Despite aggressive antibiotic therapy, bronchopulmonary colonization by Pseudomonas aeruginosa causes persistent morbidity and mortality in cystic fibrosis (CF). Chronic P. aeruginosa infection in the CF lung is associated with structured, antibiotic-tolerant bacterial aggregates known as biofilms. We have demonstrated the effects of non-bactericidal, low-dose nitric oxide (NO), a signaling molecule that induces biofilm dispersal, as a novel adjunctive therapy for P. aeruginosa biofilm infection in CF in an ex vivo model and a proof-of-concept double-blind clinical trial. Submicromolar NO concentrations alone caused disruption of biofilms within ex vivo CF sputum and a statistically significant decrease in ex vivo biofilm tolerance to tobramycin and tobramycin combined with ceftazidime. In the 12-patient randomized clinical trial, 10 ppm NO inhalation caused significant reduction in P. aeruginosa biofilm aggregates compared with placebo across 7 days of treatment. Our results suggest a benefit of using low-dose NO as adjunctive therapy to enhance the efficacy of antibiotics used to treat acute P. aeruginosa exacerbations in CF. Strategies to induce the disruption of biofilms have the potential to overcome biofilm-associated antibiotic tolerance in CF and other biofilm-related diseases.

Pseudomonas aeruginosa is a remarkably versatile environmental bacterium with an extraordinary capacity to infect the cystic fibrosis (CF) lung. Infection with P. aeruginosa occurs early, and although eradication can be achieved following early detection, chronic infection occurs in over 60% of adults with CF. Chronic infection is associated with accelerated disease progression and increased mortality. Extensive research has revealed complex mechanisms by which P. aeruginosa adapts to and persists within the CF airway. Yet knowledge gaps remain, and prevention and treatment strategies are limited by the lack of sensitive detection methods and by a narrow armoury of antibiotics. Further developments in this field are urgently needed in order to improve morbidity and mortality in people with CF. Here, we summarize current knowledge of pathophysiological mechanisms underlying P. aeruginosa infection in CF. Established treatments are discussed, and an overview is offered of novel detection methods and therapeutic strategies in development.

The bacterial communities present in the oral cavity and the lungs of 19 adult cystic fibrosis (CF) patients were compared by using terminal restriction fragment length polymorphism analysis of 16S rRNA gene PCR products amplified from nucleic acids extracted directly from bacteria in clinical samples. Sputum samples were not found to be subject to profound contamination by oral cavity bacteria. Evidence of colonization of the CF lung by certain oral bacterial species was found.

Thirty two preschool children were entered into a double blind, placebo controlled study using intermittent budesonide to treat viral induced wheeze. Active treatment was either 800 micrograms twice a day via a spacer or 1600 micrograms twice a day via a spacer and facemask in those children too young to use a mouthpiece. Treatment was started at the onset of an upper respiratory tract infection and continued for seven days or until symptoms had resolved for 24 hours. Each child remained in the study until they had completed using one pair of budesonide and placebo inhalers in random order without the need for additional oral prednisolone. Twenty five children completed 28 treatment pairs. All 25 families were asked to express a preference after completing their first treatment pair: 12 preferred budesonide and six preferred placebo; seven had no preference. Symptom scores were compared in 17 treatment pairs that were completed without the need for oral prednisolone. Mean day and night time wheeze in the first week after infection were significantly lower in those receiving budesonide. Intermittent inhalation of budesonide can modify the severity of wheezing in preschool children developing asthma after viral respiratory infections but improvements were modest with the doses used in this study.

OBJECTIVE. Newborn screening for cystic fibrosis remains controversial because improved pulmonary function has not been established. Studies to date have not accounted for differences in treatments delivered to clinically diagnosed children and newborn-screened controls. Here, we compare outcomes and treatment of patients clinically diagnosed within the newborn-screening reporting window (early-clinically diagnosed), those presenting after this period (late-clinically diagnosed), and patients diagnosed by newborn screening. PATIENTS AND METHODS. In a cross-sectional analysis of cohorts retrospectively ascertained, patients who were homozygous ΔF508 with cystic fibrosis, attending specialist cystic fibrosis centers, and 1 to 10 years of age between 2000 and 2002 were identified from the United Kingdom Cystic Fibrosis Database and stratified into newborn-screened, early-clinically diagnosed, or late-clinically diagnosed cohorts. Two analyses were performed: (1) after restricting to the most recent year of data collection, early-clinically diagnosed and late-clinically diagnosed cohorts were matched to newborn-screened patients by patient age and year of data collection (133 patients per cohort were identified); and (2) for all years of data collection, annual sets of data for early-clinically diagnosed and late-clinically diagnosed patients were matched to newborn-screened patients by patient age and year of data collection (291 data sets per cohort were identified). Median height and weight z scores, proportion of patients with height and weight <10th percentile, prevalence of chronic Pseudomonas aeruginosa infection, Shwachman-Kulczyki morbidity scores, percent predicted forced expiratory volume in 1 second, and numbers of long-term therapies were compared. RESULTS. In both analyses, newborn screening was associated with higher height z score, higher Shwachman-Kulczyki score, lower likelihood of height <10th percentile, and fewer long-term therapies compared with late-clinically diagnosed patients. No other differences were found. CONCLUSIONS. Newborn screening was associated with improved growth, reduced morbidity, and reduced therapy, yet generated equivalent pulmonary outcome compared with late clinical diagnosis, suggesting that newborn screening may slow cystic fibrosis lung disease progression.

A Task Force supported by the European Respiratory Society was set up in 1997 in order to address the major issues relevant to difficult/therapy-resistant asthma. Although the group of patients involved is small in comparison to the high numbers of patients with asthma, these patients consume a significant proportion of medical resources in terms of both time and money [1]. The major issues facing the Task Force were how to define "difficult asthma", how the patient with difficult asthma should be evaluated, the pathophysiological mechanisms underlying difficult asthma and the treatments available. The Task Force also concerned itself with defining the areas of research necessary to bring about a greater understanding of the causes of difficult asthma and novel treatments. The document resulting from this Task Force represents a consensus of different opinions, which will form the basis for further research. Formulating the definition A large number of terms are used by clinicians when referring to asthmatic patients who have "difficult to treat" disease: difficult acute, difficult chronic, chronic severe, acute severe, therapy-resistant, difficult to control, corticosteroid-resistant or corticosteroid-dependent, symptomatic, life-threatening, and fatal. An encompassing inclusive rather than exclusive definition was sought and the use of the term "difficult/therapy-resistant asthma" was adopted to include all such cases of asthma of all age groups. Since wheezing disorders in preschool children are poorly characterized, this report specifically excludes children below the age of 5 yrs. Response to therapy is included in this concept and will have research implications. It was accepted that the definition needed to be inclusive, although losing some precision, but it was also recognized that its