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Can Identifying Pulmonary Exacerbation Phenotypes Guide New Treatment Approaches for Cystic Fibrosis? Ann Am Thorac Soc 2022; 19:1799-1801. [PMID: 36318079 PMCID: PMC9667808 DOI: 10.1513/annalsats.202208-703ed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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2
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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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3
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Pseudomonas aeruginosa in the Cystic Fibrosis Lung. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:347-369. [DOI: 10.1007/978-3-031-08491-1_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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4
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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: 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: 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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5
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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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6
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Smith DJ, Klein K, Hartel G, Wainwright CE, Bell SC, Anderson GJ, Reid DW. Mutations in the HFE gene can be associated with increased lung disease severity in cystic fibrosis. Gene 2019; 683:12-17. [DOI: 10.1016/j.gene.2018.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 09/06/2018] [Accepted: 10/01/2018] [Indexed: 02/04/2023]
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7
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Hovold G, Palmcrantz V, Kahn F, Egesten A, Påhlman LI. Heparin-binding protein in sputum as a marker of pulmonary inflammation, lung function, and bacterial load in children with cystic fibrosis. BMC Pulm Med 2018; 18:104. [PMID: 29925362 PMCID: PMC6011334 DOI: 10.1186/s12890-018-0668-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 06/12/2018] [Indexed: 12/24/2022] Open
Abstract
Background Cystic fibrosis (CF) is associated with bacterial pulmonary infections and neutrophil-dominated inflammation in the airways. The aim of this study was to evaluate the neutrophil-derived protein Heparin-binding protein (HBP) as a potential sputum marker of airway inflammation and bacterial load. Methods Nineteen CF patients, aged 6–18 years, were prospectively followed for 6 months with sputum sampling at every visit to the CF clinic. A total of 41 sputum samples were collected. Sputum-HBP was analysed with ELISA, neutrophil elastase activity with a chromogenic assay, and total bacterial load with RT-PCR of the 16 s rDNA gene. Data were compared to lung function parameters and airway symptoms. Results HBP and elastase correlated to a decrease in FEV1%predicted compared to the patients´ individual baseline pulmonary function (∆FEV1), but not to bacterial load. Area under the receiver operating characteristic curve values for the detection of > 10% decrease in ∆FEV1 were 0.80 for HBP, 0.78 for elastase, and 0.54 for bacterial load. Conclusions Sputum HBP is a promising marker of airway inflammation and pulmonary function in children with CF.
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Affiliation(s)
- Gisela Hovold
- Department of Clinical Sciences Lund, Division of Infection Medicine, BMC B14, Lund University, Skåne University Hospital, Tornavägen 10, SE-22184, Lund, Sweden
| | | | - Fredrik Kahn
- Department of Clinical Sciences Lund, Division of Infection Medicine, BMC B14, Lund University, Skåne University Hospital, Tornavägen 10, SE-22184, Lund, Sweden
| | - Arne Egesten
- Department of Clinical Sciences Lund, Respiratory Medicine & Allergology, Lund University, Lund, Sweden
| | - Lisa I Påhlman
- Department of Clinical Sciences Lund, Division of Infection Medicine, BMC B14, Lund University, Skåne University Hospital, Tornavägen 10, SE-22184, Lund, Sweden.
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8
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Cystic Fibrosis Airway Microbiome: Overturning the Old, Opening the Way for the New. J Bacteriol 2018; 200:JB.00561-17. [PMID: 29084859 DOI: 10.1128/jb.00561-17] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The genetic disease cystic fibrosis (CF) is associated with chronic airway infections that are a proximal cause of death in many patients with this affliction. Classic microbiology studies focusing on canonical pathogens resulted in the development of a common set of views regarding the nature of the airway infections associated with this disease, and these ideas have influenced everything from the way infections are treated to how clinical trials for new CF-targeted antibiotics are designed and the focus of CF-related research topics. Recent culture-independent studies have prompted us to rethink, and in some cases discard, some of these long-held views. In this piece, I argue that an updated view of the complicated chronic infections associated with CF, thanks in large part to culture-independent studies of sputum and bronchoalveolar lavage fluid samples, should be leveraged to develop new strategies to treat these recalcitrant infections.
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Frayman KB, Armstrong DS, Grimwood K, Ranganathan SC. The airway microbiota in early cystic fibrosis lung disease. Pediatr Pulmonol 2017; 52:1384-1404. [PMID: 28815937 DOI: 10.1002/ppul.23782] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 07/17/2017] [Indexed: 12/12/2022]
Abstract
Infection plays a critical role in the pathogenesis of cystic fibrosis (CF) lung disease. Over the past two decades, the application of molecular and extended culture-based techniques to microbial analysis has changed our understanding of the lungs in both health and disease. CF lung disease is a polymicrobial disorder, with obligate and facultative anaerobes recovered alongside traditional pathogens in varying proportions, with some differences observed to correlate with disease stage. While healthy lungs are not sterile, differences between the lower airway microbiota of individuals with CF and disease-controls are already apparent in childhood. Understanding the evolution of the CF airway microbiota, and its relationship with clinical treatments and outcome at each disease stage, will improve our understanding of the pathogenesis of CF lung disease and potentially inform clinical management. This review summarizes current knowledge of the early development of the respiratory microbiota in healthy children and then discusses what is known about the airway microbiota in individuals with CF, including how it evolves over time and where future research priorities lie.
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Affiliation(s)
- Katherine B Frayman
- Department of Respiratory and Sleep Medicine, Royal Children's Hospital, Melbourne, Victoria, Australia.,Respiratory Diseases Group, Murdoch Children's Research Institute, Melbourne, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - David S Armstrong
- Department of Respiratory Medicine, Monash Children's Hospital, Melbourne, Victoria, Australia.,Department of Paediatrics, Monash University, Melbourne, Victoria, Australia
| | - Keith Grimwood
- School of Medicine and Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia.,Departments of Paediatrics and Infectious Diseases, Gold Coast Health, Gold Coast, Queensland, Australia
| | - Sarath C Ranganathan
- Department of Respiratory and Sleep Medicine, Royal Children's Hospital, Melbourne, Victoria, Australia.,Respiratory Diseases Group, Murdoch Children's Research Institute, Melbourne, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
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10
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Collie D, Glendinning L, Govan J, Wright S, Thornton E, Tennant P, Doherty C, McLachlan G. Lung Microbiota Changes Associated with Chronic Pseudomonas aeruginosa Lung Infection and the Impact of Intravenous Colistimethate Sodium. PLoS One 2015; 10:e0142097. [PMID: 26544950 PMCID: PMC4636361 DOI: 10.1371/journal.pone.0142097] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 10/16/2015] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Exacerbations associated with chronic lung infection with Pseudomonas aeruginosa are a major contributor to morbidity, mortality and premature death in cystic fibrosis. Such exacerbations are treated with antibiotics, which generally lead to an improvement in lung function and reduced sputum P. aeruginosa density. This potentially suggests a role for the latter in the pathogenesis of exacerbations. However, other data suggesting that changes in P. aeruginosa sputum culture status may not reliably predict an improvement in clinical status, and data indicating no significant changes in either total bacterial counts or in P. aeruginosa numbers in sputum samples collected prior to pulmonary exacerbation sheds doubt on this assumption. We used our recently developed lung segmental model of chronic Pseudomonas infection in sheep to investigate the lung microbiota changes associated with chronic P. aeruginosa lung infection and the impact of systemic therapy with colistimethate sodium (CMS). METHODOLOGY/PRINCIPAL FINDINGS We collected protected specimen brush (PSB) samples from sheep (n = 8) both prior to and 14 days after establishment of chronic local lung infection with P aeruginosa. Samples were taken from both directly infected lung segments (direct) and segments spatially remote to such sites (remote). Four sheep were treated with daily intravenous injections of CMS between days 7 and 14, and four were treated with a placebo. Necropsy examination at d14 confirmed the presence of chronic local lung infection and lung pathology in every direct lung segment. The predominant orders in lung microbiota communities before infection were Bacillales, Actinomycetales and Clostridiales. While lung microbiota samples were more likely to share similarities with other samples derived from the same lung, considerable within- and between-animal heterogeneity could be appreciated. Pseudomonadales joined the aforementioned list of predominant orders in lung microbiota communities after infection. Whilst treatment with CMS appeared to have little impact on microbial community composition after infection, or the change undergone by communities in reaching that state, when Gram negative organisms (excluding Pseudomonadales) were considered together as a group there was a significant decrease in their relative proportion that was only observed in the sheep treated with CMS. With only one exception the reduction was seen in both direct and remote lung segments. This reduction, coupled with generally increasing or stable levels of Pseudomonadales, meant that the proportion of the latter relative to total Gram negative bacteria increased in all bar one direct and one remote lung segment. CONCLUSIONS/SIGNIFICANCE The proportional increase in Pseudomonadales relative to other Gram negative bacteria in the lungs of sheep treated with systemic CMS highlights the potential for such therapies to inadvertently select or create a niche for bacteria seeding from a persistent source of chronic infection.
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Affiliation(s)
- David Collie
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
| | - Laura Glendinning
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - John Govan
- University of Edinburgh, Medical School, Edinburgh, Scotland, United Kingdom
| | - Steven Wright
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Elisabeth Thornton
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Peter Tennant
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Catherine Doherty
- University of Edinburgh, Medical School, Edinburgh, Scotland, United Kingdom
| | - Gerry McLachlan
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
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Pompilio A, Crocetta V, De Nicola S, Verginelli F, Fiscarelli E, Di Bonaventura G. Cooperative pathogenicity in cystic fibrosis: Stenotrophomonas maltophilia modulates Pseudomonas aeruginosa virulence in mixed biofilm. Front Microbiol 2015; 6:951. [PMID: 26441885 PMCID: PMC4584994 DOI: 10.3389/fmicb.2015.00951] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 08/27/2015] [Indexed: 12/23/2022] Open
Abstract
The present study was undertaken in order to understand more about the interaction occurring between S. maltophilia and P. aeruginosa, which are frequently co-isolated from CF airways. For this purpose, S. maltophilia RR7 and P. aeruginosa RR8 strains, co-isolated from the lung of a chronically infected CF patient during a pulmonary exacerbation episode, were evaluated for reciprocal effect during planktonic growth, adhesion and biofilm formation onto both polystyrene and CF bronchial cell monolayer, motility, as well as for gene expression in mixed biofilms. P. aeruginosa significantly affected S. maltophilia growth in both planktonic and biofilm cultures, due to an inhibitory activity probably requiring direct contact. Conversely, no effect was observed on P. aeruginosa by S. maltophilia. Compared with monocultures, the adhesiveness of P. aeruginosa on CFBE41o- cells was significantly reduced by S. maltophilia, which probably acts by reducing P. aeruginosa's swimming motility. An opposite trend was observed for biofilm formation, confirming the findings obtained using polystyrene. When grown in mixed biofilm with S. maltophilia, P. aeruginosa significantly over-expressed aprA, and algD-codifying for protease and alginate, respectively-while the quorum sensing related rhlR and lasI genes were down-regulated. The induced alginate expression by P. aeruginosa might be responsible for the protection of S. maltophilia against tobramycin activity we observed in mixed biofilms. Taken together, our results suggest that the existence of reciprocal interference of S. maltophilia and P. aeruginosa in CF lung is plausible. In particular, S. maltophilia might confer some selective "fitness advantage" to P. aeruginosa under the specific conditions of chronic infection or, alternatively, increase the virulence of P. aeruginosa thus leading to pulmonary exacerbation.
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Affiliation(s)
- Arianna Pompilio
- Department of Medical, Oral and Biotechnological Sciences, "G. d'Annunzio" University of Chieti-Pescara Chieti, Italy ; Aging Research Center (Ce.S.I.), "G. d'Annunzio" University Foundation Chieti, Italy
| | - Valentina Crocetta
- Department of Medical, Oral and Biotechnological Sciences, "G. d'Annunzio" University of Chieti-Pescara Chieti, Italy ; Aging Research Center (Ce.S.I.), "G. d'Annunzio" University Foundation Chieti, Italy
| | - Serena De Nicola
- Department of Medical, Oral and Biotechnological Sciences, "G. d'Annunzio" University of Chieti-Pescara Chieti, Italy ; Aging Research Center (Ce.S.I.), "G. d'Annunzio" University Foundation Chieti, Italy
| | - Fabio Verginelli
- Aging Research Center (Ce.S.I.), "G. d'Annunzio" University Foundation Chieti, Italy ; Department of Pharmacy, "G. d'Annunzio" University of Chieti-Pescara Chieti, Italy
| | | | - Giovanni Di Bonaventura
- Department of Medical, Oral and Biotechnological Sciences, "G. d'Annunzio" University of Chieti-Pescara Chieti, Italy ; Aging Research Center (Ce.S.I.), "G. d'Annunzio" University Foundation Chieti, Italy
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12
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Lam JC, Somayaji R, Surette MG, Rabin HR, Parkins MD. Reduction in Pseudomonas aeruginosa sputum density during a cystic fibrosis pulmonary exacerbation does not predict clinical response. BMC Infect Dis 2015; 15:145. [PMID: 25887462 PMCID: PMC4392784 DOI: 10.1186/s12879-015-0856-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Accepted: 02/20/2015] [Indexed: 02/01/2023] Open
Abstract
Background Pulmonary exacerbations (PEx) are critical events in cystic fibrosis (CF), responsible for reduced quality of life and permanent loss of lung function. Approximately 1/4 of PEx are associated with failure to recover lung function and/or resolve symptoms. Developing tools to optimize PEx treatment is of paramount importance. Methods We retrospectively audited all adults infected with Pseudomonas aeruginosa, experiencing PEx necessitating parenteral antibiotic therapy from 2006–2012 from our center. Quantitative analysis of sputum at admission, twice-weekly during hospitalization, and end of therapy were compared to baseline (most recent healthy) and follow-up (after PEx) samples. Change in P. aeruginosa burden from baseline was assessed for any and all morphotypes (ALL), as well as mucoid (MUC) and non-mucoid (NON) isolates specifically. PEx were identified as failures if >90% of baseline pulmonary function was not recovered. Results Forty-six patients meeting the above inclusion and exclusion criteria experienced 144 PEx during this time (median 3, IQR 2–6). Patients were treated for a median 14 days (IQR 13–16). No increase in ALL, MUC or NON were detected at PEx, nor was there an association between change in sputum density and magnitude of lung function decline. PEx failures were observed in 30% of events. Reductions of at least 1-log and 2 log P. aeruginosa sputum density was observed in 57% and 46% (ALL), 73% and 55% (MUC) and 58% and 46% (NON) of PEx, respectively. Factors associated with greater reduction of P. aeruginosa sputum density included choice of β-lactam antibiotic, antibiotics with in vitro predicted activity and treatment duration. PEx associated with reductions in P. aeruginosa sputum density were not associated with a reduced risk of PEx failure. Conclusions Enhanced killing of P. aeruginosa during PEx does not predict improved clinical outcomes. Studies accounting for the polymicrobial nature of CF respiratory disease and the heterogeneity of P. aeruginosa causing chronic infection may enable the identification of a more appropriate pathogen(s) based biomarker of PEx outcomes.
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Affiliation(s)
- John C Lam
- Department of Medicine, The University of Calgary, 3330 Hospital Dr. NW, Calgary, Alberta, T2N 4 N1, Canada.
| | - Ranjani Somayaji
- Department of Medicine, The University of Calgary, 3330 Hospital Dr. NW, Calgary, Alberta, T2N 4 N1, Canada.
| | - Michael G Surette
- McMaster University, Hamilton, Ontario, Canada. .,The Department of Microbiology, Immunology and Infectious Disease, The University of Calgary, Calgary, Canada.
| | - Harvey R Rabin
- Department of Medicine, The University of Calgary, 3330 Hospital Dr. NW, Calgary, Alberta, T2N 4 N1, Canada. .,The Department of Microbiology, Immunology and Infectious Disease, The University of Calgary, Calgary, Canada.
| | - Michael D Parkins
- Department of Medicine, The University of Calgary, 3330 Hospital Dr. NW, Calgary, Alberta, T2N 4 N1, Canada. .,The Department of Microbiology, Immunology and Infectious Disease, The University of Calgary, Calgary, Canada.
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13
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Justicia JL, Solé A, Quintana-Gallego E, Gartner S, de Gracia J, Prados C, Máiz L. Management of pulmonary exacerbations in cystic fibrosis: still an unmet medical need in clinical practice. Expert Rev Respir Med 2015; 9:183-94. [PMID: 25692532 DOI: 10.1586/17476348.2015.1016504] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Pulmonary exacerbation (PEx) is a hallmark of cystic fibrosis. Although several criteria have been proposed for the definition of PEx, no consensus has yet been reached. Very often, many PEx cases go unreported. A standardized and validated definition is needed to reduce variability in clinical practice. The pathophysiology of recurrent episodes remains unclear, and both onset and risk are multifactorial. PEx leads to increased healthcare costs, impaired quality of life and a cycle in which PEx causes loss of lung function, which predisposes to further episodes. The number of episodes affects survival. Although early diagnosis and aggressive treatment are highly recommended, measures to prevent the emergence of new PEx are even more important. In particular, inhaled antibiotics administered under new treatment schedules could play a key role in preventing exacerbations and thus delay decline in lung function and reduce mortality. The primary objective is zero exacerbations.
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Acute effects of viral respiratory tract infections on sputum bacterial density during CF pulmonary exacerbations. J Cyst Fibros 2014; 14:482-9. [PMID: 25544473 PMCID: PMC7105172 DOI: 10.1016/j.jcf.2014.11.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Revised: 11/17/2014] [Accepted: 11/22/2014] [Indexed: 01/01/2023]
Abstract
Background Airway proliferation of Pseudomonas aeruginosa bacteria is thought to trigger CF exacerbations and may be affected by the presence of viral infections. Methods A 2-year prospective study was conducted on 35 adults with CF. P. aeruginosa sputum density was analyzed during stable, exacerbation and post exacerbation assessments. Upon exacerbation, samples were sent for PCR detection of respiratory viruses and the sputum density of P. aeruginosa in patients with a viral infection versus those without was compared. Results Twenty-two patients experienced 30 exacerbations during the study period; 50% were associated with a viral infection. There was no change in sputum density of P. aeruginosa from the stable to exacerbation state when measured by quantitative culture or by PCR. Virus-associated exacerbations did not result in significant increases in P. aeruginosa sputum density compared to non-viral exacerbations. Conclusion Sputum density of P. aeruginosa was not increased at the time of CF exacerbation and was not influenced by the presence of viral infection.
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15
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Eusebio N, Amorim AA, Gamboa F, Araujo R. Molecular identification and genotyping of Pseudomonas aeruginosa isolated from cystic fibrosis and non-cystic fibrosis patients with bronchiectasis. Pathog Dis 2014; 73:1-7. [DOI: 10.1093/femspd/ftu014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Grimwood K, Kyd JM, Owen SJ, Massa HM, Cripps AW. Vaccination against respiratory Pseudomonas aeruginosa infection. Hum Vaccin Immunother 2014; 11:14-20. [PMID: 25483510 PMCID: PMC4514401 DOI: 10.4161/hv.34296] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Respiratory infections caused by Pseudomonas aeruginosa are a major clinical problem globally, particularly for patients with chronic pulmonary disorders, such as those with cystic fibrosis (CF), non-CF bronchiectasis (nCFB) and severe chronic obstructive pulmonary disease (COPD). In addition, critically ill and immunocompromised patients are also at significant risk of P. aeruginosa infection. For almost half a century, research efforts have focused toward development of a vaccine against infections caused by P. aeruginosa, but a licensed vaccine is not yet available. Significant advances in identifying potential vaccine antigens have been made. Immunisations via both the mucosal and systemic routes have been trialled in animal models and their effectiveness in clearing acute infections demonstrated. The challenge for translation of this research to human applications remains, since P. aeruginosa infections in the human respiratory tract can present both as an acute or chronic infection. In addition, immunisation prior to infection may not be possible for many patients with CF, nCFB or COPD. Therefore, development of a therapeutic vaccine provides an alternative approach for treatment of chronic infection. Preliminary animal and human studies suggest that mucosal immunisation may be effective as a therapeutic vaccine against P. aeruginosa respiratory infections. Nevertheless, more research is needed to improve our understanding of the basic biology of P. aeruginosa and the mechanisms needed to upregulate the induction of host immune pathways to prevent infection. Recognition of variability in the host immune responses for a range of patient health conditions at risk from P. aeruginosa infection is also required to support development of a successful vaccine delivery strategy and vaccine. Activation of mucosal immune responses may provide improved efficacy of vaccination for P. aeruginosa during both acute exacerbations and chronic infection.
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Affiliation(s)
- Keith Grimwood
- a School of Medicine; Griffith University; Gold Coast, Queensland Australia
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Smith DJ, Badrick AC, Zakrzewski M, Krause L, Bell SC, Anderson GJ, Reid DW. Pyrosequencing reveals transient cystic fibrosis lung microbiome changes with intravenous antibiotics. Eur Respir J 2014; 44:922-30. [DOI: 10.1183/09031936.00203013] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Chronic airway infection in adults with cystic fibrosis (CF) is polymicrobial and the impact of intravenous antibiotics on the bacterial community composition is poorly understood. We employed culture-independent molecular techniques to explore the early effects of i.v. antibiotics on the CF airway microbiome.DNA was extracted from sputum samples collected from adult subjects with CF at three time-points (before starting treatment, and at day 3 and day 8–10 of i.v. antibiotics) during treatment of an infective pulmonary exacerbation. Microbial community profiles were derived through analysis of bacterial-derived 16S ribosomal RNA by pyrosequencing and changes over time were compared.59 sputum samples were collected during 24 pulmonary exacerbations from 23 subjects. Between treatment onset and day 3 there was a significant reduction in the relative abundance of Pseudomonas and increased microbial diversity. By day 8–10, bacterial community composition was similar to pre-treatment. Changes in community composition did not predict improvements in lung function.The relative abundance of Pseudomonas falls rapidly in subjects with CF receiving i.v. antibiotic treatment for a pulmonary exacerbation and is accompanied by an increase in overall microbial diversity. However, this effect is not maintained beyond the first week of treatment.
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Abstract
Chronic obstructive pulmonary disease (COPD) is currently the third leading cause of death in the world. Although smoking is the main risk factor for this disease, only a minority of smokers develop COPD. Why this happens is largely unknown. Recent discoveries by the human microbiome project have shed new light on the importance and richness of the bacterial microbiota at different body sites in human beings. The microbiota plays a particularly important role in the development and functional integrity of the immune system. Shifts or perturbations in the microbiota can lead to disease. COPD is in part mediated by dysregulated immune responses to cigarette smoke and other environmental insults. Although traditionally the lung has been viewed as a sterile organ, by using highly sensitive genomic techniques, recent reports have identified diverse bacterial communities in the human lung that may change in COPD. This review summarizes the current knowledge concerning the lung microbiota in COPD and its potential implications for pathogenesis of the disease.
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Affiliation(s)
- Marc A Sze
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - James C Hogg
- Department of Pathology and Laboratory Medicine, The James Hogg Research Centre, Providence Heart-Lung Institute, St Paul's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Don D Sin
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada
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