Reconstitution of O-specific lipopolysaccharide expression in Burkholderia cenocepacia strain J2315, which is associated with transmissible infections in patients with cystic fibrosis

Burkholderia cenocepacia is an opportunistic bacterium that infects patients with cystic fibrosis. B. cenocepacia strains J2315, K56-2, C5424, and BC7 belong to the ET12 epidemic clone, which is transmissible among patients. We have previously shown that transposon mutants with insertions within the O antigen cluster of strain K56-2 are attenuated for survival in a rat model of lung infection. From the genomic DNA sequence of the O antigen-deficient strain J2315, we have identified an O antigen lipopolysaccharide (LPS) biosynthesis gene cluster that has an IS402 interrupting a predicted glycosyltransferase gene. A comparison with the other clonal isolates revealed that only strain K56-2, which produced O antigen and displayed serum resistance, lacked the insertion element inserted within the putative glycosyltransferase gene. We cloned the uninterrupted gene and additional flanking sequences from K56-2 and conjugated this plasmid into strains J2315, C5424, and BC7. All the exconjugants recovered the ability to form LPS O antigen. We also determined that the structure of the strain K56-2 O antigen repeat, which was absent from the LPS of strain J2315, consisted of a trisaccharide unit made of rhamnose and two N-acetylgalactosamine residues. The complexity of the gene organization of the K56-2 O antigen cluster was also investigated by reverse transcription-PCR, revealing several transcriptional units, one of which also contains genes involved in lipid A-core oligosaccharide biosynthesis.

The airway microbiome in cystic fibrosis: challenges for therapy

Although cystic fibrosis pulmonary infection is polymicrobial, routine laboratory methods focus on the detection of a small number of known pathogens. Recently, the use of strict anaerobic culture techniques and molecular technologies have identified other potential pathogens including anaerobic bacteria. Determining the role of all bacteria in a complex bacterial community and how they interact is extremely important; individual bacteria may affect how the community develops, possess virulence factors, produce quorum-sensing signals, stimulate an immune response or transfer antibiotic resistance genes, which could all contribute to disease progression. There are many challenges to managing cystic fibrosis lung infection but as knowledge about the airway microbiome continues to increase, this may lead to advances in the therapeutic management of the disease. © 2011 Future Medicine Ltd.

Quality of life and healthcare utilisation in cystic fibrosis:A multicentre UK study

The aim of our study was to discover the health status and healthcare utilisation associated with pulmonary exacerbations in cystic fibrosis (CF) and chronic Pseudomonas aeruginosa infection.

Patients with CF from five UK CF centres attended two visits, 8–12 weeks apart. They were classified at visit 1 as being in one of the three health states: no current pulmonary exacerbation; “mild” (no hospitalisation) pulmonary exacerbation; and “severe” (hospitalisation) pulmonary exacerbation. All patients completed the Cystic Fibrosis Questionnaire-Revised (CFQ-R) and EuroQol (EQ-5D) and a clinical form, and forced expiratory volume in 1 s (FEV1) was measured at visits 1 and 2. Annual healthcare utilisation data were collected.

94 patients of mean±sd age 28.5±8.2 yrs and FEV1 58.7±26.8% were recruited. 60 patients had no pulmonary exacerbation, 15 had a mild and 19 had a severe pulmonary exacerbation at visit 1. EQ-5D and CFQ-R data showed that the worse the exacerbation, the poorer the health-related quality of life (HRQoL). There were strong relationships between the CFQ-R and EQ-5D domain scores. The mean rate of pulmonary exacerbations per patient per year was 3.6 (1.5 in hospital and 2.2 at home). The mean length of stay per hospital pulmonary exacerbation was 9 days.

As exacerbation status worsens, patients experience worse HRQoL. There is a significant healthcare burden associated with treatment of pulmonary exacerbation and long-term prophylaxis.

Cystic fibrosis research in allied health and nursing professions

This report is the result of the "Allied Health and Nursing Professions Working Group" meeting which took place in Verona, Italy, November 2009, which was organised by the European Cystic Fibrosis Society, and involved 32 experts. The meeting was designed to provide a "roadmap" of high priority research questions that can be addressed by Allied Health Professionals (AHP) and nursing. The other goal was to identify research skills that would be beneficial to AHP and nursing researchers and would ultimately improve the research capacity and capability of these professions. The following tasks were accomplished: 1) a Delphi survey was used to identify high priority research areas and themes, 2) common research designs used in AHP and nursing research were evaluated in terms of their strengths and weaknesses, 3) methods for assessing the clinimetric and psychometric properties, as well as feasibility, of relevant outcome measures were reviewed, and 4) a common skill set for AHPs and nurses undertaking clinical research was agreed on and will guide the planning of future research opportunities. This report has identified important areas and themes for future research which include: adherence; physical activity/exercise; nutritional interventions; interventions for the newborn with CF and evaluation of outcome measures for use in AHP and nursing research. It has highlighted the significant challenges AHPs and nurses experience in conducting clinical research, and proposes strategies to overcome these challenges. It is hoped that this report will encourage research initiatives that assess the efficacy/effectiveness of AHP and nursing interventions in order to improve the evidence base. This should increase the quality of research conducted by these professions, justify services they currently provide, and expand their skills in new areas, with the ultimate goal of improving care for patients with CF.

Antimicrobial activity of fosfomycin and tobramycin in combination against cystic fibrosis pathogens under aerobic and anaerobic conditions

There is a need for new antibiotics or combination of antibiotics that possess activity against increasingly resistant cystic fibrosis (CF) respiratory pathogens such as Pseudomonas aeruginosa and MRSA.

Ancestral haplotype 8.1 and lung disease severity in European cystic fibrosis patients

The clinical course of cystic fibrosis (CF) lung disease varies between patients bearing identical CFTR mutations. This suggests that additional genetic modifiers may contribute to the pulmonary phenotype. The highly conserved ancestral haplotype 8.1 (8.1AH), carried by up to one quarter of Caucasians, comprises linked gene polymorphisms on chromosome 6 that play a key role in the inflammatory response: LTA +252A/G; TNF -308G/A, HSP70-2 +1267A/G and RAGE -429T/C. As inflammation is a key component inducing CF lung damage, we investigated whether the 8.1AH represents a lung function modifier in CF.

Tobramycin Inhalation Powder™:a novel drug delivery system for treating chronic Pseudomonas aeruginosa infection in cystic fibrosis

Lung disease in cystic fibrosis (CF) is typified by the development of chronic airways infection culminating in bronchiectasis and progression to end-stage respiratory disease. Pseudomonas aeruginosa, a ubiquitous gram-negative bacteria, is the archetypical CF pathogen and is associated with an accelerated clinical decline. The development and widespread use of chronic suppressive aerosolized antibacterial therapies, in particular Tobramycin Inhalation Solution (TIS), in CF has contributed to reduced lung function decline and improved survival. However, the requirement for the aerosolization of these agents through nebulizers has been associated with increased treatment burden, reduced quality of life and remain a barrier to broader uptake. Tobramycin Inhalation Powder (TIP™) has been developed by Novartis with the express purpose of delivering the same benefits as TIS in a time-effective manner. Administered via the T-326™ (Novartis) Inhaler in four individual 28-mg capsules, TIP can be administered in a quarter of the time of traditional nebulizers and is inherently portable. In clinical studies, TIP has been shown to be safe, result in equivalent or superior reductions in P. aeruginosa sputum density and produce similar improvements in pulmonary function. TIP offers significant advantages in time saving, portability and convenience over traditional nebulized TIS with comparable clinical outcomes for individuals with CF.

Expression of the NF-κB inhibitor A20 is altered in the Cystic Fibrosis epithelium

Research Question: A20 is an LPS-inducible, cytoplasmic zinc finger protein, that inhibits TLR-activated NF-?B signalling by deubiquitinating TRAF6. A20 action is facilitated by complex formation with RNF11, Itch and TAX1BP1. This study investigates if the expression of A20 is altered in the chronically inflamed Cystic Fibrosis (CF) airway epithelium.

Methods: Nasal epithelial cells from CF patients (F508del homozygous), non-CF controls and immortalised epithelial cells (16HBE14o- and CFBE41o-) were stimulated with LPS. Cytoplasmic expression of A20 and expression of NF-?B subunits was analysed. Formation of the A20 ubiquitin editing complex was also investigated.

Results: In CFBE41o-, peak LPS-induced A20 expression was delayed compared with 16HBE14o- and fell significantly below basal levels 12-24 h after LPS stimulation. This was confirmed in primary CF airway cells. Additionally, a significant inverse relationship between A20 and p65 expression was observed. Inhibitor studies showed that A20 does not undergo proteasomal degradation in CFBE41o-. A20 interacted with TAX1BP1, RNF11 and TRAF6 in 16HBE14o- cells, but these interactions were not observed in CFBE41o-.

Conclusion: he expression of A20 is significantly altered in CF and important interactions with complex members and target proteins are lost, which may contribute to the state of chronic NF-?B-driven inflammation.