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Adams JME, Moulding PB, El-Halfawy OM. Polyamine-Mediated Sensitization of Klebsiella pneumoniae to Macrolides through a Dual Mode of Action. ACS Infect Dis 2024; 10:2183-2195. [PMID: 38695481 DOI: 10.1021/acsinfecdis.4c00157] [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] [Indexed: 06/15/2024]
Abstract
Chemicals bacteria encounter at the infection site could shape their stress and antibiotic responses; such effects are typically undetected under standard lab conditions. Polyamines are small molecules typically overproduced by the host during infection and have been shown to alter bacterial stress responses. We sought to determine the effect of polyamines on the antibiotic response of Klebsiella pneumoniae, a Gram-negative priority pathogen. Interestingly, putrescine and other natural polyamines sensitized K. pneumoniae to azithromycin, a macrolide protein translation inhibitor typically used for Gram-positive bacteria. This synergy was further potentiated in the physiological buffer, bicarbonate. Chemical genomic screens suggested a dual mechanism, whereby putrescine acts at the membrane and ribosome levels. Putrescine permeabilized the outer membrane of K. pneumoniae (NPN and β-lactamase assays) and the inner membrane (Escherichia coli β-galactosidase assays). Chemically and genetically perturbing membranes led to a loss of putrescine-azithromycin synergy. Putrescine also inhibited protein synthesis in an E. coli-derived cell-free protein expression assay simultaneously monitoring transcription and translation. Profiling the putrescine-azithromycin synergy against a combinatorial array of antibiotics targeting various ribosomal sites suggested that putrescine acts as tetracyclines targeting the 30S ribosomal acceptor site. Next, exploiting the natural polyamine-azithromycin synergy, we screened a polyamine analogue library for azithromycin adjuvants, discovering four azithromycin synergists with activity starting from the low micromolar range and mechanisms similar to putrescine. This work sheds light on the bacterial antibiotic responses under conditions more reflective of those at the infection site and provides a new strategy to extend the macrolide spectrum to drug-resistant K. pneumoniae.
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Affiliation(s)
- Joshua M E Adams
- Department of Chemistry and Biochemistry, Faculty of Science, University of Regina, Regina, SK S4S 0A2, Canada
| | - Peri B Moulding
- Department of Chemistry and Biochemistry, Faculty of Science, University of Regina, Regina, SK S4S 0A2, Canada
| | - Omar M El-Halfawy
- Department of Chemistry and Biochemistry, Faculty of Science, University of Regina, Regina, SK S4S 0A2, Canada
- Department of Microbiology and Immunology, Faculty of Pharmacy, Alexandria University, Alexandria, 21521, Egypt
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2
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Ferguson DL, Gloag ES, Parsek MR, Wozniak DJ. Extracellular DNA enhances biofilm integrity and mechanical properties of mucoid Pseudomonas aeruginosa. J Bacteriol 2023; 205:e0023823. [PMID: 37791754 PMCID: PMC10601617 DOI: 10.1128/jb.00238-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 08/31/2023] [Indexed: 10/05/2023] Open
Abstract
Pseudomonas aeruginosa is one of the most common biofilm-forming pathogens responsible for lung infections of individuals with cystic fibrosis (CF). P. aeruginosa becomes tolerant to antimicrobials in the biofilm state and is difficult to treat. Production of extracellular polymeric substances (EPS), such as alginate and extracellular DNA (eDNA), can allow adherence to abiotic and biotic surfaces, antimicrobial evasion, and resilience to environmental pressures. Alginate-producing mucoid variants of P. aeruginosa are frequently isolated from CF airway samples and are associated with worsening patient outcomes. While eDNA is a major structural component of nonmucoid P. aeruginosa biofilms, the potential role of eDNA in mucoid biofilms is unclear. Here, we investigate how eDNA contributes to clinical mucoid biofilm physiology and integrity. We predicted that eDNA plays a structural and mechanical role in mucoid biofilms. To test this, we quantified biofilm eDNA in mucoid biofilms and used microscopy and rheology to visualize eDNA and detect changes in biofilm structure and mechanics upon DNaseI treatment. We showed that biofilm eDNA abundance is diverse across clinical mucoid strains and observed a temporal increase in foci of eDNA within intact mucoid biofilms. Increased cell dispersal and reduced biomass were also observed following DNaseI treatment of mucoid biofilms. Degradation of eDNA also impacted the mechanical integrity of mucoid biofilms by increasing the stiffness and decreasing the cohesion of the biofilm. These findings advance our understanding of clinical mucoid P. aeruginosa biofilms and facilitate the development of new approaches to target biofilms by exploiting the functions of EPS components. IMPORTANCE Understanding the role of eDNA in mucoid Pseudomonas aeruginosa biofilms will lead to therapeutic strategies that combat the biophysical and structural function of EPS for the eradication of bacteria in mucoid biofilms during chronic infections. This knowledge can be used to further identify unknown matrix component interactions within pathogenic biofilm-forming clinical isolates.
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Affiliation(s)
- Danielle L. Ferguson
- Department of Microbial Infection and Immunity, Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Erin S. Gloag
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
| | - Matthew R. Parsek
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | - Daniel J. Wozniak
- Department of Microbial Infection and Immunity, Microbiology, The Ohio State University, Columbus, Ohio, USA
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Corcoran TE, Bertrand CA, Myerburg MM, Weiner DJ, Frizzell SA, Li A, Agostini B, Parker RS, Shapiro ME, Muthukrishnan A, Hages ND, Mulhern BP, Pilewski JM. Nasal epithelial cell culture fluorescence recovery after photobleaching predicts cystic fibrosis therapeutic response. ERJ Open Res 2022; 8:00382-2022. [PMID: 36655223 PMCID: PMC9835985 DOI: 10.1183/23120541.00382-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 09/23/2022] [Indexed: 11/12/2022] Open
Abstract
Background Human nasal epithelial (HNE) cells can be sampled noninvasively and cultured to provide a model of the airway epithelium that reflects cystic fibrosis (CF) pathophysiology. We hypothesised that in vitro measures of HNE cell physiology would correlate directly with in vivo measures of lung physiology and therapeutic response, providing a framework for using HNE cells for therapeutic development and precision medicine. Methods We sampled nasal cells from participants with CF (CF group, n=26), healthy controls (HC group, n=14) and single CF transmembrane conductance regulator (CFTR) mutation carrier parents of the CF group (CR group, n=16). Participants underwent lung physiology and sweat chloride testing, and nuclear imaging-based measurement of mucociliary clearance (MCC) and small-molecule absorption (ABS). CF participants completed a second imaging day that included hypertonic saline (HS) inhalation to assess therapeutic response in terms of MCC. HNE measurements included Ussing chamber electrophysiology, small-molecule and liquid absorption rates, and particle diffusion rates through the HNE airway surface liquid (ASL) measured using fluorescence recovery after photobleaching (FRAP). Results Long FRAP diffusion times were associated with increased MCC response to HS in CF. This implies a strong relationship between inherent factors affecting ASL mucin concentration and therapeutic response to a hydrating therapy. MCC decreased with age in the CR group, which had a larger range of ages than the other two groups. Likely this indicates a general age-related effect that may be accentuated in this group. Measures of lung ABS correlated with sweat chloride in both the HC and CF groups, indicating that CFTR function drives this measure of paracellular small-molecule probe absorption. Conclusions Our results demonstrate the utility of HNE cultures for assessing therapeutic response for hydrating therapies. In vitro measurements of FRAP were particularly useful for predicting response and for characterising important properties of ASL mucus that were ultimately reflected in lung physiology.
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Affiliation(s)
- Timothy E. Corcoran
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Carol A. Bertrand
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael M. Myerburg
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Daniel J. Weiner
- Division of Pediatric Pulmonology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sheila A. Frizzell
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Anna Li
- School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Brittani Agostini
- Division of Pediatric Pulmonology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Robert S. Parker
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Monica E. Shapiro
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Nicholas D. Hages
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Brian P. Mulhern
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Joseph M. Pilewski
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
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Characterizing mucociliary clearance in young children with cystic fibrosis. Pediatr Res 2022; 91:612-620. [PMID: 33753897 PMCID: PMC8455702 DOI: 10.1038/s41390-021-01453-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 02/10/2021] [Accepted: 02/18/2021] [Indexed: 12/05/2022]
Abstract
BACKGROUND This research characterized mucociliary clearance (MCC) in young children with cystic fibrosis (CF). METHODS Fourteen children (5-7 years old) with CF underwent: two baseline MCC measurements (Visits 1 and 2); one MCC measurement approximately 1 year later (Visit 3); and measurements of lung clearance index (LCI), a measure of ventilation inhomogeneity. RESULTS Median (range) percent MCC through 60 min (MCC60) was similar on Visits 1 and 2 with 11.0 (0.9-33.7) and 12.8 (2.7-26.8), respectively (p = 0.95), and reproducible (Spearman Rho = 0.69; p = 0.007). Mucociliary clearance did not change significantly over 1 year with median percent MCC60 on Visit 3 [12.8 (3.7-17.6)] similar to Visit 2 (p = 0.58). Lower percent MCC60 on Visit 3 was significantly associated with higher LCI scores on Visit 3 (N = 14; Spearman Rho = -0.56; p = 0.04). CONCLUSIONS Tests of MCC were reproducible and reliable over a 2-week period and stable over a 1-year period in 5-7-year-old children with CF. Lower MCC values were associated with increased ventilation inhomogeneity. These results suggest that measurements of MCC could be used in short-term clinical trials of interventions designed to modulate MCC and as a new, non-invasive test to evaluate early lung pathology in children with CF. IMPACT This is the first study to characterize mucociliary clearance (MCC) in children with cystic fibrosis (CF) who were 5-7 years old. Measurements of mucociliary clearance were reproducible and reliable over a 2-week period and stable over a 1-year period. Variability in MCC between children was associated with differences in ventilation homogeneity, such that children with lower MCC values had increased ventilation inhomogeneity. These results suggest that measurements of MCC could be used in short-term clinical trials of interventions designed to modulate MCC and as a new, non-invasive test to evaluate early lung pathology in children with CF.
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Bojanowski CM, Lu S, Kolls JK. Mucosal Immunity in Cystic Fibrosis. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2021; 207:2901-2912. [PMID: 35802761 PMCID: PMC9270582 DOI: 10.4049/jimmunol.2100424] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 10/21/2021] [Indexed: 05/27/2023]
Abstract
The highly complex and variable genotype-phenotype relationships observed in cystic fibrosis (CF) have been an area of growing interest since the discovery of the CF transmembrane conductance regulator (CFTR) gene >30 y ago. The consistently observed excessive, yet ineffective, activation of both the innate and adaptive host immune systems and the establishment of chronic infections within the lung, leading to destruction and functional decline, remain the primary causes of morbidity and mortality in CF. The fact that both inflammation and pathogenic bacteria persist despite the introduction of modulator therapies targeting the defective protein, CFTR, highlights that we still have much to discover regarding mucosal immunity determinants in CF. Gene modifier studies have overwhelmingly implicated immune genes in the pulmonary phenotype of the disease. In this context, we aim to review recent advances in our understanding of the innate and adaptive immune systems in CF lung disease.
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Affiliation(s)
- Christine M Bojanowski
- Section of Pulmonary Diseases, Critical Care, and Environmental Medicine, Department of Medicine, Tulane University School of Medicine, New Orleans, LA;
| | - Shiping Lu
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA; and
| | - Jay K Kolls
- Center for Translational Research in Infection and Inflammation, Department of Medicine, Tulane University School of Medicine, New Orleans, LA
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6
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Laube BL, Carson KA, Evans CM, Richardson VL, Sharpless G, Zeitlin PL, Mogayzel PJ. Changes in mucociliary clearance over time in children with cystic fibrosis. Pediatr Pulmonol 2020; 55:2307-2314. [PMID: 32427408 PMCID: PMC7674244 DOI: 10.1002/ppul.24858] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 05/17/2020] [Indexed: 12/24/2022]
Abstract
OBJECTIVES (a) To quantify changes in mucociliary clearance (MCC) over time in children with cystic fibrosis (CF) and the relationship between MCC and rate of infection with Pseudomonas aeruginosa (PA); (b) to determine the impact of MCC on the evolution of CF lung disease; and (c) to explore the role of mucus composition as a determinant of MCC. METHODS Children with CF, who had previously undergone an MCC measurement (visit 1), underwent the following tests 3 to 10 years later: (a) second MCC measurement (visit 2); (b) multiple breath washout to assess ventilation inhomogeneity, expressed as lung clearance index (LCI); (c) high resolution computed tomography lung scan (HRCT); and (d) induced sputum test. Number of PA + cultures/year between visits was documented and mucus dry weight was quantified in the children and adult controls. RESULTS Nineteen children completed both visits. Median time between visits was 4.6 years. Clearance declined 30% between visits. Lower MCC on visit 2 was associated with more PA+ cultures/year between visits. Lower MCC values on visit 1 were associated with higher LCI values and higher HRCT scores on visit 2. Mucus dry weight was significantly higher in children with CF compared with controls. Higher dry weights were associated with lower MCC. CONCLUSIONS Mucociliary clearance declines significantly over time in children with CF. The decline is associated with PA infection rate and is affected by mucus composition. Children with early slowing of MCC appear to be at risk for developing ventilation inhomogeneity and parenchymal lung damage when they are older.
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Affiliation(s)
- Beth L. Laube
- Department of Pediatrics, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287
| | - Kathryn A. Carson
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205
| | - Christopher M. Evans
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, 80045
| | - Vanessa L. Richardson
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, 80045
| | - Gail Sharpless
- Department of Pediatrics, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287
| | - Pamela L. Zeitlin
- Department of Pediatrics, National Jewish Health, Denver, Colorado 80206
| | - Peter J. Mogayzel
- Department of Pediatrics, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287
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Corcoran TE, Huber AS, Myerburg MM, Weiner DJ, Locke LW, Lacy RT, Weber L, Czachowski MR, Johnston DJ, Muthukrishnan A, Lennox AT, Pilewski JM. Multiprobe Nuclear Imaging of the Cystic Fibrosis Lung as a Biomarker of Therapeutic Effect. J Aerosol Med Pulm Drug Deliv 2019; 32:242-249. [PMID: 30969149 PMCID: PMC6685188 DOI: 10.1089/jamp.2018.1491] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 02/04/2019] [Indexed: 01/03/2023] Open
Abstract
Background: Nuclear imaging biomarkers illustrate unique aspects of lung physiology and are useful for assessing therapeutic effects in cystic fibrosis (CF) lung disease. We have developed a multiprobe method to simultaneously measure mucociliary clearance (MCC) and paracellular absorption (ABS). MCC is a direct measure of mucus clearance. ABS has been related to airway surface liquid (ASL) absorption through previous in vitro studies. Methods: We describe baseline factors affecting MCC and ABS using data from a retrospective baseline group (n = 22) and the response of the measures to inhaled 7% hypertonic saline (HS) and dry powder mannitol using data from a prospective response group (n = 7). A retrospective healthy control group (n = 15) is also described. The baseline and control groups performed single measurements of MCC/ABS. The response group performed baseline measurements of MCC/ABS and measurements after each intervention. Results: ABS was correlated (Spearman's ρ = 0.51, p = 0.06) to sweat chloride, a systemic measure of cystic fibrosis transmembrane conductance regulator (CFTR) function, whereas MCC was not. Baseline MCC was depressed after Pseudomonas aeruginosa infection as we have previously described. MCC provided a more sensitive indication of therapeutic effect and indicated improved clearance with mannitol compared with HS. Conclusion: MCC provides a useful and well-established means of testing therapies directed at improving mucus clearance in the lung. ABS may provide a means of detecting local changes in ASL absorption and CFTR function in the lung. Both are useful tools for studying the key aspects of CF lung pathophysiology (ASL hyperabsorption and MCC depression) that link the basic genetic defects of CF to disease manifestations in the lung.
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Affiliation(s)
- Timothy E. Corcoran
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Alex S. Huber
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Michael M. Myerburg
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Daniel J. Weiner
- Pulmonary Medicine, Allergy, and Immunology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Landon W. Locke
- Department of Microbial Infection and Immunity, Ohio State University, Columbus, Ohio
| | - Ryan T. Lacy
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Lawrence Weber
- Nuclear Medicine Department, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Michael R. Czachowski
- Nuclear Medicine Department, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Darragh J. Johnston
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania
| | | | - Alison T. Lennox
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Joseph M. Pilewski
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Pulmonary Medicine, Allergy, and Immunology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, Pennsylvania
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Donaldson SH, Laube BL, Corcoran TE, Bhambhvani P, Zeman K, Ceppe A, Zeitlin PL, Mogayzel PJ, Boyle M, Locke LW, Myerburg MM, Pilewski JM, Flanagan B, Rowe SM, Bennett WD. Effect of ivacaftor on mucociliary clearance and clinical outcomes in cystic fibrosis patients with G551D-CFTR. JCI Insight 2018; 3:122695. [PMID: 30568035 DOI: 10.1172/jci.insight.122695] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 11/06/2018] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The ability to restore cystic fibrosis transmembrane regulator (CFTR) function with effective small molecule modulators in patients with cystic fibrosis provides an opportunity to study relationships between CFTR ion channel function, organ level physiology, and clinical outcomes. METHODS We performed a multisite, prospective, observational study of ivacaftor, prescribed in patients with the G551D-CFTR mutation. Measurements of lung mucociliary clearance (MCC) were performed before and after treatment initiation (1 and 3 months), in parallel with clinical outcome measures. RESULTS Marked acceleration in whole lung, central lung, and peripheral lung MCC was observed 1 month after beginning ivacaftor and was sustained at 3 months. Improvements in MCC correlated with improvements in forced expiratory volume in the first second (FEV1) but not sweat chloride or symptom scores. CONCLUSIONS Restoration of CFTR activity with ivacaftor led to significant improvements in MCC. This physiologic assessment provides a means to characterize future CFTR modulator therapies and may help to predict improvements in lung function. TRIAL REGISTRATION ClinicialTrials.gov, NCT01521338. FUNDING CFF Therapeutics (GOAL11K1).
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Affiliation(s)
- Scott H Donaldson
- Department of Medicine, University of North Carolina (UNC), Chapel Hill, North Carolina, USA
| | - Beth L Laube
- Department of Pediatrics, Johns Hopkins University, Baltimore, Maryland, USA
| | - Timothy E Corcoran
- Department of Medicine and Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Pradeep Bhambhvani
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Kirby Zeman
- Department of Medicine, University of North Carolina (UNC), Chapel Hill, North Carolina, USA
| | - Agathe Ceppe
- Department of Medicine, University of North Carolina (UNC), Chapel Hill, North Carolina, USA
| | - Pamela L Zeitlin
- Department of Pediatrics, Johns Hopkins University, Baltimore, Maryland, USA
| | - Peter J Mogayzel
- Department of Pediatrics, Johns Hopkins University, Baltimore, Maryland, USA
| | - Michael Boyle
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Landon W Locke
- Department of Medicine and Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Michael M Myerburg
- Department of Medicine and Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Joseph M Pilewski
- Department of Medicine and Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Brian Flanagan
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Steven M Rowe
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - William D Bennett
- Department of Medicine, University of North Carolina (UNC), Chapel Hill, North Carolina, USA
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Gloag ES, German GK, Stoodley P, Wozniak DJ. Viscoelastic properties of Pseudomonas aeruginosa variant biofilms. Sci Rep 2018; 8:9691. [PMID: 29946126 PMCID: PMC6018706 DOI: 10.1038/s41598-018-28009-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 06/05/2018] [Indexed: 01/11/2023] Open
Abstract
Pseudomonas aeruginosa evolves during chronic pulmonary infections of cystic fibrosis (CF) patients, forming pathoadapted variants that are persistent. Mucoid and rugose small-colony variants (RSCVs) are typically isolated from sputum of CF patients. These variants overproduce exopolysaccharides in the biofilm extracellular polymeric substance (EPS). Currently, changes to the biophysical properties of RSCV and mucoid biofilms due to variations in EPS are not well understood. This knowledge may reveal how lung infections resist host clearance mechanisms. Here, we used mechanical indentation and shear rheometry to analyse the viscoelasticity of RSCV and mucoid colony-biofilms compared to their isogenic parent at 2-, 4-, and 6-d. While the viscoelasticity of parental colony-biofilms underwent fluctuating temporal changes, in contrast, RSCV and mucoid colony-biofilms showed a gradual progression to more elastic-solid behaviour. Theoretical indices of mucociliary and cough clearance predict that mature 6-d parental and RSCV biofilms may show reduced cough clearance from the lung, while early mucoid biofilms may show reduced clearance by both mechanisms. We propose that viscoelasticity be considered a virulence property of biofilms.
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Affiliation(s)
- Erin S Gloag
- Department of Microbial Infection and Immunity, Microbiology, The Ohio State University, Columbus, OH, 43210, USA
| | - Guy K German
- Department of Biomedical Engineering, Binghamton University, Binghamton, NY, 13902, USA
| | - Paul Stoodley
- Department of Microbial Infection and Immunity, Microbiology, The Ohio State University, Columbus, OH, 43210, USA. .,Department of Orthopedics, The Ohio State University, Columbus, OH, 43210, USA. .,National Centre for Advanced Tribology at Southampton, University of Southampton, Southampton, SO17 1BJ, UK.
| | - Daniel J Wozniak
- Department of Microbial Infection and Immunity, Microbiology, The Ohio State University, Columbus, OH, 43210, USA
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10
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Aerodynamic properties, solubility and in vitro antibacterial efficacy of dry powders prepared by spray drying: Clarithromycin versus its hydrochloride salt. Eur J Pharm Biopharm 2016; 104:1-6. [DOI: 10.1016/j.ejpb.2016.04.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/08/2016] [Accepted: 04/16/2016] [Indexed: 12/14/2022]
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Locke LW, Myerburg MM, Weiner DJ, Markovetz MR, Parker RS, Muthukrishnan A, Weber L, Czachowski MR, Lacy RT, Pilewski JM, Corcoran TE. Pseudomonas infection and mucociliary and absorptive clearance in the cystic fibrosis lung. Eur Respir J 2016; 47:1392-401. [PMID: 27009167 DOI: 10.1183/13993003.01880-2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 02/03/2016] [Indexed: 01/05/2023]
Abstract
Airway surface liquid hyperabsorption and mucus accumulation are key elements of cystic fibrosis lung disease that can be assessed in vivo using functional imaging methods. In this study we evaluated experimental factors affecting measurements of mucociliary clearance (MCC) and small-molecule absorption (ABS) and patient factors associated with abnormal absorption and mucus clearance.Our imaging technique utilises two radiopharmaceutical probes delivered by inhalation. Measurement repeatability was assessed in 10 adult cystic fibrosis subjects. Experimental factors were assessed in 29 adult and paediatric cystic fibrosis subjects (51 scans). Patient factors were assessed in a subgroup with optimal aerosol deposition (37 scans; 24 subjects). Paediatric subjects (n=9) underwent initial and 2-year follow-up scans. Control subjects from a previously reported study are included for comparison.High rates of central aerosol deposition influenced measurements of ABS and, to a lesser extent, MCC. Depressed MCC in cystic fibrosis was only detectable in subjects with previous Pseudomonas aeruginosa infection. Cystic fibrosis subjects without P. aeruginosa had similar MCC to control subjects. Cystic fibrosis subjects had consistently higher ABS rates.We conclude that the primary experimental factor affecting MCC/ABS measurements is central deposition percentage. Depressed MCC in cystic fibrosis is associated with P. aeruginosa infection. ABS is consistently increased in cystic fibrosis.
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Affiliation(s)
- Landon W Locke
- Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael M Myerburg
- Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Daniel J Weiner
- Pulmonary Medicine, Allergy, and Immunology, Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Matthew R Markovetz
- Dept of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Robert S Parker
- Dept of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA, USA Dept of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA Dept of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA McGowan Institute for Regenerative Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Ashok Muthukrishnan
- Dept of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Lawrence Weber
- Dept of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | | | - Ryan T Lacy
- Dept of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Joseph M Pilewski
- Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA Pulmonary Medicine, Allergy, and Immunology, Children's Hospital of Pittsburgh, Pittsburgh, PA, USA Dept of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Timothy E Corcoran
- Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA Dept of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA, USA Dept of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
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Putrescine reduces antibiotic-induced oxidative stress as a mechanism of modulation of antibiotic resistance in Burkholderia cenocepacia. Antimicrob Agents Chemother 2014; 58:4162-71. [PMID: 24820075 DOI: 10.1128/aac.02649-14] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Communication of antibiotic resistance among bacteria via small molecules is implicated in transient reduction of bacterial susceptibility to antibiotics, which could lead to therapeutic failures aggravating the problem of antibiotic resistance. Released putrescine from the extremely antibiotic-resistant bacterium Burkholderia cenocepacia protects less-resistant cells from different species against the antimicrobial peptide polymyxin B (PmB). Exposure of B. cenocepacia to sublethal concentrations of PmB and other bactericidal antibiotics induces reactive oxygen species (ROS) production and expression of the oxidative stress response regulator OxyR. We evaluated whether putrescine alleviates antibiotic-induced oxidative stress. The accumulation of intracellular ROS, such as superoxide ion and hydrogen peroxide, was assessed fluorometrically with dichlorofluorescein diacetate, while the expression of OxyR and putrescine synthesis enzymes was determined in luciferase assays using chromosomal promoter-lux reporter system fusions. We evaluated wild-type and isogenic deletion mutant strains with defects in putrescine biosynthesis after exposure to sublethal concentrations of PmB and other bactericidal antibiotics. Exogenous putrescine protected against oxidative stress induced by PmB and other antibiotics, whereas reduced putrescine synthesis resulted in increased ROS generation and a parallel increased sensitivity to PmB. Of the 3 B. cenocepacia putrescine-synthesizing enzymes, PmB induced only BCAL2641, an ornithine decarboxylase. This study reveals BCAL2641 as a critical component of the putrescine-mediated communication of antibiotic resistance and as a plausible target for designing inhibitors that would block the communication of such resistance among different bacteria, ultimately reducing the window of therapeutic failure in treating bacterial infections.
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