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Greenwald MA, Meinig SL, Plott LM, Roca C, Higgs MG, Vitko NP, Markovetz MR, Rouillard KR, Carpenter J, Kesimer M, Hill DB, Schisler JC, Wolfgang MC. Mucus polymer concentration and in vivo adaptation converge to define the antibiotic response of Pseudomonas aeruginosa during chronic lung infection. mBio 2024; 15:e0345123. [PMID: 38651896 PMCID: PMC11237767 DOI: 10.1128/mbio.03451-23] [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: 12/18/2023] [Accepted: 03/26/2024] [Indexed: 04/25/2024] Open
Abstract
The airway milieu of individuals with muco-obstructive airway diseases (MADs) is defined by the accumulation of dehydrated mucus due to hyperabsorption of airway surface liquid and defective mucociliary clearance. Pathological mucus becomes progressively more viscous with age and disease severity due to the concentration and overproduction of mucin and accumulation of host-derived extracellular DNA (eDNA). Respiratory mucus of MADs provides a niche for recurrent and persistent colonization by respiratory pathogens, including Pseudomonas aeruginosa, which is responsible for the majority of morbidity and mortality in MADs. Despite high concentration inhaled antibiotic therapies and the absence of antibiotic resistance, antipseudomonal treatment failure in MADs remains a significant clinical challenge. Understanding the drivers of antibiotic tolerance is essential for developing more effective treatments that eradicate persistent infections. The complex and dynamic environment of diseased airways makes it difficult to model antibiotic efficacy in vitro. We aimed to understand how mucin and eDNA concentrations, the two dominant polymers in respiratory mucus, alter the antibiotic tolerance of P. aeruginosa. Our results demonstrate that polymer concentration and molecular weight affect P. aeruginosa survival post antibiotic challenge. Polymer-driven antibiotic tolerance was not explicitly associated with reduced antibiotic diffusion. Lastly, we established a robust and standardized in vitro model for recapitulating the ex vivo antibiotic tolerance of P. aeruginosa observed in expectorated sputum across age, underlying MAD etiology, and disease severity, which revealed the inherent variability in intrinsic antibiotic tolerance of host-evolved P. aeruginosa populations. IMPORTANCE Antibiotic treatment failure in Pseudomonas aeruginosa chronic lung infections is associated with increased morbidity and mortality, illustrating the clinical challenge of bacterial infection control. Understanding the underlying infection environment, as well as the host and bacterial factors driving antibiotic tolerance and the ability to accurately recapitulate these factors in vitro, is crucial for improving antibiotic treatment outcomes. Here, we demonstrate that increasing concentration and molecular weight of mucin and host eDNA drive increased antibiotic tolerance to tobramycin. Through systematic testing and modeling, we identified a biologically relevant in vitro condition that recapitulates antibiotic tolerance observed in ex vivo treated sputum. Ultimately, this study revealed a dominant effect of in vivo evolved bacterial populations in defining inter-subject ex vivo antibiotic tolerance and establishes a robust and translatable in vitro model for therapeutic development.
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Affiliation(s)
- Matthew A Greenwald
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Suzanne L Meinig
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Lucas M Plott
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Cristian Roca
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Matthew G Higgs
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Nicholas P Vitko
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Matthew R Markovetz
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Kaitlyn R Rouillard
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jerome Carpenter
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Mehmet Kesimer
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - David B Hill
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
- Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jonathan C Schisler
- Department of Pharmacology, The University of North Carolina, Chapel Hill, North Carolina, USA
- McAllister Heart Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Matthew C Wolfgang
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
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Rouillard KR, Esther CP, Kissner WJ, Plott LM, Bowman DW, Markovetz MR, Hill DB. Combination treatment to improve mucociliary transport of Pseudomonas aeruginosa biofilms. PLoS One 2024; 19:e0294120. [PMID: 38394229 PMCID: PMC10890754 DOI: 10.1371/journal.pone.0294120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 10/25/2023] [Indexed: 02/25/2024] Open
Abstract
People with muco-obstructive pulmonary diseases such as cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) often have acute or chronic respiratory infections that are difficult to treat due in part to the accumulation of hyperconcentrated mucus within the airway. Mucus accumulation and obstruction promote chronic inflammation and infection and reduce therapeutic efficacy. Bacterial aggregates in the form of biofilms exhibit increased resistance to mechanical stressors from the immune response (e.g., phagocytosis) and chemical treatments including antibiotics. Herein, combination treatments designed to disrupt the mechanical properties of biofilms and potentiate antibiotic efficacy are investigated against mucus-grown Pseudomonas aeruginosa biofilms and optimized to 1) alter biofilm viscoelastic properties, 2) increase mucociliary transport rates, and 3) reduce bacterial viability. A disulfide bond reducing agent (tris(2-carboxyethyl)phosphine, TCEP), a surfactant (NP40), a biopolymer (hyaluronic acid, HA), a DNA degradation enzyme (DNase), and an antibiotic (tobramycin) are tested in various combinations to maximize biofilm disruption. The viscoelastic properties of biofilms are quantified with particle tracking microrheology and transport rates are quantified in a mucociliary transport device comprised of fully differentiated primary human bronchial epithelial cells. The combination of the NP40 with hyaluronic acid and tobramycin was the most effective at increasing mucociliary transport rates, decreasing the viscoelastic properties of mucus, and reducing bacterial viability. Multimechanistic targeting of biofilm infections may ultimately result in improved clinical outcomes, and the results of this study may be translated into future in vivo infection models.
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Affiliation(s)
- Kaitlyn R. Rouillard
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC, United States of America
| | | | - William J. Kissner
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC, United States of America
| | - Lucas M. Plott
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC, United States of America
| | - Dean W. Bowman
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC, United States of America
| | - Matthew R. Markovetz
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC, United States of America
| | - David B. Hill
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC, United States of America
- Joint Department of Biomedical Engineering, UNC Chapel Hill, Chapel Hill, NC, United States of America
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Greenwald MA, Meinig SL, Plott LM, Roca C, Higgs MG, Vitko NP, Markovetz MR, Rouillard KR, Carpenter J, Kesimer M, Hill DB, Schisler JC, Wolfgang MC. Mucus polymer concentration and in vivo adaptation converge to define the antibiotic response of Pseudomonas aeruginosa during chronic lung infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.20.572620. [PMID: 38187602 PMCID: PMC10769284 DOI: 10.1101/2023.12.20.572620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
The airway milieu of individuals with muco-obstructive airway diseases (MADs) is defined by the accumulation of dehydrated mucus due to hyperabsorption of airway surface liquid and defective mucociliary clearance. Pathological mucus becomes progressively more viscous with age and disease severity due to the concentration and overproduction of mucin and accumulation of host-derived extracellular DNA (eDNA). Respiratory mucus of MADs provides a niche for recurrent and persistent colonization by respiratory pathogens, including Pseudomonas aeruginosa , which is responsible for the majority of morbidity and mortality in MADs. Despite high concentration inhaled antibiotic therapies and the absence of antibiotic resistance, antipseudomonal treatment failure in MADs remains a significant clinical challenge. Understanding the drivers of antibiotic recalcitrance is essential for developing more effective treatments that eradicate persistent infections. The complex and dynamic environment of diseased airways makes it difficult to model antibiotic efficacy in vitro . We aimed to understand how mucin and eDNA concentrations, the two dominant polymers in respiratory mucus, alter the antibiotic tolerance of P. aeruginosa . Our results demonstrate that polymer concentration and molecular weight affect P. aeruginosa survival post antibiotic challenge. Polymer-driven antibiotic tolerance was not explicitly associated with reduced antibiotic diffusion. Lastly, we established a robust and standardized in vitro model for recapitulating the ex vivo antibiotic tolerance of P. aeruginosa observed in expectorated sputum across age, underlying MAD etiology, and disease severity, which revealed the inherent variability in intrinsic antibiotic tolerance of host-evolved P. aeruginosa populations. Importance Antibiotic treatment failure in Pseudomonas aeruginosa chronic lung infections is associated with increased morbidity and mortality, illustrating the clinical challenge of bacterial infection control. Understanding the underlying infection environment, as well as the host and bacterial factors driving antibiotic tolerance and the ability to accurately recapitulate these factors in vitro , is crucial for improving antibiotic treatment outcomes. Here, we demonstrate that increasing concentration and molecular weight of mucin and host eDNA drive increased antibiotic tolerance to tobramycin. Through systematic testing and modeling, we identified a biologically relevant in vitro condition that recapitulates antibiotic tolerance observed in ex vivo treated sputum. Ultimately, this study revealed a dominant effect of in vivo evolved bacterial populations in defining inter-subject ex vivo antibiotic tolerance and establishes a robust and translatable in vitro model for therapeutic development.
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Flemming HC, van Hullebusch ED, Neu TR, Nielsen PH, Seviour T, Stoodley P, Wingender J, Wuertz S. The biofilm matrix: multitasking in a shared space. Nat Rev Microbiol 2023; 21:70-86. [PMID: 36127518 DOI: 10.1038/s41579-022-00791-0] [Citation(s) in RCA: 161] [Impact Index Per Article: 161.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2022] [Indexed: 01/20/2023]
Abstract
The biofilm matrix can be considered to be a shared space for the encased microbial cells, comprising a wide variety of extracellular polymeric substances (EPS), such as polysaccharides, proteins, amyloids, lipids and extracellular DNA (eDNA), as well as membrane vesicles and humic-like microbially derived refractory substances. EPS are dynamic in space and time and their components interact in complex ways, fulfilling various functions: to stabilize the matrix, acquire nutrients, retain and protect eDNA or exoenzymes, or offer sorption sites for ions and hydrophobic substances. The retention of exoenzymes effectively renders the biofilm matrix an external digestion system influencing the global turnover of biopolymers, considering the ubiquitous relevance of biofilms. Physico-chemical and biological interactions and environmental conditions enable biofilm systems to morph into films, microcolonies and macrocolonies, films, ridges, ripples, columns, pellicles, bubbles, mushrooms and suspended aggregates - in response to the very diverse conditions confronting a particular biofilm community. Assembly and dynamics of the matrix are mostly coordinated by secondary messengers, signalling molecules or small RNAs, in both medically relevant and environmental biofilms. Fully deciphering how bacteria provide structure to the matrix, and thus facilitate and benefit from extracellular reactions, remains the challenge for future biofilm research.
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Affiliation(s)
- Hans-Curt Flemming
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.
| | | | - Thomas R Neu
- Department of River Ecology, Helmholtz Centre for Environmental Research - UFZ, Magdeburg, Germany
| | - Per H Nielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Thomas Seviour
- Aarhus University Centre for Water Technology, Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
| | - Paul Stoodley
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, USA.,Department of Orthopaedics, The Ohio State University, Columbus, OH, USA
| | - Jost Wingender
- University of Duisburg-Essen, Biofilm Centre, Department of Aquatic Microbiology, Essen, Germany
| | - Stefan Wuertz
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
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Rouillard KR, Markovetz MR, Kissner WJ, Boone WL, Plott LM, Hill DB. Altering the viscoelastic properties of mucus-grown Pseudomonas aeruginosa biofilms affects antibiotic susceptibility. Biofilm 2023; 5:100104. [PMID: 36711323 PMCID: PMC9880403 DOI: 10.1016/j.bioflm.2023.100104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/15/2023] [Accepted: 01/19/2023] [Indexed: 01/22/2023] Open
Abstract
The viscoelastic properties of biofilms are correlated with their susceptibility to mechanical and chemical stress, and the airway environment in muco-obstructive pulmonary diseases (MOPD) facilitates robust biofilm formation. Hyperconcentrated, viscoelastic mucus promotes chronic inflammation and infection, resulting in increased mucin and DNA concentrations. The viscoelastic properties of biofilms are regulated by biopolymers, including polysaccharides and DNA, and influence responses to antibiotics and phagocytosis. We hypothesize that targeted modulation of biofilm rheology will compromise structural integrity and increase antibiotic susceptibility and mucociliary transport. We evaluate biofilm rheology on the macro, micro, and nano scale as a function of treatment with a reducing agent, a biopolymer, and/or tobramycin to define the relationship between the viscoelastic properties of biofilms and susceptibility. Disruption of the biofilm architecture is associated with altered macroscopic and microscopic moduli, rapid vector permeability, increased antibiotic susceptibility, and improved mucociliary transport, suggesting that biofilm modulating therapeutics will improve the treatment of chronic respiratory infections in MOPD.
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Affiliation(s)
- Kaitlyn R. Rouillard
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Matthew R. Markovetz
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - William J. Kissner
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - William L. Boone
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Lucas M. Plott
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - David B. Hill
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Joint Department of Biomedical Engineering, North Carolina State University and the University of North Carolina, Chapel Hill, NC, 27599, USA,Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Corresponding author. Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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6
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Abstract
The pathological properties of airway mucus in cystic fibrosis (CF) are dictated by mucus concentration and composition, with mucins and DNA being responsible for mucus viscoelastic properties. As CF pulmonary disease progresses, the concentrations of mucins and DNA increase and are associated with increased mucus viscoelasticity and decreased transport. Similarly, the biophysical properties of bacterial biofilms are heavily influenced by the composition of their extracellular polymeric substances (EPS). While the roles of polymer concentration and composition in mucus and biofilm mechanical properties have been evaluated independently, the relationship between mucus concentration and composition and the biophysical properties of biofilms grown therein remains unknown. Pseudomonas aeruginosa biofilms were grown in airway mucus as a function of overall concentration and DNA concentration to mimic healthy, and CF pathophysiology and biophysical properties were evaluated with macro- and microrheology. Biofilms were also characterized after exposure to DNase or DTT to examine the effects of DNA and mucin degradation, respectively. Identifying critical targets in biofilms for disrupting mechanical stability in highly concentrated mucus may lead to the development of efficacious biofilm therapies and ultimately improve CF patient outcomes. Overall mucus concentration was the predominant contributor to biofilm viscoelasticity and both DNA degradation and mucin reduction resulted in compromised biofilm mechanical strength. IMPORTANCE Pathological mucus in cystic fibrosis (CF) is highly concentrated and insufficiently cleared from the airway, causing chronic inflammation and infection. Pseudomonas aeruginosa establishes chronic infection in the form of biofilms within mucus, and this study determined that biofilms formed in more concentrated mucus were more robust and less susceptible to mechanical and chemical challenges compared to biofilms grown in lower concentrated mucus. Neither DNA degradation nor disulfide bond reduction was sufficient to fully degrade biofilms. Mucus rehydration should remain a priority for treating CF pulmonary disease with concomitant multimechanistic biofilm degradation agents and antibiotics to clear chronic infection.
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Patiño Vargas MI, Martinez-Garcia FD, Offens F, Becerra NY, Restrepo LM, van der Mei HC, Harmsen MC, van Kooten TG, Sharma PK. Viscoelastic properties of plasma-agarose hydrogels dictate favorable fibroblast responses for skin tissue engineering applications. BIOMATERIALS ADVANCES 2022; 139:212967. [PMID: 35882126 DOI: 10.1016/j.bioadv.2022.212967] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 05/26/2022] [Accepted: 05/31/2022] [Indexed: 12/17/2022]
Abstract
Dermal wound healing relies on the properties of the extracellular matrix (ECM). Thus, hydrogels that replicate skin ECM have reached clinical application. After a dermal injury, a transient, biodegradable fibrin clot is instrumental in wound healing. Human plasma, and its main constituent, fibrin would make a suitable biomaterial for improving wound healing and processed as hydrogels albeit with limited mechanical strength. To overcome this, plasma-agarose (PA) composite hydrogels have been developed and used to prepare diverse bioengineered tissues. To date, little is known about the influence of variable agarose concentrations on the viscoelastic properties of PA hydrogels and their correlation to cell biology. This study reports the characterization of the viscoelastic properties of different concentrations of agarose in PA hydrogels: 0 %, 0.5 %, 1 %, 1.5 %, and 2 % (w/v), and their influence on the cell number and mitochondrial activity of human dermal fibroblasts. Results show that agarose addition increased the stiffness, relaxation time constants 1 (τ1) and 2 (τ2), and fiber diameter, whereas the porosity decreased. Changes in cell metabolism occurred at the early stages of culturing and correlated to the displacement of fast (τ1) and intermediate (τ2) Maxwell elements. Fibroblasts seeded in low PA concentrations spread faster during 14 d than cells cultured in higher agarose concentrations. Collectively, these results confirm that PA viscoelasticity and hydrogel architecture strongly influenced cell behavior. Therefore, viscoelasticity is a key parameter in the design of PA-based implants.
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Affiliation(s)
- Maria Isabel Patiño Vargas
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering, Groningen, the Netherlands; Tissue Engineering and Cell Therapy Group, Faculty of Medicine, University of Antioquia, Medellín, Colombia
| | - Francisco Drusso Martinez-Garcia
- University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Groningen, the Netherlands
| | - Freya Offens
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering, Groningen, the Netherlands
| | - Natalia Y Becerra
- Tissue Engineering and Cell Therapy Group, Faculty of Medicine, University of Antioquia, Medellín, Colombia
| | - Luz M Restrepo
- Tissue Engineering and Cell Therapy Group, Faculty of Medicine, University of Antioquia, Medellín, Colombia
| | - Henny C van der Mei
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering, Groningen, the Netherlands
| | - Martin C Harmsen
- University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Groningen, the Netherlands
| | - Theo G van Kooten
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering, Groningen, the Netherlands
| | - Prashant K Sharma
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering, Groningen, the Netherlands.
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The c-di-GMP Phosphodiesterase PipA (PA0285) Regulates Autoaggregation and Pf4 Bacteriophage Production in Pseudomonas aeruginosa PAO1. Appl Environ Microbiol 2022; 88:e0003922. [PMID: 35638845 DOI: 10.1128/aem.00039-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In Pseudomonas aeruginosa PAO1, 41 genes encode proteins predicted to be involved in the production or degradation of c-di-GMP, a ubiquitous secondary messenger that regulates a variety of physiological behaviors closely related to biofilm and aggregate formation. Despite extensive effort, the entire picture of this important signaling network is still unclear, with one-third of these proteins remaining uncharacterized. Here, we show that the deletion of pipA, which produces a protein containing two PAS domains upstream of a GGDEF-EAL tandem, significantly increased the intracellular c-di-GMP level and promoted the formation of aggregates both on surfaces and in planktonic cultures. However, this regulatory effect was not contributed by either of the two classic pathways modulating biofilm formation, exopolysaccharide (EPS) overproduction or motility inhibition. Transcriptome sequencing (RNA-Seq) data revealed that the expression levels of 361 genes were significantly altered in a ΔpipA mutant strain compared to the wild type (WT), indicating the critical role of PipA in PAO1. The most remarkably downregulated genes were located on the Pf4 bacteriophage gene cluster, which corresponded to a 2-log reduction in the Pf4 phage production in the ΔpipA mutant. The sizes of aggregates in ΔpipA cultures were affected by exogenously added Pf4 phage in a concentration-dependent manner, suggesting the quantity of phage plays a part in regulating the formation of aggregates. Further analysis demonstrated that PipA is highly conserved across 83 P. aeruginosa strains. Our work therefore for the first time showed that a c-di-GMP phosphodiesterase can regulate bacteriophage production and provided new insights into the relationship between bacteriophage and bacterial aggregation. IMPORTANCE The c-di-GMP signaling pathways in P. aeruginosa are highly organized and well coordinated, with different diguanylate cyclases and phosphodiesterases playing distinct roles in a complex network. Understanding the function of each enzyme and the underlying regulatory mechanisms not only is crucial for revealing how bacteria decide the transition between motile and sessile lifestyles, but also greatly facilitates the development of new antibiofilm strategies. This work identified bacteriophage production as a novel phenotypic output controlled transcriptionally by a phosphodiesterase, PipA. Further analysis suggested that the quantity of phage may be important in regulating autoaggregation, as either a lack of phage or overproduction was associated with higher levels of aggregation. Our study therefore extended the scope of c-di-GMP-controlled phenotypes and discovered a potential signaling circuit that can be target for biofilm treatment.
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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: 2] [Impact Index Per Article: 0.7] [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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Adipose Tissue-Derived Stromal Cells Alter the Mechanical Stability and Viscoelastic Properties of Gelatine Methacryloyl Hydrogels. Int J Mol Sci 2021; 22:ijms221810153. [PMID: 34576318 PMCID: PMC8468163 DOI: 10.3390/ijms221810153] [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: 08/29/2021] [Revised: 09/14/2021] [Accepted: 09/18/2021] [Indexed: 01/22/2023] Open
Abstract
The extracellular matrix provides mechanical cues to cells within it, not just in terms of stiffness (elasticity) but also time-dependent responses to deformation (viscoelasticity). In this work, we determined the viscoelastic transformation of gelatine methacryloyl (GelMA) hydrogels caused by adipose tissue-derived stromal cells (ASCs) through mathematical modelling. GelMA-ASCs combination is of interest to model stem cell-driven repair and to understand cell-biomaterial interactions in 3D environments. Immortalised human ASCs were embedded in 5%, 10%, and 15% (w/v) GelMA hydrogels and evaluated for 14 d. GelMA had a concentration-dependent increase in stiffness, but cells decreased this stiffness over time, across concentrations. Viscoelastic changes in terms of stress relaxation increased progressively in 5% GelMA, while mathematical Maxwell analysis showed that the relative importance (Ri) of the fastest Maxwell elements increased proportionally. The 10% GelMA only showed differences at 7 d. In contrast, ASCs in 15% GelMA caused slower stress relaxation, increasing the Ri of the slowest Maxwell element. We conclude that GelMA concentration influenced the stiffness and number of Maxwell elements. ASCs changed the percentage stress relaxation and Ri of Maxwell elements transforming hydrogel viscoelasticity into a more fluid environment over time. Overall, 5% GelMA induced the most favourable ASC response.
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11
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Cai YM, Zhang YD, Yang L. NO donors and NO delivery methods for controlling biofilms in chronic lung infections. Appl Microbiol Biotechnol 2021; 105:3931-3954. [PMID: 33937932 PMCID: PMC8140970 DOI: 10.1007/s00253-021-11274-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/23/2021] [Accepted: 04/05/2021] [Indexed: 12/18/2022]
Abstract
Nitric oxide (NO), the highly reactive radical gas, provides an attractive strategy in the control of microbial infections. NO not only exhibits bactericidal effect at high concentrations but also prevents bacterial attachment and disperses biofilms at low, nontoxic concentrations, rendering bacteria less tolerant to antibiotic treatment. The endogenously generated NO by airway epithelium in healthy populations significantly contributes to the eradication of invading pathogens. However, this pathway is often compromised in patients suffering from chronic lung infections where biofilms dominate. Thus, exogenous supplementation of NO is suggested to improve the therapeutic outcomes of these infectious diseases. Compared to previous reviews focusing on the mechanism of NO-mediated biofilm inhibition, this review explores the applications of NO for inhibiting biofilms in chronic lung infections. It discusses how abnormal levels of NO in the airways contribute to chronic infections in cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD), and primary ciliary dyskinesia (PCD) patients and why exogenous NO can be a promising antibiofilm strategy in clinical settings, as well as current and potential in vivo NO delivery methods. KEY POINTS : • The relationship between abnormal NO levels and biofilm development in lungs • The antibiofilm property of NO and current applications in lungs • Potential NO delivery methods and research directions in the future.
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Affiliation(s)
- Yu-Ming Cai
- Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, UK.
| | - Ying-Dan Zhang
- School of Medicine, Southern University of Science and Technology, Shenzhen, 518000, China
| | - Liang Yang
- School of Medicine, Southern University of Science and Technology, Shenzhen, 518000, China.
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Gloag ES, Fabbri S, Wozniak DJ, Stoodley P. Biofilm mechanics: Implications in infection and survival. Biofilm 2020; 2:100017. [PMID: 33447803 PMCID: PMC7798440 DOI: 10.1016/j.bioflm.2019.100017] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 12/06/2019] [Accepted: 12/09/2019] [Indexed: 12/18/2022] Open
Abstract
It has long been recognized that biofilms are viscoelastic materials, however the importance of this attribute to the survival and persistence of these microbial communities is yet to be fully realized. Here we review work, which focuses on understanding biofilm mechanics and put this knowledge in the context of biofilm survival, particularly for biofilm-associated infections. We note that biofilm viscoelasticity may be an evolved property of these communities, and that the production of multiple extracellular polymeric slime components may be a way to ensure the development of biofilms with complex viscoelastic properties. We discuss viscoelasticity facilitating biofilm survival in the context of promoting the formation of larger and stronger biofilms when exposed to shear forces, promoting fluid-like behavior of the biofilm and subsequent biofilm expansion by viscous flow, and enabling resistance to both mechanical and chemical methods of clearance. We conclude that biofilm viscoelasticity contributes to the virulence of chronic biofilm infections.
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Affiliation(s)
- Erin S. Gloag
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, 43210, USA
| | | | - Daniel J. Wozniak
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, 43210, USA
- Department of Microbiology, The Ohio State University, Columbus, OH, 43210, USA
| | - Paul Stoodley
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, 43210, USA
- Department of Microbiology, The Ohio State University, Columbus, OH, 43210, USA
- Department of Orthopedics, The Ohio State University, Columbus, OH, 43210, USA
- National Biofilm Innovation Centre (NBIC) and National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, Southampton, SO17 1BJ, UK
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13
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Cieśluk M, Deptuła P, Piktel E, Fiedoruk K, Suprewicz Ł, Paprocka P, Kot P, Pogoda K, Bucki R. Physics Comes to the Aid of Medicine-Clinically-Relevant Microorganisms through the Eyes of Atomic Force Microscope. Pathogens 2020; 9:pathogens9110969. [PMID: 33233696 PMCID: PMC7699805 DOI: 10.3390/pathogens9110969] [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: 10/29/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 12/01/2022] Open
Abstract
Despite the hope that was raised with the implementation of antibiotics to the treatment of infections in medical practice, the initial enthusiasm has substantially faded due to increasing drug resistance in pathogenic microorganisms. Therefore, there is a need for novel analytical and diagnostic methods in order to extend our knowledge regarding the mode of action of the conventional and novel antimicrobial agents from a perspective of single microbial cells as well as their communities growing in infected sites, i.e., biofilms. In recent years, atomic force microscopy (AFM) has been mostly used to study different aspects of the pathophysiology of noninfectious conditions with attempts to characterize morphological and rheological properties of tissues, individual mammalian cells as well as their organelles and extracellular matrix, and cells’ mechanical changes upon exposure to different stimuli. At the same time, an ever-growing number of studies have demonstrated AFM as a valuable approach in studying microorganisms in regard to changes in their morphology and nanomechanical properties, e.g., stiffness in response to antimicrobial treatment or interaction with a substrate as well as the mechanisms behind their virulence. This review summarizes recent developments and the authors’ point of view on AFM-based evaluation of microorganisms’ response to applied antimicrobial treatment within a group of selected bacteria, fungi, and viruses. The AFM potential in development of modern diagnostic and therapeutic methods for combating of infections caused by drug-resistant bacterial strains is also discussed.
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Affiliation(s)
- Mateusz Cieśluk
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, PL-15222 Bialystok, Poland; (M.C.); (P.D.); (E.P.); (K.F.); (Ł.S.)
| | - Piotr Deptuła
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, PL-15222 Bialystok, Poland; (M.C.); (P.D.); (E.P.); (K.F.); (Ł.S.)
| | - Ewelina Piktel
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, PL-15222 Bialystok, Poland; (M.C.); (P.D.); (E.P.); (K.F.); (Ł.S.)
| | - Krzysztof Fiedoruk
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, PL-15222 Bialystok, Poland; (M.C.); (P.D.); (E.P.); (K.F.); (Ł.S.)
| | - Łukasz Suprewicz
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, PL-15222 Bialystok, Poland; (M.C.); (P.D.); (E.P.); (K.F.); (Ł.S.)
| | - Paulina Paprocka
- Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University in Kielce, PL-25317 Kielce, Poland; (P.P.); (P.K.)
| | - Patrycja Kot
- Department of Microbiology and Immunology, Institute of Medical Science, Collegium Medicum, Jan Kochanowski University in Kielce, PL-25317 Kielce, Poland; (P.P.); (P.K.)
| | - Katarzyna Pogoda
- Institute of Nuclear Physics Polish Academy of Sciences, PL-31342 Krakow, Poland;
| | - Robert Bucki
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Bialystok, PL-15222 Bialystok, Poland; (M.C.); (P.D.); (E.P.); (K.F.); (Ł.S.)
- Correspondence:
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14
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Pereira TC, Dijkstra RJB, Petridis X, Sharma PK, van de Meer WJ, van der Sluis LWM, de Andrade FB. Chemical and mechanical influence of root canal irrigation on biofilm removal from lateral morphological features of simulated root canals, dentine discs and dentinal tubules. Int Endod J 2020; 54:112-129. [PMID: 32880989 PMCID: PMC7839520 DOI: 10.1111/iej.13399] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 08/26/2020] [Indexed: 01/08/2023]
Abstract
Aim To investigate the anti‐biofilm efficacy of irrigation using a simulated root canal model, the chemical effect of irrigants against biofilms grown on dentine discs and their impact on biofilm viscoelasticity, the efficacy of the irrigants in decontaminating infected dentinal tubules and the capacity of bacteria to regrow. Methodology Biofilm removal, viscoelastic analysis of remaining biofilms and bacterial viability were evaluated using a simulated root canal model with lateral morphological features, dentine discs and a dentinal tubule model, respectively. Experiments were conducted using a two‐phase irrigation protocol. Phase 1: a modified salt solution (RISA) and sodium hypochlorite (NaOCl) were used at a low flow rate to evaluate the chemical action of the irrigants. Ultrasonic activation (US) of a chemically inert solution (buffer) was used to evaluate the mechanical efficacy of irrigation. Phase 2: a final irrigation with buffer at a high flow rate was performed for all groups. Optical coherence tomography (OCT), low load compression testing (LLCT) and confocal scanning laser microscopy analysis were used in the different models. One‐way analysis of variance (anova) was performed for the OCT and LLCT analysis, whilst Kruskal–Wallis and Wilcoxon ranked tests for the dentinal tubule model. Results US and high flow rate removed significantly more biofilm from the artificial lateral canal. For biofilm removal from the artificial isthmus, no significant differences were found between the groups. Within‐group analysis revealed significant differences between the steps of the experiment, with the exception of NaOCl. For the dentine discs, no significant differences regarding biofilm removal and viscoelasticity were detected. In the dentinal tubule model, NaOCl exhibited the greatest anti‐biofilm efficacy. Conclusions The mechanical effect of irrigation is important for biofilm removal. An extra high flow irrigation rate resulted in greater biofilm removal than US in the artificial isthmus. The mechanical effect of US seemed to be more effective when the surface contact biofilm–irrigant was small. After the irrigation procedures, the remaining biofilm could survive after a 5‐day period. RISA and NaOCl seemed to alter post‐treatment remaining biofilms.
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Affiliation(s)
- T C Pereira
- Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil.,Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - R J B Dijkstra
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - X Petridis
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - P K Sharma
- Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - W J van de Meer
- Department of Orthodontics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - L W M van der Sluis
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - F B de Andrade
- Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil
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15
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Rouillard KR, Markovetz MR, Bacudio LG, Hill DB, Schoenfisch MH. Pseudomonas aeruginosa Biofilm Eradication via Nitric Oxide-Releasing Cyclodextrins. ACS Infect Dis 2020; 6:1940-1950. [PMID: 32510928 DOI: 10.1021/acsinfecdis.0c00246] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Pseudomonas aeruginosa is the main contributor to the morbidity and mortality of cystic fibrosis (CF) patients. Chronic respiratory infections are rarely eradicated due to protection from CF mucus and the biofilm matrix. The composition of the biofilm matrix determines its viscoelastic properties and affects antibiotic efficacy. Nitric oxide (NO) can both disrupt the physical structure of the biofilm and eradicate interior colonies. The effects of a CF-like growth environment on P. aeruginosa biofilm susceptibility to NO were investigated using parallel plate macrorheology and particle tracking microrheology. Biofilms grown in the presence of mucins and DNA contained greater concentrations of DNA in the matrix and exhibited concomitantly larger viscoelastic moduli compared to those grown in tryptic soy broth. Greater viscoelastic moduli correlated with increased tolerance to tobramycin and colistin. Remarkably, NO-releasing cyclodextrins eradicated all biofilms at the same concentration. The capacity of NO-releasing cyclodextrins to eradicate P. aeruginosa biofilms irrespective of matrix composition suggests that NO-based therapies may be superior antibiofilm treatments compared to conventional antibiotics.
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Affiliation(s)
- Kaitlyn R. Rouillard
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Matthew R. Markovetz
- Marsico Lung Institute/CF Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Lawrence G. Bacudio
- Marsico Lung Institute/CF Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - David B. Hill
- Marsico Lung Institute/CF Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Mark H. Schoenfisch
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Vast Therapeutics, Durham, North Carolina 27703, United States
- UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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16
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Pereira TC, Dijkstra RJB, Petridis X, van der Meer WJ, Sharma PK, de Andrade FB, van der Sluis LWM. The influence of time and irrigant refreshment on biofilm removal from lateral morphological features of simulated root canals. Int Endod J 2020; 53:1705-1714. [PMID: 32502284 PMCID: PMC7754391 DOI: 10.1111/iej.13342] [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: 12/20/2019] [Revised: 05/26/2020] [Accepted: 05/29/2020] [Indexed: 12/15/2022]
Abstract
Aim To evaluate the effect of irrigant refreshment and exposure time of a 2% sodium hypochlorite solution (NaOCl) on biofilm removal from simulated lateral root canal spaces using two different flow rates. Methodology A dual‐species biofilm was formed by a Constant Depth Film Fermenter (CDFF) for 96 h in plug inserts with anatomical features resembling an isthmus or lateral canal‐like structures. The inserts were placed in a root canal model facing the main canal. NaOCl 2% and demineralized water (control group) were used as irrigant solutions. Both substances were applied at a flow rate of 0.05 and 0.1 mL s−1. The samples were divided into three groups with zero, one or two refreshments in a total exposure time of 15 min. A three‐way analysis of variance (anova) was performed to investigate the interaction amongst the independent variables and the effect of consecutive irrigant refreshment on percentage of biofilm removal. A Tukey post hoc test was used to evaluate the effect of each independent variable on percentage biofilm removal in the absence of statistically significant interactions. Results For the lateral canal, NaOCl removed significantly more biofilm irrespective of the number of refreshments and exposure time (P = 0.005). There was no significant effect in biofilm removal between the consecutive irrigant refreshments measured in the same biofilm. For the isthmus, NaOCl removed significantly more biofilm irrespective of the number of refreshments and exposure time; both NaOCl and a high flow rate removed significantly more biofilm when the exposure time was analysed (P = 0.018 and P = 0.029, respectively). Evaluating the effect of consecutive irrigant refreshment on the same biofilm, 2% NaOCl, 0.1 mL s−1 flow rate and one or two refreshments removed significant more biofilm (P = 0.04, 0.034 and 0.003, <0.001, respectively). Conclusions In this model, refreshment did not improve biofilm removal from simulated lateral root canal spaces. NaOCl removed more biofilm from the lateral canal‐ and isthmus‐like structure. A higher flow rate removed significantly more biofilm from the isthmus‐like structure. There was always remaining biofilm left after the irrigation procedures.
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Affiliation(s)
- T C Pereira
- Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil.,Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - R J B Dijkstra
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - X Petridis
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - W J van der Meer
- Department of Orthodontics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - P K Sharma
- Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - F B de Andrade
- Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil
| | - L W M van der Sluis
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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17
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Gu H, Lee SW, Carnicelli J, Zhang T, Ren D. Magnetically driven active topography for long-term biofilm control. Nat Commun 2020; 11:2211. [PMID: 32371860 PMCID: PMC7200660 DOI: 10.1038/s41467-020-16055-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 04/10/2020] [Indexed: 12/15/2022] Open
Abstract
Microbial biofilm formation on indwelling medical devices causes persistent infections that cannot be cured with conventional antibiotics. To address this unmet challenge, we engineer tunable active surface topographies with micron-sized pillars that can beat at a programmable frequency and force level in an electromagnetic field. Compared to the flat and static controls, active topographies with the optimized design prevent biofilm formation and remove established biofilms of uropathogenic Escherichia coli (UPEC), Pseudomonas aeruginosa, and Staphylococcus aureus, with up to 3.7 logs of biomass reduction. In addition, the detached biofilm cells are found sensitized to bactericidal antibiotics to the level comparable to exponential-phase planktonic cells. Based on these findings, a prototype catheter is engineered and found to remain clean for at least 30 days under the flow of artificial urine medium, while the control catheters are blocked by UPEC biofilms within 5 days.
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Affiliation(s)
- Huan Gu
- Department of Biomedical and Chemical Engineering, Syracuse University, 329 Link Hall, Syracuse, New York, 13244, USA
- Syracuse Biomaterials Institute, Syracuse University, 318 Bowne Hall, Syracuse, New York, 13244, USA
| | - Sang Won Lee
- Department of Biomedical and Chemical Engineering, Syracuse University, 329 Link Hall, Syracuse, New York, 13244, USA
- Syracuse Biomaterials Institute, Syracuse University, 318 Bowne Hall, Syracuse, New York, 13244, USA
| | - Joseph Carnicelli
- Department of Biomedical and Chemical Engineering, Syracuse University, 329 Link Hall, Syracuse, New York, 13244, USA
- Syracuse Biomaterials Institute, Syracuse University, 318 Bowne Hall, Syracuse, New York, 13244, USA
| | - Teng Zhang
- Syracuse Biomaterials Institute, Syracuse University, 318 Bowne Hall, Syracuse, New York, 13244, USA
- Department of Mechanical and Aerospace Engineering, Syracuse University, 214 Link Hall, Syracuse, New York, 13244, USA
| | - Dacheng Ren
- Department of Biomedical and Chemical Engineering, Syracuse University, 329 Link Hall, Syracuse, New York, 13244, USA.
- Syracuse Biomaterials Institute, Syracuse University, 318 Bowne Hall, Syracuse, New York, 13244, USA.
- Department of Civil and Environmental Engineering, Syracuse University, 151 Link Hall, Syracuse, New York, 13244, USA.
- Department of Biology, Syracuse University, 114 Life Sciences Complex, Syracuse, New York, 13244, USA.
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18
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Activity of Antibiotics against Pseudomonas aeruginosa in an In Vitro Model of Biofilms in the Context of Cystic Fibrosis: Influence of the Culture Medium. Antimicrob Agents Chemother 2020; 64:AAC.02204-19. [PMID: 32015047 DOI: 10.1128/aac.02204-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 01/24/2020] [Indexed: 12/28/2022] Open
Abstract
Pseudomonas aeruginosa is a major cause of respiratory biofilm-related infections in patients with cystic fibrosis. We developed an in vitro pharmacodynamic model to study the activity of antipseudomonal antibiotics against PAO1 biofilms grown in artificial sputum medium with agar [ASM(+)] versus that against biofilms grown in Trypticase soy broth supplemented with glucose and NaCl (TGN). We measured bacterial counts, metabolic activity (fluorescein diacetate [FDA] hydrolysis), and biomass (crystal violet absorbance). Biofilms grew slower in ASM(+) than in TGN but reached the same CFU counts and metabolic activity in both media and a slightly higher biomass after 48 h in ASM(+) than in TGN. The concentration-response curves of the antibiotics after 24 h of incubation with mature biofilms showed maximal effects ranging from a 3 (ciprofloxacin)- to a 1.5 (ceftazidime, meropenem)-log10-CFU decrease, with tobramycin and colistin showing intermediate values. These maximal reductions in the numbers of CFU were similar in both media for ciprofloxacin and β-lactams but lower in ASM(+) than in TGN for tobramycin and colistin; they were reached at concentrations lower than the human maximum concentration in plasma for ciprofloxacin and β-lactams only. The reductions in metabolic activity and in biomass were low in both media. Small-colony variants were selected by tobramycin in ASM(+) and by ciprofloxacin in both media. The model was then successfully applied to 4 isolates from patients with cystic fibrosis. These biofilms showed CFU counts similar to those of PAO1 biofilms in ASM(+) but a higher biomass than PAO1 biofilms in ASM(+) and moderate differences in their susceptibility to antibiotics from that of PAO1 biofilms grown in this medium. This model proved useful to establish the pharmacodynamic profile of drugs against P. aeruginosa biofilms in the context of cystic fibrosis.
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19
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Rouillard KR, Hill DB, Schoenfisch MH. Antibiofilm and mucolytic action of nitric oxide delivered via gas or macromolecular donor using in vitro and ex vivo models. J Cyst Fibros 2020; 19:1004-1010. [PMID: 32205069 DOI: 10.1016/j.jcf.2020.03.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/02/2020] [Accepted: 03/05/2020] [Indexed: 01/06/2023]
Abstract
BACKGROUND The combination of antibacterial and mucolytic actions makes nitric oxide (NO) an attractive dual-action cystic fibrosis (CF) therapeutic. The delivery of any therapeutic agent through pathological mucus is difficult, and the use of inhaled NO gas is inherently limited by toxicity concerns. Herein, we directly compare the ability of NO to eradicate infection and decrease mucus viscoelastic moduli as a function of delivery method (i.e., as a gas or water-soluble chitosan donor). METHODS To compare bactericidal action in tissue, an ex vivo porcine lung model was infected and treated with either gaseous NO or NO-releasing chitosan for 5 h. In vitro Pseudomonas aeruginosa biofilm viability was quantified after NO treatment. Human bronchial epithelial mucus and CF sputum were exposed to NO and their viscoelastic moduli measured with parallel plate macrorheology. RESULTS Larger NO concentrations were achieved in solution when delivered by chitosan relative to gas exposure. The bactericidal action in tissue of the NO-releasing chitosan was greater compared to NO gas in the infected tissue model. Chitosan delivery also resulted in improved antibiofilm action and reduced biofilm viability (2-log) while gaseous delivery had no impact at an equivalent dose (~0.8 µmol/mL). At equivalent NO doses, mucus and sputum rheology were significantly reduced after treatment with NO-releasing chitosan with NO gas having no significant effect. CONCLUSIONS Delivery of NO by chitosan allows for larger in-solution concentrations than achievable via direct gas with superior bactericidal and mucolytic action.
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Affiliation(s)
- Kaitlyn R Rouillard
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - David B Hill
- Marsico Lung Institute/CF Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Mark H Schoenfisch
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Vast Therapeutics, Durham, NC, USA; UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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20
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Petridis X, Busanello FH, So MVR, Dijkstra RJB, Sharma PK, van der Sluis LWM. Chemical efficacy of several NaOCl concentrations on biofilms of different architecture: new insights on NaOCl working mechanisms. Int Endod J 2019; 52:1773-1788. [PMID: 31389008 PMCID: PMC7328853 DOI: 10.1111/iej.13198] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/03/2019] [Indexed: 01/20/2023]
Abstract
AIM To investigate the anti-biofilm efficacy and working mechanism of several NaOCl concentrations on dual-species biofilms of different architecture as well as the changes induced on the architecture of the remaining biofilms. METHODOLOGY Streptococcus oralis J22 and Actinomyces naeslundii T14V-J1 were co-cultured under different growth conditions on saliva-coated hydroxyapatite discs. A constant-depth film fermenter (CDFF) was used to grow steady-state, four-day mature biofilms (dense architecture). Biofilms were grown under static conditions for 4 days within a confined space (less dense architecture). Twenty microlitres of buffer, 2-, 5-, and 10% NaOCl were applied statically on the biofilms for 60 s. Biofilm disruption and dissolution, as well as bubble formation, were evaluated with optical coherence tomography (OCT). The viscoelastic profile of the biofilms post-treatment was assessed with low load compression testing (LLCT). The bacteria/extracellular polysaccharide (EPS) content of the biofilms was examined through confocal laser scanning microscopy (CLSM). OCT, LLCT and CLSM data were analysed through one-way analysis of variance (ANOVA) and Tukey's HSD post-hoc test. Linear regression analysis was performed to test the correlation between bubble formation and NaOCl concentration. The level of significance was set at a < 0.05. RESULTS The experimental hypothesis according to which enhanced biofilm disruption, dissolution and bubble formation were anticipated with increasing NaOCl concentration was generally confirmed in both biofilm types. Distinct differences between the two biofilm types were noted with regard to NaOCl anti-biofilm efficiency as well as the effect that the several NaOCl concentrations had on the viscoelasticity profile and the bacteria/EPS content. Along with the bubble generation patterns observed, these led to the formulation of a concentration and biofilm structure-dependent theory of biofilm removal. CONCLUSIONS Biofilm architecture seems to be an additional determining factor of the penetration capacity of NaOCl, and consequently of its anti-biofilm efficiency.
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Affiliation(s)
- X Petridis
- Department of Conservative Dentistry, Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - F H Busanello
- Conservative Dentistry Department, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - M V R So
- Conservative Dentistry Department, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - R J B Dijkstra
- Department of Conservative Dentistry, Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - P K Sharma
- Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - L W M van der Sluis
- Department of Conservative Dentistry, Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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