scholarly journals Ecological Succession of Polymicrobial Communities in the Cystic Fibrosis Airways

mSystems ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Rutvij A. Khanolkar ◽  
Shawn T. Clark ◽  
Pauline W. Wang ◽  
David M. Hwang ◽  
Yvonne C. W. Yau ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Burkholderia Cepacia ◽  
Ecological Succession ◽  
Content Type ◽  
Temporal Complexity ◽  
Microbe Interactions ◽  
Lung Infections ◽  
Polymicrobial Communities ◽  
Review Current

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. 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.

scholarly journals In Vitro Activity of a Novel Glycopolymer against Biofilms of Burkholderia cepacia Complex Cystic Fibrosis Clinical Isolates

2019 ◽  
Vol 63 (6) ◽  
Author(s):  
Vidya P. Narayanaswamy ◽  
Andrew P. Duncan ◽  
John J. LiPuma ◽  
William P. Wiesmann ◽  
Shenda M. Baker ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Burkholderia Cepacia ◽  
Laser Scanning Microscopy ◽  
Burkholderia Cenocepacia ◽  
Burkholderia Cepacia Complex ◽  
Confocal Laser ◽  
Content Type ◽  
Biofilm Removal ◽  
Increased Risk

ABSTRACT Burkholderia cepacia complex (Bcc) lung infections in cystic fibrosis (CF) patients are often associated with a steady decline in lung function and death. The formation of biofilms and inherent multidrug resistance are virulence factors associated with Bcc infection and contribute to increased risk of mortality in CF patients. New therapeutic strategies targeting bacterial biofilms are anticipated to enhance antibiotic penetration and facilitate resolution of infection. Poly (acetyl, arginyl) glucosamine (PAAG) is a cationic glycopolymer therapeutic being developed to directly target biofilm integrity. In this study, 13 isolates from 7 species were examined, including Burkholderia multivorans, Burkholderia cenocepacia, Burkholderia gladioli, Burkholderia dolosa, Burkholderia vietnamiensis, and B. cepacia. These isolates were selected for their resistance to standard clinical antibiotics and their ability to form biofilms in vitro. Biofilm biomass was quantitated using static tissue culture plate (TCP) biofilm methods and a minimum biofilm eradication concentration (MBEC) assay. Confocal laser scanning microscopy (CLSM) visualized biofilm removal by PAAG during treatment. Both TCP and MBEC methods demonstrated a significant dose-dependent relationship with regard to biofilm removal by 50 to 200 μg/ml PAAG following a 1-h treatment (P < 0.01). A significant reduction in biofilm thickness was observed following a 10-min treatment of Bcc biofilms with PAAG compared to that with vehicle control (P < 0.001) in TCP, MBEC, and CLSM analyses. PAAG also rapidly permeabilizes bacteria within the first 10 min of treatment. Glycopolymers, such as PAAG, are a new class of large-molecule therapeutics that support the treatment of recalcitrant Bcc biofilm.

scholarly journals Use of a Multiplex Transcript Method for Analysis of Pseudomonas aeruginosa Gene Expression Profiles in the Cystic Fibrosis Lung

2016 ◽  
Vol 84 (10) ◽  
pp. 2995-3006 ◽  
Author(s):  
Alex H. Gifford ◽  
Sven D. Willger ◽  
Emily L. Dolben ◽  
Lisa A. Moulton ◽  
Dana B. Dorman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Expression Profiles ◽  
Clinical Isolates ◽  
Probe Design ◽  
Content Type ◽  
Lung Infections

The discovery of therapies that modulatePseudomonas aeruginosavirulence or that can eradicate chronicP. aeruginosalung infections associated with cystic fibrosis (CF) will be advanced by an improved understanding ofP. aeruginosabehaviorin vivo. We demonstrate the use of multiplexed Nanostring technology to monitor relative abundances ofP. aeruginosatranscripts across clinical isolates, in serial samples, and for the purposes of comparing microbial physiologyin vitroandin vivo. The expression of 75 transcripts encoded by genes implicated in CF lung disease was measured in a variety ofP. aeruginosastrains as well as RNA serial sputum samples from fourP. aeruginosa-colonized subjects with CF collected over 6 months. We present data on reproducibility, the results from different methods of normalization, and demonstrate high concordance between transcript relative abundance data obtained by Nanostring or transcriptome sequencing (RNA-Seq) analysis. Furthermore, we address considerations regarding sequence variation between strains during probe design. Analysis ofP. aeruginosagrownin vitroidentified transcripts that correlated with the different phenotypes commonly observed in CF clinical isolates.P. aeruginosatranscript profiles in RNA from CF sputum indicated alginate productionin vivo, and transcripts involved in quorum-sensing regulation were less abundant in sputum than strains grown in the laboratory.P. aeruginosagene expression patterns from sputum clustered closely together relative to patterns for laboratory-grown cultures; in contrast, laboratory-grownP. aeruginosashowed much greater transcriptional variation with only loose clustering of strains with different phenotypes. The clustering within and between subjects was surprising in light of differences in inhaled antibiotic and respiratory symptoms, suggesting that the pathways represented by these 75 transcripts are stable in chronic CFP. aeruginosalung infections.

scholarly journals Is the Potable Water System an Advantageous Preinfection Niche for Bacteria Colonizing the Cystic Fibrosis Lung?

mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Matthew J. Wargo
Keyword(s):  
Cystic Fibrosis ◽  
Burkholderia Cepacia ◽  
Stenotrophomonas Maltophilia ◽  
Potable Water ◽  
Water System ◽  
Achromobacter Xylosoxidans ◽  
Low Oxygen ◽  
Content Type ◽  
Lung Infections ◽  
Successful Colonization

ABSTRACTPeople with cystic fibrosis are susceptible to lung infections from a variety of bacteria, a number of which also reside in the potable water system, includingPseudomonas aeruginosa,Stenotrophomonas maltophilia,Achromobacter xylosoxidans,Burkholderia cepaciacomplex, and nontuberculosisMycobacteria. Here, I propose chemical and physical aspects of the potable water system along with bacterial lifestyle strategies in this system that may enhance successful colonization of cystic fibrosis lungs by these bacteria, including iron and copper levels, lipids, and low growth rates within low-oxygen biofilms.

scholarly journals In Vitro Activity of Ceftolozane-Tazobactam and Other Antimicrobial Agents against Burkholderia cepacia Complex and Burkholderia gladioli

2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Dale M. Mazer ◽  
Carol Young ◽  
Linda M. Kalikin ◽  
Theodore Spilker ◽  
John J. LiPuma
Keyword(s):  
Cystic Fibrosis ◽  
Burkholderia Cepacia ◽  
Antimicrobial Agents ◽  
Vitro Activity ◽  
Burkholderia Cepacia Complex ◽  
In Vitro Activity ◽  
Content Type ◽  
Burkholderia Gladioli

ABSTRACT We tested the activities of ceftolozane-tazobactam and 13 other antimicrobial agents against 221 strains of Burkholderia cepacia complex and Burkholderia gladioli. Most strains (82%) were cultured from persons with cystic fibrosis, and most (85%) were recovered since 2011. The ceftolozane-tazobactam MIC was ≤8 μg/ml for 77% of the strains. However, the MIC range was broad (≤0.5 to >64 μg/ml; MIC50/90, 2/32 μg/ml). Significant differences in susceptibility to some antimicrobial agents were observed between species.

scholarly journals Localization of Burkholderia cepacia Complex Bacteria in Cystic Fibrosis Lungs and Interactions with Pseudomonas aeruginosa in Hypoxic Mucus

2014 ◽  
Vol 82 (11) ◽  
pp. 4729-4745 ◽  
Author(s):  
Ute Schwab ◽  
Lubna H. Abdullah ◽  
Olivia S. Perlmutt ◽  
Daniel Albert ◽  
C. William Davis ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Burkholderia Cepacia ◽  
Single Cells ◽  
Burkholderia Cenocepacia ◽  
Burkholderia Cepacia Complex ◽  
Test Medium ◽  
Fermentation Products ◽  
Content Type

ABSTRACTThe localization ofBurkholderia cepaciacomplex (Bcc) bacteria in cystic fibrosis (CF) lungs, alone or during coinfection withPseudomonas aeruginosa, is poorly understood. We performed immunohistochemistry for Bcc andP. aeruginosabacteria on 21 coinfected or singly infected CF lungs obtained at transplantation or autopsy. Parallelin vitroexperiments examined the growth of two Bcc species,Burkholderia cenocepaciaandBurkholderia multivorans, in environments similar to those occupied byP. aeruginosain the CF lung. Bcc bacteria were predominantly identified in the CF lung as single cells or small clusters within phagocytes and mucus but not as “biofilm-like structures.” In contrast,P. aeruginosawas identified in biofilm-like masses, but densities appeared to be reduced during coinfection with Bcc bacteria. Based on chemical analyses of CF and non-CF respiratory secretions, a test medium was defined to study Bcc growth and interactions withP. aeruginosain an environment mimicking the CF lung. When test medium was supplemented with alternative electron acceptors under anaerobic conditions,B. cenocepaciaandB. multivoransused fermentation rather than anaerobic respiration to gain energy, consistent with the identification of fermentation products by high-performance liquid chromatography (HPLC). Both Bcc species also expressed mucinases that produced carbon sources from mucins for growth. In the presence ofP. aeruginosain vitro, both Bcc species grew anaerobically but not aerobically. We propose that Bcc bacteria (i) invade aP. aeruginosa-infected CF lung when the airway lumen is anaerobic, (ii) inhibitP. aeruginosabiofilm-like growth, and (iii) expand the host bacterial niche from mucus to also include macrophages.

scholarly journals Pseudomonas aeruginosa Volatilome Characteristics and Adaptations in Chronic Cystic Fibrosis Lung Infections

mSphere ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Trenton J. Davis ◽  
Ava V. Karanjia ◽  
Charity N. Bhebhe ◽  
Sarah B. West ◽  
Matthew Richardson ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Chemical Diversity ◽  
Chronic Infections ◽  
Lung Function Decline ◽  
Content Type ◽  
Flight Mass Spectrometry ◽  
Patient Health ◽  
Lung Infections

ABSTRACT Pseudomonas aeruginosa chronic lung infections in individuals with cystic fibrosis (CF) significantly reduce quality of life and increase morbidity and mortality. Tracking these infections is critical for monitoring patient health and informing treatments. We are working toward the development of novel breath-based biomarkers to track chronic P. aeruginosa lung infections in situ. Using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC–TOF-MS), we characterized the in vitro volatile metabolomes (“volatilomes”) of 81 P. aeruginosa isolates collected from 17 CF patients over at least a 5-year period of their chronic lung infections. We detected 539 volatiles produced by the P. aeruginosa isolates, 69 of which were core volatiles that were highly conserved. We found that each early infection isolate has a unique volatilome, and as infection progresses, the volatilomes of isolates from the same patient become increasingly dissimilar, to the point that these intrapatient isolates are no more similar to one another than to isolates from other patients. We observed that the size and chemical diversity of P. aeruginosa volatilomes do not change over the course of chronic infections; however, the relative abundances of core hydrocarbons, alcohols, and aldehydes do change and are correlated with changes in phenotypes associated with chronic infections. This study indicates that it may be feasible to track P. aeruginosa chronic lung infections by measuring changes to the infection volatilome and lays the groundwork for exploring the translatability of this approach to direct measurement using patient breath. IMPORTANCE Pseudomonas aeruginosa is a leading cause of chronic lung infections in cystic fibrosis (CF), which are correlated with lung function decline. Significant clinical efforts are therefore aimed at detecting infections and tracking them for phenotypic changes, such as mucoidy and antibiotic resistance. Both the detection and tracking of lung infections rely on sputum cultures, but due to improvements in CF therapies, sputum production is declining, although risks for lung infections persist. Therefore, we are working toward the development of breath-based diagnostics for CF lung infections. In this study, we characterized of the volatile metabolomes of 81 P. aeruginosa clinical isolates collected from 17 CF patients over a duration of at least 5 years of a chronic lung infection. We found that the volatilome of P. aeruginosa adapts over time and is correlated with infection phenotype changes, suggesting that it may be possible to track chronic CF lung infections with a breath test.

scholarly journals Activity of Cysteamine against the Cystic Fibrosis Pathogen Burkholderia cepacia Complex

2016 ◽  
Vol 60 (10) ◽  
pp. 6200-6206 ◽  
Author(s):  
Douglas Fraser-Pitt ◽  
Derry Mercer ◽  
Emma Lovie ◽  
Jennifer Robertson ◽  
Deborah O'Neil
Keyword(s):  
Cystic Fibrosis ◽  
Biofilm Formation ◽  
Burkholderia Cepacia ◽  
Standard Of Care ◽  
Burkholderia Cepacia Complex ◽  
Content Type ◽  
Folate Pathway ◽  
The Impact ◽  
Slow Growing

ABSTRACTThere are no wholly successful chemotherapeutic strategies againstBurkholderia cepaciacomplex (BCC) colonization in cystic fibrosis (CF). We assessed the impact of cysteamine (Lynovex) in combination with standard-of-care CF antibioticsin vitroagainst BCC CF isolates by the concentration at which 100% of bacteria were killed (MIC100) and checkerboard assays under CLSI standard conditions. Cysteamine facilitated the aminoglycoside-, fluoroquinolone- and folate pathway inhibitor-mediated killing of BCC organisms that were otherwise resistant or intermediately sensitive to these antibiotic classes. Slow-growing BCC strains are often recalcitrant to treatment and form biofilms. In assessing the impact of cysteamine on biofilms, we demonstrated inhibition of BCC biofilm formation at sub-MIC100s of cysteamine.

scholarly journals “Switching Partners”: Piperacillin-Avibactam Is a Highly Potent Combination against Multidrug-Resistant Burkholderia cepacia Complex and Burkholderia gladioli Cystic Fibrosis Isolates

2019 ◽  
Vol 57 (8) ◽  
Author(s):  
Elise T. Zeiser ◽  
Scott A. Becka ◽  
Brigid M. Wilson ◽  
Melissa D. Barnes ◽  
John J. LiPuma ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Burkholderia Cepacia ◽  
Multidrug Resistant ◽  
Burkholderia Cepacia Complex ◽  
Content Type ◽  
Burkholderia Gladioli ◽  
Alternative Antibiotic ◽  
And Control

ABSTRACT In persons with cystic fibrosis (CF), airway infection with Burkholderia cepacia complex (Bcc) species or Burkholderia gladioli presents a significant challenge due to inherent resistance to multiple antibiotics. Two chromosomally encoded inducible β-lactamases, a Pen-like class A and AmpC are produced in Bcc and B. gladioli. Previously, ceftazidime-avibactam demonstrated significant potency against Bcc and B. gladioli isolated from the sputum of individuals with CF; however, 10% of the isolates tested resistant to ceftazidime-avibactam. Here, we describe an alternative antibiotic combination to overcome ceftazidime-avibactam resistance. Antimicrobial susceptibility testing was performed on Bcc and B. gladioli clinical and control isolates. Biochemical analysis was conducted on purified PenA1 and AmpC1 β-lactamases from Burkholderia multivorans ATCC 17616. Analytic isoelectric focusing and immunoblotting were conducted on cellular extracts of B. multivorans induced by various β-lactams or β-lactam-β-lactamase inhibitor combinations. Combinations of piperacillin-avibactam, as well as piperacillin-tazobactam plus ceftazidime-avibactam (the clinically available counterpart), were tested against a panel of ceftazidime-avibactam nonsusceptible Bcc and B. gladioli. The piperacillin-avibactam and piperacillin-tazobactam-ceftazidime-avibactam combinations restored susceptibility to 99% of the isolates tested. Avibactam is a potent inhibitor of PenA1 (apparent inhibitory constant [Ki app] = 0.5 μM), while piperacillin was found to inhibit AmpC1 (Ki app = 2.6 μM). Moreover, piperacillin, tazobactam, ceftazidime, and avibactam, as well as combinations thereof, did not induce expression of blapenA1 and blaampC1 in the B. multivorans ATCC 17616 background. When ceftazidime-avibactam is combined with piperacillin-tazobactam, the susceptibility of Bcc and B. gladioli to ceftazidime and piperacillin is restored in vitro. Both the lack of blapenA1 induction and potent inactivation of PenA1 by avibactam likely provide the major contributions toward susceptibility. With in vivo validation, piperacillin-tazobactam-ceftazidime-avibactam may represent salvage therapy for individuals with CF and highly drug-resistant Bcc and B. gladioli infections.

scholarly journals In VitroSusceptibility ofBurkholderia cepaciaComplex Isolated from Cystic Fibrosis Patients to Ceftazidime-Avibactam and Ceftolozane-Tazobactam

2018 ◽  
Vol 62 (9) ◽  
Author(s):  
A. Van Dalem ◽  
M. Herpol ◽  
F. Echahidi ◽  
C. Peeters ◽  
I. Wybo ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Burkholderia Cepacia ◽  
Content Type

ABSTRACTWe tested thein vitrosusceptibility of ceftazidime-avibactam and ceftolozane-tazobactam and 13 other antibiotics against 91Burkholderia cepaciacomplex (BCC) strains isolated from cystic fibrosis patients since 2012. The highest susceptibility (82%) was found for trimethoprim-sulfamethoxazole. Eighty-one and 63% of all BCC strains were susceptible to ceftazidime-avibactam and ceftolozane-tazobactam, respectively. For temocillin, ceftazidime, piperacillin-tazobactam, and meropenem, at least 50% of the strains were susceptible.B. stabilisseems to be more resistant than other BCC species.

scholarly journals Three Distinct Contact-Dependent Growth Inhibition Systems Mediate Interbacterial Competition by the Cystic Fibrosis Pathogen Burkholderia dolosa

2018 ◽  
Vol 200 (22) ◽  
Author(s):  
Andrew I. Perault ◽  
Peggy A. Cotter
Keyword(s):  
Cystic Fibrosis ◽  
Respiratory Tract ◽  
Growth Inhibition ◽  
Burkholderia Cepacia ◽  
Target Cells ◽  
Content Type ◽  
Dependent Growth ◽  
Polymicrobial Communities ◽  
Contact Dependent Growth Inhibition ◽  
Polymicrobial Infections

ABSTRACT The respiratory tracts of individuals afflicted with cystic fibrosis (CF) harbor complex polymicrobial communities. By an unknown mechanism, species of the Gram-negative Burkholderia cepacia complex, such as Burkholderia dolosa, can displace other bacteria in the CF lung, causing cepacia syndrome, which has a poor prognosis. The genome of B. dolosa strain AU0158 (BdAU0158) contains three loci that are predicted to encode contact-dependent growth inhibition (CDI) systems. CDI systems function by translocating the toxic C terminus of a large exoprotein directly into target cells, resulting in growth inhibition or death unless the target cells produce a cognate immunity protein. We demonstrate here that each of the three bcpAIOB loci in BdAU0158 encodes a distinct CDI system that mediates interbacterial competition in an allele-specific manner. While only two of the three bcpAIOB loci were expressed under the in vitro conditions tested, the third conferred immunity under these conditions due to the presence of an internal promoter driving expression of the bcpI gene. One BdAU0158 bcpAIOB allele is highly similar to bcpAIOB in Burkholderia thailandensis strain E264 (BtE264), and we showed that their BcpI proteins are functionally interchangeable, but contact-dependent signaling (CDS) phenotypes were not observed in BdAU0158. Our findings suggest that the CDI systems of BdAU0158 may provide this pathogen an ecological advantage during polymicrobial infections of the CF respiratory tract. IMPORTANCE Human-associated polymicrobial communities can promote health and disease, and interbacterial interactions influence the microbial ecology of such communities. Polymicrobial infections of the cystic fibrosis respiratory tract impair lung function and lead to the death of individuals suffering from this disorder; therefore, a greater understanding of these microbial communities is necessary for improving treatment strategies. Bacteria utilize contact-dependent growth inhibition systems to kill neighboring competitors and maintain their niche within multicellular communities. Several cystic fibrosis pathogens have the potential to gain an ecological advantage during infection via contact-dependent growth inhibition systems, including Burkholderia dolosa. Our research is significant, as it has identified three functional contact-dependent growth inhibition systems in B. dolosa that may provide this pathogen a competitive advantage during polymicrobial infections.

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