The lung microbiota in children with cystic fibrosis captured by induced sputum sampling.

BACKGROUND: Spatial topography of the cystic fibrosis (CF) lung microbiota is poorly understood in childhood. How best to sample the respiratory tract in children for microbiota analysis, and the utility of microbiota profiling in clinical management of early infection remains unclear. By comparison with bronchoalveolar lavage (BAL), we assessed the ability of induced sputum (IS) sampling to characterise the lower airway microbiota. METHODS: Sample sets from IS and two or three matched BAL compartments were obtained for microbiota analysis as part of the CF-Sputum Induction Trial (UKCRN_14615, ISRCTNR_12473810). Microbiota profiles and pathogen detection were compared between matched samples. RESULTS: Twenty-eight patients, aged 1.1-17.7 years, provided 30 sample sets. Within-patient BAL comparisons revealed spatial heterogeneity in 8/30 (27%) sample sets indicating that the lower airway microbiota from BAL is frequently compartmentalised in children with CF. IS samples closely resembled one or more matched BAL compartments in 15/30 (50%) sets, and were related in composition in a further 9/30 (30%). IS detected 86.2% of the Top 5 genera found across matched BAL samples. The sensitivity of IS to detect specific CF-pathogens identified in matched BAL samples at relative abundance ≥5% varied between 43 and 100%, with negative predictive values between 73 and 100%. CONCLUSIONS: Spatial heterogeneity of the lower airway microbiota was observed in BAL samples and presents difficulties for consistent lung sampling. IS captured a microbiota signature representative of the lower airway in 80% of cases, and is a straightforward, non-invasive intervention that can be performed frequently to aid pathogen diagnosis and understand microbiota evolution in children with CF.

Phenotypic and Genotypic Adaptations in Pseudomonas aeruginosa Biofilms following Long-Term Exposure to an Alginate Oligomer Therapy.

Chronic Pseudomonas aeruginosa lung infections in cystic fibrosis (CF) evolve to generate environmentally adapted biofilm communities, leading to increased patient morbidity and mortality. OligoG CF-5/20, a low-molecular-weight inhaled alginate oligomer therapy, is currently in phase IIb/III clinical trials in CF patients. Experimental evolution of P. aeruginosa in response to OligoG CF-5/20 was assessed using a bead biofilm model allowing continuous passage (45 days; ∼245 generations). Mutants isolated after OligoG CF-5/20 treatment typically had a reduced biofilm-forming ability and altered motility profile. Genotypically, OligoG CF-5/20 provided no selective pressure on genomic mutations within morphotypes. Chronic exposure to azithromycin, a commonly prescribed antibiotic in CF patients, with or without OligoG CF-5/20 in the biofilm evolution model also had no effect on rates of resistance acquisition. Interestingly, however, cross-resistance to other antibiotics (e.g., aztreonam) was reduced in the presence of OligoG CF-5/20. Collectively, these findings show no apparent adverse effects from long-term exposure to OligoG CF-5/20, instead resulting in both fewer colonies with multidrug resistance (MDR)-associated phenotypes and improved antibiotic susceptibility of P. aeruginosaIMPORTANCE The emergence of multidrug-resistant (MDR) pathogens within biofilms in the cystic fibrosis lung results in increased morbidity. An inhalation therapy derived from alginate, OligoG CF-5/20, is currently in clinical trials for cystic fibrosis patients. OligoG CF-5/20 has been shown to alter sputum viscoelasticity, disrupt mucin polymer networks, and disrupt MDR pseudomonal biofilms. Long-term exposure to inhaled therapeutics may induce selective evolutionary pressures on bacteria within the lung biofilm. Here, a bead biofilm model with repeated exposure of P. aeruginosa to OligoG CF-5/20 (alone and in combination with azithromycin) was conducted to study these long-term effects and characterize the phenotypic and genotypic adaptations which result. These findings, over 6 weeks, show that long-term use of OligoG CF-5/20 does not lead to extensive mutational changes and may potentially decrease the pathogenicity of the bacterial biofilm and improve the susceptibility of P. aeruginosa to other classes of antibiotics.

Using multifaceted education to improve management in acute viral bronchiolitis.

OBJECTIVE: To establish current bronchiolitis management across hospitals in Wales, improve compliance with national guidelines and standardise evidence-based clinical practice. DESIGN: A complete audit cycle with implementation of a multifaceted education bundle prior to the follow-up audit. SETTING: Twelve acute paediatric departments between 1 November and 31 December in 2012 and 2013. PATIENTS: All infants under 12 months with a clinical diagnosis of bronchiolitis. INTERVENTIONS: The first audit assessed management of bronchiolitis with reference to both the Scottish Intercollegiate Guideline Network (SIGN) guidelines and local hospital guidelines. Following analysis and dissemination of these results, an education bundle was implemented nationwide, with completion of the audit cycle to assess change. MAIN OUTCOME MEASURES: Compliance with SIGN recommendations for investigation, treatment and discharge. Compliance with the education bundle requirements also assessed in 2013. RESULTS: Data were collected for 1599 infants. The education bundle was delivered in all hospitals. The level of severity, defined by oxygen saturations in air at presentation, length of stay and paediatric intensive care unit transfers, was equivalent for both years. Mean compliance percentage (95% CI) across Wales significantly improved between 2012 and 2013, with compliance with investigations increasing from 50% (46% to 53%) to 71% (68% to 74%), with management increasing from 65% (61% to 68%) to 74% (71% to 77%), and overall compliance improving from 38% (37% to 39%) to 59% (56% to 62%) in 2013. CONCLUSIONS: This audit demonstrated a significant improvement in compliance following implementation of our educational bundle. This has enabled improvement in standardised and evidence-based patient care across Wales.

Effectiveness of pulse-oximetry in addition to routine neonatal examination in detection of congenital heart disease in asymptomatic newborns.

OBJECTIVE: To assess the feasibility and effectiveness of pulse-oximetry as a screening tool in the detection of critical congenital heart disease (CCHD) in newborns. METHODS: Post-natal babies born between 01/01/2007-31/12/2009 were eligible. Post-ductal pulse-oximetry was performed using Nellcor® NPB 40 pulse oximeter with reusable OXI-A/N saturation probe. Saturations ≥95% were deemed normal. If saturations were <95%, an echocardiogram was done. The regional paediatric cardiology database and death records identified babies later diagnosed with CCHD. RESULTS: 6329/9613 eligible babies were studied and pulse-oximetry was performed at a mean age of 28 hours (range 6-72 hours). Fourteen babies had saturations <95%. CCHD was diagnosed in 7/14 babies; 4/7 had no clinical signs. Of the remaining 7 babies, 3 had non-critical but significant CHD and 4 had an undiagnosed respiratory illness or sepsis. All babies with low saturations had identifiable pathologies. One baby with normal saturations was later diagnosed with transposition of the great arteries. The sensitivity and specificity of identifying an unwell baby was 93.3% and 100% respectively; the sensitivity and specificity of identifying CCHD was 87.5% and 99.8% respectively. Clinical examination alone would have missed 4/7 (57%) of these. CONCLUSION: Pulse-oximetry is safe, acceptable, non-invasive and effective. Our study supports the routine use of pulse oximetry as part of the newborn check.