Health-related quality of life in Cystic Fibrosis patients infected with transmissible Pseudomonas aeruginosa strains: cohort study.

OBJECTIVES: To assess the impact on health-related quality of life (HRQoL) in adult cystic fibrosis (CF) patients of chronic infection with the Liverpool Epidemic Strain (LES) of Pseudomonas aeruginosa (Psa). DESIGN: Cohort study. PARTICIPANTS: Adult CF patients attending a single CF centre. SETTING: Outpatient clinic. MAIN OUTCOME MEASURES: HRQoL measures of adult CF patients chronically infected with LES and Psa strains measured by CFQ-UK. RESULTS: Patients infected by transmissible Psa strains had worse physical functioning, respiratory symptoms, treatment burden, vitality, role, health perception and emotion than those with unique Psa strains (P < 0.01), and significantly poorer physical functioning, respiratory symptoms, treatment burden, body image, weight, role, and emotion than those without any Psa infection (P < 0.05). Furthermore, in a matched cohort of 39 patients, those with LES infection reported significantly worse physical functioning, treatment burden, respiratory symptoms and health perception than those with unique Psa infection (P < 0.02). CONCLUSION: Chronic infection with transmissible Psa strains, particularly LES, confers a worse quality of life in adult CF patients. Coupled with the established poorer clinical outcome, this reinforces the need to prevent the spread of such strains in CF community.

Increasing resistance of the Liverpool Epidemic Strain (LES) of Pseudomonas aeruginosa (Psa) to antibiotics in cystic fibrosis (CF)--a cause for concern?

BACKGROUND: Transmissible Pseudomonas aeruginosa (Psa) strains such as the Liverpool Epidemic Strain (LES) are now widespread throughout UK CF clinics: their susceptibility to antibiotics is therefore important. To study this, we compared antibiogram patterns of Psa strains in our CF clinic over 5 years, looking at differences in resistance patterns between strains and changes to these over time. METHODS: The antibiograms of sputum samples between 2004 and 2008 from patients attending our centre were included. We compared Psa isolate antibiotic resistance (to six anti-pseudomonal antibiotics) patterns for patients infected with LES with those infected with other Psa strains, both in the total population in 2004 (125 patients) and 2008 (166 patients) and also longitudinally from annual review samples 2004 to 2008 in matched and unmatched patient groups. RESULTS: LES exhibited significantly more resistant isolates in 2004 (p<0.0001). There was an increase in antibiotic resistance in both LES and other Psa strains over time (p<0.001). Cox proportional hazards analysis of both unmatched (n=125) and matched (n=56) patients in 2004 revealed that LES infected patients were more likely to develop antibiotic resistant isolates over time (hazard ratio 8.1, p<0.001). Fewer LES isolates were classed as fully sensitive in both matched and unmatched groups at the end of study period (p<0.001). CONCLUSION: This study shows a worrying trend in antibiotic resistance in the Psa isolates amongst patients chronically infected with LES. This highlights the need to prevent cross infection through segregation and also the need to develop new strategies to treat these organisms.

Impact of 18F-FDG PET scan on the prevalence of benign thoracic lesions at surgical resection / Impacto do estudo com 18F-FDG PET sobre a prevalência de achados de lesões torácicas benignas em ressecções cirúrgicas

OBJECTIVE: The main utility of 18-fluorodeoxyglucose positron emission tomography (FDG-PET) lies in the staging of lung cancer. However, it can also be used to differentiate indeterminate pulmonary lesions, but its impact on the resection of benign lesions at surgery is unknown. The aim of this study was to compare the prevalence of benign lesions at thoracotomy carried out for suspected lung cancer, before and after the introduction of PET scanning in a large thoracic surgical centre. MATERIALS AND METHODS: We reviewed our prospectively recorded surgical database for all consecutive patients undergoing thoracotomy for suspected or proven lung cancer and compared the prevalence of benign lesions in 2 consecutive 2-year groups, before (group I) and after (group II) the introduction of FDG-PET scan respectively. RESULTS: Surgical resection was performed on 1233 patients during the study period. The prevalence of benign lesions at surgery in groups I and II was similar (44/626 and 41/607, both 7 percent), and also in group II between those who underwent FDG-PET scan and the remainder (21/301 and 20/306 respectively, both 7 percent). In group II, of the 21 patients with benign lesions, who underwent FDG-PET, 19 had a false positive scan (mean standardised uptake value 5.3 [range 2.6-12.7]). Of these, 13 and 4 patients respectively had non-diagnostic bronchoscopy and percutaneous transthoracic lung biopsy pre thoracotomy. There was no difference in the proportion of different benign lesions resected between group I and those with FDG-PET in group II. CONCLUSION: The introduction of FDG-PET scanning has not altered the proportion of patients undergoing thoracotomy for ultimately benign lesions, mainly due to the avidity for the isotope of some non-malignant lesions. Such false positive results need to be considered when patients with unconfirmed lung cancer are contemplated for surgical resection.

OBJETIVO: A principal utilidade da tomografia por emissão de pósitrons com 18-fluordeoxiglicose (FDG-PET) está no estadiamento do câncer de pulmão. Porém, ela também pode ser utilizada para diferenciar lesões pulmonares indeterminadas, mas seu impacto na ressecção cirúrgica de lesões benignas é desconhecido. O objetivo deste estudo foi comparar a prevalência de lesões benignas em toracotomias feitas por suspeição de câncer de pulmão, antes e após a introdução do FDG-PET, em um centro de referência de cirurgia torácica. MATERIAIS E MÉTODOS: Os autores analisaram, prospectivamente, uma base de dados cirúrgicos de todos os pacientes consecutivos submetidos a toracotomia por câncer de pulmão suspeito ou comprovado e compararam a prevalência de lesões benignas em dois grupos ao longo de dois anos consecutivos, respectivamente antes (grupo I) e depois (grupo II) da introdução da FDG-PET. RESULTADOS: Ressecção cirúrgica foi feita em 1.233 pacientes durante o período do estudo. A prevalência de lesões benignas na cirurgia nos grupos I e II foi similar (44/626 e 41/607, ambas correspondendo a 7 por cento), e também no grupo II, entre aqueles submetidos a FDG-PET e os restantes (21/301 e 20/306 respectivamente, ambos correspondendo a 7 por cento). No grupo II, dos 21 pacientes com lesões benignas submetidos a FDG-PET, 19 tiveram um estudo falso-positivo (valor médio padrão de captação 5.3 [faixa 2.6-12.7]). Desses, respectivamente 13 e 4 pacientes tiveram broncoscopia não diagnóstica e biópsia transtorácica percutânea de pulmão antes da toracotomia. Não houve diferença na proporção de lesões benignas diferentes ressecadas entre o grupo I e aqueles submetidos a FDG-PET no grupo II. CONCLUSÃO:A introdução da FDG-PET não alterou a proporção de pacientes submetidos a toracotomia por lesões benignas, principalmente devido à avidez pelo isótopo de algumas lesões não malignas. Tais resultados falsos-positivos devem ser considerados nos casos em que se contempla a possibilidade de ressecção cirúrgica em pacientes com câncer de pulmão não confirmado.

Pseudomonas aeruginosa population diversity and turnover in cystic fibrosis chronic infections.

RATIONALE: Pseudomonas aeruginosa isolates from chronic cystic fibrosis lung infections display multiple phenotypes indicating extensive population diversity. OBJECTIVES: We aimed to examine how such diversity is distributed within and between patients, and to study the dynamics of single-strain phenotypic diversity in multiple patients through time. METHODS: Sets of 40 P. aeruginosa isolates per sputum samples were analyzed for a series of phenotypic and genotypic characteristics. Population differentiation between patients, between samples within patients, and between isolates within samples was analyzed. MEASUREMENTS AND MAIN RESULTS: We characterized 15 traits for a total of 1,720 isolates of an important and widely disseminated epidemic strain of P. aeruginosa from 10 chronically infected patients with cystic fibrosis multiply sampled during 2009. Overall, 43 sputum samples were analyzed and 398 haplotypes of the Liverpool Epidemic Strain were identified. The majority of phenotypic diversity occurred within patients. Such diversity is highly dynamic, displaying rapid turnover of haplotypes through time. P. aeruginosa populations within each individual sputum sample harbored extensive diversity. Although we observed major changes in the haplotype composition within patients between samples taken at intervals of several months, the compositions varied much less during exacerbation periods, despite the use of intravenous antibiotics. Our data also highlight a correlation between periods of pulmonary exacerbation and the overproduction of pyocyanin, a quorum sensing-controlled virulence factor. CONCLUSIONS: These results significantly advance our understanding of the within-host population biology of P. aeruginosa during infection of patients with cystic fibrosis, and provide in vivo evidence for a link between pyocyanin production and patient morbidity.

Effect of antibiotic treatment on bacteriophage production by a cystic fibrosis epidemic strain of Pseudomonas aeruginosa.

Phage production in response to antibiotics varied among four isolates of a Pseudomonas aeruginosa cystic fibrosis (CF) epidemic strain. Whereas ciprofloxacin induced higher levels of phage production, other CF-relevant antibiotics led to reduced production. We detected free phages directly in CF patient sputum samples by both plaque (40% positive) and PCR (76% positive) assays. Our observations suggest that the choice of antibiotics could influence the number of free phages within the CF lung environment.

Impact of Pseudomonas aeruginosa genomic instability on the application of typing methods for chronic cystic fibrosis infections.

The Liverpool epidemic strain (LES) of Pseudomonas aeruginosa is widespread among cystic fibrosis (CF) patients in the United Kingdom and has emerged recently in North America. In this study, we report the analysis of 24 "anomalous" CF isolates of P. aeruginosa that produced inconsistent results with regard to either pulsed-field gel electrophoresis (PFGE) or PCR tests for the LES. We used a new typing method, the ArrayTube genotyping system, to determine that of the 24 anomalous isolates tested, 13 were confirmed as the LES. LES isolates could not be clearly distinguished from non-LES isolates by two other commonly used genetic fingerprinting tests, randomly amplified polymorphic DNA (RAPD) analysis and BOX-PCR, and varied considerably in their carriage of LES genomic islands and prophages. The genomic instability of the LES suggests that identification of this emerging transmissible strain could be a challenging task, and it questions whether discrimination is always a desirable feature of bacterial typing methods in the context of chronic CF infections.

Empyema due to a highly transmissible Pseudomonas aeruginosa strain in an adult cystic fibrosis patient.

Chronic pulmonary infection with Pseudomonas aeruginosa occurs in up to 85 % of individuals with cystic fibrosis (CF) by the time they reach adulthood, and is the major cause of morbidity and mortality: nearly all patients die from progressive respiratory failure due to repeated pulmonary exacerbations. However, despite the predilection of this organism for the lungs of CF people, infection of the pleura is much less common and is not well described in the CF population. We describe what is believed to be the first case of pleural empyema due to a particularly pathogenic transmissible strain of P. aeruginosa (the Liverpool epidemic strain) in an adult CF patient.

Fluctuations in phenotypes and genotypes within populations of Pseudomonas aeruginosa in the cystic fibrosis lung during pulmonary exacerbations.

Chronic respiratory infection by Pseudomonas aeruginosa contributes significantly to the morbidity and mortality associated with cystic fibrosis (CF). Using a series of phenotypic and genotypic tests on collections of 40 isolates per sputum sample, we analysed fluctuations within sputum populations of the P. aeruginosa Liverpool epidemic strain (LES) during pulmonary exacerbations. For each of three patients, three sequential sputum samples were analysed: (1) on presentation with exacerbation at the Regional Adult Cystic Fibrosis Unit, Liverpool; (2) a few days into intravenous antibiotic treatment; (3) when the patient had recovered. Fluctuations were observed in morphotype distribution, the production of virulence-associated quorum-sensing-dependent exoproducts (the phenazine compound pyocyanin and the elastase LasA), antibiotic susceptibility profiles and levels of auxotrophy. PCR assays were used to screen isolates for the presence of novel regions of the LES genome (islands and prophages) and to detect free phages. In one patient there was an increase in the prevalence of the LESGI-5 genomic island during the sampling period from 10 to 97.5 % carriage. LES phages 2-4 were detected in either the majority or all sputum samples tested, indicating widespread phage activity during the sampling period. The results of this study are indicative that significant fluctuations occur within P. aeruginosa populations during short periods of pulmonary exacerbation and intravenous antibiotic therapy.

Management of cystic fibrosis related diabetes: a survey of UK cystic fibrosis centers.

INTRODUCTION: Cystic fibrosis related diabetes (CFRD), a poor prognostic factor in cystic fibrosis (CF), is an increasing problem and guidelines regarding its management have recently been published. However, the evidence base for CFRD screening and diagnosis is not comprehensive and its current management in the UK is unknown. We therefore conducted a questionnaire survey of all recognized UK CF centers to assess clinical practice and determine adherence to these recent recommendations. METHODS: A questionnaire survey (regarding screening, diagnosis, treatment and monitoring of CFRD) sent to all 45 recognized CF centers (>50 patients) in the UK. RESULTS: Completed questionnaires were returned by 37 centers (82%). Although 35 (95%) centers screened patients annually for CFRD, 12 (34%) used a single investigation whereas the remaining 23 (66%) used two or more methods. As regards diagnosis only 11 (30%) used the recommended combination of oral glucose tolerance test (OGTT) and serial glucose monitoring, with 18 (49%) using OGTT alone. Insulin was the preferred treatment of choice in 36 (97%) centers, and pediatric centers were less likely to use oral hypoglycemic agents (4/17 vs. 9/16; chi(2) = 3.6, P < 0.05). 29 (78%) centers carried out an annual diabetes review and in 34 (92%) patients were cared for jointly between the CF and endocrinology teams. Glycosylated hemoglobin and serial glucose monitoring were the most common investigations used to monitor glycemic control. CONCLUSIONS: This survey highlights the disparities in the management of CFRD with regards to screening and diagnostic practice, and poor adherence to national guidelines.

Long-term effect of insulin treatment in cystic fibrosis-related diabetes.

BACKGROUND: Although insulin treatment confers short-term benefit in cystic fibrosis-related diabetes (CFRD), few studies have compared its long-term effect on the clinical outcome. OBJECTIVES: In this study, we aimed to investigate the long-term impact of insulin treatment on pulmonary function, nutritional status and hospital admissions in patients with CFRD. METHODS: We reviewed pulmonary function, body mass index (BMI) and hospital admissions 5 years before and 3 years after insulin therapy in 42 adult CFRD patients. RESULTS: Prior to treatment, over a period of 5 years, the annual rate of change in forced expiratory volume in 1 s (FEV(1)) was -3.2%, forced vital capacity (FVC) -2.5%, and BMI -0.07%. At treatment of CFRD (baseline), the mean FEV(1) was 51.6% predicted (range 24-96), FVC 66.4% (range 29-103) and BMI 19.5 (range 15.3-29.5). At 3 months following insulin treatment, there was a significant improvement in all parameters, which was maintained at 1 year for FEV(1) (55.1%; p < 0.002), 2 years for FVC (72.1%; p < 0.01) and at 3 years for BMI (20.4%; p < 0.002). After 3 months, FEV(1) declined at a rate similar to that before treatment (-3.2 vs. -3.1% per year; p = 0.77), such that the mean FEV(1) after treatment returned to pretreatment baseline values at 34 months. There was no difference in the number of hospital admissions with insulin treatment. CONCLUSIONS: Insulin enhances the nutritional state and temporarily improves pulmonary function in CFRD patients, on average delaying the decline in FEV(1) by 34 months.

Acute renal failure in CF patients chronically infected by the Liverpool epidemic Pseudomonas aeruginosa strain (LES).

Although acute renal failure has been described in children with CF in relation to intravenous aminoglycoside use, there are no reports in the adult CF literature. We describe 8 cases of acute renal failure in adult CF patients, all occurring during the use of intravenous aminoglycosides for the treatment of pulmonary exacerbations with an epidemic multi-resistant Pseudomonas aeruginosa strain. Potential contributory factors are discussed. These cases demonstrate another complication of infection by epidemic Pseudomonas strains in CF, and confirm the need for effective segregation policies to prevent this.

PCR-based detection of a cystic fibrosis epidemic strain of Pseudomonas Aeruginosa.

BACKGROUND: The Liverpool epidemic strain (LES) of Pseudomonas aeruginosa is widespread among patients with cystic fibrosis (CF) in specialist centers around Liverpool and elsewhere in the UK. This study evaluates a new diagnostic PCR assay based on a unique DNA sequence (PS21) of LES, for its identification of colonies directly from sputum. METHODS: One hundred and fifty-eight sputum samples from 92 patients were cultured and P. aeruginosa isolates were typed by PS21 PCR and pulsed-field gel electrophoresis (PFGE). Subsequently, PS21 PCR was performed directly on sputum and the results were compared with culture, PFGE, and PS21 PCR typing. RESULTS: Eighty patients were colonized with P. aeruginosa, 63 by LES (79%). There was 100% concordance between PS21 PCR on colonies and PFGE typing. The sensitivity and specificity of PS21 PCR directly on sputum was 98.2% and 93.6%, respectively. CONCLUSIONS: This study shows that PS21 PCR can be used for simple and rapid screening of LES colonization in CF patients.

A randomized double-blinded placebo-controlled crossover trial of nebulized taurolidine in adult cystic fibrosis patients infected with Burkholderia cepacia.

Burkholderia cepacia is an aggressive pathogen that colonizes cystic fibrosis (CF) patients, causing greatly increased morbidity and mortality. It is resistant to most antibiotics, but sensitive in vitro to a novel agent, taurolidine. This has not previously been used against B. cepacia, nor given in nebulized form. We assessed the effect of nebulized taurolidine on United Kingdom epidemic (ET12) B. cepacia infection in 20 adult CF patients attending our regional adult cystic fibrosis outpatient clinic using a prospective, randomized, double-blinded placebo-controlled crossover trial. Nebulized taurolidine (4 mL 2% solution) or saline (4 mL 0.9% solution) was given twice daily. Each arm lasted 4 weeks, with a 2-week intervening washout period. Sputum B. cepacia colony counts (primary outcome measure), spirometry, and symptoms (secondary outcome measures) were assessed. Eighteen patients completed the study. There was no change in B. cepacia colony counts or spirometry, nor symptom scores. We conclude that, although taurolidine is well tolerated in nebulized form, in this study it had no in vivo anti-B. cepacia activity.