A retrospective study of silicone stent placement for management of anastomotic airway complications in lung transplant recipients: short- and long-term outcomes.

BACKGROUND: Airway anastomotic complications remain a major cause of morbidity and mortality after lung transplantation (LT). Few data are available with regard to the use of silicone stents for these airway disorders. The aim of this retrospective study was to evaluate the clinical efficacy and safety of silicone stents for such an indication. METHODS: Data of adult lung transplant recipients who had procedures performed between January 1997 and December 2007 at our institution were reviewed retrospectively. We included patients with post-transplant airway complications who required bronchoscopic intervention with a silicone stent. RESULTS: In 17 of 117 (14.5%) LT recipients, silicone stents were inserted at a mean time of 165 (range 5 to 360) days after surgery in order to palliate 23 anastomotic airway stenoses. Symptomatic improvement was noted in all patients, and mean forced expiratory volume in 1 second (FEV(1)) increased by 672 +/- 496 ml (p < 0.001) after stent insertion. The stent-related complication rate was 0.13/patient per month. The latter consisted of obstructive granulomas (n = 10), mucus plugging (n = 7) and migration (n = 7), which were of mild to moderate severity and were successfully managed endoscopically. Mean stent duration was 266 days (range 24 to 1,407 days). Successful stent removal was achieved in 16 of 23 cases (69.5%) without recurrence of stenosis. Overall survival was similar in patients with and without airway complications (p = 0.36). CONCLUSIONS: Silicone stents allow clinical and lung function improvement in patients with LT-related airway complications. Stent-related complications were of mild to moderate severity, and were appropriately managed endoscopically. Permanent resolution of airway stenosis was obtained in most patients, allowing definitive stent removal without recurrence.

Genomic analysis of an emerging multiresistant Staphylococcus aureus strain rapidly spreading in cystic fibrosis patients revealed the presence of an antibiotic inducible bacteriophage.

BACKGROUND: Staphylococcus aureus is a major human pathogen responsible for a variety of nosocomial and community-acquired infections. Recent reports show that the prevalence of Methicillin-Resistant S. aureus (MRSA) infections in cystic fibrosis (CF) patients is increasing. In 2006 in Marseille, France, we have detected an atypical MRSA strain with a specific antibiotic susceptibility profile and a unique growth phenotype. Because of the clinical importance of the spread of such strain among CF patients we decided to sequence the genome of one representative isolate (strain CF-Marseille) to compare this to the published genome sequences. We also conducted a retrospective epidemiological analysis on all S. aureus isolated from 2002 to 2007 in CF patients from our institution. RESULTS: CF-Marseille is multidrug resistant, has a hetero-Glycopeptide-Intermediate resistance S. aureus phenotype, grows on Cepacia agar with intense orange pigmentation and has a thickened cell wall. Phylogenetic analyses using Complete Genome Hybridization and Multi Locus VNTR Assay showed that CF-Marseille was closely related to strain Mu50, representing vancomycin-resistant S. aureus. Analysis of CF-Marseille shows a similar core genome to that of previously sequenced MRSA strains but with a different genomic organization due to the presence of specific mobile genetic elements i.e. a new SCCmec type IV mosaic cassette that has integrated the pUB110 plasmid, and a new phage closely related to phiETA3. Moreover this phage could be seen by electron microscopy when mobilized with several antibiotics commonly used in CF patients including, tobramycin, ciprofloxacin, cotrimoxazole, or imipenem. Phylogenetic analysis of phenotypically similar h-GISA in our study also suggests that CF patients are colonized by polyclonal populations of MRSA that represents an incredible reservoir for lateral gene transfer. CONCLUSION: In conclusion, we demonstrated the emergence and spreading of a new isolate of MRSA in CF patients in Marseille, France, that has probably been selected in the airways by antibiotic pressure. Antibiotic-mediated phage induction may result in high-frequency transfer and the unintended consequence of promoting the spread of virulence and/or antibiotic resistance determinants. The emergence of well-adapted MRSA is worrying in such population chronically colonized and receiving many antibiotics and represents a model for emergence of uncontrollable super bugs in a specific niche. REVIEWERS: This article was reviewed by Eric Bapteste, Pierre Pontarotti, and Igor Zhulin. For the full reviews, please go to the Reviewers' comments section.

Phenotypes of asthma revisited upon the presence of atopy.

Immunological studies claimed that atopic and non-atopic asthma share more similarities than differences. However, these two phenotypes of asthma are considered to be distinguishable upon distinct clinical patterns, which were not systematically assessed before in a large population. We studied characteristics discriminating atopic from non-atopic asthma among 751 asthmatic patients and 80 factors were analysed in univariate and multivariate analysis. Age, age of onset of asthma, female/male ratio were higher in non-atopic (n=200) than in atopic (n=551) asthmatics. Familial asthma, seasonal symptoms, rhinitis, conjunctivitis, allergen-triggered symptoms, improvement in altitude, exercise-induced asthma were associated with atopy. Non-atopic asthmatics displayed lower FEV(1) and FVC. Smoking was more frequent and asthma was more severe in these patients. Younger age, early onset, male sex, rhinitis and smoking were independent factors discriminating atopic from non-atopic asthma. This study establishes in a large population of asthmatics that although similarities exist between atopic and non-atopic asthma, two clinical phenotypes can still distinguish both kinds of asthma.