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Cogen JD, Quon BS. Update on the diagnosis and management of cystic fibrosis pulmonary exacerbations. J Cyst Fibros 2024:S1569-1993(24)00047-X. [PMID: 38677887 DOI: 10.1016/j.jcf.2024.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/28/2024] [Accepted: 04/05/2024] [Indexed: 04/29/2024]
Abstract
Pulmonary exacerbations in people with cystic fibrosis are associated with significant morbidity and reduced quality of life. Pulmonary exacerbation treatment guidelines, published by an expert panel assembled by the Cystic Fibrosis Foundation nearly 15 years ago, were primarily consensus-based as there were several gaps in the evidence base. In particular, limited evidence existed regarding optimal pulmonary exacerbation treatment strategies, including duration of antibiotic therapy, treatment location, antibiotic selection, and the role of systemic corticosteroids. Over the last decade, results from observational studies and large multi-center randomized controlled trials have begun to answer important questions related to pulmonary exacerbation treatment. This review focuses on the diagnosis, etiology, and changing epidemiology of pulmonary exacerbations, and also summarizes the most recent and up-to-date studies describing pulmonary exacerbation treatment. Finally, this review provides consideration for future pulmonary exacerbation research priorities, particularly in the current highly effective modulator therapy era.
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Affiliation(s)
- Jonathan D Cogen
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Seattle Children's Hospital, University of Washington, Seattle, Washington, USA.
| | - Bradley S Quon
- Division of Respiratory Medicine, Department of Medicine, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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2
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Wnorowska U, Łysik D, Piktel E, Zakrzewska M, Okła S, Lesiak A, Spałek J, Mystkowska J, Savage PB, Janmey P, Fiedoruk K, Bucki R. Ceragenin-mediated disruption of Pseudomonas aeruginosa biofilms. PLoS One 2024; 19:e0298112. [PMID: 38346040 PMCID: PMC10861078 DOI: 10.1371/journal.pone.0298112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 01/16/2024] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND Microbial biofilms, as a hallmark of cystic fibrosis (CF) lung disease and other chronic infections, remain a desirable target for antimicrobial therapy. These biopolymer-based viscoelastic structures protect pathogenic organisms from immune responses and antibiotics. Consequently, treatments directed at disrupting biofilms represent a promising strategy for combating biofilm-associated infections. In CF patients, the viscoelasticity of biofilms is determined mainly by their polymicrobial nature and species-specific traits, such as Pseudomonas aeruginosa filamentous (Pf) bacteriophages. Therefore, we examined the impact of microbicidal ceragenins (CSAs) supported by mucolytic agents-DNase I and poly-aspartic acid (pASP), on the viability and viscoelasticity of mono- and bispecies biofilms formed by Pf-positive and Pf-negative P. aeruginosa strains co-cultured with Staphylococcus aureus or Candida albicans. METHODS The in vitro antimicrobial activity of ceragenins against P. aeruginosa in mono- and dual-species cultures was assessed by determining minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC). Inhibition of P. aeruginosa mono- and dual-species biofilms formation by ceragenins alone and in combination with DNase I or poly-aspartic acid (pASP) was estimated by the crystal violet assay. Additionally, the viability of the biofilms was measured by colony-forming unit (CFU) counting. Finally, the biofilms' viscoelastic properties characterized by shear storage (G') and loss moduli (G"), were analyzed with a rotational rheometer. RESULTS Our results demonstrated that ceragenin CSA-13 inhibits biofilm formation and increases its fluidity regardless of the Pf-profile and species composition; however, the Pf-positive biofilms are characterized by elevated viscosity and elasticity parameters. CONCLUSION Due to its microbicidal and viscoelasticity-modifying properties, CSA-13 displays therapeutic potential in biofilm-associated infections, especially when combined with mucolytic agents.
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Affiliation(s)
- Urszula Wnorowska
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Białystok, Poland
| | - Dawid Łysik
- Institute of Biomedical Engineering, Bialystok University of Technology, Bialystok, Poland
| | - Ewelina Piktel
- Independent Laboratory of Nanomedicine, Medical University of Białystok, Białystok, Poland
| | - Magdalena Zakrzewska
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Białystok, Poland
| | - Sławomir Okła
- Institute of Medical Sciences, Collegium Medicum, Jan Kochanowski University of Kielce, Kielce, Poland
| | - Agata Lesiak
- Institute of Medical Sciences, Collegium Medicum, Jan Kochanowski University of Kielce, Kielce, Poland
| | - Jakub Spałek
- Institute of Medical Sciences, Collegium Medicum, Jan Kochanowski University of Kielce, Kielce, Poland
| | - Joanna Mystkowska
- Institute of Biomedical Engineering, Bialystok University of Technology, Bialystok, Poland
| | - Paul B. Savage
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, United States of America
| | - Paul Janmey
- Department of Physiology and Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Krzysztof Fiedoruk
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Białystok, Poland
| | - Robert Bucki
- Department of Medical Microbiology and Nanobiomedical Engineering, Medical University of Białystok, Białystok, Poland
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3
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Houston CJ, Alkhatib A, Einarsson GG, Tunney MM, Taggart CC, Downey DG. Diminished airway host innate response in people with cystic fibrosis who experience frequent pulmonary exacerbations. Eur Respir J 2024; 63:2301228. [PMID: 38135443 PMCID: PMC10882324 DOI: 10.1183/13993003.01228-2023] [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: 07/20/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023]
Abstract
RATIONALE Pulmonary exacerbations are clinically impactful events that accelerate cystic fibrosis (CF) lung disease progression. The pathophysiological mechanisms underlying an increased frequency of pulmonary exacerbations have not been explored. OBJECTIVES To compare host immune response during intravenous antibiotic treatment of pulmonary exacerbations in people with CF who have a history of frequent versus infrequent exacerbations. METHODS Adults with CF were recruited at onset of antibiotic treatment of a pulmonary exacerbation and were categorised as infrequent or frequent exacerbators based on their pulmonary exacerbation frequency in the previous 12 months. Clinical parameters, sputum bacterial load and sputum inflammatory markers were measured on day 0, day 5 and at the end of treatment. Shotgun proteomic analysis was performed on sputum using liquid chromatography-mass spectrometry. MEASUREMENTS AND MAIN RESULTS Many sputum proteins were differentially enriched between infrequent and frequent exacerbators (day 0 n=23 and day 5 n=31). The majority of these proteins had a higher abundance in infrequent exacerbators and were secreted innate host defence proteins with antimicrobial, antiprotease and immunomodulatory functions. Several differentially enriched proteins were validated using ELISA and Western blot including secretory leukocyte protease inhibitor (SLPI), lipocalin-1 and cystatin SA. Sputum from frequent exacerbators demonstrated potent ability to cleave exogenous recombinant SLPI in a neutrophil elastase dependent manner. Frequent exacerbators had increased sputum inflammatory markers (interleukin (IL)-1β and IL-8) and total bacterial load compared to infrequent exacerbators. CONCLUSIONS A diminished innate host protein defence may play a role in the pathophysiological mechanisms of frequent CF pulmonary exacerbations. Frequent exacerbators may benefit from therapies targeting this dysregulated host immune response.
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Affiliation(s)
- Claire J Houston
- Airway Innate Immunity Research Group, Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Aya Alkhatib
- School of Pharmacy, Queen's University Belfast, Belfast, UK
| | | | | | - Clifford C Taggart
- Airway Innate Immunity Research Group, Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
- Joint senior authors
| | - Damian G Downey
- Belfast Health and Social Care Trust, Belfast, UK
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
- Joint senior authors
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4
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Graham BI, Harris JK, Zemanick ET, Wagner BD. Integrating airway microbiome and blood proteomics data to identify multi-omic networks associated with response to pulmonary infection. THE MICROBE 2023; 1:100023. [PMID: 38264413 PMCID: PMC10805068 DOI: 10.1016/j.microb.2023.100023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
Host response to airway infections can vary widely. Cystic fibrosis (CF) pulmonary exacerbations provide an opportunity to better understand the interplay between respiratory microbes and the host. This study aimed to investigate the observed heterogeneity in airway infection recovery by analyzing microbiome and host response (i.e., blood proteome) data collected during the onset of 33 pulmonary infection events. We used sparse multiple canonical correlation network (SmCCNet) analysis to integrate these two types of -omics data along with a clinical measure of recovery. Four microbe-protein SmCCNet subnetworks at infection onset were identified that strongly correlate with recovery. Our findings support existing knowledge regarding CF airway infections. Additionally, we discovered novel microbe-protein subnetworks that are associated with recovery and merit further investigation.
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Affiliation(s)
- Brenton I.M. Graham
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - J. Kirk Harris
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Edith T. Zemanick
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Brandie D. Wagner
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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5
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Somayaji R, Quon BS. Breath of fresh insight: unraveling the evolution of our understanding of cystic fibrosis pulmonary exacerbations. Curr Opin Pulm Med 2023; 29:587-594. [PMID: 37642491 DOI: 10.1097/mcp.0000000000001010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
PURPOSE OF REVIEW Pulmonary exacerbations are critical events with significant negative impacts in persons with cystic fibrosis, but their diagnosis and management are highly variable. Highly effective modulator therapies have greatly improved health and reduced exacerbation events, but have also reshaped how they present. This review discusses the complexities of the diagnosis and management of pulmonary exacerbations as well as the emerging work and evidence in this area. RECENT FINDINGS The shifting epidemiology and our understanding of risk factors for pulmonary exacerbations are discussed. As symptoms may be more subtle in the modulator context, novel technologies including studies of remote monitoring are presented. The continued relevance of pulmonary exacerbations, the heterogeneity in their management, as well as current and forthcoming clinical trials to optimize treatment approaches are detailed. SUMMARY In spite of the dramatic reductions in pulmonary exacerbations, airway infections persist, a proportion of persons with cystic fibrosis either on or off modulator therapies continue to experience exacerbation events, and long-term data is lacking. Innovative approaches and studies will be crucial to enable standardized and generalizable strategies to improve outcomes in persons with cystic fibrosis.
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Affiliation(s)
- Ranjani Somayaji
- Department of Medicine, Cumming School of Medicine
- Department of Microbiology, Immunology and Infectious Disease
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Canada
| | - Bradley S Quon
- Department of Medicine, Faculty of Medicine, University of British Columbia
- Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, Canada
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6
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Wagner BD, Zemanick ET, Sagel SD, Robertson CE, Stevens MJ, Mayer-Hamblett N, Retsch-Bogart G, Ramsey BW, Harris JK. Limited effects of azithromycin on the oropharyngeal microbiome in children with CF and early pseudomonas infection. BMC Microbiol 2023; 23:312. [PMID: 37891457 PMCID: PMC10612347 DOI: 10.1186/s12866-023-03073-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
BACKGROUND Tobramycin inhalation solution (TIS) and chronic azithromycin (AZ) have known clinical benefits for children with CF, likely due to antimicrobial and anti-inflammatory activity. The effects of chronic AZ in combination with TIS on the airway microbiome have not been extensively investigated. Oropharyngeal swab samples were collected in the OPTIMIZE multicenter, randomized, placebo-controlled trial examining the addition of AZ to TIS in 198 children with CF and early P. aeruginosa infection. Bacterial small subunit rRNA gene community profiles were determined. The effects of TIS and AZ were assessed on oropharyngeal microbial diversity and composition to uncover whether effects on the bacterial community may be a mechanism of action related to the observed changes in clinical outcomes. RESULTS Substantial changes in bacterial communities (total bacterial load, diversity and relative abundance of specific taxa) were observed by week 3 of TIS treatment for both the AZ and placebo groups. On average, these shifts were due to changes in non-traditional CF taxa that were not sustained at the later study visits (weeks 13 and 26). Bacterial community measures did not differ between the AZ and placebo groups. CONCLUSIONS This study provides further evidence that the mechanism for AZ's effect on clinical outcomes is not due solely to action on airway microbial composition.
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Affiliation(s)
- Brandie D Wagner
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado, Aurora, CO, USA.
- Children's Hospital Colorado, Aurora, CO, USA.
| | - Edith T Zemanick
- Children's Hospital Colorado, Aurora, CO, USA
- Department of Pediatrics, University of Colorado, Aurora, CO, USA
| | - Scott D Sagel
- Children's Hospital Colorado, Aurora, CO, USA
- Department of Pediatrics, University of Colorado, Aurora, CO, USA
| | | | - Mark J Stevens
- Children's Hospital Colorado, Aurora, CO, USA
- Department of Pediatrics, University of Colorado, Aurora, CO, USA
| | - Nicole Mayer-Hamblett
- Department of Pediatrics, University of Washington, Seattle, WA, USA
- Department of Biostatistics, University of Washington, Seattle, WA, USA
- Seattle Children's Hospital, Seattle, WA, USA
| | | | - Bonnie W Ramsey
- Department of Pediatrics, University of Washington, Seattle, WA, USA
- Seattle Children's Hospital, Seattle, WA, USA
| | - J Kirk Harris
- Children's Hospital Colorado, Aurora, CO, USA
- Department of Pediatrics, University of Colorado, Aurora, CO, USA
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7
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Thornton CS, Parkins MD. Microbial Epidemiology of the Cystic Fibrosis Airways: Past, Present, and Future. Semin Respir Crit Care Med 2023; 44:269-286. [PMID: 36623820 DOI: 10.1055/s-0042-1758732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Progressive obstructive lung disease secondary to chronic airway infection, coupled with impaired host immunity, is the leading cause of morbidity and mortality in cystic fibrosis (CF). Classical pathogens found in the airways of persons with CF (pwCF) include Pseudomonas aeruginosa, Staphylococcus aureus, the Burkholderia cepacia complex, Achromobacter species, and Haemophilus influenzae. While traditional respiratory-tract surveillance culturing has focused on this limited range of pathogens, the use of both comprehensive culture and culture-independent molecular approaches have demonstrated complex highly personalized microbial communities. Loss of bacterial community diversity and richness, counteracted with relative increases in dominant taxa by traditional CF pathogens such as Burkholderia or Pseudomonas, have long been considered the hallmark of disease progression. Acquisition of these classic pathogens is viewed as a harbinger of advanced disease and postulated to be driven in part by recurrent and frequent antibiotic exposure driven by frequent acute pulmonary exacerbations. Recently, CF transmembrane conductance regulator (CFTR) modulators, small molecules designed to potentiate or restore diminished protein levels/function, have been successfully developed and have profoundly influenced disease course. Despite the multitude of clinical benefits, structural lung damage and consequent chronic airway infection persist in pwCF. In this article, we review the microbial epidemiology of pwCF, focus on our evolving understanding of these infections in the era of modulators, and identify future challenges in infection surveillance and clinical management.
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Affiliation(s)
- Christina S Thornton
- Department of Medicine, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Michael D Parkins
- Department of Medicine, Cumming School of Medicine, University of Calgary, Alberta, Canada.,Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Alberta, Canada
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8
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Brackenborough K, Ellis H, Flight WG. Respiratory Viruses and Cystic Fibrosis. Semin Respir Crit Care Med 2023; 44:196-208. [PMID: 36535663 DOI: 10.1055/s-0042-1758728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The threat of respiratory virus infection to human health and well-being has been clearly highlighted by the coronavirus disease 2019 (COVID-19) pandemic. For people with cystic fibrosis (CF), the clinical significance of viral infections long predated the emergence of severe acute respiratory syndrome coronavirus 2. This article reviews the epidemiology, diagnosis, and treatment of respiratory virus infection in the context of CF as well as the current understanding of interactions between viruses and other microorganisms in the CF lung. The incidence of respiratory virus infection in CF varies by age with young children typically experiencing more frequent episodes than adolescents and adults. At all ages, respiratory viruses are very common in CF and are associated with pulmonary exacerbations. Respiratory viruses are identified at up to 69% of exacerbations, while viruses are also frequently detected during clinical stability. The full impact of COVID-19 in CF is yet to be established. Early studies found that rates of COVID-19 were lower in CF cohorts than in the general population. The reasons for this are unclear but may be related to the effects of shielding, infection control practices, maintenance CF therapies, or the inflammatory milieu in the CF lung. Observational studies have consistently identified that prior solid organ transplantation is a key risk factor for poor outcomes from COVID-19 in CF. Several key priorities for future research are highlighted. First, the impact of highly effective CFTR modulator therapy on the epidemiology and pathophysiology of viral infections in CF requires investigation. Second, the impact of respiratory viruses on the development and dynamics of the CF lung microbiota is poorly understood and viral infection may have important interactions with bacteria and fungi in the airway. Finally, bacteriophages represent a key focus of future investigation both for their role in transmission of antimicrobial resistance and as a promising treatment modality for multiresistant pathogens.
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Affiliation(s)
- Kate Brackenborough
- Oxford Centre for Respiratory Medicine, Oxford University Hospitals National Health Service Foundation Trust, Oxford, United Kingdom
| | - Huw Ellis
- Oxford Centre for Respiratory Medicine, Oxford University Hospitals National Health Service Foundation Trust, Oxford, United Kingdom
| | - William G Flight
- Oxford Centre for Respiratory Medicine, Oxford University Hospitals National Health Service Foundation Trust, Oxford, United Kingdom.,Research and Development, GlaxoSmithKline plc, Brentford, United Kingdom
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9
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Carter SC, Franciosi AN, O’Shea KM, O’Carroll OM, Sharma A, Bell A, Keogan B, O’Reilly P, Coughlan S, Law SM, Gray RD, Hisert KB, Singh PK, Cooke G, Grogan B, De Gascun CF, Gallagher CG, Nicholson TT, Quon BS, McKone EF. Acute Pulmonary Exacerbation Phenotypes in Patients with Cystic Fibrosis. Ann Am Thorac Soc 2022; 19:1818-1826. [PMID: 35713619 PMCID: PMC9667812 DOI: 10.1513/annalsats.202111-1266oc] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Rationale: The etiology of cystic fibrosis (CF) pulmonary exacerbations (PEx) is likely multifactorial with viral, bacterial, and non-infectious pathways contributing. Objectives: To determine whether viral infection status and CRP (C-reactive protein) can classify subphenotypes of PEx that differ in outcomes and biomarker profiles. Methods: Patients were recruited at time of admission for a PEx. Nasal swabs and sputum samples were collected and processed using the respiratory panel of the FilmArray multiplex polymerase chain reaction (PCR). Serum and plasma biomarkers were measured. PEx were classified using serum CRP and viral PCR: "pauci-inflammatory" if CRP < 5 mg/L, "non-viral with systemic inflammation" if CRP ⩾ 5 mg/L and no viral infection detected by PCR and "viral with systemic inflammation" if CRP ⩾ 5 mg/L and viral infection detected by PCR. Results: Discovery cohort (n = 59) subphenotype frequencies were 1) pauci-inflammatory (37%); 2) non-viral with systemic inflammation (41%); and 3) viral with systemic inflammation (22%). Immunoglobulin G, immunoglobulin M, interleukin-10, interleukin-13, serum calprotectin, and CRP levels differed across phenotypes. Reduction from baseline in forced expiratory volume in 1 second as percent predicted (FEV1pp) at onset of exacerbation differed between non-viral with systemic inflammation and viral with systemic inflammation (-6.73 ± 1.78 vs. -13.5 ± 2.32%; P = 0.025). Non-viral with systemic inflammation PEx had a trend toward longer duration of intravenous antibiotics versus pauci-inflammation (18.1 ± 1.17 vs. 14.8 ± 1.19 days, P = 0.057). There were no differences in percent with lung function recovery to <10% of baseline FEV1pp. Similar results were seen in local and external validation cohorts comparing a pauci-inflammatory to viral/non-viral inflammatory exacerbation phenotypes. Conclusions: Subphenotypes of CF PEx exist with differences in biomarker profile, clinical presentation, and outcomes.
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Affiliation(s)
- Suzanne C. Carter
- National Referral Centre for Adult Cystic Fibrosis, St. Vincent’s University Hospital, Dublin, Ireland
- University College Dublin School of Medicine, Dublin, Ireland
| | | | - Kate M. O’Shea
- University College Dublin School of Medicine, Dublin, Ireland
| | - Orla M. O’Carroll
- National Referral Centre for Adult Cystic Fibrosis, St. Vincent’s University Hospital, Dublin, Ireland
| | - Ashutosh Sharma
- Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Aoife Bell
- University College Dublin School of Medicine, Dublin, Ireland
| | - Brian Keogan
- National Virus Reference Laboratory, University College Dublin, Dublin, Ireland
| | - Paul O’Reilly
- National Virus Reference Laboratory, University College Dublin, Dublin, Ireland
| | - Suzie Coughlan
- National Virus Reference Laboratory, University College Dublin, Dublin, Ireland
| | - Sheonagh M. Law
- Centre for Inflammation Research, University of Edinburgh, Edinburgh, Scotland
| | - Robert D. Gray
- Centre for Inflammation Research, University of Edinburgh, Edinburgh, Scotland
| | - Katherine B. Hisert
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, National Jewish Health, Denver, Colorado
- University of Washington, Seattle, Washington; and
| | | | - Gordon Cooke
- University College Dublin School of Medicine, Dublin, Ireland
- Technological University Dublin, Dublin, Ireland
| | - Brenda Grogan
- National Referral Centre for Adult Cystic Fibrosis, St. Vincent’s University Hospital, Dublin, Ireland
| | | | - Charles G. Gallagher
- National Referral Centre for Adult Cystic Fibrosis, St. Vincent’s University Hospital, Dublin, Ireland
- University College Dublin School of Medicine, Dublin, Ireland
| | - Trevor T. Nicholson
- National Referral Centre for Adult Cystic Fibrosis, St. Vincent’s University Hospital, Dublin, Ireland
| | - Bradley S. Quon
- Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Edward F. McKone
- National Referral Centre for Adult Cystic Fibrosis, St. Vincent’s University Hospital, Dublin, Ireland
- University College Dublin School of Medicine, Dublin, Ireland
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10
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Thornton CS, Acosta N, Surette MG, Parkins MD. Exploring the Cystic Fibrosis Lung Microbiome: Making the Most of a Sticky Situation. J Pediatric Infect Dis Soc 2022; 11:S13-S22. [PMID: 36069903 PMCID: PMC9451016 DOI: 10.1093/jpids/piac036] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 05/16/2022] [Indexed: 01/02/2023]
Abstract
Chronic lower respiratory tract infections are a leading contributor to morbidity and mortality in persons with cystic fibrosis (pwCF). Traditional respiratory tract surveillance culturing has focused on a limited range of classic pathogens; however, comprehensive culture and culture-independent molecular approaches have demonstrated complex communities highly unique to each individual. Microbial community structure evolves through the lifetime of pwCF and is associated with baseline disease state and rates of disease progression including occurrence of pulmonary exacerbations. While molecular analysis of the airway microbiome has provided insight into these dynamics, challenges remain including discerning not only "who is there" but "what they are doing" in relation to disease progression. Moreover, the microbiome can be leveraged as a multi-modal biomarker for both disease activity and prognostication. In this article, we review our evolving understanding of the role these communities play in pwCF and identify challenges in translating microbiome data to clinical practice.
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Affiliation(s)
- Christina S Thornton
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA,Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Nicole Acosta
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Michael G Surette
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada,Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Michael D Parkins
- Corresponding Author: Michael D. Parkins, MD, MSc, FRCPC, Associate Professor, Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada; Department of Medicine, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1, Canada; Snyder Institute for Chronic Diseases, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1, Canada. E-mail:
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11
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Caverly LJ, VanDevanter DR. The Elusive Role of Airway Infection in Cystic Fibrosis Exacerbation. J Pediatric Infect Dis Soc 2022; 11:S40-S45. [PMID: 36069900 DOI: 10.1093/jpids/piac062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 06/22/2022] [Indexed: 11/14/2022]
Abstract
Cystic fibrosis (CF) pulmonary exacerbations (PEx) are clinical events that commonly result in increased treatment burden, decreased quality of life, and accelerated lung disease progression. CF PEx have historically been approached as though dealing with acute infections, and antibiotic treatments have been associated with improved outcomes. In this review, we discuss data supporting a causal role of CF airway infection in PEx as well studies that highlight our knowledge gaps in regard to PEx definitions, pathophysiology, and optimal treatment approaches. In the era of highly effective cystic fibrosis transmembrane conductance regulator modulator therapy, and the continually increasing health and longevity of persons with CF, a better understanding of PEx and further optimization of PEx antibiotic treatment approaches are needed.
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Affiliation(s)
- Lindsay J Caverly
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Donald R VanDevanter
- Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
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12
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Antibiotics Drive Expansion of Rare Pathogens in a Chronic Infection Microbiome Model. mSphere 2022; 7:e0031822. [PMID: 35972133 PMCID: PMC9599657 DOI: 10.1128/msphere.00318-22] [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] [Indexed: 11/20/2022] Open
Abstract
Chronic (long-lasting) infections are globally a major and rising cause of morbidity and mortality. Unlike typical acute infections, chronic infections are ecologically diverse, characterized by the presence of a polymicrobial mix of opportunistic pathogens and human-associated commensals. To address the challenge of chronic infection microbiomes, we focus on a particularly well-characterized disease, cystic fibrosis (CF), where polymicrobial lung infections persist for decades despite frequent exposure to antibiotics. Epidemiological analyses point to conflicting results on the benefits of antibiotic treatment yet are confounded by the dependency of antibiotic exposures on prior pathogen presence, limiting their ability to draw causal inferences on the relationships between antibiotic exposure and pathogen dynamics. To address this limitation, we develop a synthetic infection microbiome model representing CF metacommunity diversity and benchmark on clinical data. We show that in the absence of antibiotics, replicate microbiome structures in a synthetic sputum medium are highly repeatable and dominated by oral commensals. In contrast, challenge with physiologically relevant antibiotic doses leads to substantial community perturbation characterized by multiple alternate pathogen-dominant states and enrichment of drug-resistant species. These results provide evidence that antibiotics can drive the expansion (via competitive release) of previously rare opportunistic pathogens and offer a path toward microbiome-informed conditional treatment strategies. IMPORTANCE We develop and clinically benchmark an experimental model of the cystic fibrosis (CF) lung infection microbiome to investigate the impacts of antibiotic exposures on chronic, polymicrobial infections. We show that a single experimental model defined by metacommunity data can partially recapitulate the diversity of individual microbiome states observed across a population of people with CF. In the absence of antibiotics, we see highly repeatable community structures, dominated by oral microbes. Under clinically relevant antibiotic exposures, we see diverse and frequently pathogen-dominated communities, and a nonevolutionary enrichment of antimicrobial resistance on the community scale, mediated by competitive release. The results highlight the potential importance of nonevolutionary (community-ecological) processes in driving the growing global crisis of increasing antibiotic resistance.
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13
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Surface Motility Favors Codependent Interaction between Pseudomonas aeruginosa and Burkholderia cenocepacia. mSphere 2022; 7:e0015322. [PMID: 35862793 PMCID: PMC9429929 DOI: 10.1128/msphere.00153-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Interactions between different bacterial species shape bacterial communities and their environments. The opportunistic pathogens Pseudomonas aeruginosa and Burkholderia cenocepacia both can colonize the lungs of individuals affected by cystic fibrosis. Using the social surface behavior called swarming motility as a study model, we noticed intricate interactions between B. cenocepacia K56-2 and P. aeruginosa PA14. While strain K56-2 does not swarm under P. aeruginosa favorable swarming conditions, co-inoculation with a nonmotile PA14 flagellum-less ΔfliC mutant restored spreading for both strains. We show that P. aeruginosa provides the wetting agent rhamnolipids allowing K56-2 to perform swarming motility, while aflagellated PA14 appears to “hitchhike” along with K56-2 cells in the swarming colony. IMPORTANCEPseudomonas aeruginosa and Burkholderia cenocepacia are important opportunistic pathogens often found together in the airways of persons with cystic fibrosis. Laboratory cocultures of both species often ends with one taking over the other. We used a surface motility assay to study the social interactions between populations of these bacterial species. Under our conditions, B. cenocepacia cannot swarm without supplementation of the wetting agent produced by P. aeruginosa. In a mixed colony of both species, an aflagellated mutant of P. aeruginosa provides the necessary wetting agent to B. cenocepacia, allowing both bacteria to swarm and colonize a surface. We highlight this peculiar interaction where both bacteria set aside their antagonistic tendencies to travel together.
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14
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Pailhoriès H, Herrmann JL, Velo-Suarez L, Lamoureux C, Beauruelle C, Burgel PR, Héry-Arnaud G. Antibiotic resistance in chronic respiratory diseases: from susceptibility testing to the resistome. Eur Respir Rev 2022; 31:31/164/210259. [PMID: 35613743 DOI: 10.1183/16000617.0259-2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 03/02/2022] [Indexed: 12/28/2022] Open
Abstract
The development of resistome analysis, i.e. the comprehensive analysis of antibiotic-resistance genes (ARGs), is enabling a better understanding of the mechanisms of antibiotic-resistance emergence. The respiratory microbiome is a dynamic and interactive network of bacteria, with a set of ARGs that could influence the response to antibiotics. Viruses such as bacteriophages, potential carriers of ARGs, may also form part of this respiratory resistome. Chronic respiratory diseases (CRDs) such as cystic fibrosis, severe asthma, chronic obstructive pulmonary disease and bronchiectasis, managed with long-term antibiotic therapies, lead to multidrug resistance. Antibiotic susceptibility testing provides a partial view of the bacterial response to antibiotics in the complex lung environment. Assessing the ARG network would allow personalised, targeted therapeutic strategies and suitable antibiotic stewardship in CRDs, depending on individual resistome and microbiome signatures. This review summarises the influence of pulmonary antibiotic protocols on the respiratory microbiome, detailing the variable consequences according to antibiotic class and duration of treatment. The different resistome-profiling methods are explained to clarify their respective place in antibiotic-resistance analysis in the lungs. Finally, this review details current knowledge on the respiratory resistome related to therapeutic strategies and provides insight into the application of resistome analysis to counter the emergence of multidrug-resistant respiratory pathogens.
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Affiliation(s)
- Hélène Pailhoriès
- Laboratoire de Bactériologie, Institut de Biologie en Santé - PBH, CHU Angers, Angers, France.,HIFIH Laboratory UPRES EA3859, SFR ICAT 4208, Angers University, Angers, France
| | - Jean-Louis Herrmann
- Université Paris-Saclay, UVSQ, INSERM, Infection and Inflammation, Montigny-le-Bretonneux, France.,AP-HP, Groupe Hospitalo-Universitaire Paris-Saclay, Hôpital Raymond Poincaré, Garches, France
| | - Lourdes Velo-Suarez
- Brest Center for Microbiota Analysis (CBAM), Brest University Hospital, Brest, France
| | - Claudie Lamoureux
- Dept of Bacteriology, Virology, Hospital Hygiene, and Parasitology-Mycology, Brest University Hospital, Brest, France.,Université de Brest, INSERM, EFS, UMR 1078, GGB, Brest, France
| | - Clémence Beauruelle
- Dept of Bacteriology, Virology, Hospital Hygiene, and Parasitology-Mycology, Brest University Hospital, Brest, France.,Université de Brest, INSERM, EFS, UMR 1078, GGB, Brest, France
| | - Pierre-Régis Burgel
- Respiratory Medicine and National Cystic Fibrosis Reference Center, Cochin Hospital, Assistance Publique-Hôpitaux de Paris, Université de Paris, Institut Cochin, INSERM U1016, Paris, France
| | - Geneviève Héry-Arnaud
- Brest Center for Microbiota Analysis (CBAM), Brest University Hospital, Brest, France .,Dept of Bacteriology, Virology, Hospital Hygiene, and Parasitology-Mycology, Brest University Hospital, Brest, France.,Université de Brest, INSERM, EFS, UMR 1078, GGB, Brest, France
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15
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Widder S, Zhao J, Carmody LA, Zhang Q, Kalikin LM, Schloss PD, LiPuma JJ. Association of bacterial community types, functional microbial processes and lung disease in cystic fibrosis airways. THE ISME JOURNAL 2022; 16:905-914. [PMID: 34689185 PMCID: PMC8941020 DOI: 10.1038/s41396-021-01129-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 09/16/2021] [Accepted: 09/23/2021] [Indexed: 12/30/2022]
Abstract
Bacterial infection and inflammation of the airways are the leading causes of morbidity and mortality in persons with cystic fibrosis (CF). The ecology of the bacterial communities inhabiting CF airways is poorly understood, especially with respect to how community structure, dynamics, and microbial metabolic activity relate to clinical outcomes. In this study, the bacterial communities in 818 sputum samples from 109 persons with CF were analyzed by sequencing bacterial 16S rRNA gene amplicons. We identified eight alternative community types (pulmotypes) by using a Dirichlet multinomial mixture model and studied their temporal dynamics in the cohort. Across patients, the pulmotypes displayed chronological patterns in the transition among each other. Furthermore, significant correlations between pulmotypes and patient clinical status were detected by using multinomial mixed effects models, principal components regression, and statistical testing. Constructing pulmotype-specific metabolic activity profiles, we found that pulmotype microbiota drive distinct community functions including mucus degradation or increased acid production. These results indicate that pulmotypes are the result of ordered, underlying drivers such as predominant metabolism, ecological competition, and niche construction and can form the basis for quantitative, predictive models supporting clinical treatment decisions.
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Affiliation(s)
- Stefanie Widder
- Department of Medicine 1, Research Laboratory of Infection Biology, Medical University of Vienna, Vienna, Austria.
- Konrad Lorenz Institute for Evolution and Cognition Research, Klosterneuburg, Austria.
| | - Jiangchao Zhao
- Department of Animal Science, Division of Agriculture, University of Arkansas, Fayetteville, AR, 72701, USA.
| | - Lisa A Carmody
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Qingyang Zhang
- Department of Mathematical Science, Fulbright College of Art and Science, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Linda M Kalikin
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Patrick D Schloss
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - John J LiPuma
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
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16
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Smith SS, Kim R, Douglas R. Is there a Role for Antibiotics in the Treatment of Chronic Rhinosinusitis? J Allergy Clin Immunol 2022; 149:1504-1512. [PMID: 35217148 DOI: 10.1016/j.jaci.2022.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/14/2022] [Accepted: 02/14/2022] [Indexed: 11/15/2022]
Abstract
Rhinosinusitis is one of the most common reasons for adult outpatient antibiotic prescriptions, though there is little clinical evidence to support this practice, especially for chronic rhinosinusitis. Despite considerable research, the etiology of chronic rhinosinusitis, including the pathogenic role of microbes, remains poorly understood. Rigorous studies of the efficacy of antibiotic treatment of chronic sinusitis are surprisingly few in number and the results are somewhat conflicting. This article will review the rationales for and against the treatment of chronic rhinosinusitis with antibiotics, based on current evidence and understanding of pathophysiology, and will also summarize the current guidelines.
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Affiliation(s)
- Stephanie Shintani Smith
- Department of Otolaryngology-Head and Neck Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL; Center for Health Services and Outcomes Research, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL.
| | - Raymond Kim
- Department of Surgery, The University of Auckland, Auckland, New Zealand
| | - Richard Douglas
- Department of Surgery, The University of Auckland, Auckland, New Zealand
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17
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Abstract
Microbial communities in the airways of persons with CF (pwCF) are variable, may include genera that are not typically associated with CF, and their composition can be difficult to correlate with long-term disease outcomes. Leveraging two large data sets characterizing sputum communities of 167 pwCF and associated metadata, we identified five bacterial community types. These communities explain 24% of the variability in lung function in this cohort, far more than single factors like Simpson diversity, which explains only 4%. Subjects with Pseudomonas-dominated communities tended to be older and have reduced percent predicted FEV1 (ppFEV1) compared to subjects with Streptococcus-dominated communities, consistent with previous findings. To assess the predictive power of these five communities in a longitudinal setting, we used random forests to classify 346 additional samples from 24 subjects observed 8 years on average in a range of clinical states. Subjects with mild disease were more likely to be observed at baseline, that is, not in the context of a pulmonary exacerbation, and community structure in these subjects was more self-similar over time, as measured by Bray-Curtis distance. Interestingly, we found that subjects with mild disease were more likely to remain in a mixed Pseudomonas community, providing some support for the climax-attack model of the CF airway. In contrast, patients with worse outcomes were more likely to show shifts among community types. Our results suggest that bacterial community instability may be a risk factor for lung function decline and indicates the need to understand factors that drive shifts in community composition. IMPORTANCE While much research supports a polymicrobial view of the CF airway, one in which the community is seen as the pathogenic unit, only controlled experiments using model bacterial communities can unravel the mechanistic role played by different communities. This report uses a large data set to identify a small number of communities as a starting point in the development of tractable model systems. We describe a set of five communities that explain 24% of the variability in lung function in our data set, far more than single factors like Simpson diversity, which explained only 4%. In addition, we report that patients with severe disease experienced more shifts among community types, suggesting that bacterial community instability may be a risk factor for lung function decline. Together, these findings provide a proof of principle for selecting bacterial community model systems.
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18
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Systems Biology and Bile Acid Signalling in Microbiome-Host Interactions in the Cystic Fibrosis Lung. Antibiotics (Basel) 2021; 10:antibiotics10070766. [PMID: 34202495 PMCID: PMC8300688 DOI: 10.3390/antibiotics10070766] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/14/2021] [Accepted: 06/21/2021] [Indexed: 12/16/2022] Open
Abstract
The study of the respiratory microbiota has revealed that the lungs of healthy and diseased individuals harbour distinct microbial communities. Imbalances in these communities can contribute to the pathogenesis of lung disease. How these imbalances occur and establish is largely unknown. This review is focused on the genetically inherited condition of Cystic Fibrosis (CF). Understanding the microbial and host-related factors that govern the establishment of chronic CF lung inflammation and pathogen colonisation is essential. Specifically, dissecting the interplay in the inflammation–pathogen–host axis. Bile acids are important host derived and microbially modified signal molecules that have been detected in CF lungs. These bile acids are associated with inflammation and restructuring of the lung microbiota linked to chronicity. This community remodelling involves a switch in the lung microbiota from a high biodiversity/low pathogen state to a low biodiversity/pathogen-dominated state. Bile acids are particularly associated with the dominance of Proteobacterial pathogens. The ability of bile acids to impact directly on both the lung microbiota and the host response offers a unifying principle underpinning the pathogenesis of CF. The modulating role of bile acids in lung microbiota dysbiosis and inflammation could offer new potential targets for designing innovative therapeutic approaches for respiratory disease.
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19
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Wagner Mackenzie B, Dassi C, Vivekanandan A, Zoing M, Douglas RG, Biswas K. Longitudinal analysis of sinus microbiota post endoscopic surgery in patients with cystic fibrosis and chronic rhinosinusitis: a pilot study. Respir Res 2021; 22:106. [PMID: 33849523 PMCID: PMC8045235 DOI: 10.1186/s12931-021-01697-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 03/29/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cystic fibrosis is a debilitating, autosomal recessive disease which results in chronic upper and lower airway infection and inflammation. In this study, four adult patients presenting with cystic fibrosis and chronic rhinosinusitis were recruited. Culture and molecular techniques were employed to evaluate changes in microbial profiles, host gene expression and antimicrobial resistance (AMR) in the upper respiratory tract over time. METHODS Swab samples from the sinonasal cavity were collected at the time of surgery and at follow-up clinics at regular time intervals for up to 18 months. Nucleic acids were extracted, and DNA amplicon sequencing was applied to describe bacterial and fungal composition. In parallel, RNA was used to evaluate the expression of 17 AMR genes and two inflammatory markers (interleukins 6 and 8) using custom qPCR array cards. Molecular results were compared with routine sinus and sputum culture reports within each patient. RESULTS Bacterial amplicon sequencing and swab culture reports from the sinonasal cavity were mostly congruent and relatively stable for each patient across time. The predominant species detected in patients P02 and P04 were Pseudomonas aeruginosa, Staphylococcus aureus in patient P03, and a mixture of Enterobacter and S. aureus in patient P01. Fungal profiles were variable and less subject specific than bacterial communities. Increased expressions of interleukins 6 and 8 were observed in all patients throughout the sampling period compared with other measured genes. The most prevalent AMR gene detected was ampC. However, the prevalence of AMR gene expression was low in all patient samples across varying time-points. CONCLUSIONS We observed a surprising degree of stability of sinonasal microbial composition, and inflammatory and AMR gene expression across all patients post sinus surgery.
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Affiliation(s)
- Brett Wagner Mackenzie
- Department of Surgery, The University of Auckland, 85 Park Road, Grafton, 1023, Auckland, New Zealand.
| | - Camila Dassi
- Department of Surgery, The University of Auckland, 85 Park Road, Grafton, 1023, Auckland, New Zealand
| | - Anitha Vivekanandan
- Department of Surgery, The University of Auckland, 85 Park Road, Grafton, 1023, Auckland, New Zealand
| | - Melissa Zoing
- Department of Surgery, The University of Auckland, 85 Park Road, Grafton, 1023, Auckland, New Zealand
| | - Richard G Douglas
- Department of Surgery, The University of Auckland, 85 Park Road, Grafton, 1023, Auckland, New Zealand
| | - Kristi Biswas
- Department of Surgery, The University of Auckland, 85 Park Road, Grafton, 1023, Auckland, New Zealand
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20
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Temperate and chronic virus competition leads to low lysogen frequency. J Theor Biol 2021; 523:110710. [PMID: 33839160 DOI: 10.1016/j.jtbi.2021.110710] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 04/04/2021] [Accepted: 04/05/2021] [Indexed: 11/23/2022]
Abstract
The canonical bacteriophage is obligately lytic: the virus infects a bacterium and hijacks cell functions to produce large numbers of new viruses which burst from the cell. These viruses are well-studied, but there exist a wide range of coexisting virus lifestyles that are less understood. Temperate viruses exhibit both a lytic cycle and a latent (lysogenic) cycle, in which viral genomes are integrated into the bacterial host. Meanwhile, chronic (persistent) viruses use cell functions to produce more viruses without killing the cell; chronic viruses may also exhibit a latent stage in addition to the productive stage. Here, we study the ecology of these competing viral strategies. We demonstrate the conditions under which each strategy is dominant, which aids in control of human bacterial infections using viruses. We find that low lysogen frequencies provide competitive advantages for both virus types; however, chronic viruses maximize steady state density by eliminating lysogeny entirely, while temperate viruses exhibit a non-zero 'sweet spot' lysogen frequency. Viral steady state density maximization leads to coexistence of temperate and chronic viruses, explaining the presence of multiple viral strategies in natural environments.
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21
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Abstract
Culture-independent studies have revealed that chronic lung infections in persons with cystic fibrosis (pwCF) are rarely limited to one microbial species. Interactions among bacterial members of these polymicrobial communities in the airways of pwCF have been reported to modulate clinically relevant phenotypes. Furthermore, it is clear that a single polymicrobial community in the context of CF airway infections cannot explain the diversity of clinical outcomes. While large 16S rRNA gene-based studies have allowed us to gain insight into the microbial composition and predicted functional capacities of communities found in the CF lung, here we argue that in silico approaches can help build clinically relevant in vitro models of polymicrobial communities that can in turn be used to experimentally test and validate computationally generated hypotheses. Furthermore, we posit that combining computational and experimental approaches will enhance our understanding of mechanisms that drive microbial community function and identify new therapeutics to target polymicrobial infections.
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22
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Abstract
Cystic fibrosis patients frequently suffer from recurring respiratory infections caused by colonizing pathogenic and commensal bacteria. Although modern therapies can sometimes alleviate respiratory symptoms by ameliorating residual function of the protein responsible for the disorder, management of chronic respiratory infections remains an issue. In cystic fibrosis, dynamic and complex communities of microbial pathogens and commensals can colonize the lung. Cultured isolates from lung sputum reveal high inter- and intraindividual variability in pathogen strains, sequence variants, and phenotypes; disease progression likely depends on the precise combination of infecting lineages. Routine clinical protocols, however, provide a limited overview of the colonizer populations. Therefore, a more comprehensive and precise identification and characterization of infecting lineages could assist in making corresponding decisions on treatment. Here, we describe longitudinal tracking for four cystic fibrosis patients who exhibited extreme clinical phenotypes and, thus, were selected from a pilot cohort of 11 patients with repeated sampling for more than a year. Following metagenomics sequencing of lung sputum, we find that the taxonomic identity of individual colonizer lineages can be easily established. Crucially, even superficially clonal pathogens can be subdivided into multiple sublineages at the sequence level. By tracking individual allelic differences over time, an assembly-free clustering approach allows us to reconstruct multiple lineage-specific genomes with clear structural differences. Our study showcases a culture-independent shotgun metagenomics approach for longitudinal tracking of sublineage pathogen dynamics, opening up the possibility of using such methods to assist in monitoring disease progression through providing high-resolution routine characterization of the cystic fibrosis lung microbiome.
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23
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Jean-Pierre F, Henson MA, O'Toole GA. Metabolic Modeling to Interrogate Microbial Disease: A Tale for Experimentalists. Front Mol Biosci 2021; 8:634479. [PMID: 33681294 PMCID: PMC7930556 DOI: 10.3389/fmolb.2021.634479] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 01/19/2021] [Indexed: 12/14/2022] Open
Abstract
The explosion of microbiome analyses has helped identify individual microorganisms and microbial communities driving human health and disease, but how these communities function is still an open question. For example, the role for the incredibly complex metabolic interactions among microbial species cannot easily be resolved by current experimental approaches such as 16S rRNA gene sequencing, metagenomics and/or metabolomics. Resolving such metabolic interactions is particularly challenging in the context of polymicrobial communities where metabolite exchange has been reported to impact key bacterial traits such as virulence and antibiotic treatment efficacy. As novel approaches are needed to pinpoint microbial determinants responsible for impacting community function in the context of human health and to facilitate the development of novel anti-infective and antimicrobial drugs, here we review, from the viewpoint of experimentalists, the latest advances in metabolic modeling, a computational method capable of predicting metabolic capabilities and interactions from individual microorganisms to complex ecological systems. We use selected examples from the literature to illustrate how metabolic modeling has been utilized, in combination with experiments, to better understand microbial community function. Finally, we propose how such combined, cross-disciplinary efforts can be utilized to drive laboratory work and drug discovery moving forward.
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Affiliation(s)
- Fabrice Jean-Pierre
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Michael A Henson
- Department of Chemical Engineering and Institute for Applied Life Sciences, University of Massachusetts, Amherst, MA, United States
| | - George A O'Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
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24
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Scialo F, Amato F, Cernera G, Gelzo M, Zarrilli F, Comegna M, Pastore L, Bianco A, Castaldo G. Lung Microbiome in Cystic Fibrosis. Life (Basel) 2021; 11:life11020094. [PMID: 33513903 PMCID: PMC7911450 DOI: 10.3390/life11020094] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 12/21/2022] Open
Abstract
The defective mucociliary clearance due to CFTR malfunctioning causes predisposition to the colonization of pathogens responsible for the recurrent inflammation and rapid deterioration of lung function in patients with cystic fibrosis (CF). This has also a profound effect on the lung microbiome composition, causing a progressive reduction in its diversity, which has become a common characteristic of patients affected by CF. Although we know that the lung microbiome plays an essential role in maintaining lung physiology, our comprehension of how the microbial components interact with each other and the lung, as well as how these interactions change during the disease's course, is still at an early stage. Many challenges exist and many questions still to be answered, but there is no doubt that manipulation of the lung microbiome could help to develop better therapies for people affected by CF.
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Affiliation(s)
- Filippo Scialo
- Dipartimento di Scienze Mediche Traslazionali, University of Campania “L. Vanvitelli”, 80131 Napoli, Italy;
- CEINGE, Biotecnologie Avanzate, 80145 Napoli, Italy; (F.A.); (G.C.); (M.G.); (F.Z.); (M.C.); (L.P.); (G.C.)
- Correspondence:
| | - Felice Amato
- CEINGE, Biotecnologie Avanzate, 80145 Napoli, Italy; (F.A.); (G.C.); (M.G.); (F.Z.); (M.C.); (L.P.); (G.C.)
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università di Napoli Federico II, 80145 Napoli, Italy
| | - Gustavo Cernera
- CEINGE, Biotecnologie Avanzate, 80145 Napoli, Italy; (F.A.); (G.C.); (M.G.); (F.Z.); (M.C.); (L.P.); (G.C.)
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università di Napoli Federico II, 80145 Napoli, Italy
| | - Monica Gelzo
- CEINGE, Biotecnologie Avanzate, 80145 Napoli, Italy; (F.A.); (G.C.); (M.G.); (F.Z.); (M.C.); (L.P.); (G.C.)
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università di Napoli Federico II, 80145 Napoli, Italy
| | - Federica Zarrilli
- CEINGE, Biotecnologie Avanzate, 80145 Napoli, Italy; (F.A.); (G.C.); (M.G.); (F.Z.); (M.C.); (L.P.); (G.C.)
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università di Napoli Federico II, 80145 Napoli, Italy
| | - Marika Comegna
- CEINGE, Biotecnologie Avanzate, 80145 Napoli, Italy; (F.A.); (G.C.); (M.G.); (F.Z.); (M.C.); (L.P.); (G.C.)
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università di Napoli Federico II, 80145 Napoli, Italy
| | - Lucio Pastore
- CEINGE, Biotecnologie Avanzate, 80145 Napoli, Italy; (F.A.); (G.C.); (M.G.); (F.Z.); (M.C.); (L.P.); (G.C.)
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università di Napoli Federico II, 80145 Napoli, Italy
| | - Andrea Bianco
- Dipartimento di Scienze Mediche Traslazionali, University of Campania “L. Vanvitelli”, 80131 Napoli, Italy;
| | - Giuseppe Castaldo
- CEINGE, Biotecnologie Avanzate, 80145 Napoli, Italy; (F.A.); (G.C.); (M.G.); (F.Z.); (M.C.); (L.P.); (G.C.)
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università di Napoli Federico II, 80145 Napoli, Italy
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25
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Pust MM, Wiehlmann L, Davenport C, Rudolf I, Dittrich AM, Tümmler B. The human respiratory tract microbial community structures in healthy and cystic fibrosis infants. NPJ Biofilms Microbiomes 2020; 6:61. [PMID: 33319812 PMCID: PMC7738502 DOI: 10.1038/s41522-020-00171-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 11/13/2020] [Indexed: 02/06/2023] Open
Abstract
The metagenome development of the human respiratory tract was investigated by shotgun metagenome metagenomic sequencing of cough swabs from healthy children and children with cystic fibrosis (CF) between 3 weeks and 6 years of age. A healthy microbial community signature was associated with increased absolute abundances in terms of bacterial–human cell ratios of core and rare species across all age groups, with a higher diversity of rare species and a tightly interconnected species co-occurrence network, in which individual members were found in close proximity to each other and negative correlations were absent. Even without typical CF pathogens, the CF infant co-occurrence network was found to be less stable and prone to fragmentation due to fewer connections between species, a higher number of bridging species and the presence of negative species correlations. Detection of low-abundant DNA of the CF hallmark pathogen Pseudomonas aeruginosa was neither disease- nor age-associated in our cohort. Healthy and CF children come into contact with P. aeruginosa on a regular basis and from early on.
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Affiliation(s)
- Marie-Madlen Pust
- Clinic for Paediatric Pneumology, Allergology, and Neonatology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Lutz Wiehlmann
- Research Core Unit Genomics, Hannover Medical School, Hannover, Germany
| | - Colin Davenport
- Research Core Unit Genomics, Hannover Medical School, Hannover, Germany
| | - Isa Rudolf
- Clinic for Paediatric Pneumology, Allergology, and Neonatology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Anna-Maria Dittrich
- Clinic for Paediatric Pneumology, Allergology, and Neonatology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, Hannover, Germany
| | - Burkhard Tümmler
- Clinic for Paediatric Pneumology, Allergology, and Neonatology, Hannover Medical School, Hannover, Germany. .,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover Medical School, Hannover, Germany.
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26
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Abstract
Antimicrobial therapies against cystic fibrosis (CF) lung infections are largely aimed at the traditional, well-studied CF pathogens such as Pseudomonas aeruginosa and Burkholderia cepacia complex, despite the fact that the CF lung harbors a complex and dynamic polymicrobial community. A clinical focus on the dominant pathogens ignores potentially important community-level interactions in disease pathology, perhaps explaining why these treatments are often less effective than predicted based on in vitro testing. Antimicrobial therapies against cystic fibrosis (CF) lung infections are largely aimed at the traditional, well-studied CF pathogens such as Pseudomonas aeruginosa and Burkholderia cepacia complex, despite the fact that the CF lung harbors a complex and dynamic polymicrobial community. A clinical focus on the dominant pathogens ignores potentially important community-level interactions in disease pathology, perhaps explaining why these treatments are often less effective than predicted based on in vitro testing. A better understanding of the ecological dynamics of this ecosystem may enable clinicians to harness these interactions and thereby improve treatment outcomes. Like all ecosystems, the CF lung microbial community develops through a series of stages, each of which may present with distinct microbial communities that generate unique host-microbe and microbe-microbe interactions, metabolic profiles, and clinical phenotypes. While insightful models have been developed to explain some of these stages and interactions, there is no unifying model to describe how these infections develop and persist. Here, we review current perspectives on the ecology of the CF airway and present the CF Ecological Succession (CFES) model that aims to capture the spatial and temporal complexity of CF lung infection, address current challenges in disease management, and inform the development of ecologically driven therapeutic strategies.
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Heirali A, Thornton C, Acosta N, Somayaji R, Laforest Lapointe I, Storey D, Rabin H, Waddell B, Rossi L, Arrieta MC, Surette M, Parkins MD. Sputum microbiota in adults with CF associates with response to inhaled tobramycin. Thorax 2020; 75:1058-1064. [PMID: 33139451 DOI: 10.1136/thoraxjnl-2019-214191] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 08/03/2020] [Accepted: 08/09/2020] [Indexed: 11/03/2022]
Abstract
BACKGROUND Inhaled tobramycin powder/solution (TIP/S) use has resulted in improved clinical outcomes in patients with cystic fibrosis (CF) with chronic Pseudomonas aeruginosa. However, TIP/S effect on the CF sputum microbiome has not been explored. We hypothesised that TIP/S has additional 'off-target' effects beyond merely P. aeruginosa and that baseline microbiome prior to initiation of therapy is associated with subsequent patient response. METHODS We drew sputum samples from a prospectively collected biobank. Patients were included if they had one sputum sample in the 18 months before and after TIP/S. Bacterial 16S rRNA gene profiling was used to characterise the sputum microbiome. RESULTS Forty-one patients met our inclusion criteria and 151 sputum samples were assessed. At baseline, median age was 30.4 years (IQR 24.2-35.2) and forced expiratory volume in 1 (FEV1) second was 57% predicted (IQR 44-74). Nineteen patients were defined a priori as responders having no net decrease in FEV1 in the year following TIP/S. No significant changes were observed in key microbiome metrics of alpha (within-sample) or beta (between-sample) diversity for samples collected before and after TIP/S. However, significant beta-diversity (Bray-Curtis) differences were noted at baseline between patients based on response status. Notably, responders were observed to have a higher abundance of Staphylococcus in pretherapy baseline samples. CONCLUSIONS Our longitudinal study demonstrates that the sputum microbiome of patients with CF is relatively stable following inhaled tobramycin over many months. Intriguingly, our findings suggest that baseline microbiome may associate with patient response to TIP/S-suggesting the sputum microbiome could be used to personalise therapy.
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Affiliation(s)
- Alya Heirali
- Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | | | - Nicole Acosta
- Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | | | | | - Douglas Storey
- Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Harvey Rabin
- Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Barbara Waddell
- Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Laura Rossi
- Microbiology, McMaster University, Hamilton, Ontario, Canada
| | - Marie Claire Arrieta
- Pediatrics, Calgary, Alberta, Canada.,Physiology & Pharmacology, University of Calgary, Calgary, Alberta, Canada
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28
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Nelson MT, Wolter DJ, Eng A, Weiss EJ, Vo AT, Brittnacher MJ, Hayden HS, Ravishankar S, Bautista G, Ratjen A, Blackledge M, McNamara S, Nay L, Majors C, Miller SI, Borenstein E, Simon RH, LiPuma JJ, Hoffman LR. Maintenance tobramycin primarily affects untargeted bacteria in the CF sputum microbiome. Thorax 2020; 75:780-790. [PMID: 32631930 PMCID: PMC7875198 DOI: 10.1136/thoraxjnl-2019-214187] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 05/15/2020] [Accepted: 05/28/2020] [Indexed: 01/16/2023]
Abstract
RATIONALE The most common antibiotic used to treat people with cystic fibrosis (PWCF) is inhaled tobramycin, administered as maintenance therapy for chronic Pseudomonas aeruginosa lung infections. While the effects of inhaled tobramycin on P. aeruginosa abundance and lung function diminish with continued therapy, this maintenance treatment is known to improve long-term outcomes, underscoring how little is known about why antibiotics work in CF infections, what their effects are on complex CF sputum microbiomes and how to improve these treatments. OBJECTIVES To rigorously define the effect of maintenance tobramycin on CF sputum microbiome characteristics. METHODS AND MEASUREMENTS We collected sputum from 30 PWCF at standardised times before, during and after a single month-long course of maintenance inhaled tobramycin. We used traditional culture, quantitative PCR and metagenomic sequencing to define the dynamic effects of this treatment on sputum microbiomes, including abundance changes in both clinically targeted and untargeted bacteria, as well as functional gene categories. MAIN RESULTS CF sputum microbiota changed most markedly by 1 week of antibiotic therapy and plateaued thereafter, and this shift was largely driven by changes in non-dominant taxa. The genetically conferred functional capacities (ie, metagenomes) of subjects' sputum communities changed little with antibiotic perturbation, despite taxonomic shifts, suggesting functional redundancy within the CF sputum microbiome. CONCLUSIONS Maintenance treatment with inhaled tobramycin, an antibiotic with demonstrated long-term mortality benefit, primarily impacted clinically untargeted bacteria in CF sputum, highlighting the importance of monitoring the non-canonical effects of antibiotics and other treatments to accurately define and improve their clinical impact.
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Affiliation(s)
- Maria T Nelson
- Pediatrics, University of Washington School of Medicine, Seattle, Washington, USA
- Medical Scientist Training Program, University of Washington School of Medicine, Seattle, Washington, United States
- Molecular and Cellular Biology, University of Washington School of Medicine, Seattle, Washington, United States
| | - Daniel J Wolter
- Pediatrics, University of Washington School of Medicine, Seattle, Washington, USA
- Pediatrics, Seattle Children's Hospital, Seattle, Washington, USA
| | - Alexander Eng
- Genome Sciences, University of Washington School of Medicine, Seattle, Washington, USA
| | - Eli J Weiss
- Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Anh T Vo
- Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | | | - Hillary S Hayden
- Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Sumedha Ravishankar
- Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Gilbert Bautista
- Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Anina Ratjen
- Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
| | | | - Sharon McNamara
- Pediatrics, Seattle Children's Hospital, Seattle, Washington, USA
| | - Laura Nay
- Pediatrics, Seattle Children's Hospital, Seattle, Washington, USA
| | - Cheryl Majors
- Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Samuel I Miller
- Genome Sciences, University of Washington School of Medicine, Seattle, Washington, USA
- Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, United States
| | - Elhanan Borenstein
- Genome Sciences, University of Washington School of Medicine, Seattle, Washington, USA
- Blavatnik School of Computer Science, Tel Aviv University, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Richard H Simon
- Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - John J LiPuma
- Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan, USA
| | - Luke R Hoffman
- Pediatrics, University of Washington School of Medicine, Seattle, Washington, USA
- Pediatrics, Seattle Children's Hospital, Seattle, Washington, USA
- Microbiology, University of Washington School of Medicine, Seattle, Washington, USA
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29
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Parallel Analysis of Cystic Fibrosis Sputum and Saliva Reveals Overlapping Communities and an Opportunity for Sample Decontamination. mSystems 2020; 5:5/4/e00296-20. [PMID: 32636336 PMCID: PMC7343308 DOI: 10.1128/msystems.00296-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Cystic fibrosis is an inherited disease characterized by chronic respiratory tract infection and progressive lung disease. Studies of cystic fibrosis lung microbiology often rely on expectorated sputum to reflect the microbiota present in the lower airways. Passage of sputum through the oropharynx during collection, however, contributes microbes present in saliva to the sample, which could confound interpretation of results. Using culture-independent DNA sequencing-based analyses, we characterized the bacterial communities in pairs of expectorated sputum and saliva samples to generate a model for “decontaminating” sputum in silico. Our results demonstrate that salivary contamination of expectorated sputum does not have a large effect on most sputum samples and that observations of high bacterial diversity likely accurately reflect taxa present in cystic fibrosis lower airways. Culture-independent studies of the cystic fibrosis (CF) airway microbiome typically rely on expectorated sputum to assess the microbial makeup of lower airways. These studies have revealed rich bacterial communities. There is often considerable overlap between taxa observed in sputum and those observed in saliva, raising questions about the reliability of expectorated sputum as a sample representing lower airway microbiota. These concerns prompted us to compare pairs of sputum and saliva samples from 10 persons with CF. Using 16S rRNA gene sequencing and droplet digital PCR (ddPCR), we analyzed 37 pairs of sputum and saliva samples, each collected from the same person on the same day. We developed an in silico postsequencing decontamination procedure to remove from sputum the fraction of DNA reads estimated to have been contributed by saliva during expectoration. We demonstrate that while there was often sizeable overlap in community membership between sample types, expectorated sputum typically contains a higher bacterial load and a less diverse community compared to saliva. The differences in diversity between sputum and saliva were more pronounced in advanced disease stage, owing to increased relative abundance of the dominant taxa in sputum. Our effort to model saliva contamination of sputum in silico revealed generally minor effects on community structure after removal of contaminating reads. Despite considerable overlap in taxa observed between expectorated sputum and saliva samples, the impact of saliva contamination on measures of lower airway bacterial community composition in CF using expectorated sputum appears to be minimal. IMPORTANCE Cystic fibrosis is an inherited disease characterized by chronic respiratory tract infection and progressive lung disease. Studies of cystic fibrosis lung microbiology often rely on expectorated sputum to reflect the microbiota present in the lower airways. Passage of sputum through the oropharynx during collection, however, contributes microbes present in saliva to the sample, which could confound interpretation of results. Using culture-independent DNA sequencing-based analyses, we characterized the bacterial communities in pairs of expectorated sputum and saliva samples to generate a model for “decontaminating” sputum in silico. Our results demonstrate that salivary contamination of expectorated sputum does not have a large effect on most sputum samples and that observations of high bacterial diversity likely accurately reflect taxa present in cystic fibrosis lower airways.
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High-Resolution Longitudinal Dynamics of the Cystic Fibrosis Sputum Microbiome and Metabolome through Antibiotic Therapy. mSystems 2020; 5:5/3/e00292-20. [PMID: 32576651 PMCID: PMC7311317 DOI: 10.1128/msystems.00292-20] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Microbial diversity in the cystic fibrosis (CF) lung decreases over decades as pathogenic bacteria such as Pseudomonas aeruginosa take over. The dynamics of the CF microbiome and metabolome over shorter time frames, however, remain poorly studied. Here, we analyze paired microbiome and metabolome data from 594 sputum samples collected over 401 days from six adult CF subjects (subject mean = 179 days) through periods of clinical stability and 11 CF pulmonary exacerbations (CFPE). While microbiome profiles were personalized (permutational multivariate analysis of variance [PERMANOVA] r 2 = 0.79, P < 0.001), we observed significant intraindividual temporal variation that was highest during clinical stability (linear mixed-effects [LME] model, P = 0.002). This included periods where the microbiomes of different subjects became highly similar (UniFrac distance, <0.05). There was a linear increase in the microbiome alpha-diversity and in the log ratio of anaerobes to pathogens with time (n = 14 days) during the development of a CFPE (LME P = 0.0045 and P = 0.029, respectively). Collectively, comparing samples across disease states showed there was a reduction of these two measures during antibiotic treatment (LME P = 0.0096 and P = 0.014, respectively), but the stability data and CFPE data were not significantly different from each other. Metabolome alpha-diversity was higher during CFPE than during stability (LME P = 0.0085), but no consistent metabolite signatures of CFPE across subjects were identified. Virulence-associated metabolites from P. aeruginosa were temporally dynamic but were not associated with any disease state. One subject died during the collection period, enabling a detailed look at changes in the 194 days prior to death. This subject had over 90% Pseudomonas in the microbiome at the beginning of sampling, and that level gradually increased to over 99% prior to death. This study revealed that the CF microbiome and metabolome of some subjects are dynamic through time. Future work is needed to understand what drives these temporal dynamics and if reduction of anaerobes correlate to clinical response to CFPE therapy.IMPORTANCE Subjects with cystic fibrosis battle polymicrobial lung infections throughout their lifetime. Although antibiotic therapy is a principal treatment for CF lung disease, we have little understanding of how antibiotics affect the CF lung microbiome and metabolome and how much the community changes on daily timescales. By analyzing 594 longitudinal CF sputum samples from six adult subjects, we show that the sputum microbiome and metabolome are dynamic. Significant changes occur during times of stability and also through pulmonary exacerbations (CFPEs). Microbiome alpha-diversity increased as a CFPE developed and then decreased during treatment in a manner corresponding to the reduction in the log ratio of anaerobic bacteria to classic pathogens. Levels of metabolites from the pathogen P. aeruginosa were also highly variable through time and were negatively associated with anaerobes. The microbial dynamics observed in this study may have a significant impact on the outcome of antibiotic therapy for CFPEs and overall subject health.
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31
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Jorth P, Ehsan Z, Rezayat A, Caldwell E, Pope C, Brewington JJ, Goss CH, Benscoter D, Clancy JP, Singh PK. Direct Lung Sampling Indicates That Established Pathogens Dominate Early Infections in Children with Cystic Fibrosis. Cell Rep 2020; 27:1190-1204.e3. [PMID: 31018133 DOI: 10.1016/j.celrep.2019.03.086] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 12/17/2018] [Accepted: 03/22/2019] [Indexed: 01/09/2023] Open
Abstract
Culture and sequencing have produced divergent hypotheses about cystic fibrosis (CF) lung infections. Culturing suggests that CF lungs are uninfected before colonization by a limited group of CF pathogens. Sequencing suggests diverse communities of mostly oral bacteria inhabit lungs early on and diversity decreases as disease progresses. We studied the lung microbiota of CF children using bronchoscopy and sequencing, with measures to reduce contamination. We found no evidence for oral bacterial communities in lung lavages that lacked CF pathogens. Lavage microbial diversity varied widely, but decreases in diversity appeared to be driven by increased CF pathogen abundance, which reduced the signal from contaminants. Streptococcus, Prevotella, and Veillonella DNA was detected in some lavages containing CF pathogens, but DNA from these organisms was vastly exceeded by CF pathogen DNA and was not associated with inflammation. These findings support the hypothesis that established CF pathogens are primarily responsible for CF lung infections.
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Affiliation(s)
- Peter Jorth
- Departments of Pathology and Laboratory Medicine, Medicine, and Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; Department of Microbiology and Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Zarmina Ehsan
- Pulmonology and Sleep Medicine, Children's Mercy-Kansas City, Kansas City, MO 64108, USA
| | - Amir Rezayat
- Department of Microbiology and Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Ellen Caldwell
- Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Christopher Pope
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - John J Brewington
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Christopher H Goss
- Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Dan Benscoter
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - John P Clancy
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA.
| | - Pradeep K Singh
- Department of Microbiology and Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA.
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Valentini TD, Lucas SK, Binder KA, Cameron LC, Motl JA, Dunitz JM, Hunter RC. Bioorthogonal non-canonical amino acid tagging reveals translationally active subpopulations of the cystic fibrosis lung microbiota. Nat Commun 2020; 11:2287. [PMID: 32385294 PMCID: PMC7210995 DOI: 10.1038/s41467-020-16163-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 04/20/2020] [Indexed: 12/20/2022] Open
Abstract
Culture-independent studies of cystic fibrosis lung microbiota have provided few mechanistic insights into the polymicrobial basis of disease. Deciphering the specific contributions of individual taxa to CF pathogenesis requires comprehensive understanding of their ecophysiology at the site of infection. We hypothesize that only a subset of CF microbiota are translationally active and that these activities vary between subjects. Here, we apply bioorthogonal non-canonical amino acid tagging (BONCAT) to visualize and quantify bacterial translational activity in expectorated sputum. We report that the percentage of BONCAT-labeled (i.e. active) bacterial cells varies substantially between subjects (6-56%). We use fluorescence-activated cell sorting (FACS) and genomic sequencing to assign taxonomy to BONCAT-labeled cells. While many abundant taxa are indeed active, most bacterial species detected by conventional molecular profiling show a mixed population of both BONCAT-labeled and unlabeled cells, suggesting heterogeneous growth rates in sputum. Differentiating translationally active subpopulations adds to our evolving understanding of CF lung disease and may help guide antibiotic therapies targeting bacteria most likely to be susceptible.
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Affiliation(s)
- Talia D Valentini
- Department of Microbiology & Immunology, University of Minnesota, 689 23rd Avenue SE, Minneapolis, MN, 55455, United States
| | - Sarah K Lucas
- Department of Microbiology & Immunology, University of Minnesota, 689 23rd Avenue SE, Minneapolis, MN, 55455, United States
| | - Kelsey A Binder
- Department of Microbiology & Immunology, University of Minnesota, 689 23rd Avenue SE, Minneapolis, MN, 55455, United States
| | - Lydia C Cameron
- Department of Microbiology & Immunology, University of Minnesota, 689 23rd Avenue SE, Minneapolis, MN, 55455, United States
| | - Jason A Motl
- Academic Health Center, University Flow Cytometry Resource, University of Minnesota, 6th St SE, Minneapolis, MN, 55455, United States
| | - Jordan M Dunitz
- Division of Pulmonary, Allergy, Critical Care & Sleep Medicine, University of Minnesota, 420 Delaware St. SE, Minneapolis, MN, 55455, United States
| | - Ryan C Hunter
- Department of Microbiology & Immunology, University of Minnesota, 689 23rd Avenue SE, Minneapolis, MN, 55455, United States.
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Nelson MT, Pope CE, Marsh RL, Wolter DJ, Weiss EJ, Hager KR, Vo AT, Brittnacher MJ, Radey MC, Hayden HS, Eng A, Miller SI, Borenstein E, Hoffman LR. Human and Extracellular DNA Depletion for Metagenomic Analysis of Complex Clinical Infection Samples Yields Optimized Viable Microbiome Profiles. Cell Rep 2020; 26:2227-2240.e5. [PMID: 30784601 PMCID: PMC6435281 DOI: 10.1016/j.celrep.2019.01.091] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 11/20/2018] [Accepted: 01/25/2019] [Indexed: 01/27/2023] Open
Abstract
Metagenomic sequencing is a promising approach for identifying and characterizing organisms and their functional characteristics in complex, polymicrobial infections, such as airway infections in people with cystic fibrosis. These analyses are often hampered, however, by overwhelming quantities of human DNA, yielding only a small proportion of microbial reads for analysis. In addition, many abundant microbes in respiratory samples can produce large quantities of extracellular bacterial DNA originating either from biofilms or dead cells. We describe a method for simultaneously depleting DNA from intact human cells and extracellular DNA (human and bacterial) in sputum, using selective lysis of eukaryotic cells and endonuclease digestion. We show that this method increases microbial sequencing depth and, consequently, both the number of taxa detected and coverage of individual genes such as those involved in antibiotic resistance. This finding underscores the substantial impact of DNA from sources other than live bacteria in micro-biological analyses of complex, chronic infection specimens. Nelson et al. describe a method for reducing both human cellular DNA and extracellular DNA (human and bacterial) in a complex respiratory sample using hypotonic lysis and endonuclease digestion. This method increases effective microbial sequencing depth and minimizes bias introduced into subsequent phylogenetic analysis by bacterial extracellular DNA.
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Affiliation(s)
- Maria T Nelson
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98105, USA; Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98105, USA; Medical Scientist Training Program, University of Washington School of Medicine, Seattle, WA 98105, USA
| | - Christopher E Pope
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98105, USA
| | - Robyn L Marsh
- Child Health Division, Menzies School of Health Research, Charles Darwin University, Casuarina, NT 0811, Australia
| | - Daniel J Wolter
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98105, USA; Pulmonary and Sleep Medicine, Seattle Children's Hospital, Seattle, WA 98105, USA
| | - Eli J Weiss
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98105, USA
| | - Kyle R Hager
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98105, USA
| | - Anh T Vo
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98105, USA
| | - Mitchell J Brittnacher
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98105, USA
| | - Matthew C Radey
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98105, USA
| | - Hillary S Hayden
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98105, USA
| | - Alexander Eng
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98105, USA
| | - Samuel I Miller
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98105, USA; Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98105, USA; Department of Medicine, University of Washington School of Medicine, Seattle, WA 98105, USA
| | - Elhanan Borenstein
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98105, USA; Department of Computer Science and Engineering, University of Washington School of Medicine, Seattle, WA 98105, USA; Blavatnik School of Computer Science, Tel Aviv University, Tel Aviv 6997801, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel; Santa Fe Institute, Santa Fe, NM 87501, USA
| | - Lucas R Hoffman
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98105, USA; Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98105, USA; Pulmonary and Sleep Medicine, Seattle Children's Hospital, Seattle, WA 98105, USA.
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Ibironke O, McGuinness LR, Lu SE, Wang Y, Hussain S, Weisel CP, Kerkhof LJ. Species-level evaluation of the human respiratory microbiome. Gigascience 2020; 9:giaa038. [PMID: 32298431 PMCID: PMC7162353 DOI: 10.1093/gigascience/giaa038] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 03/06/2020] [Accepted: 03/25/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Changes to human respiratory tract microbiome may contribute significantly to the progression of respiratory diseases. However, there are few studies examining the relative abundance of microbial communities at the species level along the human respiratory tract. FINDINGS Bronchoalveolar lavage, throat swab, mouth rinse, and nasal swab samples were collected from 5 participants. Bacterial ribosomal operons were sequenced using the Oxford Nanopore MinION to determine the relative abundance of bacterial species in 4 compartments along the respiratory tract. More than 1.8 million raw operon reads were obtained from the participants with ∼600,000 rRNA reads passing quality assurance/quality control (70-95% identify; >1,200 bp alignment) by Discontiguous MegaBLAST against the EZ BioCloud 16S rRNA gene database. Nearly 3,600 bacterial species were detected overall (>750 bacterial species within the 5 dominant phyla: Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Fusobacteria. The relative abundance of bacterial species along the respiratory tract indicated that most microbes (95%) were being passively transported from outside into the lung. However, a small percentage (<5%) of bacterial species were at higher abundance within the lavage samples. The most abundant lung-enriched bacterial species were Veillonella dispar and Veillonella atypica while the most abundant mouth-associated bacterial species were Streptococcus infantis and Streptococcus mitis. CONCLUSIONS Most bacteria detected in lower respiratory samples do not seem to colonize the lung. However, >100 bacterial species were found to be enriched in bronchoalveolar lavage samples (compared to mouth/nose) and may play a substantial role in lung health.
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Affiliation(s)
- Olufunmilola Ibironke
- Environmental and Occupational Health Sciences Institute, School of Public Health, Rutgers–the State University of New Jersey, 170 Frelinghuysen Road, Piscataway, NJ, USA 08854, NJ, USA
| | - Lora R McGuinness
- Department of Marine and Coastal Sciences, Rutgers–the State University of New Jersey, 71 Dudley Road, New Brunswick, NJ USA 08901
| | - Shou-En Lu
- Environmental and Occupational Health Sciences Institute, School of Public Health, Rutgers–the State University of New Jersey, 170 Frelinghuysen Road, Piscataway, NJ, USA 08854, NJ, USA
| | - Yaquan Wang
- Environmental and Occupational Health Sciences Institute, School of Public Health, Rutgers–the State University of New Jersey, 170 Frelinghuysen Road, Piscataway, NJ, USA 08854, NJ, USA
| | - Sabiha Hussain
- Department of Pulmonary Medicine, Rutgers University-Robert Wood Johnsonchool, 125 Paterson Street, Suite 5200B New Brunswick, NJ 08901
| | - Clifford P Weisel
- Department of Pulmonary Medicine, Rutgers University-Robert Wood Johnsonchool, 125 Paterson Street, Suite 5200B New Brunswick, NJ 08901
| | - Lee J Kerkhof
- Department of Marine and Coastal Sciences, Rutgers–the State University of New Jersey, 71 Dudley Road, New Brunswick, NJ USA 08901
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35
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Shi X, Gao Z, Lin Q, Zhao L, Ma Q, Kang Y, Yu J. Meta-analysis Reveals Potential Influence of Oxidative Stress on the Airway Microbiomes of Cystic Fibrosis Patients. GENOMICS PROTEOMICS & BIOINFORMATICS 2020; 17:590-602. [PMID: 32171662 PMCID: PMC7212475 DOI: 10.1016/j.gpb.2018.03.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 03/25/2018] [Accepted: 03/28/2018] [Indexed: 12/11/2022]
Abstract
The lethal chronic airway infection of the cystic fibrosis (CF) patients is predisposed by colonization of specific CF-philic pathogens or the CF microbiomes, but key processes and reasons of the microbiome settlement in the patients are yet to be fully understood, especially their survival and metabolic dynamics from normal to diseased status under treatment. Here, we report our meta-analysis results on CF airway microbiomes based on metabolic networks reconstructed from genome information at species level. The microbiomes of CF patients appear to engage much more redox-related activities than those of controls, and by constructing a large dataset of anti-oxidative stress (anti-OS) genes, our quantitative evaluation of the anti-OS capacity of each bacterial species in the CF microbiomes confirms strong conservation of the anti-OS responses within genera and also shows that the CF pathogens have significantly higher anti-OS capacity than commensals and other typical respiratory pathogens. In addition, the anti-OS capacity of a relevant species correlates with its relative fitness for the airways of CF patients over that for the airways of controls. Moreover, the total anti-OS capacity of the respiratory microbiome of CF patients is collectively higher than that of controls, which increases with disease progression, especially after episodes of acute exacerbation and antibiotic treatment. According to these results, we propose that the increased OS in the airways of CF patients may play an important role in reshaping airway microbiomes to a more resistant status that favors the pre-infection colonization of the CF pathogens for a higher anti-OS capacity.
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Affiliation(s)
- Xing Shi
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100190, China
| | - Zhancheng Gao
- Department of Respiratory & Critical Care Medicine, Peking University People's Hospital, Beijing 100044, China
| | - Qiang Lin
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Liping Zhao
- Department of Biochemistry and Microbiology, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Qin Ma
- Bioinformatics and Mathematical Biosciences Lab, Department of Agronomy, Horticulture and Plant Science and Department of Mathematics and Statistics, South Dakota State University, Brookings, SD 57007, USA
| | - Yu Kang
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Jun Yu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100190, China.
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mSphere of Influence: a Community To Study Communities. mSphere 2020; 5:5/1/e00047-20. [PMID: 32024707 PMCID: PMC7002304 DOI: 10.1128/msphere.00047-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dominique Limoli studies polymicrobial interactions during cystic fibrosis respiratory disease. In this mSphere of Influence article, she reflects on how two papers (D. A. Hogan, S. D. Willger, E. L. Dolben, T. H. Hampton, et al., PLoS One 11:e0149998, 2016, https://doi.org/10.1371/journal.pone.0149998, and P. Jorth, B. Dominique Limoli studies polymicrobial interactions during cystic fibrosis respiratory disease. In this mSphere of Influence article, she reflects on how two papers (D. A. Hogan, S. D. Willger, E. L. Dolben, T. H. Hampton, et al., PLoS One 11:e0149998, 2016, https://doi.org/10.1371/journal.pone.0149998, and P. Jorth, B. J. Staudinger, X. Wu, K. B. Hisert, et al., Cell Host & Microbe 18:307–319, 2015, https://doi.org/10.1016/j.chom.2015.07.006) have influenced her thinking and research direction, which aims to understand interspecies bacterial communication during airway infections. These studies highlighted for her a need for new perspectives on the pathology of chronic infections in order to improve interventions.
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Bailey KL, Murphy PJ, Lineberry OK, Haack MR, Dickinson JD, Kalil AC. Procalcitonin predicts the severity of cystic fibrosis pulmonary exacerbations and readmissions in adult patients: a prospective cohort study. J Investig Med 2020; 68:856-863. [PMID: 31969379 DOI: 10.1136/jim-2019-001183] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/07/2019] [Indexed: 11/04/2022]
Abstract
Patients with cystic fibrosis (CF) experience multiple pulmonary exacerbations throughout their lifetime, resulting in repeated antibiotic exposure and hospital admissions. Reliable diagnostic markers to guide antibiotic treatment in patients with CF, however, are lacking. Given that the CF airway is characterized by persistent and frequent bacterial infection, our goal was to determine if procalcitonin (PCT) could be used as a severity and prognostic marker of CF exacerbation. We enrolled 40 participants at the time of diagnosis of CF pulmonary exacerbation. Inclusion criteria: age ≥19 years with exacerbation requiring antibiotics as determined by the treating physician. Exclusion criteria: antibiotics initiated more than 48 hours prior to enrollment, and pregnancy. Blood samples were collected on enrollment day and after 7-10 days of treatment. Of the 40 patients enrolled, 23 (57.5%) had detectable levels of PCT (≥0.05 ng/mL). PCT levels were significantly associated with pulmonary exacerbation scores (p=0.01) and per cent decrease in forced expiratory volume in 1 second (FEV1) (p=0.01) compared with the best in the last 12 months. Those who had worsening PCT during treatment had less improvement in FEV1 (p=0.001) and were more likely to be readmitted to the hospital sooner (p<0.0001). Likewise, those who had a detectable PCT at the time of admission were more likely to be readmitted sooner (p=0.03). PCT elevation during antibiotic treatment is associated with less improvement in FEV1 and earlier readmission. A detectable PCT level occurs only in more severe CF exacerbations. Multicenter trials are needed to confirm whether PCT may play a role in the clinical care of patients with CF.
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Affiliation(s)
- Kristina L Bailey
- Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, Nebraska, USA .,Int Med-Pulmonary, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Peter J Murphy
- Int Med-Pulmonary, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Olena K Lineberry
- Int Med-Pulmonary, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Matthew R Haack
- Int Med-Pulmonary, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - John D Dickinson
- Int Med-Pulmonary, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Andre C Kalil
- Int Med-Infectious Disease, University of Nebraska Medical Center, Omaha, Nebraska, USA
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Magalhães AP, Jorge P, Pereira MO. Pseudomonas aeruginosa and Staphylococcus aureus communication in biofilm infections: insights through network and database construction. Crit Rev Microbiol 2019; 45:712-728. [DOI: 10.1080/1040841x.2019.1700209] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Andreia Patrícia Magalhães
- CEB - Centre of Biological Engineering, LIBRO - Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Braga, Portugal
| | - Paula Jorge
- CEB - Centre of Biological Engineering, LIBRO - Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Braga, Portugal
| | - Maria Olívia Pereira
- CEB - Centre of Biological Engineering, LIBRO - Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Braga, Portugal
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Abstract
Antibiotic resistance is a growing concern for management of common bacterial infections. Here, we show that antibiotics can be effective at subinhibitory levels when bacteria carry latent phage. Our findings suggest that specific treatment strategies based on the identification of latent viruses in individual bacterial strains may be an effective personalized medicine approach to antibiotic stewardship. Most bacteria and archaea are infected by latent viruses that change their physiology and responses to environmental stress. We use a population model of the bacterium-phage relationship to examine the role that latent phage play in the bacterial population over time in response to antibiotic treatment. We demonstrate that the stress induced by antibiotic administration, even if bacteria are resistant to killing by antibiotics, is sufficient to control the infection under certain conditions. This work expands the breadth of understanding of phage-antibiotic synergy to include both temperate and chronic viruses persisting in their latent form in bacterial populations. IMPORTANCE Antibiotic resistance is a growing concern for management of common bacterial infections. Here, we show that antibiotics can be effective at subinhibitory levels when bacteria carry latent phage. Our findings suggest that specific treatment strategies based on the identification of latent viruses in individual bacterial strains may be an effective personalized medicine approach to antibiotic stewardship.
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40
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Clark ST, Guttman DS, Hwang DM. Diversification of Pseudomonas aeruginosa within the cystic fibrosis lung and its effects on antibiotic resistance. FEMS Microbiol Lett 2019; 365:4834010. [PMID: 29401362 DOI: 10.1093/femsle/fny026] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 01/30/2018] [Indexed: 12/13/2022] Open
Abstract
The evolution and diversification of bacterial pathogens within human hosts represent potential barriers to the diagnosis and treatment of life-threatening infections. Tremendous genetic and phenotypic diversity is characteristic of host adaptation in strains of Pseudomonas aeruginosa that infect the airways of individuals with chronic lung diseases and prove to be extremely difficult to eradicate. In this MiniReview, we examine recent advances in understanding within-host diversity and antimicrobial resistance in P. aeruginosa populations from the lower airways of individuals with the fatal genetic disease cystic fibrosis and the potential impacts that this diversity may have on detecting and interpreting antimicrobial susceptibility within these populations.
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Affiliation(s)
- Shawn T Clark
- Toronto General Hospital Research Institute, University Health Network, 101 College Street, PMCRT - MaRS Centre, Toronto, Ontario M5G 1L7, Canada
| | - David S Guttman
- Department of Cell & Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario M5S 3G5, Canada.,Centre for the Analysis of Genome Evolution & Function, University of Toronto, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada
| | - David M Hwang
- Toronto General Hospital Research Institute, University Health Network, 101 College Street, PMCRT - MaRS Centre, Toronto, Ontario M5G 1L7, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
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Bevivino A, Bacci G, Drevinek P, Nelson MT, Hoffman L, Mengoni A. Deciphering the Ecology of Cystic Fibrosis Bacterial Communities: Towards Systems-Level Integration. Trends Mol Med 2019; 25:1110-1122. [PMID: 31439509 DOI: 10.1016/j.molmed.2019.07.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/14/2019] [Accepted: 07/23/2019] [Indexed: 02/06/2023]
Abstract
Despite over a decade of cystic fibrosis (CF) microbiome research, much remains to be learned about the overall composition, metabolic activities, and pathogenicity of the microbes in CF airways, limiting our understanding of the respiratory microbiome's relation to disease. Systems-level integration and modeling of host-microbiome interactions may allow us to better define the relationships between microbiological characteristics, disease status, and treatment response. In this way, modeling could pave the way for microbiome-based development of predictive models, individualized treatment plans, and novel therapeutic approaches, potentially serving as a paradigm for approaching other chronic infections. In this review, we describe the challenges facing this effort and propose research priorities for a systems biology approach to CF lung disease.
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Affiliation(s)
- Annamaria Bevivino
- Department for Sustainability, Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Rome, Italy.
| | - Giovanni Bacci
- Department of Biology, University of Florence, Sesto Fiorentino, Florence, Italy
| | - Pavel Drevinek
- Department of Medical Microbiology, Department of Paediatrics, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic
| | - Maria T Nelson
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Lucas Hoffman
- Department of Pediatrics, University of Washington, Seattle, WA, USA; Department of Microbiology, University of Washington, Seattle, WA, USA; Center for Clinical and Translational Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Alessio Mengoni
- Department of Biology, University of Florence, Sesto Fiorentino, Florence, Italy
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Altered Stool Microbiota of Infants with Cystic Fibrosis Shows a Reduction in Genera Associated with Immune Programming from Birth. J Bacteriol 2019; 201:JB.00274-19. [PMID: 31209076 DOI: 10.1128/jb.00274-19] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 05/24/2019] [Indexed: 12/28/2022] Open
Abstract
Previous work from our group indicated an association between the gastrointestinal microbiota of infants with cystic fibrosis (CF) and airway disease in this population. Here we report that stool microbiota of infants with CF demonstrates an altered but largely unchanging within-individual bacterial diversity (alpha diversity) over the first year of life, in contrast to the infants without CF (control cohort), which showed the expected increase in alpha diversity over the first year. The beta diversity, or between-sample diversity, of these two cohorts was significantly different over the first year of life and was statistically significantly associated with airway exacerbations, confirming our earlier findings. Compared with control infants, infants with CF had reduced levels of Bacteroides, a bacterial genus associated with immune modulation, as early as 6 weeks of life, and this significant reduction of Bacteroides spp. in the cohort with CF persisted over the entire first year of life. Only two other genera were significantly different across the first year of life: Roseburia was significantly reduced and Veillonella was significantly increased. Other genera showed differences between the two cohorts but only at selected time points. In vitro studies demonstrated that exposure of the apical face of polarized intestinal cell lines to Bacteroides species supernatants significantly reduced production of interleukin 8 (IL-8), suggesting a mechanism whereby changes in the intestinal microbiota could impact inflammation in CF. This work further establishes an association between gastrointestinal microbiota, inflammation, and airway disease in infants with CF and presents a potential opportunity for therapeutic interventions beginning in early life.IMPORTANCE There is growing evidence for a link between gastrointestinal bacterial communities and airway disease progression in CF. We demonstrate that infants with CF ≤1 year of age show a distinct stool microbiota versus that of control infants of a comparable age. We detected associations between the gut microbiome and airway exacerbation events in the cohort of infants with CF, and in vitro studies provided one possible mechanism for this observation. These data clarify that current therapeutics do not establish in infants with CF a gastrointestinal microbiota like that in healthy infants, and we suggest that interventions that direct the gastrointestinal microbiota closer to a healthy state may provide systemic benefits to these patients during a critical window of immune programming that might have implications for lifelong health.
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Metabolic Modeling of Cystic Fibrosis Airway Communities Predicts Mechanisms of Pathogen Dominance. mSystems 2019; 4:mSystems00026-19. [PMID: 31020043 PMCID: PMC6478966 DOI: 10.1128/msystems.00026-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 03/29/2019] [Indexed: 01/08/2023] Open
Abstract
Cystic fibrosis (CF) is a genetic disease in which chronic airway infections and lung inflammation result in respiratory failure. CF airway infections are usually caused by bacterial communities that are difficult to eradicate with available antibiotics. Using species abundance data for clinically stable adult CF patients assimilated from three published studies, we developed a metabolic model of CF airway communities to better understand the interactions between bacterial species and between the bacterial community and the lung environment. Our model predicted that clinically observed CF pathogens could establish dominance over other community members across a range of lung nutrient conditions. Heterogeneity of species abundances across 75 patient samples could be predicted by assuming that sample-to-sample heterogeneity was attributable to random variations in the CF nutrient environment. Our model predictions provide new insights into the metabolic determinants of pathogen dominance in the CF lung and could facilitate the development of improved treatment strategies. Cystic fibrosis (CF) is a fatal genetic disease characterized by chronic lung infections due to aberrant mucus production and the inability to clear invading pathogens. The traditional view that CF infections are caused by a single pathogen has been replaced by the realization that the CF lung usually is colonized by a complex community of bacteria, fungi, and viruses. To help unravel the complex interplay between the CF lung environment and the infecting microbial community, we developed a community metabolic model comprised of the 17 most abundant bacterial taxa, which account for >95% of reads across samples, from three published studies in which 75 sputum samples from 46 adult CF patients were analyzed by 16S rRNA gene sequencing. The community model was able to correctly predict high abundances of the “rare” pathogens Enterobacteriaceae, Burkholderia, and Achromobacter in three patients whose polymicrobial infections were dominated by these pathogens. With these three pathogens removed, the model correctly predicted that the remaining 43 patients would be dominated by Pseudomonas and/or Streptococcus. This dominance was predicted to be driven by relatively high monoculture growth rates of Pseudomonas and Streptococcus as well as their ability to efficiently consume amino acids, organic acids, and alcohols secreted by other community members. Sample-by-sample heterogeneity of community composition could be qualitatively captured through random variation of the simulated metabolic environment, suggesting that experimental studies directly linking CF lung metabolomics and 16S sequencing could provide important insights into disease progression and treatment efficacy. IMPORTANCE Cystic fibrosis (CF) is a genetic disease in which chronic airway infections and lung inflammation result in respiratory failure. CF airway infections are usually caused by bacterial communities that are difficult to eradicate with available antibiotics. Using species abundance data for clinically stable adult CF patients assimilated from three published studies, we developed a metabolic model of CF airway communities to better understand the interactions between bacterial species and between the bacterial community and the lung environment. Our model predicted that clinically observed CF pathogens could establish dominance over other community members across a range of lung nutrient conditions. Heterogeneity of species abundances across 75 patient samples could be predicted by assuming that sample-to-sample heterogeneity was attributable to random variations in the CF nutrient environment. Our model predictions provide new insights into the metabolic determinants of pathogen dominance in the CF lung and could facilitate the development of improved treatment strategies.
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44
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Hahn A, Fanous H, Jensen C, Chaney H, Sami I, Perez GF, Koumbourlis AC, Louie S, Bost JE, van den Anker JN, Freishtat RJ, Zemanick ET, Crandall KA. Changes in microbiome diversity following beta-lactam antibiotic treatment are associated with therapeutic versus subtherapeutic antibiotic exposure in cystic fibrosis. Sci Rep 2019; 9:2534. [PMID: 30796252 PMCID: PMC6385179 DOI: 10.1038/s41598-019-38984-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 01/04/2019] [Indexed: 01/10/2023] Open
Abstract
In persons with cystic fibrosis (CF), decreased airway microbial diversity is associated with lower lung function. Conflicting data exist on the impact of short-term antibiotics for treatment of acute pulmonary exacerbations. However, whether differences in antibiotic exposure impacts airway microbiome changes has not been studied. We hypothesized that subtherapeutic beta-lactam antibiotic exposure, determined by the pharmacokinetics and pharmacodynamics (PK/PD) after intravenous (IV) antibiotic administration, would be associated with different patterns of changes in CF airway microbial diversity. Eligible children were enrolled when well; study assessments were performed around the time of pulmonary exacerbation. Plasma drug concentrations and bacterial minimum inhibitory concentrations (MICs) were used to determine therapeutic versus subtherapeutic beta-lactam antibiotic exposure. Respiratory samples were collected from children, and extracted bacterial DNA was amplified for the V4 region of the 16S rRNA gene. Twenty children experienced 31 APEs during the study; 45% (n = 14) of antibiotic courses were deemed therapeutic. Those in the therapeutic group had more significant decreases in alpha diversity at end of treatment and post-recovery compared to baseline than those in the subtherapeutic group. Therapeutic and subtherapeutic beta-lactam use is associated with different patterns of changes in CF airway microbial diversity following antibiotic administration.
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Affiliation(s)
- Andrea Hahn
- Division of Infectious Diseases, Children's National Health System (CNHS), 111 Michigan Ave NW, Washington DC, 20010, USA.
- Department of Pediatrics, George Washington University (GWU) School of Medicine and Health Sciences, 2300 Eye Street NW, Washington DC, 20037, USA.
| | - Hani Fanous
- Division of Pulmonary and Sleep Medicine, CNHS, 111 Michigan Ave NW, Washington DC, 20010, USA
| | - Caroline Jensen
- GWU School of Medicine and Health Sciences, 2300 Eye Street NW, Washington DC, 20037, USA
| | - Hollis Chaney
- Department of Pediatrics, George Washington University (GWU) School of Medicine and Health Sciences, 2300 Eye Street NW, Washington DC, 20037, USA
- Division of Pulmonary and Sleep Medicine, CNHS, 111 Michigan Ave NW, Washington DC, 20010, USA
| | - Iman Sami
- Department of Pediatrics, George Washington University (GWU) School of Medicine and Health Sciences, 2300 Eye Street NW, Washington DC, 20037, USA
- Division of Pulmonary and Sleep Medicine, CNHS, 111 Michigan Ave NW, Washington DC, 20010, USA
| | - Geovanny F Perez
- Department of Pediatrics, George Washington University (GWU) School of Medicine and Health Sciences, 2300 Eye Street NW, Washington DC, 20037, USA
- Division of Pulmonary and Sleep Medicine, CNHS, 111 Michigan Ave NW, Washington DC, 20010, USA
| | - Anastassios C Koumbourlis
- Department of Pediatrics, George Washington University (GWU) School of Medicine and Health Sciences, 2300 Eye Street NW, Washington DC, 20037, USA
- Division of Pulmonary and Sleep Medicine, CNHS, 111 Michigan Ave NW, Washington DC, 20010, USA
| | - Stan Louie
- Department of Clinical Pharmacy, University of Southern California School of Pharmacy, 1985 Zonal Ave, Los Angeles, CA, 90089, USA
| | - James E Bost
- Division of Biostatistics and Study Methodology, CNHS, 111 Michigan Ave NW, Washington DC, 20010, USA
| | - John N van den Anker
- Department of Pediatrics, George Washington University (GWU) School of Medicine and Health Sciences, 2300 Eye Street NW, Washington DC, 20037, USA
- Division of Clinical Pharmacology, CNHS, 111 Michigan Ave NW, Washington DC, 20010, USA
| | - Robert J Freishtat
- Department of Pediatrics, George Washington University (GWU) School of Medicine and Health Sciences, 2300 Eye Street NW, Washington DC, 20037, USA
- Division of Emergency Medicine, CNHS, 111 Michigan Ave NW, Washington DC, 20010, USA
| | - Edith T Zemanick
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, 13123 E. 16th Ave, Aurora, CO, 80045, USA
| | - Keith A Crandall
- Computational Biology Institute, GWU, 45085 University Drive, Ashburn, VA, 20147, USA
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McCurtain JL, Gilbertsen AJ, Evert C, Williams BJ, Hunter RC. Agmatine accumulation by Pseudomonas aeruginosa clinical isolates confers antibiotic tolerance and dampens host inflammation. J Med Microbiol 2019; 68:446-455. [PMID: 30688634 DOI: 10.1099/jmm.0.000928] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
PURPOSE In the cystic fibrosis (CF) airways, Pseudomonas aeruginosa undergoes diverse physiological changes in response to inflammation, antibiotic pressure, oxidative stress and a dynamic bioavailable nutrient pool. These include loss-of-function mutations that result in reduced virulence, altered metabolism and other phenotypes that are thought to confer a selective advantage for long-term persistence. Recently, clinical isolates of P. aeruginosa that hyperproduce agmatine (decarboxylated arginine) were cultured from individuals with CF. Sputum concentrations of this metabolite were also shown to correlate with disease severity. This raised the question of whether agmatine accumulation might also confer a selective advantage for P. aeruginosa during chronic colonization of the lung. METHODOLOGY AND RESULTS We screened a library of P. aeruginosa CF clinical isolates and found that ~5 % of subjects harboured isolates with an agmatine hyperproducing phenotype. Agmatine accumulation was a direct result of mutations in aguA, encoding the arginine deiminase that catalyses the conversion of agmatine into various polyamines. We also found that agmatine hyperproducing isolates (aguA-) had increased tolerance to the cationic antibiotics gentamicin, tobramycin and colistin relative to their chromosomally complemented strains (aguA+). Finally, we revealed that agmatine diminishes IL-8 production by airway epithelial cells in response to bacterial infection, with a consequent decrease in neutrophil recruitment to the murine airways in an acute pneumonia model. CONCLUSION These data highlight a potential new role for bacterial-derived agmatine that may have important consequences for the long-term persistence of P. aeruginosa in the CF airways.
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Affiliation(s)
- Jennifer L McCurtain
- 1 Department of Microbiology & Immunology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Adam J Gilbertsen
- 2 Pulmonary, Allergy, Critical Care and Sleep Division, University of Minnesota, Minneapolis, MN 55455, USA
| | - Clayton Evert
- 1 Department of Microbiology & Immunology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Bryan J Williams
- 2 Pulmonary, Allergy, Critical Care and Sleep Division, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ryan C Hunter
- 1 Department of Microbiology & Immunology, University of Minnesota, Minneapolis, MN 55455, USA
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Kiedrowski MR, Bomberger JM. Viral-Bacterial Co-infections in the Cystic Fibrosis Respiratory Tract. Front Immunol 2018; 9:3067. [PMID: 30619379 PMCID: PMC6306490 DOI: 10.3389/fimmu.2018.03067] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 12/11/2018] [Indexed: 12/15/2022] Open
Abstract
A majority of the morbidity and mortality associated with the genetic disease Cystic Fibrosis (CF) is due to lung disease resulting from chronic respiratory infections. The CF airways become chronically colonized with bacteria in childhood, and over time commensal lung microbes are displaced by bacterial pathogens, leading to a decrease in microbial diversity that correlates with declining patient health. Infection with the pathogen Pseudomonas aeruginosa is a major predictor of morbidity and mortality in CF, with CF individuals often becoming chronically colonized with P. aeruginosa in early adulthood and thereafter having an increased risk of hospitalization. Progression of CF respiratory disease is also influenced by infection with respiratory viruses. Children and adults with CF experience frequent respiratory viral infections with respiratory syncytial virus (RSV), rhinovirus, influenza, parainfluenza, and adenovirus, with RSV and influenza infection linked to the greatest decreases in lung function. Along with directly causing severe respiratory symptoms in CF populations, the impact of respiratory virus infections may be more far-reaching, indirectly promoting bacterial persistence and pathogenesis in the CF respiratory tract. Acquisition of P. aeruginosa in CF patients correlates with seasonal respiratory virus infections, and CF patients colonized with P. aeruginosa experience increased severe exacerbations and declines in lung function during respiratory viral co-infection. In light of such observations, efforts to better understand the impact of viral-bacterial co-infections in the CF airways have been a focus of clinical and basic research in recent years. This review summarizes what has been learned about the interactions between viruses and bacteria in the CF upper and lower respiratory tract and how co-infections impact the health of individuals with CF.
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Affiliation(s)
| | - Jennifer M. Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
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Refining the Application of Microbial Lipids as Tracers of Staphylococcus aureus Growth Rates in Cystic Fibrosis Sputum. J Bacteriol 2018; 200:JB.00365-18. [PMID: 30249710 DOI: 10.1128/jb.00365-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/19/2018] [Indexed: 02/04/2023] Open
Abstract
Chronic lung infections in cystic fibrosis (CF) could be treated more effectively if the effects of antimicrobials on pathogens in situ were known. Here, we compared changes in the microbial community composition and pathogen growth rates in longitudinal studies of seven pediatric CF patients undergoing intravenous antibiotic administration during pulmonary exacerbations. The microbial community composition was determined by counting rRNA with NanoString DNA analysis, and growth rates were obtained by incubating CF sputum with heavy water and tracing incorporation of deuterium into two branched-chain ("anteiso") fatty acids (a-C15:0 and a-C17:0) using gas chromatography-mass spectrometry (GC/MS). Prior to this study, both lipids were thought to be specific for Staphylococcaceae; hence, their isotopic enrichment was interpreted as a growth proxy for Staphylococcus aureus Our experiments revealed, however, that Prevotella is also a relevant microbial producer of a-C17:0 fatty acid in some CF patients; thus, deuterium incorporation into these lipids is better interpreted as a more general pathogen growth rate proxy. Even accounting for a small nonmicrobial background source detected in some patient samples, a-C15:0 fatty acid still appears to be a relatively robust proxy for CF pathogens, revealing a median generation time of ∼1.5 days, similar to prior observations. Contrary to our expectation, pathogen growth rates remained relatively stable throughout exacerbation treatment. We suggest two straightforward "best practices" for application of stable-isotope probing to CF sputum metabolites: (i) parallel determination of microbial community composition in CF sputum using culture-independent tools and (ii) assessing background levels of the diagnostic metabolite.IMPORTANCE In chronic lung infections, populations of microbial pathogens change and mature in ways that are often unknown, which makes it challenging to identify appropriate treatment options. A promising tool to better understand the physiology of microorganisms in a patient is stable-isotope probing, which we previously developed to estimate the growth rates of S. aureus in cystic fibrosis (CF) sputum. Here, we tracked microbial communities in a cohort of CF patients and found that anteiso fatty acids can also originate from other sources in CF sputum. This awareness led us to develop a new workflow for the application of stable-isotope probing in this context, improving our ability to estimate pathogen generation times in clinical samples.
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48
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Evolution of drug resistance in an antifungal-naive chronic Candida lusitaniae infection. Proc Natl Acad Sci U S A 2018; 115:12040-12045. [PMID: 30389707 PMCID: PMC6255150 DOI: 10.1073/pnas.1807698115] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Management of the limited number of antimicrobials currently available requires the identification of infections that contain drug-resistant isolates and the discovery of factors that promote the evolution of drug resistance. Here, we report a single fungal infection in which we have identified numerous subpopulations that differ in their alleles of a single gene that impacts drug resistance. The diversity at this locus was markedly greater than the reported heterogeneity of alleles conferring antibiotic resistance in bacterial infections. Analysis of genomes from hundreds of Clavispora (Candida) lusitaniae isolates, through individual and pooled isolate sequencing, from a single individual with cystic fibrosis revealed at least 25 nonsynonymous mutations in MRR1, which encodes a transcription factor capable of inducing fluconazole (FLZ) resistance in Candida species. Isolates with high-activity Mrr1 variants were resistant to FLZ due to elevated expression of the MDR1-encoded efflux pump. We found that high Mrr1-regulated Mdr1 activity protected against host and bacterial factors, suggesting drug resistance can be selected for indirectly and perhaps explaining the Mrr1 heterogeneity in this individual who had no prior azole exposure. Regional analysis of C. lusitaniae populations from the upper and lower lobes of the right lung suggested intermingling of subpopulations throughout. Our retrospective characterization of sputum and lung populations by pooled sequencing found that alleles that confer FLZ resistance were a minority in each pool, possibly explaining why they were undetected before unsuccessful FLZ therapy. New susceptibility testing regimes may detect problematical drug-resistant subpopulations in heterogeneous single-species infections.
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Hahn A, Warnken S, Pérez-Losada M, Freishtat RJ, Crandall KA. Microbial diversity within the airway microbiome in chronic pediatric lung diseases. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2018; 63:316-325. [PMID: 29225146 PMCID: PMC5992000 DOI: 10.1016/j.meegid.2017.12.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/22/2017] [Accepted: 12/07/2017] [Indexed: 12/31/2022]
Abstract
The study of the airway microbiome in children is an area of emerging research, especially in relation to the role microbial diversity may play in acute and chronic inflammation. Three such pediatric airway diseases include cystic fibrosis, asthma, and chronic lung disease of prematurity. In cystic fibrosis, the presence of Pseudomonas spp. is associated with decreased microbial diversity. Decreasing microbial diversity is also associated with poor lung function. In asthma, early viral infections appear to drive changes in bacterial diversity which may be associated with asthma risk. Premature infants with Ureaplasma spp. are at higher risk for chronic lung disease due to inflammation. Microbiome changes due to prematurity also appear to affect the inflammatory response to viral infections post-natally. Importantly, microbial diversity can be measured using metataxonomic (e.g., 16S rRNA sequencing) and metagenomic (e.g., shotgun sequencing) approaches. A metagenomics approach may be preferable as it can provide further granularity of the sample composition, identifying the bacterial species or strain, information on additional microbial components, including fungal and viral components, information about functional genomics of the microbiome, and information about antimicrobial resistance mutations. Future studies of pediatric airway diseases incorporating these techniques may provide evidence for new treatment approaches for these vulnerable patient populations.
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Affiliation(s)
- Andrea Hahn
- Division of Infectious Diseases, Children's National Health System (CNHS), Washington, D.C. 20010, USA; Department of Pediatrics, George Washington University (GWU) School of Medicine and Health Sciences (SMHS), Washington, D.C. 20052, USA.
| | - Stephanie Warnken
- Computational Biology Institute, Milken Institute School of Public Health, GWU, Washington, D.C. 20052, USA
| | - Marcos Pérez-Losada
- Computational Biology Institute, Milken Institute School of Public Health, GWU, Washington, D.C. 20052, USA; CIBIO-InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão 4485-661, Portugal
| | - Robert J Freishtat
- Department of Pediatrics, George Washington University (GWU) School of Medicine and Health Sciences (SMHS), Washington, D.C. 20052, USA; Division of Emergency Medicine, CNHS, Washington, D.C. 20010, USA
| | - Keith A Crandall
- Computational Biology Institute, Milken Institute School of Public Health, GWU, Washington, D.C. 20052, USA
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Huang Q, Wang Y, Xia Y, Li L, Luo J, Xia S, Sun Y, Miao Y, Wang K, Chen Y. Testing the neutral theory of biodiversity with the microbiome dataset from cystic fibrosis patients. Medicine (Baltimore) 2018; 97:e12248. [PMID: 30212959 PMCID: PMC6156045 DOI: 10.1097/md.0000000000012248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Cystic fibrosis (CF) is a hereditary disease that is characterized by defective mucociliary clearance, airway obstruction, chronic infection, and persistent inflammation. Cystic fibrosis pulmonary exacerbation (CFPE) majorly causes the morbidity of CF patients. Although CF has been demonstrated to change the composition of lung microbial community, previous studies have not made efforts to study the differences in the mechanism of assembly and diversity maintenance of lung microbial community in CF patients. In this study, we applied the neutral theory of biodiversity to comparatively investigate the assembly and diversity maintenance of the lung microbial community before and after the antibiotic treatment by reanalyzing the dataset from Fodor et al's study. We found that no one sample in the lung microbial communities of the sputum samples of Exacerbation group, nor those of End-of-treatment group satisfied the predictions of neutral model, suggesting that the neutral-process does not dominate in CF patients before and after antibiotic treatments. By comparing the biodiversity parameter between Exacerbation and End-of-treatment group, we found that the former had the significantly higher biodiversity, but the change in diversity parameter is slight and the P value is close to.05 (P value = .41). Therefore, our second finding is that although CFPE may increase the biodiversity of lung microbial community, the change is not essential.
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Affiliation(s)
- Qi Huang
- Department of Gastroenterology, State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Gastroenterology, Guangdong Gastrointestinal Disease Research Center, Nanfang Hospital, Southern Medical University, Guangzhou
- Department of Gastroenterology, The First Affiliated Hospital of Kunming Medical University, Yunnan Institute of Digestive Disease, Kunming
| | - Yaqiang Wang
- Institute of Mathematics and Information Science, Baoji University of Arts and Sciences, Baoji, Shaanxi
| | - Yao Xia
- Computational Biology and Medical Ecology Lab, State Key Lab of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences
| | - Lianwei Li
- Computational Biology and Medical Ecology Lab, State Key Lab of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences
| | - Juan Luo
- Department of Gastroenterology, The First Affiliated Hospital of Kunming Medical University, Yunnan Institute of Digestive Disease, Kunming
| | - Shuxian Xia
- Department of Gastroenterology, State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Gastroenterology, Guangdong Gastrointestinal Disease Research Center, Nanfang Hospital, Southern Medical University, Guangzhou
- Department of Gastroenterology, The First Affiliated Hospital of Kunming Medical University, Yunnan Institute of Digestive Disease, Kunming
| | - Yang Sun
- Department of Gastroenterology, The First Affiliated Hospital of Kunming Medical University, Yunnan Institute of Digestive Disease, Kunming
| | - Yinglei Miao
- Department of Gastroenterology, The First Affiliated Hospital of Kunming Medical University, Yunnan Institute of Digestive Disease, Kunming
| | - Kunhua Wang
- Department of General Surgery, The First Affiliated Hospital of Kunming Medical University, Yunnan Institute of digestive disease, Kunming, China
| | - Ye Chen
- Department of Gastroenterology, State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Gastroenterology, Guangdong Gastrointestinal Disease Research Center, Nanfang Hospital, Southern Medical University, Guangzhou
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