1
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Herrmann C, Lingner M, Herrmann S, Brockhausen I, Tümmler B. Mucin adhesion of serial cystic fibrosis airways Pseudomonas aeruginosa isolates. Front Cell Infect Microbiol 2024; 14:1448104. [PMID: 39239637 PMCID: PMC11374773 DOI: 10.3389/fcimb.2024.1448104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Accepted: 07/30/2024] [Indexed: 09/07/2024] Open
Abstract
The chronic airway infections with Pseudomonas aeruginosa are the major co-morbidity in people with cystic fibrosis (CF). Within CF lungs, P. aeruginosa persists in the conducting airways together with human mucins as the most abundant structural component of its microenvironment. We investigated the adhesion of 41 serial CF airway P. aeruginosa isolates to airway mucin preparations from CF sputa. Mucins and bacteria were retrieved from five modulator-naïve patients with advanced CF lung disease. The P. aeruginosa isolates from CF airways and non-CF reference strains showed a strain-specific signature in their adhesion to ovine, porcine and bovine submaxillary mucins and CF airway mucins ranging from no or low to moderate and strong binding. Serial CF clonal isolates and colony morphotypes from the same sputum sample were as heterogeneous in their affinity to mucin as representatives of other clones thus making 'mucin binding' one of the most variable intraclonal phenotypic traits of P. aeruginosa known to date. Most P. aeruginosa CF airway isolates did not adhere more strongly to CF airway mucins than to plastic surfaces. The strong binders, however, exhibited a strain-specific affinity gradient to O-glycans, CF airway and mammalian submaxillary mucins.
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Affiliation(s)
- Christian Herrmann
- Institut für Biophysikalische Chemie, Medizinische Hochschule Hannover, Hannover, Germany
- Klinik für Pädiatrische Pneumologie, Allergologie und Neonatologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Meike Lingner
- Institut für Biophysikalische Chemie, Medizinische Hochschule Hannover, Hannover, Germany
- Klinik für Pädiatrische Pneumologie, Allergologie und Neonatologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Susanne Herrmann
- Institut für Biophysikalische Chemie, Medizinische Hochschule Hannover, Hannover, Germany
- Klinik für Pädiatrische Pneumologie, Allergologie und Neonatologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Inka Brockhausen
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Burkhard Tümmler
- Institut für Biophysikalische Chemie, Medizinische Hochschule Hannover, Hannover, Germany
- Klinik für Pädiatrische Pneumologie, Allergologie und Neonatologie, Medizinische Hochschule Hannover, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research, Hannover, Germany
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2
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Wiehlmann L, Klockgether J, Hammerbacher AS, Salunkhe P, Horatzek S, Munder A, Peilert JF, Gulbins E, Eberl L, Tümmler B. A VirB4 ATPase of the mobile accessory genome orchestrates core genome-encoded features of physiology, metabolism, and virulence of Pseudomonas aeruginosa TBCF10839. Front Cell Infect Microbiol 2023; 13:1234420. [PMID: 37577372 PMCID: PMC10413270 DOI: 10.3389/fcimb.2023.1234420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 07/10/2023] [Indexed: 08/15/2023] Open
Abstract
Pseudomonas aeruginosa TBCF10839 is a highly virulent strain that can persist and replicate in human neutrophils. Screening of a signature-tagged mutagenesis (STM) TBCF10839 transposon library in phagocytosis tests identified a mutant that carried the transposon in the VirB4 homolog 5PG21 of an integrative and conjugative element (ICE)-associated type IV secretion system of the pKLC102 subtype. 5P21 TBCF10839 insertion mutants were deficient in metabolic versatility, secretion, quorum sensing, and virulence. The mutants were efficiently killed in phagocytosis tests in vitro and were avirulent in an acute murine airway infection model in vivo. The inactivation of 5PG21 silenced the rhl, las, and pqs operons and the gene expression for the synthesis of hydrogen cyanide, the antimetabolite l-2-amino-4-methoxy-trans-3-butenoic acid, and the H2- and H3-type VI secretion systems and their associated effectors. The mutants were impaired in the utilization of carbon sources and stored compounds that are not funneled into intermediary metabolism. This showcase demonstrates that a single gene of the mobile accessory genome can become an essential element to operate the core genome-encoded features of metabolism and virulence.
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Affiliation(s)
- Lutz Wiehlmann
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
- Research Core Unit Genomics, Hannover Medical School, Hannover, Germany
| | - Jens Klockgether
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Anna-Silke Hammerbacher
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Prabhakar Salunkhe
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Sonja Horatzek
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Antje Munder
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease, German Center for Lung Research, Hannover, Germany
| | | | - Erich Gulbins
- Department of Surgery, University of Cincinnati College of Medicine, Cincinnati, OH, United States
- Institute of Molecular Biology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Burkhard Tümmler
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease, German Center for Lung Research, Hannover, Germany
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3
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Lynch JP, Zhanel GG. Pseudomonas aeruginosa Pneumonia: Evolution of Antimicrobial Resistance and Implications for Therapy. Semin Respir Crit Care Med 2022; 43:191-218. [PMID: 35062038 DOI: 10.1055/s-0041-1740109] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Pseudomonas aeruginosa (PA), a non-lactose-fermenting gram-negative bacillus, is a common cause of nosocomial infections in critically ill or debilitated patients, particularly ventilator-associated pneumonia (VAP), and infections of urinary tract, intra-abdominal, wounds, skin/soft tissue, and bloodstream. PA rarely affects healthy individuals, but may cause serious infections in patients with chronic structural lung disease, comorbidities, advanced age, impaired immune defenses, or with medical devices (e.g., urinary or intravascular catheters, foreign bodies). Treatment of pseudomonal infections is difficult, as PA is intrinsically resistant to multiple antimicrobials, and may acquire new resistance determinants even while on antimicrobial therapy. Mortality associated with pseudomonal VAP or bacteremias is high (> 35%) and optimal therapy is controversial. Over the past three decades, antimicrobial resistance (AMR) among PA has escalated globally, via dissemination of several international multidrug resistant "epidemic" clones. We discuss the importance of PA as a cause of pneumonia including health care-associated pneumonia, hospital-acquired pneumonia, VAP, the emergence of AMR to this pathogen, and approaches to therapy (both empirical and definitive).
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Affiliation(s)
- Joseph P Lynch
- Division of Pulmonary, Critical Care Medicine, Allergy, and Clinical Immunology, Department of Medicine, The David Geffen School of Medicine at UCLA, Los Angeles, California
| | - George G Zhanel
- Department of Medical Microbiology/Infectious Diseases, University of Manitoba, Max Rady College of Medicine, Winnipeg, Manitoba, Canada
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4
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Martin I, Kenna DTD, Morales S, Alton EWFW, Davies JC. Variability in Bacteriophage and Antibiotic Sensitivity in Serial Pseudomonas aeruginosa Isolates from Cystic Fibrosis Airway Cultures over 12 Months. Microorganisms 2021; 9:microorganisms9030660. [PMID: 33810202 PMCID: PMC8004851 DOI: 10.3390/microorganisms9030660] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 01/21/2023] Open
Abstract
Antibiotic treatment for Pseudomonas aeruginosa (Pa) in cystic fibrosis is limited in efficacy and may lead to multi-drug resistance (MDR). Alternatives such as bacteriophages are being explored but well designed, and controlled trials are crucial. The rational selection of patients with bacteriophage susceptible infections is required for both safety and efficacy monitoring. We questioned whether bacteriophage susceptibility profiles were constant or variable over time, variability having been reported with antibiotics. Serial Pa isolates (n = 102) from 24 chronically infected cystic fibrosis (CF) patients over one year were investigated with plaque and antibiotic disc diffusion assays. Variable number tandem repeat (VNTR) analysis identified those patients with >1 isolate. A median (range) of 4 (3–6) isolates/patient were studied. Twenty-one (87.5%) individuals had a single VNTR type; three (12.5%) had two VNTR types at different times. Seventy-five percent of isolates were sensitive to bacteriophage at ≥ 1 concentration; 50% of isolates were antibiotic multidrug resistant. Serial isolates, even when representing a single VNTR type, varied in sensitivity to both bacteriophages and antibiotics. The rates of sensitivity to bacteriophage supports the development of this therapy; however, the variability in response has implications for the selection of patients in future trials which must be on the basis of current, not past, isolate testing.
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Affiliation(s)
- Isaac Martin
- National Heart and Lung Institute, Imperial College London, Emmanuel Kaye Building, London SW3 6LY, UK; (E.W.F.W.A.); (J.C.D.)
- Royal Brompton & Harefield Hospitals, Sydney St., London SW3 6NP, UK
- Correspondence: ; Tel.: +1-(647)-223-7782
| | - Dervla T. D. Kenna
- Antimicrobial Resistance and Healthcare Associated Infections (AMRHAI) Reference Unit, National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK;
| | - Sandra Morales
- AmpliPhi Biosciences Corporation, Global Research, Brookvale, NSW 2100, Australia;
| | - Eric W. F. W. Alton
- National Heart and Lung Institute, Imperial College London, Emmanuel Kaye Building, London SW3 6LY, UK; (E.W.F.W.A.); (J.C.D.)
- Royal Brompton & Harefield Hospitals, Sydney St., London SW3 6NP, UK
| | - Jane C. Davies
- National Heart and Lung Institute, Imperial College London, Emmanuel Kaye Building, London SW3 6LY, UK; (E.W.F.W.A.); (J.C.D.)
- Royal Brompton & Harefield Hospitals, Sydney St., London SW3 6NP, UK
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5
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Lee C, Klockgether J, Fischer S, Trcek J, Tümmler B, Römling U. Why? - Successful Pseudomonas aeruginosa clones with a focus on clone C. FEMS Microbiol Rev 2021; 44:740-762. [PMID: 32990729 PMCID: PMC7685784 DOI: 10.1093/femsre/fuaa029] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 07/12/2020] [Indexed: 12/20/2022] Open
Abstract
The environmental species Pseudomonas aeruginosa thrives in a variety of habitats. Within the epidemic population structure of P. aeruginosa, occassionally highly successful clones that are equally capable to succeed in the environment and the human host arise. Framed by a highly conserved core genome, individual members of successful clones are characterized by a high variability in their accessory genome. The abundance of successful clones might be funded in specific features of the core genome or, although not mutually exclusive, in the variability of the accessory genome. In clone C, one of the most predominant clones, the plasmid pKLC102 and the PACGI-1 genomic island are two ubiquitous accessory genetic elements. The conserved transmissible locus of protein quality control (TLPQC) at the border of PACGI-1 is a unique horizontally transferred compository element, which codes predominantly for stress-related cargo gene products such as involved in protein homeostasis. As a hallmark, most TLPQC xenologues possess a core genome equivalent. With elevated temperature tolerance as a characteristic of clone C strains, the unique P. aeruginosa and clone C specific disaggregase ClpG is a major contributor to tolerance. As other successful clones, such as PA14, do not encode the TLPQC locus, ubiquitous denominators of success, if existing, need to be identified.
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Affiliation(s)
- Changhan Lee
- Department of Microbiology, Tumor and Cell Biology, Biomedicum C8, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Jens Klockgether
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Clinical Research Group 'Pseudomonas Genomics', Hannover Medical School, D-30625 Hannover, Germany
| | - Sebastian Fischer
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Clinical Research Group 'Pseudomonas Genomics', Hannover Medical School, D-30625 Hannover, Germany
| | - Janja Trcek
- Faculty of Natural Sciences and Mathematics, Department of Biology, University of Maribor, Maribor, 2000, Slovenia
| | - Burkhard Tümmler
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Clinical Research Group 'Pseudomonas Genomics', Hannover Medical School, D-30625 Hannover, Germany
| | - Ute Römling
- Department of Microbiology, Tumor and Cell Biology, Biomedicum C8, Karolinska Institutet, SE-171 77 Stockholm, Sweden
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6
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Addy C, Caskey S, Downey D. Gram negative infections in cystic fibrosis: a review of preventative and treatment options. Expert Opin Orphan Drugs 2020. [DOI: 10.1080/21678707.2020.1713748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Charlotte Addy
- Centre for Medical Education, Queen’s University Belfast, Belfast, UK
- Northern Ireland Regional Adult CF Centre, Belfast Health and Social Care Trust, Belfast, UK
| | - Steven Caskey
- Northern Ireland Regional Adult CF Centre, Belfast Health and Social Care Trust, Belfast, UK
| | - Damian Downey
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK
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7
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Brown N, Buse C, Lewis A, Martin D, Nettleton S. Pathways, practices and architectures: Containing antimicrobial resistance in the cystic fibrosis clinic. Health (London) 2019; 25:196-213. [DOI: 10.1177/1363459319866894] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Antimicrobial resistance and the adaptation of microbial life to antibiotics are recognised as a major healthcare challenge. Whereas most social science engagement with antimicrobial resistance has focussed on aspects of ‘behaviour’ (prescribing, antibiotic usage, patient ‘compliance’, etc.), this article instead explores antimicrobial resistance in the context of building design and healthcare architecture, focussing on the layout, design and ritual practices of three cystic fibrosis outpatient clinics. Cystic fibrosis is a life-threatening multi-system genetic condition, often characterised by frequent respiratory infections and antibiotic treatment. Preventing antimicrobial resistance and cross-infection in cystic fibrosis increasingly depends on the spatiotemporal isolation of both people and pathogens. Our research aims to bring to the fore the role of the built environment exploring how containment and segregation are varyingly performed in interaction with material design, focussing on three core themes. These include, first, aspects of flow, movement and the spatiotemporal choreography of cystic fibrosis care. Second, the management of waiting and the materiality of the waiting room is a recurrent concern in our fieldwork. Finally, we take up the question of air, the intangibility of airborne risks and their material mitigation in the cystic fibrosis clinic.
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8
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Cramer N, Sedlacek L, Tümmler B, Welte T. Low transmission risk of Pseudomonas aeruginosa in a bronchiectasis clinic based on the knowledge of bacterial population biology. Eur Respir J 2019; 53:13993003.02191-2018. [PMID: 30635293 DOI: 10.1183/13993003.02191-2018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 12/19/2018] [Indexed: 01/08/2023]
Affiliation(s)
- Nina Cramer
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Ludwig Sedlacek
- Institute for Medical Microbiology and Hospital Epidemiology, 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 (BREATH), German Center for Lung Research, Hannover, Germany
| | - Tobias Welte
- Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research, Hannover, Germany.,Dept for Respiratory Medicine, Hannover Medical School, Hannover, Germany
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9
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Rowbotham NJ, Palser SC, Smith SJ, Smyth AR. Infection prevention and control in cystic fibrosis: a systematic review of interventions. Expert Rev Respir Med 2019; 13:425-434. [DOI: 10.1080/17476348.2019.1595594] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Nicola J Rowbotham
- Evidence Based Child Health Group, Division of Child Health, Obstetrics & Gynaecology, Queens Medical Centre, Nottingham, UK
| | - Sally C Palser
- Evidence Based Child Health Group, Division of Child Health, Obstetrics & Gynaecology, Queens Medical Centre, Nottingham, UK
| | - Sherie J Smith
- Evidence Based Child Health Group, Division of Child Health, Obstetrics & Gynaecology, Queens Medical Centre, Nottingham, UK
| | - Alan R Smyth
- Evidence Based Child Health Group, Division of Child Health, Obstetrics & Gynaecology, Queens Medical Centre, Nottingham, UK
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10
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Parkins MD, Somayaji R, Waters VJ. Epidemiology, Biology, and Impact of Clonal Pseudomonas aeruginosa Infections in Cystic Fibrosis. Clin Microbiol Rev 2018; 31:e00019-18. [PMID: 30158299 PMCID: PMC6148191 DOI: 10.1128/cmr.00019-18] [Citation(s) in RCA: 158] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chronic lower airway infection with Pseudomonas aeruginosa is a major contributor to morbidity and mortality in individuals suffering from the genetic disease cystic fibrosis (CF). Whereas it was long presumed that each patient independently acquired unique strains of P. aeruginosa present in their living environment, multiple studies have since demonstrated that shared strains of P. aeruginosa exist among individuals with CF. Many of these shared strains, often referred to as clonal or epidemic strains, can be transmitted from one CF individual to another, potentially reaching epidemic status. Numerous epidemic P. aeruginosa strains have been described from different parts of the world and are often associated with an antibiotic-resistant phenotype. Importantly, infection with these strains often portends a worse prognosis than for infection with nonclonal strains, including an increased pulmonary exacerbation rate, exaggerated lung function decline, and progression to end-stage lung disease. This review describes the global epidemiology of clonal P. aeruginosa strains in CF and summarizes the current literature regarding the underlying biology and clinical impact of globally important CF clones. Mechanisms associated with patient-to-patient transmission are discussed, and best-evidence practices to prevent infections are highlighted. Preventing new infections with epidemic P. aeruginosa strains is of paramount importance in mitigating CF disease progression.
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Affiliation(s)
- Michael D Parkins
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Ranjani Somayaji
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Valerie J Waters
- Translational Medicine, Research Institute, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- Department of Pediatrics, Division of Infectious Diseases, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
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11
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Abstract
Purpose of Review The purpose of this review is to discuss the risk of bacterial cross-infection for bronchiectasis patients in the outpatient setting. Cross-infection has primarily been a matter of concern in cystic fibrosis (CF). There is considerable evidence of transmission of pathogens between CF patients, and this has led to guideline recommendations advocating strict segregation policies. Guidelines in bronchiectasis do not specifically address the issue of cross-infection. If cross-infection is prevalent, it may have significant implications for patients and the practical running of specialist care. Recent Findings Multiple UK-based studies have now published evidence of cross-infection with Pseudomonas aeruginosa within cohorts of bronchiectasis patients; however, the risk does not appear to be high. There is also evidence suggesting cross-infection from CF patients to bronchiectasis patients. Summary The current evidence for cross-infection in bronchiectasis is limited, but suggests a small risk with Pseudomonas aeruginosa. Longitudinal studies looking at Pseudomonas aeruginosa and other pathogens are now required.
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Zinne N, Krueger M, Hoeltig D, Tuemmler B, Boyle EC, Biancosino C, Hoeffler K, Braubach P, Rajab TK, Ciubotaru A, Rohde J, Waldmann KH, Haverich A. Treatment of infected lungs by ex vivo perfusion with high dose antibiotics and autotransplantation: A pilot study in pigs. PLoS One 2018; 13:e0193168. [PMID: 29505574 PMCID: PMC5837087 DOI: 10.1371/journal.pone.0193168] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 02/06/2018] [Indexed: 11/30/2022] Open
Abstract
The emergence of multi-drug resistant bacteria threatens to end the era of antibiotics. Drug resistant bacteria have evolved mechanisms to overcome antibiotics at therapeutic doses and further dose increases are not possible due to systemic toxicity. Here we present a pilot study of ex vivo lung perfusion (EVLP) with high dose antibiotic therapy followed by autotransplantation as a new therapy of last resort for otherwise incurable multidrug resistant lung infections. Severe Pseudomonas aeruginosa pneumonia was induced in the lower left lungs (LLL) of 18 Mini-Lewe pigs. Animals in the control group (n = 6) did not receive colistin. Animals in the conventional treatment group (n = 6) received intravenous application of 2 mg/kg body weight colistin daily. Animals in the EVLP group (n = 6) had their LLL explanted and perfused ex vivo with a perfusion solution containing 200 μg/ml colistin. After two hours of ex vivo treatment, autotransplantation of the LLL was performed. All animals were followed for 4 days following the initiation of treatment. In the control and conventional treatment groups, the infection-related mortality rate after five days was 66.7%. In the EVLP group, there was one infection-related mortality and one procedure-related mortality, for an overall mortality rate of 33.3%. Moreover, the clinical symptoms of infection were less severe in the EVLP group than the other groups. Ex vivo lung perfusion with very high dose antibiotics presents a new therapeutic option of last resort for otherwise incurable multidrug resistant pneumonia without toxic side effects on other organs.
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Affiliation(s)
- Norman Zinne
- Department of Cardiothoracic, Transplantation, and Vascular Surgery, Hannover Medical School, Hannover, Lower Saxony, Germany
- * E-mail:
| | - Marcus Krueger
- Department of Cardiothoracic, Transplantation, and Vascular Surgery, Hannover Medical School, Hannover, Lower Saxony, Germany
| | - Doris Hoeltig
- Clinic for Swine, Small Ruminants, Forensic Medicine, and Ambulatory Service, University of Veterinary Medicine Hannover, Hannover, Lower Saxony, Germany
| | - Burkhard Tuemmler
- Clinic for Paediatric Pneumology, Allergology, and Neonatology, Hannover Medical School, Hannover, Lower Saxony, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hannover, Lower Saxony, Germany
| | - Erin C. Boyle
- Department of Cardiothoracic, Transplantation, and Vascular Surgery, Hannover Medical School, Hannover, Lower Saxony, Germany
| | - Christian Biancosino
- Department of Cardiothoracic, Transplantation, and Vascular Surgery, Hannover Medical School, Hannover, Lower Saxony, Germany
| | - Klaus Hoeffler
- Department of Cardiothoracic, Transplantation, and Vascular Surgery, Hannover Medical School, Hannover, Lower Saxony, Germany
| | - Peter Braubach
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hannover, Lower Saxony, Germany
- Institute for Pathology, Hannover Medical School, Hannover, Lower Saxony, Germany
| | - Taufiek K. Rajab
- Department of Surgery, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Anatol Ciubotaru
- Department of Cardiothoracic, Transplantation, and Vascular Surgery, Hannover Medical School, Hannover, Lower Saxony, Germany
| | - Judith Rohde
- Department of Infectious Diseases, Institute for Microbiology, University of Veterinary Medicine Hannover, Hannover, Lower Saxony, Germany
| | - Karl-Heinz Waldmann
- Clinic for Swine, Small Ruminants, Forensic Medicine, and Ambulatory Service, University of Veterinary Medicine Hannover, Hannover, Lower Saxony, Germany
| | - Axel Haverich
- Department of Cardiothoracic, Transplantation, and Vascular Surgery, Hannover Medical School, Hannover, Lower Saxony, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hannover, Lower Saxony, Germany
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13
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Hutchins CF, Moore G, Thompson KA, Webb J, Walker JT. Contamination of hospital tap water: the survival and persistence of Pseudomonas aeruginosa on conventional and 'antimicrobial' outlet fittings. J Hosp Infect 2017; 97:156-161. [PMID: 28602704 DOI: 10.1016/j.jhin.2017.06.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/02/2017] [Indexed: 12/30/2022]
Abstract
BACKGROUND Pseudomonas aeruginosa infections have been linked to contaminated hospital taps, highlighting the potential for tap outlet fittings (OF) to harbour biofilm. P. aeruginosa may be transferred to OFs via contaminated cleaning cloths. Suggested interventions include flushing regimens and alternative OF designs. AIM To investigate the transfer of P. aeruginosa from a contaminated cleaning cloth to conventional and 'antimicrobial/antibiofilm' OFs and to determine whether this contamination persists and/or leads to contamination of tap water. METHODS Microfibre cloths contaminated with P. aeruginosa (108 cfu/mL) were used to wipe four different types of OF [one of conventional design (OF-A) and three marketed as 'antimicrobial' and/or 'antibiofilm' (OF- B, -C and -D)]. OFs were inserted into an experimental water distribution system for up to 24 h. Survival was assessed by culture. Single and multiple water samples were collected and cultured for P. aeruginosa. FINDINGS The median number of P. aeruginosa transferred from cloth to OF was 5.7 × 105 cfu (OF-A), 1.9 × 106 cfu (OF-B), 1.4 × 105 cfu (OF-C) and 2.9 × 106 cfu (OF-D). Numbers declined on all OFs during the 24 h period with log reductions ranging from 3.5 (OF-C) to 5.2 (OF-B; P > 0.05). All water samples delivered immediately after OF contamination contained P. aeruginosa at ≥10 cfu per 100 mL. Contamination of water delivered from OF-A persisted despite continued flushing. Water delivered from OF-B did not contain P. aeruginosa beyond the first flush. CONCLUSION Contaminated cleaning cloths may transfer P. aeruginosa to OFs, leading to contamination of tap water. Although not removing the potential for contamination, 'antimicrobial/antibiofilm' OFs may prevent P. aeruginosa from continually contaminating water delivered from the outlet.
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Affiliation(s)
- C F Hutchins
- Biosafety, Air and Water Microbiology Group, Public Health England, Porton Down, UK; Centre for Biological Sciences, Faculty of Natural and Environmental Sciences and Institute for Life Sciences, University of Southampton, Southampton, UK.
| | - G Moore
- Biosafety, Air and Water Microbiology Group, Public Health England, Porton Down, UK
| | - K-A Thompson
- Biosafety, Air and Water Microbiology Group, Public Health England, Porton Down, UK
| | - J Webb
- Centre for Biological Sciences, Faculty of Natural and Environmental Sciences and Institute for Life Sciences, University of Southampton, Southampton, UK
| | - J T Walker
- Biosafety, Air and Water Microbiology Group, Public Health England, Porton Down, UK
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Saiman L, Siegel JD, LiPuma JJ, Brown RF, Bryson EA, Chambers MJ, Downer VS, Fliege J, Hazle LA, Jain M, Marshall BC, O’Malley C, Pattee SR, Potter-Bynoe G, Reid S, Robinson KA, Sabadosa KA, Schmidt HJ, Tullis E, Webber J, Weber DJ. Infection Prevention and Control Guideline for Cystic Fibrosis: 2013 Update. Infect Control Hosp Epidemiol 2016; 35 Suppl 1:S1-S67. [DOI: 10.1086/676882] [Citation(s) in RCA: 270] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The 2013 Infection Prevention and Control (IP&C) Guideline for Cystic Fibrosis (CF) was commissioned by the CF Foundation as an update of the 2003 Infection Control Guideline for CF. During the past decade, new knowledge and new challenges provided the following rationale to develop updated IP&C strategies for this unique population:1.The need to integrate relevant recommendations from evidence-based guidelines published since 2003 into IP&C practices for CF. These included guidelines from the Centers for Disease Control and Prevention (CDC)/Healthcare Infection Control Practices Advisory Committee (HICPAC), the World Health Organization (WHO), and key professional societies, including the Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA). During the past decade, new evidence has led to a renewed emphasis on source containment of potential pathogens and the role played by the contaminated healthcare environment in the transmission of infectious agents. Furthermore, an increased understanding of the importance of the application of implementation science, monitoring adherence, and feedback principles has been shown to increase the effectiveness of IP&C guideline recommendations.2.Experience with emerging pathogens in the non-CF population has expanded our understanding of droplet transmission of respiratory pathogens and can inform IP&C strategies for CF. These pathogens include severe acute respiratory syndrome coronavirus and the 2009 influenza A H1N1. Lessons learned about preventing transmission of methicillin-resistantStaphylococcus aureus(MRSA) and multidrug-resistant gram-negative pathogens in non-CF patient populations also can inform IP&C strategies for CF.
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Heirali A, McKeon S, Purighalla S, Storey DG, Rossi L, Costilhes G, Drews SJ, Rabin HR, Surette MG, Parkins MD. Assessment of the Microbial Constituents of the Home Environment of Individuals with Cystic Fibrosis (CF) and Their Association with Lower Airways Infections. PLoS One 2016; 11:e0148534. [PMID: 26859493 PMCID: PMC4747485 DOI: 10.1371/journal.pone.0148534] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/19/2016] [Indexed: 02/01/2023] Open
Abstract
INTRODUCTION Cystic fibrosis (CF) airways are colonized by a polymicrobial community of organisms, termed the CF microbiota. We sought to define the microbial constituents of the home environment of individuals with CF and determine if it may serve as a latent reservoir for infection. METHODS Six patients with newly identified CF pathogens were included. An investigator collected repeat sputum and multiple environmental samples from their homes. Bacteria were cultured under both aerobic and anaerobic conditions. Morphologically distinct colonies were selected, purified and identified to the genus and species level through 16S rRNA gene sequencing. When concordant organisms were identified in sputum and environment, pulsed-field gel electrophoresis (PFGE) was performed to determine relatedness. Culture-independent bacterial profiling of each sample was carried out by Illumina sequencing of the V3 region of the 16s RNA gene. RESULTS New respiratory pathogens prompting investigation included: Mycobacterium abscessus(2), Stenotrophomonas maltophilia(3), Pseudomonas aeruginosa(3), Pseudomonas fluorescens(1), Nocardia spp.(1), and Achromobacter xylosoxidans(1). A median 25 organisms/patient were cultured from sputum. A median 125 organisms/home were cultured from environmental sites. Several organisms commonly found in the CF lung microbiome were identified within the home environments of these patients. Concordant species included members of the following genera: Brevibacterium(1), Microbacterium(1), Staphylococcus(3), Stenotrophomonas(2), Streptococcus(2), Sphingomonas(1), and Pseudomonas(4). PFGE confirmed related strains (one episode each of Sphinogomonas and P. aeruginosa) from the environment and airways were identified in two patients. Culture-independent assessment confirmed that many organisms were not identified using culture-dependent techniques. CONCLUSIONS Members of the CF microbiota can be found as constituents of the home environment in individuals with CF. While the majority of isolates from the home environment were not genetically related to those isolated from the lower airways of individuals with CF suggesting alternate sources of infection were more common, a few genetically related isolates were indeed identified. As such, the home environment may rarely serve as either the source of infection or a persistent reservoir for re-infection after clearance.
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Affiliation(s)
- Alya Heirali
- Department of Microbiology Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Suzanne McKeon
- Department of Microbiology Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada
| | - Swathi Purighalla
- Department of Microbiology Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada
| | - Douglas G. Storey
- Department of Microbiology Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Laura Rossi
- The Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Geoffrey Costilhes
- Department of Microbiology Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada
| | - Steven J. Drews
- Department of Laboratory Medicine & Pathology, University of Alberta, Edmonton, AB, Canada
| | - Harvey R. Rabin
- Department of Microbiology Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada
- Department of Medicine, The University of Calgary, Calgary, AB, Canada
| | - Michael G. Surette
- Department of Microbiology Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada
- The Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Michael D. Parkins
- Department of Microbiology Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada
- Department of Medicine, The University of Calgary, Calgary, AB, Canada
- * E-mail:
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Infection control knowledge, beliefs and behaviours amongst cystic fibrosis patients with epidemic Pseudomonas aeruginosa. BMC Pulm Med 2015; 15:138. [PMID: 26542115 PMCID: PMC4635525 DOI: 10.1186/s12890-015-0116-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/01/2015] [Indexed: 01/26/2023] Open
Abstract
Background Epidemic P. aeruginosa (ePA) infections are common in cystic fibrosis (CF) and have been associated with accelerated clinical decline. Factors associated with ePA are unclear, and evidence based infection control interventions are lacking. Methods We prospectively collect all bacterial pathogens from adult CF patients. We performed PA strain typing on retrospectively collected enrolment samples and recent isolates to identify patients infected with ePA. All patients attending our clinic were approached to complete a survey on infection control knowledge, beliefs and exposures. We analyzed responses of those with ePA relative to the entire cohort without ePA as well as those infected with unique strains of P. aeruginosa to assess for risk factors for ePA and differences in infection control knowledge, beliefs or behaviours. Results Of 144 participants, 30 patients had ePA (two Liverpool epidemic strain, 28 Prairie epidemic strain), 83 % of which had established infection prior to transition to the adult clinic. Risk of concomitant infecting pathogens was no different between groups although, Staphylococcus aureus and non-tuberculous mycobacteria were less common in those with ePA. Patients with ePA were more likely to have attended CF-camp and have a history of CF fundraising. Patients with ePA did not differ with respect to beliefs regarding pathogens or transmission risk, except they believed indirect contact posed little risk. Furthermore, patients with ePA were more likely to continue to associate with others with CF despite extensive counselling. Use of peer-peer online networking was minimal in both groups. Conclusion Infections with ePA are closely linked to past exposures, now routinely discouraged. As socialization is the greatest risk factor for ePA, infection control strategies for ePA must focus on discouraging face-to-face interactions amongst CF patients. As peer support remains a desire amongst patients, investment in technologies and strategies that enable indirect communication and support are required.
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Akya A, Salimi A, Nomanpour B, Ahmadi K. Prevalence and Clonal Dissemination of Metallo-Beta-Lactamase-Producing Pseudomonas aeruginosa in Kermanshah. Jundishapur J Microbiol 2015; 8:e20980. [PMID: 26421137 PMCID: PMC4584137 DOI: 10.5812/jjm.20980v2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Revised: 08/16/2014] [Accepted: 08/28/2014] [Indexed: 11/27/2022] Open
Abstract
Background: Pseudomonas aeruginosa is an opportunistic pathogen associated with nosocomial infections. The emergence and dissemination of metallo-beta-lactamases (MBLs) has contributed to the high rate of resistance among P. aeruginosa isolates. Objectives: The purpose of this study was to describe the prevalence and the clonal dissemination of MBL- producing P. aeruginosa isolates collected from major hospitals in Kermanshah. Materials and Methods: Antibiotic susceptibility testing was performed using the minimal inhibitory concentrations. The MBLs were investigated using the Double-Disk Synergy Test (DDST) and Polymerase Chain Reaction. Molecular typing was performed by Pulsed-Field Gel Electrophoresis (PFGE). Results: Of the 60 P. aeruginosa isolates included in this study, 30 (50%) were resistant to Gentamicin, 38 (63.3%) to Piperacillin, 42 (70%) to Ceftazidime, and 45 (75%) to Cefepime. Twenty-nine (48.3%) isolates were MBL producers in the DDST test. Five (8.3%) isolates were positive for the VIM gene. PFGE analysis among the MBL producers revealed 12 distinct clonal patterns. Conclusions: The inter- and intra-hospital dissemination of resistant clones is a matter of concern and is an indicator of the level of the improvement and surveillance of standard hygiene, particularly disinfection and hand washing before and after contact with patients. Given the emergence of MBL-producing strains, surveillance has become an important procedure to control the transmission of resistant strains.
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Affiliation(s)
- Alisha Akya
- Nosocomial Infection Research Centre, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, IR Iran
- Corresponding author: Alisha Akya, Nosocomial Infection Research Centre, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, IR Iran. Tel: +98-83134274618, Fax: +98-83134262252, E-mail:
| | - Afsaneh Salimi
- Student Research Committee, Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, IR Iran
| | - Bizhan Nomanpour
- School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, IR Iran
| | - Kamal Ahmadi
- Student Research Committee, Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, IR Iran
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Ouidir T, Jarnier F, Cosette P, Jouenne T, Hardouin J. Characterization of N-terminal protein modifications in Pseudomonas aeruginosa PA14. J Proteomics 2014; 114:214-25. [PMID: 25464366 DOI: 10.1016/j.jprot.2014.11.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 09/10/2014] [Accepted: 11/01/2014] [Indexed: 01/26/2023]
Abstract
UNLABELLED Even though protein initiator methionine excision (NME) and N-terminal acetylation (NTA) have been relatively well investigated in eukaryotic proteomes, few studies were dedicated to these modifications in bacteria up to now. In this work, we investigated, for the first time, the N-terminal proteome of the bacterium Pseudomonas aeruginosa PA14 by studying the NME and NTA processes using proteomic approaches. For NME, most of proteins had their initiator Met cleaved (63%) and the nature of the penultimate residue seems to be essential for this cleavage. Concerning NTA, two methods were applied (protein fractionation and peptide enrichment). This allowed us to identify 117 Nα-acetylated proteins, among them 113 have not yet been described as modified in bacteria. Most often, the non-acetylated form was over-represented compared to the acetylated form, arguing that this latter was a minor part of the total abundance of a given protein. Furthermore, some proteins with acetylated initiator methionine were observed. The present work significantly enlarges the number of N-terminally modified proteins in bacteria and confirms that these modifications are a general and fundamental process, not only restricted to eukaryotes. BIOLOGICAL SIGNIFICANCE Protein modifications in prokaryotes have been detected more recently than in eukaryotes. Methionine cleavage and N-terminal acetylation are two common protein N-terminal modifications. Despite their importance in bacterial processes, they are less investigated. The characterization of N-terminal acetylation in bacteria is a challenge because no antibody exists and it is a less frequent modification than in eukaryotes. We used proteomic approaches (enrichment, fractionation, nanoLC-MS/MS, and bioinformatic analyses) to investigate the N-terminal methionine excision and to profile the N-terminal acetylome of P. aeruginosa strain PA14. From our results, around 60% of the proteins had their iMet cleaved. In total, 117 proteins were identified constituting the largest dataset in prokaryotes. Among them, proteins kept their initiator methionine and were acetylated. These results may facilitate the design of experiments to better understand the role of acetylation at the protein N-terminus of P. aeruginosa PA14.
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Affiliation(s)
- Tassadit Ouidir
- CNRS, UMR 6270, Polymères, Biopolymères, Surfaces Laboratory, F-76820 Mont-Saint-Aignan, France; Normandy Univ, UR, France; PISSARO Proteomic Facility, IRIB, F-76820 Mont-Saint-Aignan, France
| | - Frédérique Jarnier
- Normandy Univ, UR, France; PISSARO Proteomic Facility, IRIB, F-76820 Mont-Saint-Aignan, France
| | - Pascal Cosette
- CNRS, UMR 6270, Polymères, Biopolymères, Surfaces Laboratory, F-76820 Mont-Saint-Aignan, France; Normandy Univ, UR, France; PISSARO Proteomic Facility, IRIB, F-76820 Mont-Saint-Aignan, France
| | - Thierry Jouenne
- CNRS, UMR 6270, Polymères, Biopolymères, Surfaces Laboratory, F-76820 Mont-Saint-Aignan, France; Normandy Univ, UR, France; PISSARO Proteomic Facility, IRIB, F-76820 Mont-Saint-Aignan, France
| | - Julie Hardouin
- CNRS, UMR 6270, Polymères, Biopolymères, Surfaces Laboratory, F-76820 Mont-Saint-Aignan, France; Normandy Univ, UR, France; PISSARO Proteomic Facility, IRIB, F-76820 Mont-Saint-Aignan, France.
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Chekabab SM, Harel J, Dozois CM. Interplay between genetic regulation of phosphate homeostasis and bacterial virulence. Virulence 2014; 5:786-93. [PMID: 25483775 DOI: 10.4161/viru.29307] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Bacterial pathogens, including those of humans, animals, and plants, encounter phosphate (Pi)-limiting or Pi-rich environments in the host, depending on the site of infection. The environmental Pi-concentration results in modulation of expression of the Pho regulon that allows bacteria to regulate phosphate assimilation pathways accordingly. In many cases, modulation of Pho regulon expression also results in concomitant changes in virulence phenotypes. Under Pi-limiting conditions, bacteria use the transcriptional-response regulator PhoB to translate the Pi starvation signal sensed by the bacterium into gene activation or repression. This regulator is employed not only for the maintenance of bacterial Pi homeostasis but also to differentially regulate virulence. The Pho regulon is therefore not only a regulatory circuit of phosphate homeostasis but also plays an important adaptive role in stress response and bacterial virulence. Here we focus on recent findings regarding the mechanisms of gene regulation that underlie the virulence responses to Pi stress in Vibrio cholerae, Pseudomonas spp., and pathogenic E. coli.
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Affiliation(s)
- Samuel Mohammed Chekabab
- a Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA); Université de Montréal; Faculté de Médecine Vétérinaire ; Saint-Hyacinthe , QC Canada
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20
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Benamara H, Rihouey C, Abbes I, Ben Mlouka MA, Hardouin J, Jouenne T, Alexandre S. Characterization of membrane lipidome changes in Pseudomonas aeruginosa during biofilm growth on glass wool. PLoS One 2014; 9:e108478. [PMID: 25265483 PMCID: PMC4181303 DOI: 10.1371/journal.pone.0108478] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 08/31/2014] [Indexed: 12/31/2022] Open
Abstract
Bacteria cells within biofilms are physiologically distinct from their planktonic counterparts. In particular they are more resistant to detrimental environmental conditions. In this study, we monitored the evolution of the phospholipid composition of the inner and outer membranes of P. aeruginosa during the biofilm formation (i.e., from 1-, 2-, to 6-day-old biofilm). Lipidome analyses were performed by electrospray ionization mass spectrometry. In addition to the lipidomic analysis, the fatty acid composition was analysed by gas chromatography/mass spectrometry. We found that the lipidome alterations of the inner and the outer membranes varied with the biofilm age. These alterations in phospholipid compositions reflect a higher diversity in sessile organisms than in planktonic counterparts. The diversity is characterized by the presence of PE 30∶1, PE 31∶0 and PG 31∶0 for the lower masses as well as PE 38∶1, 38∶2, 39∶1, 39∶2 and PG 38∶0, 38∶1, 38∶2, 39∶1, 39∶2 for the higher masses. However, this lipidomic feature tends to disappear with the biofilm age, in particular the high mass phospholipids tend to disappear. The amount of branched chains phospholipids mainly located in the outer membrane decreased with the biofilm age, whereas the proportion of cyclopropylated phospholipids increased in both membranes. In bacteria present in oldest biofilms, i.e., 6-day-old, the phospholipid distribution moved closer to that of planktonic bacteria.
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Affiliation(s)
- Hayette Benamara
- Polymères Biopolymères, Surfaces Laboratory - UMR 6270, CNRS - Université de Rouen, Mont-Saint-Aignan, France
- Normandie Université, Mont-Saint-Aignan, France
| | - Christophe Rihouey
- Polymères Biopolymères, Surfaces Laboratory - UMR 6270, CNRS - Université de Rouen, Mont-Saint-Aignan, France
- Normandie Université, Mont-Saint-Aignan, France
- PISSARO proteomic facility, IRIB - Université de Rouen, Mont-Saint-Aignan, France
| | - Imen Abbes
- Polymères Biopolymères, Surfaces Laboratory - UMR 6270, CNRS - Université de Rouen, Mont-Saint-Aignan, France
- Normandie Université, Mont-Saint-Aignan, France
| | - Mohamed Amine Ben Mlouka
- Polymères Biopolymères, Surfaces Laboratory - UMR 6270, CNRS - Université de Rouen, Mont-Saint-Aignan, France
- Normandie Université, Mont-Saint-Aignan, France
- PISSARO proteomic facility, IRIB - Université de Rouen, Mont-Saint-Aignan, France
| | - Julie Hardouin
- Polymères Biopolymères, Surfaces Laboratory - UMR 6270, CNRS - Université de Rouen, Mont-Saint-Aignan, France
- Normandie Université, Mont-Saint-Aignan, France
- PISSARO proteomic facility, IRIB - Université de Rouen, Mont-Saint-Aignan, France
| | - Thierry Jouenne
- Polymères Biopolymères, Surfaces Laboratory - UMR 6270, CNRS - Université de Rouen, Mont-Saint-Aignan, France
- Normandie Université, Mont-Saint-Aignan, France
- PISSARO proteomic facility, IRIB - Université de Rouen, Mont-Saint-Aignan, France
| | - Stéphane Alexandre
- Polymères Biopolymères, Surfaces Laboratory - UMR 6270, CNRS - Université de Rouen, Mont-Saint-Aignan, France
- Normandie Université, Mont-Saint-Aignan, France
- * E-mail:
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Jain M, Saiman LM, Sabadosa K, LiPuma JJ. Point: does the risk of cross infection warrant exclusion of adults with cystic fibrosis from cystic fibrosis foundation events? Yes. Chest 2014; 145:678-680. [PMID: 24135971 DOI: 10.1378/chest.13-2404] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Affiliation(s)
- Manu Jain
- Department of Medicine and Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, IL.
| | - Lisa M Saiman
- Department of Pediatrics, Columbia University Medical Center, Department of Infection Prevention and Control, New York-Presbyterian Hospital, Lebanon, NH
| | - Kathy Sabadosa
- Dartmouth Institute for Health Policy & Clinical Practice, Geisel School of Medicine, New York, NY
| | - John J LiPuma
- The Department of Pediatrics and Communicable Disease, University of Michigan Medical School, Ann Arbor, MI
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Sall KM, Casabona MG, Bordi C, Huber P, de Bentzmann S, Attrée I, Elsen S. A gacS deletion in Pseudomonas aeruginosa cystic fibrosis isolate CHA shapes its virulence. PLoS One 2014; 9:e95936. [PMID: 24780952 PMCID: PMC4004566 DOI: 10.1371/journal.pone.0095936] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 03/30/2014] [Indexed: 11/21/2022] Open
Abstract
Pseudomonas aeruginosa, a human opportunistic pathogen, is capable of provoking acute and chronic infections that are associated with defined sets of virulence factors. During chronic infections, the bacterium accumulates mutations that silence some and activate other genes. Here we show that the cystic fibrosis isolate CHA exhibits a unique virulence phenotype featuring a mucoid morphology, an active Type III Secretion System (T3SS, hallmark of acute infections), and no Type VI Secretion System (H1-T6SS). This virulence profile is due to a 426 bp deletion in the 3′ end of the gacS gene encoding an essential regulatory protein. The absence of GacS disturbs the Gac/Rsm pathway leading to depletion of the small regulatory RNAs RsmY/RsmZ and, in consequence, to expression of T3SS, while switching off the expression of H1-T6SS and Pel polysaccharides. The CHA isolate also exhibits full ability to swim and twitch, due to active flagellum and Type IVa pili. Thus, unlike the classical scheme of balance between virulence factors, clinical strains may adapt to a local niche by expressing both alginate exopolysaccharide, a hallmark of membrane stress that protects from antibiotic action, host defences and phagocytosis, and efficient T3S machinery that is considered as an aggressive virulence factor.
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Affiliation(s)
- Khady Mayebine Sall
- INSERM, UMR-S 1036, Biology of Cancer and Infection, Grenoble, France
- CNRS, ERL 5261, Bacterial Pathogenesis and Cellular Responses, Grenoble, France
- UJF-Grenoble 1, Grenoble, France
- CEA, DSV/iRTSV, Grenoble, France
| | - Maria Guillermina Casabona
- INSERM, UMR-S 1036, Biology of Cancer and Infection, Grenoble, France
- CNRS, ERL 5261, Bacterial Pathogenesis and Cellular Responses, Grenoble, France
- UJF-Grenoble 1, Grenoble, France
- CEA, DSV/iRTSV, Grenoble, France
| | - Christophe Bordi
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, UMR 7255 CNRS - Aix Marseille University, Marseille, France
| | - Philippe Huber
- INSERM, UMR-S 1036, Biology of Cancer and Infection, Grenoble, France
- CNRS, ERL 5261, Bacterial Pathogenesis and Cellular Responses, Grenoble, France
- UJF-Grenoble 1, Grenoble, France
- CEA, DSV/iRTSV, Grenoble, France
| | - Sophie de Bentzmann
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, UMR 7255 CNRS - Aix Marseille University, Marseille, France
| | - Ina Attrée
- INSERM, UMR-S 1036, Biology of Cancer and Infection, Grenoble, France
- CNRS, ERL 5261, Bacterial Pathogenesis and Cellular Responses, Grenoble, France
- UJF-Grenoble 1, Grenoble, France
- CEA, DSV/iRTSV, Grenoble, France
| | - Sylvie Elsen
- INSERM, UMR-S 1036, Biology of Cancer and Infection, Grenoble, France
- CNRS, ERL 5261, Bacterial Pathogenesis and Cellular Responses, Grenoble, France
- UJF-Grenoble 1, Grenoble, France
- CEA, DSV/iRTSV, Grenoble, France
- * E-mail:
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De Soyza A, Hall AJ, Mahenthiralingam E, Drevinek P, Kaca W, Drulis-Kawa Z, Stoitsova SR, Toth V, Coenye T, Zlosnik JEA, Burns JL, Sá-Correia I, De Vos D, Pirnay JP, Kidd TJ, Reid D, Manos J, Klockgether J, Wiehlmann L, Tümmler B, McClean S, Winstanley C. Developing an international Pseudomonas aeruginosa reference panel. Microbiologyopen 2013; 2:1010-23. [PMID: 24214409 PMCID: PMC3892346 DOI: 10.1002/mbo3.141] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 09/27/2013] [Accepted: 10/07/2013] [Indexed: 01/22/2023] Open
Abstract
Pseudomonas aeruginosa is a major opportunistic pathogen in cystic fibrosis (CF) patients and causes a wide range of infections among other susceptible populations. Its inherent resistance to many antimicrobials also makes it difficult to treat infections with this pathogen. Recent evidence has highlighted the diversity of this species, yet despite this, the majority of studies on virulence and pathogenesis focus on a small number of strains. There is a pressing need for a P. aeruginosa reference panel to harmonize and coordinate the collective efforts of the P. aeruginosa research community. We have collated a panel of 43 P. aeruginosa strains that reflects the organism's diversity. In addition to the commonly studied clones, this panel includes transmissible strains, sequential CF isolates, strains with specific virulence characteristics, and strains that represent serotype, genotype or geographic diversity. This focussed panel of P. aeruginosa isolates will help accelerate and consolidate the discovery of virulence determinants, improve our understanding of the pathogenesis of infections caused by this pathogen, and provide the community with a valuable resource for the testing of novel therapeutic agents.
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Affiliation(s)
- Anthony De Soyza
- Institute of Cellular Medicine, Newcastle University, Newcastle, U.K
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Bezuidt OK, Klockgether J, Elsen S, Attree I, Davenport CF, Tümmler B. Intraclonal genome diversity of Pseudomonas aeruginosa clones CHA and TB. BMC Genomics 2013; 14:416. [PMID: 23799896 PMCID: PMC3697988 DOI: 10.1186/1471-2164-14-416] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 06/19/2013] [Indexed: 01/01/2023] Open
Abstract
Background Adaptation of Pseudomonas aeruginosa to different living conditions is accompanied by microevolution resulting in genomic diversity between strains of the same clonal lineage. In order to detect the impact of colonized habitats on P. aeruginosa microevolution we determined the genomic diversity between the highly virulent cystic fibrosis (CF) isolate CHA and two temporally and geographically unrelated clonal variants. The outcome was compared with the intraclonal genome diversity between three more closely related isolates of another clonal complex. Results The three clone CHA isolates differed in their core genome in several dozen strain specific nucleotide exchanges and small deletions from each other. Loss of function mutations and non-conservative amino acid replacements affected several habitat- and lifestyle-associated traits, for example, the key regulator GacS of the switch between acute and chronic disease phenotypes was disrupted in strain CHA. Intraclonal genome diversity manifested in an individual composition of the respective accessory genome whereby the highest number of accessory DNA elements was observed for isolate PT22 from a polluted aquatic habitat. Little intraclonal diversity was observed between three spatiotemporally related outbreak isolates of clone TB. Although phenotypically different, only a few individual SNPs and deletions were detected in the clone TB isolates. Their accessory genome mainly differed in prophage-like DNA elements taken up by one of the strains. Conclusions The higher geographical and temporal distance of the clone CHA isolates was associated with an increased intraclonal genome diversity compared to the more closely related clone TB isolates derived from a common source demonstrating the impact of habitat adaptation on the microevolution of P. aeruginosa. However, even short-term habitat differentiation can cause major phenotypic diversification driven by single genomic variation events and uptake of phage DNA.
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Affiliation(s)
- Oliver Ki Bezuidt
- Klinische Forschergruppe, Klinik für Pädiatrische Pneumologie, Allergologie und Neonatologie, Medizinische Hochschule Hannover, Hannover D-30625, Germany
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Conway SP, Brownlee KG, Denton M, Peckham DG. Antibiotic Treatment of Multidrug-Resistant Organisms in Cystic Fibrosis. ACTA ACUST UNITED AC 2012; 2:321-32. [PMID: 14719998 DOI: 10.1007/bf03256660] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Respiratory tract infection with eventual respiratory failure is the major cause of morbidity and mortality in cystic fibrosis (CF). Infective exacerbations need to be treated promptly and effectively to minimize potentially accelerated attrition of lung function. The choice of antibiotic depends on in vitro sensitivity patterns. However, physicians treating patients with CF are increasingly faced with infection with multidrug-resistant isolates of Pseudomonas aeruginosa. In addition, innately resistant organisms such as Burkholderia cepacia complex, Stenotrophomonas maltophilia and Achromobacter (Alcaligenes) xylosoxidans are becoming more prevalent. Infection with methicillin-resistant Staphylococcus aureus (MRSA) is also a problem. These changing patterns probably result from greater patient longevity and increased antibiotic use for acute exacerbations and maintenance care. Multidrug-resistant P. aeruginosa infection may be treated successfully by using two antibiotics with different mechanisms of action. In practice antibiotic choices have usually been made on a best-guess basis, but recent research suggests that more directed therapy can be achieved through the application of multiple-combination bactericidal testing (MCBT). Aerosol delivery of tobramycin for inhalation solution achieves high endobronchial concentrations that may overcome bacterial resistance as defined by standard laboratory protocols. Resistance to colistin is rare and this antibiotic should be seen as a valuable second-line drug to be reserved for multidrug-resistant P. aeruginosa. The efficacy of new antibiotic groups such as the macrolides needs to be evaluated.CF units should adopt strict segregation policies to interrupt person-to-person spread of B. cepacia complex. Treatment of panresistant strains is difficult and often arbitrary. Combination antibiotic therapy is recommended, usually tobramycin and high-dose meropenem and/or ceftazidime, but the choice of treatment regimen should always be guided by the clinical response.The clinical significance of S. maltophilia, A. xylosoxidans and MRSA infection in CF lung disease remains uncertain. If patients show clinical decline and are chronically colonized/infected with either of the former two pathogens, treatment is recommended but efficacy data are lacking. There are defined microbiological reasons for attempting eradication of MRSA but there are no proven deleterious effects of this infection on lung function in patients with CF. Various treatment protocols exist but none has been subject to a randomized, controlled trial. Multidrug-resistant microorganisms are an important and growing issue in the care of patients with CF. Each patient infected with such strains should be assessed individually and antibiotic treatment planned according to in vitro sensitivity, patient drug tolerance, and results of in vitro studies which may direct the physician to antibiotic combinations most likely to succeed.
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Affiliation(s)
- S P Conway
- Paediatric and Adult Regional Cystic Fibrosis Centres, St James' and Seacroft University Hospitals, Leeds, UK.
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Klockgether J, Miethke N, Kubesch P, Bohn YS, Brockhausen I, Cramer N, Eberl L, Greipel J, Herrmann C, Herrmann S, Horatzek S, Lingner M, Luciano L, Salunkhe P, Schomburg D, Wehsling M, Wiehlmann L, Davenport CF, Tümmler B. Intraclonal diversity of the Pseudomonas aeruginosa cystic fibrosis airway isolates TBCF10839 and TBCF121838: distinct signatures of transcriptome, proteome, metabolome, adherence and pathogenicity despite an almost identical genome sequence. Environ Microbiol 2012; 15:191-210. [PMID: 22882573 DOI: 10.1111/j.1462-2920.2012.02842.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Microevolution of closely related Pseudomonas aeruginosa was compared in the clone TB strains TBCF10839 and TBCF121838 which had been isolated from two unrelated individuals with cystic fibrosis who had acquired clone TB during a local outbreak. Compared with the strain PAO1 reference sequence the two clone TB genomes shared 23 155 nucleotide exchanges, 32 out-of-frame indels in the coding region and another repertoire of replacement and genomic islands such as PAGI-1, PAGI-2, PAGI-5, LESGI-1 and LES-prophage 4. Only TBCF121838 carried a genomic island known from Ralstonia pickettii. Six of the seven strain-specific sequence variations in the core genome were detected in genes affecting motility, biofilm formation or virulence, i.e. non-synonymous nucleotide substitutions in mexS, PA3729, PA5017, mifR, a frameshift mutation in pilF (TBCF121838) and an intragenic deletion in pilQ (TBCF10839). Despite their almost identical genome sequence the two strains differed strongly from each other in transcriptome and metabolome profiles, mucin adherence and phagocytosis assays. TBCF121838 was susceptible to killing by neutrophils, but TBCF10839 could grow in leucocytes. Microevolution in P. aeruginosa apparently can generate novel complex traits by few or even single mutations provided that predisposing mutational events had occurred before in the clonal lineage.
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Affiliation(s)
- Jens Klockgether
- Klinische Forschergruppe, Zentrum Biochemie und Zentrum Kinder- und Jugendmedizin, OE 6710, D-30625 Hannover, Germany.
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Molecular epidemiology ofPseudomonas aeruginosa in cystic fibrosis patients from Southeast Austria. Wien Klin Wochenschr 2012; 124:262-5. [DOI: 10.1007/s00508-012-0156-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 01/09/2012] [Indexed: 11/27/2022]
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Wiehlmann L, Cramer N, Ulrich J, Hedtfeld S, Weißbrodt H, Tümmler B. Effective prevention of Pseudomonas aeruginosa cross-infection at a cystic fibrosis centre – Results of a 10-year prospective study. Int J Med Microbiol 2012; 302:69-77. [DOI: 10.1016/j.ijmm.2011.11.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 11/04/2011] [Accepted: 11/06/2011] [Indexed: 11/28/2022] Open
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Munder A, Wölbeling F, Kerber-Momot T, Wedekind D, Baumann U, Gulbins E, Tümmler B. Acute intratracheal Pseudomonas aeruginosa infection in cystic fibrosis mice is age-independent. Respir Res 2011; 12:148. [PMID: 22059807 PMCID: PMC3248876 DOI: 10.1186/1465-9921-12-148] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 11/07/2011] [Indexed: 02/04/2023] Open
Abstract
Background Since the discovery of the human CFTR gene in 1989 various mouse models for cystic fibrosis (CF) have been generated and used as a very suitable and popular tool to approach research on this life-threatening disease. Age related changes regarding the course of disease and susceptibility towards pulmonary infections have been discussed in numerous studies. Methods Here, we investigated CftrTgH(neoim)Hgu and Cftrtm1Unc-Tg(FABPCFTR)1Jaw/J CF mice and their non-CF littermates during an acute lung infection with Pseudomonas aeruginosa for age dependent effects of their lung function and immune response. Mice younger than three or older than six months were intratracheally infected with P. aeruginosa TBCF10839. The infection was monitored by lung function of the animals using non-invasive head-out spirometry and the time course of physiological parameters over 192 hours. Quantitative bacteriology and lung histopathology of a subgroup of animals were used as endpoint parameters. Results Age-dependent changes in lung function and characteristic features for CF like a shallower, faster breathing pattern were observed in both CF mouse models in uninfected state. In contrast infected CF mice did not significantly differ from their non-CF littermates in susceptibility and severity of lung infection in both mouse models and age groups. The transgenic Cftrtm1Unc-Tg(FABPCFTR)1Jaw/J and their non-CF littermates showed a milder course of infection than the CftrTgH(neoim)Hgu CF and their congenic C57Bl/6J non-CF mice suggesting that the genetic background was more important for outcome than Cftr dysfunction. Conclusions Previous investigations of the same mouse lines have shown a higher airway susceptibility of older CF mice to intranasally applied P. aeruginosa. The different outcome of intranasal and intratracheal instillation of bacteria implies that infected CF epithelium is impaired during the initial colonization of upper airways, but not in the subsequent response of host defense.
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Affiliation(s)
- Antje Munder
- Clinical Research Group, Clinic for Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.
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31
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Mercier A, Beaumesnil M, Chaillou E, Troussier F, Darviot E, Chiffoleau M, Giniès JL. [Multidisciplinary consultation at the home of children with cystic fibrosis: experience of a specialized center]. Arch Pediatr 2011; 18:1340-1. [PMID: 22041592 DOI: 10.1016/j.arcped.2011.09.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 09/21/2011] [Indexed: 11/17/2022]
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Genotypic and phenotypic variation in Pseudomonas aeruginosa reveals signatures of secondary infection and mutator activity in certain cystic fibrosis patients with chronic lung infections. Infect Immun 2011; 79:4802-18. [PMID: 21930755 DOI: 10.1128/iai.05282-11] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Evolutionary adaptation of Pseudomonas aeruginosa to the cystic fibrosis lung is limited by genetic variation, which depends on rates of horizontal gene transfer and mutation supply. Because each may increase following secondary infection or mutator emergence, we sought to ascertain the incidence of secondary infection and genetic variability in populations containing or lacking mutators. Forty-nine strains collected over 3 years from 16 patients were phenotyped for antibiotic resistance and mutator status and were genotyped by repetitive-sequence PCR (rep-PCR), pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). Though phenotypic and genetic polymorphisms were widespread and clustered more strongly within than between longitudinal series, their distribution revealed instances of secondary infection. Sequence data, however, indicated that interlineage recombination predated initial strain isolation. Mutator series were more likely to be multiply antibiotic resistant, but not necessarily more variable in their nucleotide sequences, than nonmutators. One mutator and one nonmutator series were sequenced at mismatch repair loci and analyzed for gene content using DNA microarrays. Both were wild type with respect to mutL, but mutators carried an 8-bp mutS deletion causing a frameshift mutation. Both series lacked 126 genes encoding pilins, siderophores, and virulence factors whose inactivation has been linked to adaptation during chronic infection. Mutators exhibited loss of severalfold more genes having functions related to mobile elements, motility, and attachment. A 105-kb, 86-gene deletion was observed in one nonmutator that resulted in loss of virulence factors related to pyoverdine synthesis and elements of the multidrug efflux regulon. Diminished DNA repair activity may facilitate but not be absolutely required for rapid evolutionary change.
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Dusane DH, Zinjarde SS, Venugopalan VP, McLean RJC, Weber MM, Rahman PKSM. Quorum sensing: implications on rhamnolipid biosurfactant production. Biotechnol Genet Eng Rev 2011; 27:159-84. [PMID: 21415897 DOI: 10.1080/02648725.2010.10648149] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Quorum sensing (QS) has received significant attention in the past few decades. QS describes population density dependent cell to cell communication in bacteria using diffusible signal molecules. These signal molecules produced by bacterial cells, regulate various physiological processes important for social behavior and pathogenesis. One such process regulated by quorum sensing molecules is the production of a biosurfactant, rhamnolipid. Rhamnolipids are important microbially derived surface active agents produced by Pseudomonas spp. under the control of two interrelated quorum sensing systems; namely las and rhl. Rhamnolipids possess antibacterial, antifungal and antiviral properties. They are important in motility, cell to cell interactions, cellular differentiation and formation of water channels that are characteristics of Pseudomonas biofilms. Rhamnolipids have biotechnological applications in the uptake of hydrophobic substrates, bioremediation of contaminated soils and polluted waters. Rhamnolipid biosurfactants are biodegradable as compared to chemical surfactants and hence are more preferred in environmental applications. In this review, we examine the biochemical and genetic mechanism of rhamnolipid production by P. aeruginosa and propose the application of QS signal molecules in enhancing the rhamnolipid production.
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Affiliation(s)
- Devendra H Dusane
- Institute of Bioinformatics and Biotechnology, University of Pune, India.
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Hauser AR, Jain M, Bar-Meir M, McColley SA. Clinical significance of microbial infection and adaptation in cystic fibrosis. Clin Microbiol Rev 2011; 24:29-70. [PMID: 21233507 PMCID: PMC3021203 DOI: 10.1128/cmr.00036-10] [Citation(s) in RCA: 287] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A select group of microorganisms inhabit the airways of individuals with cystic fibrosis. Once established within the pulmonary environment in these patients, many of these microbes adapt by altering aspects of their structure and physiology. Some of these microbes and adaptations are associated with more rapid deterioration in lung function and overall clinical status, whereas others appear to have little effect. Here we review current evidence supporting or refuting a role for the different microbes and their adaptations in contributing to poor clinical outcomes in cystic fibrosis.
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Affiliation(s)
- Alan R Hauser
- Department of Microbiology/Immunology, Northwestern University, 303 E. Chicago Ave., Searle 6-495, Chicago, IL 60611, USA.
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35
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Benamara H, Rihouey C, Jouenne T, Alexandre S. Impact of the biofilm mode of growth on the inner membrane phospholipid composition and lipid domains in Pseudomonas aeruginosa. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1808:98-105. [PMID: 20849811 DOI: 10.1016/j.bbamem.2010.09.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 09/02/2010] [Accepted: 09/03/2010] [Indexed: 11/30/2022]
Abstract
Many studies using genetic and proteomic approaches have revealed phenotypic differences between planktonic and sessile bacteria but the mechanisms of biofilm formation and the switch between the two growth modes are not well understood yet. In this study, we focused on inner membrane lipidome modifications when Pseudomonas aeruginosa cells were grown as biofilm. Lipid analyses were performed by Electrospray Ionization Mass Spectrometry. Results showed a drastic decrease of the uneven-numbered chain phospholipids and a slight increase of long chain PEs in sessile organisms as compared with planktonic counterparts, suggesting a better lipid stability in the bilayer and a decrease in membrane fluidity. The impact of sessile growth on lipid domains was then investigated by Brewster Angle Microscopy (BAM) and Atomic Force Microscopy (AFM). Observations showed that inner membrane lipids of P. aeruginosa formed domains when the pressure was close to physiological conditions and that these domains were larger for lipids extracted from biofilm bacteria. This is coherent with the mass spectrometry analyses.
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Affiliation(s)
- Hayette Benamara
- PBS laboratory, UMR 6270, FR 3038, CNRS, Proteomic Platform of the IFRMP23, University of Rouen, 76821 Mont-Saint-Aignan cedex, France
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36
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Abstract
Infection of the airways remains the primary cause of morbidity and mortality in persons with cystic fibrosis (CF). This review describes salient features of the epidemiologies of microbial species that are involved in respiratory tract infection in CF. The apparently expanding spectrum of species causing infection in CF and recent changes in the incidences and prevalences of infection due to specific bacterial, fungal, and viral species are described. The challenges inherent in tracking and interpreting rates of infection in this patient population are discussed.
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37
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Griese M, Busch P, Caroli D, Mertens B, Eismann C, Harari M, Staudter H, Kappler M. Rehabilitation Programs for Cystic Fibrosis - View from a CF Center. Open Respir Med J 2010; 4:1-8. [PMID: 20200661 PMCID: PMC2831191 DOI: 10.2174/1874306401004010001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 10/07/2009] [Accepted: 10/20/2009] [Indexed: 12/05/2022] Open
Abstract
Background: Rehabilitation programs are comprehensive interventions which effectively improve the health status and reduce costs in chronic respiratory illnesses. Because patients with cystic fibrosis have been discouraged to participate for concerns of microbial cross infection, the efficacy of systematic rehabilitation is unknown for this group. Methods: We retrospectively studied 142 cystic fibrosis patients aged 2-46 years who participated in rehabilitation programs taking place in Germany/Switzerland and in Israel, focusing on changes in lung function and weight. Results: During 172 stays in 97 patients in Israel and 68 stays in 45 patients rehabilitating in Germany/Switzerland, overall lung function and weight improved. Outcome did not differ between Israel and German/Swiss sites. Interestingly, lung function improved during the initial phase of the stay, whereas weight gain was sustained throughout. The study uncovered gaps in reporting sufficient individual outcome information back to the admitting centre. Conclusions: Rehabilitation programs specified for cystic fibrosis patients need to be assessed prospectively to optimize treatment of this life limiting condition.
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Affiliation(s)
- M Griese
- Cystic Fibrosis Center, Dr. von Haunersches Kinderspital, University of Munich, Lindwurmstr. 4, D-80337 Munich, Germany
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Garvis S, Munder A, Ball G, de Bentzmann S, Wiehlmann L, Ewbank JJ, Tümmler B, Filloux A. Caenorhabditis elegans semi-automated liquid screen reveals a specialized role for the chemotaxis gene cheB2 in Pseudomonas aeruginosa virulence. PLoS Pathog 2009; 5:e1000540. [PMID: 19662168 PMCID: PMC2714965 DOI: 10.1371/journal.ppat.1000540] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Accepted: 07/14/2009] [Indexed: 11/26/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic human pathogen that causes infections in a variety of animal and plant hosts. Caenorhabditis elegans is a simple model with which one can identify bacterial virulence genes. Previous studies with C. elegans have shown that depending on the growth medium, P. aeruginosa provokes different pathologies: slow or fast killing, lethal paralysis and red death. In this study, we developed a high-throughput semi-automated liquid-based assay such that an entire genome can readily be scanned for virulence genes in a short time period. We screened a 2,200-member STM mutant library generated in a cystic fibrosis airway P. aeruginosa isolate, TBCF10839. Twelve mutants were isolated each showing at least 70% attenuation in C. elegans killing. The selected mutants had insertions in regulatory genes, such as a histidine kinase sensor of two-component systems and a member of the AraC family, or in genes involved in adherence or chemotaxis. One mutant had an insertion in a cheB gene homologue, encoding a methylesterase involved in chemotaxis (CheB2). The cheB2 mutant was tested in a murine lung infection model and found to have a highly attenuated virulence. The cheB2 gene is part of the chemotactic gene cluster II, which was shown to be required for an optimal mobility in vitro. In P. aeruginosa, the main player in chemotaxis and mobility is the chemotactic gene cluster I, including cheB1. We show that, in contrast to the cheB2 mutant, a cheB1 mutant is not attenuated for virulence in C. elegans whereas in vitro motility and chemotaxis are severely impaired. We conclude that the virulence defect of the cheB2 mutant is not linked with a global motility defect but that instead the cheB2 gene is involved in a specific chemotactic response, which takes place during infection and is required for P. aeruginosa pathogenicity. The increase in hospital acquired and multi-drug resistant bacterial infections calls for an urgent development of new antimicrobials. As such, the identification and characterization of novel molecular targets involved in bacterial virulence has become a common goal for researchers. The use of non-mammalian hosts, such as the nematode Caenorhabditis elegans, is useful to accelerate this process. In our study, we developed a high-throughput screening method, which further facilitates the use of C. elegans, and allows the rapid screening of a large collection of bacterial mutants at the genomic scale. We have used Pseudomonas aeruginosa, a potent opportunistic pathogen, to perform this study. The screening of more than 2,000 mutant strains allowed the characterization of a mutant affected in the cheB2 gene. Importantly, this mutant was shown to be impaired in a mouse model of infection, supporting that our new screen is a good model to identify virulence genes relevant for infection in mammals. The cheB2 gene encodes a component of a chemotaxis pathway, which is likely involved in the perception of stimuli during the infection process, and allows an appropriate adaptive response for a successful infection. Our method could be applied to other bacterial pathogens and will help researchers discover candidate genes leading to the design of novel antimicrobials.
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Affiliation(s)
- Steven Garvis
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, UPR9027, Centre National de la Recherche Scientifique, IMM, Marseille, France
| | - Antje Munder
- Klinische Forschergruppe, Center of Biochemistry and Pediatrics, Hannover Medical School, Hannover, Germany
| | - Geneviève Ball
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, UPR9027, Centre National de la Recherche Scientifique, IMM, Marseille, France
| | - Sophie de Bentzmann
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, UPR9027, Centre National de la Recherche Scientifique, IMM, Marseille, France
| | - Lutz Wiehlmann
- Klinische Forschergruppe, Center of Biochemistry and Pediatrics, Hannover Medical School, Hannover, Germany
| | - Jonathan J. Ewbank
- Centre d'Immunologie de Marseille-Luminy, Université de la Méditerranée, Case 906, Marseille, France
- INSERM, U631, Marseille, France
- CNRS, UMR6102, Marseille, France
| | - Burkhard Tümmler
- Klinische Forschergruppe, Center of Biochemistry and Pediatrics, Hannover Medical School, Hannover, Germany
| | - Alain Filloux
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, UPR9027, Centre National de la Recherche Scientifique, IMM, Marseille, France
- Imperial College London, Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, South Kensington Campus, London, United Kingdom
- * E-mail:
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Abstract
The treatment of cystic fibrosis has improved significantly over the past three decades. Median survival has improved by decades and is now estimated to be 37 years. Many factors contribute to improvements in disease severity and outcome. This paper reviews the current evidence of three groups of important factors: genetic, environmental and healthcare related.
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Affiliation(s)
- Linda L Wolfenden
- Emory Cystic Fibrosis Center, Emory University, Atlanta, Georgia, USA.
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40
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Bohn YST, Brandes G, Rakhimova E, Horatzek S, Salunkhe P, Munder A, van Barneveld A, Jordan D, Bredenbruch F, Häussler S, Riedel K, Eberl L, Jensen PØ, Bjarnsholt T, Moser C, Hoiby N, Tümmler B, Wiehlmann L. Multiple roles of Pseudomonas aeruginosa TBCF10839 PilY1 in motility, transport and infection. Mol Microbiol 2008; 71:730-47. [PMID: 19054330 PMCID: PMC2680260 DOI: 10.1111/j.1365-2958.2008.06559.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Polymorphonuclear neutrophils are the most important mammalian host defence cells against infections with Pseudomonas aeruginosa. Screening of a signature tagged mutagenesis library of the non-piliated P. aeruginosa strain TBCF10839 uncovered that transposon inactivation of its pilY1 gene rendered the bacterium more resistant against killing by neutrophils than the wild type and any other of the more than 3000 tested mutants. Inactivation of pilY1 led to the loss of twitching motility in twitching-proficient wild-type PA14 and PAO1 strains, predisposed to autolysis and impaired the secretion of quinolones and pyocyanin, but on the other hand promoted growth in stationary phase and bacterial survival in murine airway infection models. The PilY1 population consisted of a major full-length and a minor shorter PilY1* isoform. PilY1* was detectable in small extracellular quinolone-positive aggregates, but not in the pilus. P. aeruginosa PilY1 is not an adhesin on the pilus tip, but assists in pilus biogenesis, twitching motility, secretion of secondary metabolites and in the control of cell density in the bacterial population.
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Affiliation(s)
- Yu-Sing Tammy Bohn
- Klinische Forschergruppe, Medizinische Hochschule Hannover, Carl-Neuberg-Strasse, Hannover, Germany
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41
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Affiliation(s)
- Steven Conway
- Regional Paediatric and Adult Cystic Fibrosis Centres, Childrens' Day Hospital, St James' University Hospital Beckett Street, Leeds LS9 7TF, UK.
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42
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Rakhimova E, Munder A, Wiehlmann L, Bredenbruch F, Tümmler B. Fitness of isogenic colony morphology variants of Pseudomonas aeruginosa in murine airway infection. PLoS One 2008; 3:e1685. [PMID: 18301762 PMCID: PMC2246019 DOI: 10.1371/journal.pone.0001685] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Accepted: 01/25/2008] [Indexed: 11/18/2022] Open
Abstract
Chronic lung infections with Pseudomonas aeruginosa are associated with the diversification of the persisting clone into niche specialists and morphotypes, a phenomenon called 'dissociative behaviour'. To explore the potential of P. aeruginosa to change its morphotype by single step loss-of-function mutagenesis, a signature-tagged mini-Tn5 plasposon library of the cystic fibrosis airway isolate TBCF10839 was screened for colony morphology variants under nine different conditions in vitro. Transposon insertion into 1% of the genome changed colony morphology into eight discernable morphotypes. Half of the 55 targets encode features of primary or secondary metabolism whereby quinolone production was frequently affected. In the other half the transposon had inserted into genes of the functional categories transport, regulation or motility/chemotaxis. To mimic dissociative behaviour of isogenic strains in lungs, pools of 25 colony morphology variants were tested for competitive fitness in an acute murine airway infection model. Six of the 55 mutants either grew better or worse in vivo than in vitro, respectively. Metabolic proficiency of the colony morphology variant was a key determinant for survival in murine airways. The most common morphotype of self-destructive autolysis did unexpectedly not impair fitness. Transposon insertions into homologous genes of strain PAO1 did not reproduce the TBCF10839 mutant morphotypes for 16 of 19 examined loci pointing to an important role of the genetic background on colony morphology. Depending on the chosen P. aeruginosa strain, functional genome scans will explore other areas of the evolutionary landscape. Based on our discordant findings of mutant phenotypes in P. aeruginosa strains PAO1, PA14 and TBCF10839, we conclude that the current focus on few reference strains may miss modes of niche adaptation and dissociative behaviour that are relevant for the microevolution of complex traits in the wild.
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Affiliation(s)
- Elza Rakhimova
- Clinical Research Group, OE6710, Hanover Medical School, Hanover, Germany
| | - Antje Munder
- Clinical Research Group, OE6710, Hanover Medical School, Hanover, Germany
| | - Lutz Wiehlmann
- Clinical Research Group, OE6710, Hanover Medical School, Hanover, Germany
| | - Florian Bredenbruch
- Helmholtz Centre for Infection Research, Division of Cell Biology and Immunology, Braunschweig, Germany
| | - Burkhard Tümmler
- Clinical Research Group, OE6710, Hanover Medical School, Hanover, Germany
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43
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Abstract
The modern history of cystic fibrosis (CF) is one of continuous improvement. Guidelines and evidence-based medicine provide a general roadmap for directing improvement efforts. Data and measurement are central to quality improvement (QI), a way of keeping score and staying on track. This article describes the history and context of QI in CF, the use of guidelines and data with some examples from the work of one regional consortium, some approaches to developing QI skills with a view to implementing and managing desired changes in CF clinic settings, and the potential benefits and impact of public reporting and data transparency.
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Affiliation(s)
- Hebe B Quinton
- Clinical Research Section, Department of Medicine, Dartmouth Medical School, One Medical Center Drive, Lebanon, NH 03756, USA.
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44
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Abstract
In this article, the authors outline some of the major historical events that signaled the need to better understand mechanisms of infection in cystic fibrosis (CF). The authors discuss general principles of infection control, focusing on issues of particular importance to patients who have CF. The authors also describe the major pathogens associated with the CF airway, provide a review of findings from inpatient and outpatient studies of infection control, and provide an outline of future directions for investigation.
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Affiliation(s)
- Jonathan B Zuckerman
- Department of Medicine, The University of Vermont College of Medicine, E-126 Given Building, 89 Beaumont Avenue, Burlington, VT 05405-0068, USA.
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45
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Montanari S, Oliver A, Salerno P, Mena A, Bertoni G, Tümmler B, Cariani L, Conese M, Döring G, Bragonzi A. Biological cost of hypermutation in Pseudomonas aeruginosa strains from patients with cystic fibrosis. Microbiology (Reading) 2007; 153:1445-1454. [PMID: 17464058 DOI: 10.1099/mic.0.2006/003400-0] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The high prevalence of hypermutable (mismatch repair-deficient) Pseudomonas aeruginosa strains in patients with cystic fibrosis (CF) is thought to be driven by their co-selection with adaptive mutations required for long-term persistence. Whether the increased mutation rate of naturally hypermutable strains is associated with a biological benefit or cost for the colonization of secondary environments is not known. Thirty-nine P. aeruginosa strains were collected from ten patients with CF during their course of chronic lung infections and screened for hypermutability. Seven hypermutable P. aeruginosa strains (18 %) isolated from six patients with CF (60 %) were identified and assigned to five different genotypes. Complementation and sequence analysis in the mutS, mutL and uvrD genes of these hypermutable P. aeruginosa strains revealed novel mutations. To understand the consequences of hypermutation for the fitness of the organisms, five pairs of clinical wild-type/hypermutable, clonally related P. aeruginosa strains and the laboratory strains PAO1/PAO1DeltamutS were subjected to competition in vitro and in the agar-beads mouse model of chronic airway infection. When tested in competition assay in vitro, the wild-type outcompeted four clinical hypermutable strains and the PAO1DeltamutS strain. In vivo, all of the hypermutable strains were less efficient at establishing lung infection than their wild-type clones. These results suggest that P. aeruginosa hypermutation is associated with a biological cost, reducing the potential for colonization of new environments and therefore strain transmissibility.
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Affiliation(s)
- Sara Montanari
- Institute for Experimental Treatment of Cystic Fibrosis, Scientific Institute H. S. Raffaele, Milano, Italy
| | - Antonio Oliver
- Servicio de Microbiologìa Hospital Son Dureta, Palma de Mallorca, Spain
| | - Paola Salerno
- Institute for Experimental Treatment of Cystic Fibrosis, Scientific Institute H. S. Raffaele, Milano, Italy
| | - Ana Mena
- Servicio de Microbiologìa Hospital Son Dureta, Palma de Mallorca, Spain
| | - Giovanni Bertoni
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, Milano, Italy
| | - Burkhard Tümmler
- Klinische Forschergruppe, OE 6710, Medizinische Hochschule Hannover, Hannover, Germany
| | - Lisa Cariani
- Ospedale Maggiore Policlinico, CF Clinic, Milano, Italy
| | - Massimo Conese
- Institute for Experimental Treatment of Cystic Fibrosis, Scientific Institute H. S. Raffaele, Milano, Italy
| | - Gerd Döring
- Institute of Medical Microbiology and Hygiene, Universitätsklinikum Tübingen, Tübingen, Germany
| | - Alessandra Bragonzi
- Institute for Experimental Treatment of Cystic Fibrosis, Scientific Institute H. S. Raffaele, Milano, Italy
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Wiehlmann L, Wagner G, Cramer N, Siebert B, Gudowius P, Morales G, Köhler T, van Delden C, Weinel C, Slickers P, Tümmler B. Population structure of Pseudomonas aeruginosa. Proc Natl Acad Sci U S A 2007; 104:8101-6. [PMID: 17468398 PMCID: PMC1876578 DOI: 10.1073/pnas.0609213104] [Citation(s) in RCA: 227] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The metabolically versatile Gram-negative bacterium Pseudomonas aeruginosa inhabits terrestrial, aquatic, animal-, human-, and plant-host-associated environments and is an important causative agent of nosocomial infections, particularly in intensive-care units. The population genetics of P. aeruginosa was investigated by an approach that is generally applicable to the rapid, robust, and informative genotyping of bacteria. DNA, amplified from the bacterial colony by circles of multiplex primer extension, is hybridized onto a microarray to yield an electronically portable binary multimarker genotype that represents the core genome by single nucleotide polymorphisms and the accessory genome by markers of genomic islets and islands. The 240 typed P. aeruginosa strains of diverse habitats and geographic origin segregated into two large nonoverlapping clusters and 45 isolated clonal complexes with few or no partners. The majority of strains belonged to few dominant clones widespread in disease and environmental habitats. The most frequent genotype was represented by the sequenced strain PA14. Core and accessory genome were found to be nonrandomly assembled in P. aeruginosa. Individual clones preferred a specific repertoire of accessory segments. Even the most promiscuous genomic island, pKLC102, had integrated preferentially into a subset of clones. Moreover, some physically distant loci of the core genome, including oriC, showed nonrandom associations of genotypes, whereas other segments in between were freely recombining. Thus, the P. aeruginosa genome is made up of clone-typical segments in core and accessory genome and of blocks in the core with unrestricted gene flow in the population.
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Affiliation(s)
- Lutz Wiehlmann
- *Klinische Forschergruppe, OE 6710, Medizinische Hochschule Hannover, Carl-Neuberg Strasse 1, D-30625 Hannover, Germany
- To whom correspondence may be addressed. E-mail: or
| | - Gerd Wagner
- CLONDIAG Chip Technologies GmbH, Löbstedter Strasse 103–105, D-07749 Jena, Germany
| | - Nina Cramer
- *Klinische Forschergruppe, OE 6710, Medizinische Hochschule Hannover, Carl-Neuberg Strasse 1, D-30625 Hannover, Germany
| | - Benny Siebert
- *Klinische Forschergruppe, OE 6710, Medizinische Hochschule Hannover, Carl-Neuberg Strasse 1, D-30625 Hannover, Germany
| | - Peter Gudowius
- *Klinische Forschergruppe, OE 6710, Medizinische Hochschule Hannover, Carl-Neuberg Strasse 1, D-30625 Hannover, Germany
| | - Gracia Morales
- Departamento de Biotecnologia Microbiana, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Cientificas, Campus Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain
| | - Thilo Köhler
- Département de Microbiologie et de Médecine Moléculaire, Centre Medical Universitaire, Université de Genève, 9 Avenue Champel, CH-1211 Geneva, Switzerland; and
| | - Christian van Delden
- Département de Microbiologie et de Médecine Moléculaire, Centre Medical Universitaire, Université de Genève, 9 Avenue Champel, CH-1211 Geneva, Switzerland; and
- Service des Maladies Infectieuses, Hôpital Universitaire de Genève, Rue Micheli-du-Crest 24, CH-1211 Geneva 14, Switzerland
| | - Christian Weinel
- *Klinische Forschergruppe, OE 6710, Medizinische Hochschule Hannover, Carl-Neuberg Strasse 1, D-30625 Hannover, Germany
| | - Peter Slickers
- CLONDIAG Chip Technologies GmbH, Löbstedter Strasse 103–105, D-07749 Jena, Germany
| | - Burkhard Tümmler
- *Klinische Forschergruppe, OE 6710, Medizinische Hochschule Hannover, Carl-Neuberg Strasse 1, D-30625 Hannover, Germany
- To whom correspondence may be addressed. E-mail: or
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Festini F, Buzzetti R, Bassi C, Braggion C, Salvatore D, Taccetti G, Mastella G. Isolation measures for prevention of infection with respiratory pathogens in cystic fibrosis: a systematic review. J Hosp Infect 2006; 64:1-6. [PMID: 16835001 DOI: 10.1016/j.jhin.2006.02.021] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2005] [Accepted: 02/21/2006] [Indexed: 11/24/2022]
Abstract
Respiratory infections are the most important cause of morbidity and mortality in patients with cystic fibrosis (CF). These infections are typically caused by a limited number of respiratory pathogens, particularly Burkholderia cepacia complex (BCC) and Pseudomonas aeruginosa (PA). Since the 1980s, several outbreaks of unique strains of PA and BCC among CF patients attending the same CF care centres have been described, leading to a sharp decline in the patients' health. One of the measures adopted in CF centres to interrupt ongoing outbreaks is the separation of patients with a respiratory tract culture that is positive for PA or BCC from patients who are not infected. This type of measure has been implemented routinely in many CF centres to prevent cross-transmission of PA and BCC. The aim of this review was to determine what evidence is available to support the efficacy of isolation (or segregation) practices in preventing, delaying or reducing the risk for CF patients of acquiring PA and BCC. A systematic review of scientific literature from 1980 to 31 December 2004 was performed. Existing guidelines regarding infection control in CF were also analysed. In total, 398 relevant papers were retrieved. Only 10 well-designed studies were found that evaluated the efficacy of isolation practices in preventing the transmission of respiratory pathogens in CF care centres (one prospective controlled study, one retrospective cohort study, five 'before-after' studies and three cross-sectional studies. No systematic reviews or randomized controlled trials exist on this subject. In the absence of studies with an experimental, controlled design, the efficacy of isolation practices in preventing the transmission of respiratory pathogens in CF remains unproven. However, notwithstanding the considerable limits represented by the study designs, which were mainly retrospective, the observational studies reviewed seem to support the implementation of isolation (or segregation) measures to reduce the risk of transmission of BCC and PA in CF patients.
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Affiliation(s)
- F Festini
- Italian Cystic Fibrosis Research Foundation, Verona, Italy.
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Abstract
Work over the past few years has provided evidence that quorum sensing is a generic regulatory mechanism that allows bacteria to launch a unified, coordinated response in a population density-dependent manner to accomplish tasks which would be difficult, if not impossible, to achieve for a single bacterial cell. Quorum sensing systems are widespread among pseudomonads and the one of the human opportunistic pathogen Pseudomonas aeruginosa belongs to the most extensively studied cell-to-cell communication systems. In this organism, quorum sensing is highly complex and is made up of two interlinked N-acyl homoserine lactone (AHL)-dependent regulatory circuits, which are further modulated by a non-AHL-related signal molecule and numerous regulators acting both at the transcriptional and post-transcriptional level. This genetic complexity may be one of the key elements responsible for the tremendous environmental versatility of P. aeruginosa. Work of the past few years showed that quorum sensing is essential for the expression of a battery of virulence factors as well as for biofilm formation in P. aeruginosa and thus represents an attractive target for the design of novel drugs for the treatment of P. aeruginosa infections. Furthermore, the cell-to-cell communication ability was also demonstrated in a number of additional pseudomonads.
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Affiliation(s)
- Mario Juhas
- University of Oxford, Nuffield Department of Clinical Laboratory Sciences, Headington, Oxford OX3 9DU, UK.
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Salunkhe P, Töpfer T, Buer J, Tümmler B. Genome-wide transcriptional profiling of the steady-state response of Pseudomonas aeruginosa to hydrogen peroxide. J Bacteriol 2005; 187:2565-72. [PMID: 15805502 PMCID: PMC1070385 DOI: 10.1128/jb.187.8.2565-2572.2005] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The steady-state response of Pseudomonas aeruginosa to the oxidative-stress-generating agent hydrogen peroxide was analyzed by PAO1 transcriptome profiling. In total, 694, 411, and 237 genes were upregulated and 668, 576, and 468 genes were downregulated in P. aeruginosa strains TB, 892, and PAO1, respectively. The expression profiles of the two variants of the TB clone were significantly more related to each other than the expression profile of either strain was to that of PAO1. Exposure to H(2)O(2) activated by more than 10-fold the expression of the cyoABCD operon, which is key for aerobic respiration, and of oxidative-stress response elements such as the catalase KatB, the alkyl hydroperoxide reductase AhpF, and the thioredoxin reductase 2 operon. Genes for iron and sulfur homeostasis were upregulated. Most enzymes necessary for the conversion of amino acids into the citric acid cycle were globally downregulated at the transcriptional level. Nitrate respiration and arginine fermentation were shut off in the clone TB strains and attenuated in the PAO strain. The transcriptional profiles indicate that the two clone TB strains are more proficient in coping with H(2)O(2)-mediated oxidative stress than the reference strain PAO. According to this data, we recommend study of the transcriptome of strain PAO1 in parallel with those of at least two strains of another clone in order to differentiate common responses from clone- and strain-specific responses and to minimize overinterpretations of microarray data.
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Affiliation(s)
- Prabhakar Salunkhe
- Clinical Reseach Group, OE 6710, Hannover Medical School, Carl Neuberg Str. 1, D-30625 Hannover, Germany.
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Juhas M, Wiehlmann L, Salunkhe P, Lauber J, Buer J, Tümmler B. GeneChip expression analysis of the VqsR regulon of Pseudomonas aeruginosa TB. FEMS Microbiol Lett 2005; 242:287-95. [PMID: 15621450 DOI: 10.1016/j.femsle.2004.11.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2004] [Revised: 11/04/2004] [Accepted: 11/08/2004] [Indexed: 11/25/2022] Open
Abstract
Two interlinked quorum sensing circuits, las and rhl, which control pathogenesis of Pseudomonas aeruginosa are further modulated by numerous regulators, including VqsR (virulence and quorum sensing regulator). High-density oligonucleotide microarrays were used to compare the global expression profile of a wild-type and VqsR mutant in ABC minimal medium. The expression of a large group of metabolic genes, ECF sigma factors as well as of many quorum-sensing genes previously not assigned to VqsR-regulon was found to be affected by the disruption of vqsR.
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Affiliation(s)
- Mario Juhas
- Clinical Research Group OE 6711, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany.
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