are often critically ill and/or immunocompromised. Antibiotic options are limited and are currently centered on beta-lactam-beta-lactamase inhibitor (BL-BLI) combinations and the siderophore cephalosporin cefiderocol. AREAS COVERED This article reviews the mechanisms of P. aeruginosa resistance and their potential impact on the activity of current treatment options, along with evidence for the clinical efficacy of BL-BLI combinations in P. aeruginosa infections, some of which specifically target infections due to CR organisms. The preclinical and clinical evidence supporting cefiderocol as a treatment option for P. aeruginosa involving infections is also reviewed. EXPERT OPINION Cefiderocol is active against most known P. aeruginosa mechanisms mediating carbapenem resistance. It is stable against different serine- and metallo-beta-lactamases, and, due to its iron channel-dependent uptake mechanism, is not impacted by porin channel loss. Furthermore, the periplasmic level of cefiderocol is not affected by upregulated efflux pumps. The potential for on-treatment resistance development currently appears to be low, although more clinical data are required. Information from surveillance programs, real-world compassionate use, and clinical studies demonstrate that cefiderocol is an important treatment option for CR P. aeruginosa infections.
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Affiliation(s)
- Rafael Canton
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- CIBER de Enfermedades Infecciosas, Instituto de Salud Carlos III, Madrid, Spain
| | - Yohei Doi
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Patricia J Simner
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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12
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The polyamino-isoprenyl potentiator NV716 revives disused antibiotics against Gram-negative bacteria in broth, infected monocytes, or biofilms, by disturbing the barrier effect of their outer membrane. Eur J Med Chem 2022; 238:114496. [DOI: 10.1016/j.ejmech.2022.114496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 05/13/2022] [Accepted: 05/25/2022] [Indexed: 11/24/2022]
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13
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Boudet A, Sorlin P, Pouget C, Chiron R, Lavigne JP, Dunyach-Remy C, Marchandin H. Biofilm Formation in Methicillin-Resistant Staphylococcus aureus Isolated in Cystic Fibrosis Patients Is Strain-Dependent and Differentially Influenced by Antibiotics. Front Microbiol 2021; 12:750489. [PMID: 34721354 PMCID: PMC8554194 DOI: 10.3389/fmicb.2021.750489] [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: 07/30/2021] [Accepted: 09/22/2021] [Indexed: 12/17/2022] Open
Abstract
Cystic fibrosis (CF) is a genetic disease with lung abnormalities making patients particularly predisposed to pulmonary infections. Staphylococcus aureus is the most frequently identified pathogen, and multidrug-resistant strains (MRSA, methicillin-resistant S. aureus) have been associated with more severe lung dysfunction leading to eradication recommendations. Diverse bacterial traits and adaptive skills, including biofilm formation, may, however, make antimicrobial therapy challenging. In this context, we compared the ability of a collection of genotyped MRSA isolates from CF patients to form biofilm with and without antibiotics (ceftaroline, ceftobiprole, linezolid, trimethoprim, and rifampicin). Our study used standardized approaches not previously applied to CF MRSA, the BioFilm Ring test® (BRT®), the Antibiofilmogram®, and the BioFlux™ 200 system which were adapted for use with the artificial sputum medium (ASM) mimicking conditions more relevant to the CF lung. We included 63 strains of 10 multilocus sequence types (STs) isolated from 35 CF patients, 16 of whom had chronic colonization. The BRT® showed that 27% of the strains isolated in 37% of the patients were strong biofilm producers. The Antibiofilmogram® performed on these strains showed that broad-spectrum cephalosporins had the lowest minimum biofilm inhibitory concentrations (bMIC) on a majority of strains. A focus on four chronically colonized patients with inclusion of successively isolated strains showed that ceftaroline, ceftobiprole, and/or linezolid bMICs may remain below the resistance thresholds over time. Studying the dynamics of biofilm formation by strains isolated 3years apart in one of these patients using BioFlux™ 200 showed that inhibition of biofilm formation was observed for up to 36h of exposure to bMIC and ceftaroline and ceftobiprole had a significantly greater effect than linezolid. This study has brought new insights into the behavior of CF MRSA which has been little studied for its ability to form biofilm. Biofilm formation is a common characteristic of prevalent MRSA clones in CF. Early biofilm formation was strain-dependent, even within a sample, and not only observed during chronic colonization. Ceftaroline and ceftobiprole showed a remarkable activity with a long-lasting inhibitory effect on biofilm formation and a conserved activity on certain strains adapted to the CF lung environment after years of colonization.
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Affiliation(s)
- Agathe Boudet
- VBIC, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, Nîmes, France
| | - Pauline Sorlin
- HydroSciences Montpellier, Université de Montpellier, CNRS, IRD, Département de Microbiologie, CHU de Nîmes, Montpellier, France
| | | | - Raphaël Chiron
- HydroSciences Montpellier, Université de Montpellier, CNRS, IRD, Centre de Ressources et de Compétences de la Mucoviscidose, CHU de Montpellier, Montpellier, France
| | - Jean-Philippe Lavigne
- VBIC, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, Nîmes, France
| | - Catherine Dunyach-Remy
- VBIC, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, Nîmes, France
| | - Hélène Marchandin
- HydroSciences Montpellier, Université de Montpellier, CNRS, IRD, Département de Microbiologie, CHU de Nîmes, Montpellier, France
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14
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Impact of artificial sputum media formulation on Pseudomonas aeruginosa secondary metabolite production. J Bacteriol 2021; 203:e0025021. [PMID: 34398662 PMCID: PMC8508215 DOI: 10.1128/jb.00250-21] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
In vitro culture media are being developed to understand how host site-specific nutrient profiles influence microbial pathogenicity and ecology. To mimic the cystic fibrosis (CF) lung environment, a variety of artificial sputum media (ASM) have been created. However, the composition of these ASM vary in the concentration of key nutrients, including amino acids, lipids, DNA, and mucin. In this work, we used feature-based molecular networking (FBMN) to perform comparative metabolomics of Pseudomonas aeruginosa, the predominant opportunistic pathogen infecting the lungs of people with CF, cultured in nine different ASM. We found that the concentration of aromatic amino acids and iron from mucin added to the media contributes to differences in the production of P. aeruginosa virulence-associated secondary metabolites. IMPORTANCE Different media formulations aiming to replicate in vivo infection environments contain different nutrients, which affects interpretation of experimental results. Inclusion of undefined components, such as commercial porcine gastric mucin (PGM), in an otherwise chemically defined medium can alter the nutrient content of the medium in unexpected ways and influence experimental outcomes.
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15
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Langendonk RF, Neill DR, Fothergill JL. The Building Blocks of Antimicrobial Resistance in Pseudomonas aeruginosa: Implications for Current Resistance-Breaking Therapies. Front Cell Infect Microbiol 2021; 11:665759. [PMID: 33937104 PMCID: PMC8085337 DOI: 10.3389/fcimb.2021.665759] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 03/29/2021] [Indexed: 12/12/2022] Open
Abstract
P. aeruginosa is classified as a priority one pathogen by the World Health Organisation, and new drugs are urgently needed, due to the emergence of multidrug-resistant (MDR) strains. Antimicrobial-resistant nosocomial pathogens such as P. aeruginosa pose unwavering and increasing threats. Antimicrobial stewardship has been a challenge during the COVID-19 pandemic, with a majority of those hospitalized with SARS-CoV2 infection given antibiotics as a safeguard against secondary bacterial infection. This increased usage, along with increased handling of sanitizers and disinfectants globally, may further accelerate the development and spread of cross-resistance to antibiotics. In addition, P. aeruginosa is the primary causative agent of morbidity and mortality in people with the life-shortening genetic disease cystic fibrosis (CF). Prolonged periods of selective pressure, associated with extended antibiotic treatment and the actions of host immune effectors, results in widespread adaptive and acquired resistance in P. aeruginosa found colonizing the lungs of people with CF. This review discusses the arsenal of resistance mechanisms utilized by P. aeruginosa, how these operate under high-stress environments such as the CF lung and how their interconnectedness can result in resistance to multiple antibiotic classes. Intrinsic, adaptive and acquired resistance mechanisms will be described, with a focus on how each layer of resistance can serve as a building block, contributing to multi-tiered resistance to antimicrobial activity. Recent progress in the development of anti-resistance adjuvant therapies, targeting one or more of these building blocks, should lead to novel strategies for combatting multidrug resistant P. aeruginosa. Anti-resistance adjuvant therapy holds great promise, not least because resistance against such therapeutics is predicted to be rare. The non-bactericidal nature of anti-resistance adjuvants reduce the selective pressures that drive resistance. Anti-resistance adjuvant therapy may also be advantageous in facilitating efficacious use of traditional antimicrobials, through enhanced penetration of the antibiotic into the bacterial cell. Promising anti-resistance adjuvant therapeutics and targets will be described, and key remaining challenges highlighted. As antimicrobial stewardship becomes more challenging in an era of emerging and re-emerging infectious diseases and global conflict, innovation in antibiotic adjuvant therapy can play an important role in extending the shelf-life of our existing antimicrobial therapeutic agents.
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Affiliation(s)
- R. Frèdi Langendonk
- Institute of Infection, Veterinary and Ecological Science, University of Liverpool, Liverpool, United Kingdom
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16
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Antimicrobial Susceptibility Testing in Pseudomonas aeruginosa Biofilms: One Step Closer to a Standardized Method. Antibiotics (Basel) 2020; 9:antibiotics9120880. [PMID: 33316877 PMCID: PMC7763878 DOI: 10.3390/antibiotics9120880] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 11/30/2022] Open
Abstract
The ability of Pseudomonas aeruginosa to form biofilm during a long-term infection makes it difficult to treat patients correctly. The current clinical antimicrobial susceptibility testing methods are based on the study of planktonic strains. A standardized protocol to analyze the antimicrobial susceptibility in biofilms is necessary for routine laboratories. The aims of this study were to develop a simple biofilm model and to study the antimicrobial susceptibility of P. aeruginosa strains in biofilm growth. Different artificial sputum media, and aerobiosis and microaerobiosis conditions were analyzed using a microtiter plate method and P. aeruginosa PAO1 as reference strain. Planktonic and biofilm antimicrobial susceptibility to cefepime, imipenem, azithromycin, gentamicin, tobramycin, and ciprofloxacin were determined in clinical and non-clinical P. aeruginosa strains. The Synthetic Cystic Fibrosis Medium was proposed as a good medium. The biofilm greatly increased the resistance to tested antimicrobials, except for azithromycin. Cefepime and imipenem showed poor anti-biofilm effect while tobramycin, gentamicin, and ciprofloxacin showed good activity in some strains. Azithromycin showed a better activity in biofilm than in planktonic state when aerobic conditions were used. This study establishes useful information to test antimicrobial susceptibility in P. aeruginosa biofilms, and includes possible antimicrobial options to treat long-term infected patients.
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17
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Abbott IJ, Roberts JA, Meletiadis J, Peleg AY. Antimicrobial pharmacokinetics and preclinical in vitro models to support optimized treatment approaches for uncomplicated lower urinary tract infections. Expert Rev Anti Infect Ther 2020; 19:271-295. [PMID: 32820686 DOI: 10.1080/14787210.2020.1813567] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Urinary tract infections (UTIs) are extremely common. Millions of people, particularly healthy women, are affected worldwide every year. One-in-two women will have a recurrence within 12-months of an initial UTI. Inadequate treatment risks worsening infection leading to acute pyelonephritis, bacteremia and sepsis. In an era of increasing antimicrobial resistance, it is critical to provide optimized antimicrobial treatment. AREAS COVERED Literature was searched using PubMed and Google Scholar (up to 06/2020), examining the etiology, diagnosis and oral antimicrobial therapy for uncomplicated UTIs, with emphasis on urinary antimicrobial pharmacokinetics (PK) and the application of dynamic in vitro models for the pharmacodynamic (PD) profiling of pathogen response. EXPERT OPINION The majority of antimicrobial agents included in international guidelines were developed decades ago without well-described dose-response relationships. Microbiology laboratories still apply standard diagnostic methodology that has essentially remained unchanged for decades. Furthermore, it is uncertain how relevant standard in vitro susceptibility is for predicting antimicrobial efficacy in urine. In order to optimize UTI treatments, clinicians must exploit the urine-specific PK of antimicrobial agents. Dynamic in vitro models are valuable tools to examine the PK/PD and urodynamic variables associated with UTIs, while informing uropathogen susceptibility reporting, optimized dosing schedules, clinical trials and treatment guidelines.
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Affiliation(s)
- Iain J Abbott
- Department of Infectious Diseases, the Alfred Hospital and Central Clinical School, Monash University, Melbourne, Australia
| | - Jason A Roberts
- University of Queensland Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, Australia.,School of Pharmacy, Centre for Translational Anti-infective Pharmacodynamics, The University of Queensland, Brisbane, Australia.,Department of Intensive Care Medicine, Royal Brisbane and Women's Hospital, Brisbane, Australia.,Division of Anaesthesiology Critical Care Emergency and Pain Medicine, Nîmes University Hospital, University of Montpellier, Nîmes, France
| | - Joseph Meletiadis
- Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Haidari, Greece
| | - Anton Y Peleg
- Department of Infectious Diseases, the Alfred Hospital and Central Clinical School, Monash University, Melbourne, Australia.,Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Australia
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18
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Deschamps E, Schaumann A, Schmitz-Afonso I, Afonso C, Dé E, Loutelier-Bourhis C, Alexandre S. Membrane phospholipid composition of Pseudomonas aeruginosa grown in a cystic fibrosis mucus-mimicking medium. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183482. [PMID: 33002450 DOI: 10.1016/j.bbamem.2020.183482] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 09/18/2020] [Accepted: 09/21/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND Pseudomonas aeruginosa is a bacterium able to induce serious pulmonary infections in cystic fibrosis (CF) patients. This bacterium is very often antibiotic resistant, partly because of its membrane impermeability, which is linked to the membrane lipid composition. This work aims to study the membrane phospholipids of P. aeruginosa grown in CF sputum-like media. METHODS Three media were used: Mueller Hilton broth (MHB), synthetic cystic fibrosis medium (SCFM) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) complemented SCFM (SCFM-PC). Lipids were extracted and LC-MS/MS analyses were performed. Growth curves, atomic force microscopy images and minimal inhibitory concentration determination were performed in order to compare the growth and potentially link lipid modifications to antibiotic resistance. RESULTS Semi-quantification showed phospholipid quantity variation depending on the growth medium. Phosphatidylcholines were detected in traces in SCFM. MS/MS experiments showed an increase of phospholipids derived from DOPC in SCFM-PC. We observed no influence of the medium on the bacterial growth and a minor influence on the bacterial shape. MIC values were generally higher in SCFM and SCFM-PC than in MHB. CONCLUSIONS We defined a CF sputum-like media which can be used for the membrane lipid extraction of P. aeruginosa. We also showed that the growth medium does have an influence on its membrane lipid composition and antibiotic resistance, especially for SCFM-PC in which P. aeruginosa uses DOPC, in order to make its own membrane. GENERAL SIGNIFICANCE Our results show that considerable caution must be taken when choosing a medium for lipid identification and antibiotic testing -especially for phospholipids-enriched media.
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Affiliation(s)
- Estelle Deschamps
- Normandie Univ, PBS, UMR 6270 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, CURIB, Bvd De Broglie, 76821 Mont-Saint-Aignan, Cedex, France; Normandie Univ, COBRA, UMR 6014 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 rue Tesnière, 76821 Mont-Saint-Aignan, Cedex, France
| | - Annick Schaumann
- Normandie Univ, PBS, UMR 6270 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, CURIB, Bvd De Broglie, 76821 Mont-Saint-Aignan, Cedex, France
| | - Isabelle Schmitz-Afonso
- Normandie Univ, COBRA, UMR 6014 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 rue Tesnière, 76821 Mont-Saint-Aignan, Cedex, France
| | - Carlos Afonso
- Normandie Univ, COBRA, UMR 6014 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 rue Tesnière, 76821 Mont-Saint-Aignan, Cedex, France
| | - Emmanuelle Dé
- Normandie Univ, PBS, UMR 6270 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, CURIB, Bvd De Broglie, 76821 Mont-Saint-Aignan, Cedex, France
| | - Corinne Loutelier-Bourhis
- Normandie Univ, COBRA, UMR 6014 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 rue Tesnière, 76821 Mont-Saint-Aignan, Cedex, France
| | - Stéphane Alexandre
- Normandie Univ, PBS, UMR 6270 and FR 3038, Université de Rouen, INSA de Rouen, CNRS, CURIB, Bvd De Broglie, 76821 Mont-Saint-Aignan, Cedex, France.
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