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BackgroundPatients with Cystic Fibrosis are subject to repeated respiratory tract infections, with recent increasing isolation of unusual pathogens. Ralstonia species have lately been isolated at our institution, an organism historically frequently misidentified as Burkholderia or Pseudomonas. The prevalence of Ralstonia spp. in cystic fibrosis populations has yet to be determined, along with its clinical implications.Case presentationsSeven patients out of the 301 followed at our cystic fibrosis clinic have had Ralstonia strains identified in their respiratory tract. Most strains identified were multi-drug resistant. After aquisition of Ralstonia spp., the patients' clinical course was characterized by more frequent and more severe respiratory infections along with prolonged hospitalizations, greater decline of lung function, and greater mortality. The mortality rate in this group of patients was 86%. No other factor that could explain such a dramatic evolution was identified upon review of patient data. Some of the strains involved were recognized as clones on Pulse Field Electrophoresis Gel, raising the question of person-to-person transmission.ConclusionNew pathogens are identified with the evolution of the microbiota in cystic fibrosis respiratory tracts. In our cohort of patients, acquisition of Ralstonia spp. was associated with dramatic outcomes in terms of disease acceleration and raised mortality rates. It is of critical importance to continue to better define the prevalence and clinical impact of Ralstonia in cystic fibrosis populations.

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Aims/hypothesis Cystic fibrosis-related diabetes (CFRD) affects up to 50% of adults with cystic fibrosis (CF) and its presence is associated with adverse effects on nutritional status and pulmonary function. Early diagnosis could minimise CFRD morbidity, yet current methods of an OGTT at 0 and 2 h yield unreliable results. Our aim was to determine which indices from a 2 h OGTT with sampling every 30 min might improve prediction of CFRD. Methods Cross-sectional analysis at baseline (n = 293) and observational prospective analysis (n = 185; mean follow-up of 7.5 ± 4.2 years) of the Montreal Cystic Fibrosis Cohort were performed. Blood glucose and insulinaemia OGTT variables were studied in relation to lung function (forced expiratory volume in 1 s [FEV1]), BMI and risk of developing CFRD. Results At baseline, maximum OGTT glucose (G max ) was negatively associated with FEV1 (p = 0.003). Other OGTT values, including classical 2 h glucose, were not. A higher G max was associated with lower insulin secretory capacity, delayed insulin peak timing and greater pancreatic insufficiency (p < 0.01). G max was positively associated with the risk of developing CFRD (p = 0.0029); no individual with a G max < 8 mmol/l developed CFRD over the following decade. No OGTT variable correlated to the rate of change in BMI or FEV1. Conclusions/interpretation In adults with CF, G max is strongly associated with the risk of developing CFRD; G max < 8 mmol/l could identify those at very low risk of future CFRD. G max is higher in individuals with pancreatic insufficiency and is associated with poorer insulin secretory capacity and pulmonary function. KeywordsAdult . Blood glucose variables . Cystic fibrosis . Lung function . Oral glucose tolerance test Abbreviations AUC INS/GLU I AUC /G AUC CF Cystic fibrosis CFRD Cystic fibrosis-related diabetes CFTR CF transmembrane conductance regulator FEV1 Forced expiratory volume in 1 s G AUC Total AUC for glucose G max Peak OGTT glucose I AUC Total AUC for insulin IGT Impaired glucose tolerance I max Peak OGTT insulin ISI Insulin sensitivity index MCFC Montreal Cystic Fibrosis Cohort NGT Normal glucose tolerance * Rémi Rabasa-Lhoret