***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: Background : A study was undertaken to investigate the incidence , diagnostic yield of non-invasive and bronchoscopic techniques , and risk factors of airway colonisation in patients with bronchiectasis in a stable clinical situation . Methods : A 2 year prospect i ve study of 77 patients with bronchiectasis in a stable clinical condition was performed in an 800 bed tertiary university hospital . The interventions used were pharyngeal swabs , sputum cultures and quantitative protected specimen brush ( PSB ) bacterial cultures ( cut off point ≥102 cfu/ml ) and bronchoalveolar lavage ( BAL )  ( cut off point ≥103 cfu/ml ) . Results : The incidence of bronchial colonisation with potential pathogenic microorganisms ( PPMs ) was 64 % . The most frequent PPMs isolated were Haemophilus influenzae ( 55 % ) and Pseudomonas spp ( 26 % ) . Resistance to antibiotics was found in 30 % of the isolated pathogens . When the sample was appropriate , the operative characteristics of the sputum cultures were similar to those obtained with the PSB taken as a gold st and ard . Risk factors associated with bronchial colonisation by PPMs in the multivariate analysis were : ( 1 ) diagnosis of bronchiectasis before the age of 14 years ( odds ratio (OR)=3.92 , 95 % CI 1.29 to 11.95 ) , ( 2 ) forced expiratory volume in 1 second ( FEV1 ) < 80 % predicted ( OR=3.91 , 95 % CI 1.30 to 11.78 ) , and ( 3 ) presence of varicose or cystic bronchiectasis ( OR=4.80 , 95 % CI 1.11 to 21.46 ) . Conclusions : Clinical ly stable patients with bronchiectasis have a high prevalence of bronchial colonisation by PPMs . Sputum culture is a good alternative to bronchoscopic procedures for evaluation of this colonisation . Early diagnosis of bronchiectasis , presence of varicose-cystic bronchiectasis , and FEV1 < 80 % predicted appear to be risk factors for bronchial colonisation with PPMs RATIONALE Bronchiectasis is a chronic debilitating disease with few evidence -based long-term treatments . OBJECTIVES A r and omized controlled trial assessing the efficacy of nebulized gentamicin therapy over 1 year in patients with non-cystic fibrosis bronchiectasis . METHODS Sixty-five patients were r and omized to either twice-daily nebulized gentamicin , 80 mg , or nebulized 0.9 % saline , for 12 months . All were review ed at three-monthly intervals during treatment and at 3 months ' follow-up . MEASUREMENTS AND MAIN RESULTS At each review the following were assessed : quantitative and qualitative sputum bacteriology ; sputum purulence and 24-hour volume ; FEV(1 ) , FVC , and forced expiratory flow , midexpiratory phase ; exercise capacity ; Leicester Cough Question naire and St. George 's Respiratory Question naire ; and exacerbation frequency .  Fifty-seven patients completed the study . At the end of 12 months ' treatment , compared with the saline group , in the gentamicin group there was reduced sputum bacterial density with 30.8 % eradication in those infected with Pseudomonas aeruginosa and 92.8 % eradication in those infected with other pathogens ; less sputum purulence ( 8.7 % vs. 38.5 % ; P < 0.0001 ) ; greater exercise capacity ( 510 [ 350 - 690 ] m vs. 415 [ 267.5 - 530 ] m ; P = 0.03 ) ; and fewer exacerbations ( 0 [ 0 - 1 ] vs. 1.5 [ 1 - 2 ] ; P < 0.0001 ) with increased time to first exacerbation ( 120 [ 87 - 161.5 ] d vs. 61.5 [ 20.7 - 122.7 ] d ; P = 0.02 ) . The gentamicin group had greater improvements in Leicester Cough Question naire ( 81.4 % vs. 20 % ; P < 0.01 ) and St. George 's Respiratory Question naire ( 87.5 % vs. 19.2 % ; P < 0.004 ) score . No differences were seen in 24-hour sputum volume , FEV(1 ) , FVC , or forced expiratory flow , midexpiratory phase . No P. aeruginosa isolates developed resistance to gentamicin . At follow-up , all outcome measures were similar to baseline . CONCLUSIONS Regular , long-term nebulized gentamicin is of significant benefit in non-cystic fibrosis bronchiectasis but treatment needs to be continuous for its ongoing efficacy . Clinical trial registered with www . clinical trials.gov ( NCT 00749866 ) RATIONALE There are no risk stratification tools for morbidity and mortality in bronchiectasis . Identifying patients at risk of exacerbations , hospital admissions , and mortality is vital for future research . OBJECTIVES This study describes the derivation and validation of the Bronchiectasis Severity Index ( BSI ) . METHODS Derivation of the BSI used data from a prospect i ve cohort study ( Edinburgh , UK , 2008 - 2012 ) enrolling 608 patients .  Cox proportional hazard regression was used to identify independent predictors of mortality and hospitalization over 4-year follow-up . The score was vali date d in independent cohorts from Dundee , UK ( n = 218 ) ; Leuven , Belgium ( n = 253 ) ; Monza , Italy ( n = 105 ) ; and Newcastle , UK ( n = 126 ) . MEASUREMENTS AND MAIN RESULTS Independent predictors of future hospitalization were prior hospital admissions , Medical Research Council dyspnea score greater than or equal to 4 , FEV1 < 30 % predicted , Pseudomonas aeruginosa colonization , colonization with other pathogenic organisms , and three or more lobes involved on high-resolution computed tomography . Independent predictors of mortality were older age , low FEV1 , lower body mass index , prior hospitalization , and three or more exacerbations in the year before the study . The derived BSI predicted mortality and hospitalization : area under the receiver operator characteristic curve ( AUC ) 0.80 ( 95 % confidence interval , 0.74 - 0.86 ) for mortality and AUC 0.88 ( 95 % confidence interval , 0.84 - 0.91 ) for hospitalization , respectively . There was a clear difference in exacerbation frequency and quality of life using the St. George 's Respiratory Question naire between patients classified as low , intermediate , and high risk by the score ( P < 0.0001 for all comparisons ) . In the validation cohorts , the AUC for mortality ranged from 0.81 to 0.84 and for hospitalization from 0.80 to 0.88 . CONCLUSIONS The BSI is a useful clinical predictive tool that identifies patients at risk of future mortality , hospitalization , and exacerbations across healthcare systems This phase II , r and omised , double-blind , multicentre study ( NCT00930982 ) investigated the safety and efficacy of ciprofloxacin dry powder for inhalation ( DPI ) in patients with non-cystic fibrosis bronchiectasis . Adults who were culture positive for pre-defined potential respiratory pathogens ( including Pseudomonas aeruginosa and Haemophilus influenzae ) were r and omised to ciprofloxacin DPI 32.5 mg or placebo administered twice daily for 28 days ( with 56 days of follow-up ) . Bacterial density in sputum ( primary end-point ) , pulmonary function tests , health-related quality of life and safety were monitored throughout the study . 60 subjects received ciprofloxacin DPI 32.5 mg and 64 received placebo . Subjects on ciprofloxacin DPI had a significant reduction ( p<0.001 ) in total sputum bacterial load at the end of treatment ( -3.62 log10 CFU·g−1 ( range -9.78–5.02 log10 CFU·g−1 ) ) compared with placebo ( -0.27 log10 CFU·g−1 ( range -7.96–5.25 log10 CFU·g−1 ) ) ; the counts increased thereafter . In the ciprofloxacin DPI group , 14 ( 35 % ) out of 40 subjects reported pathogen eradication at end of treatment versus four ( 8 % ) out of 49 in the placebo group ( p=0.001 ) . No abnormal safety results were reported and rates of bronchospasm were low . Ciprofloxacin DPI 32.5 mg twice daily for 28 days was well tolerated and achieved significant reductions in total bacterial load compared with placebo in subjects with non-cystic fibrosis bronchiectasis Rationale Despite the potentially important roles for infection in adult non-cystic fibrosis ( CF ) bronchiectasis disease progression , the bacterial species present in the lower airways of these patients is poorly characterised . Objectives To provide a comprehensive cross-sectional analysis of bacterial content of lower airway sample s from patients with non-CF bronchiectasis using culture-independent microbiology . Methods Paired induced sputum and bronchoalveolar lavage sample s , obtained from 41 adult patients with non-CF bronchiectasis , were analysed by 16S ribosomal RNA gene pyrosequencing . Assessment of species distribution and dispersal allowed ‘ core ’ and ‘ satellite ’ bacterial population s to be defined for this patient group . Microbiota characteristics correlated with clinical markers of disease . Measurement and main results 140 bacterial species were identified , including those associated with respiratory tract infections and opportunistic infections more generally . A group of core species , consisting of species detected frequently and in high abundance , was defined . Core species included those currently associated with infection in bronchiectasis , such as Pseudomonas aeruginosa , Haemophilus influenzae and Streptococcus pneumoniae , and many species that would be unlikely to be reported through st and ard diagnostic surveillance . These included members of the genera Veillonella , Prevotella and Neisseria . The comparative contribution of core and satellite groups suggested a low level of r and om species acquisition . Bacterial diversity was significantly positively correlated with forced expiratory volume in 1 s ( FEV1 ) and bacterial community composition similarity correlated significantly with FEV1 , neutrophil count and Leicester cough score . Conclusions Characteristics of the lower airways microbiota of adult patients with non-CF bronchiectasis correlate significantly with clinical markers of disease severity Patients with bronchiectasis suffer from sputum production , recurrent exacerbations , and progressive airway destruction .  Erythromycin is effective in diffuse panbronchiolitis , another suppurative airway disorder , although its efficacy is unknown in idiopathic bronchiectasis . A double-blind placebo-controlled study was therefore conducted to evaluate the effects of 8-week administration of low dose erythromycin ( 500 mg b.i.d . ) in steady-state idiopathic bronchiectasis . Patients in the erythromycin group ( n=11 , 8 female , mean age 50+/-15 yrs ) , but not the  placebo group ( n=10 , 8 female , mean age 59+/-16 yrs ) had significantly improved forced expiratory volume in one second , forced vital capacity and 24-h sputum volume after 8 weeks ( p<0.05 ) . There was no parallel improvement in sputum pathogens , leukocytes , interleukin (IL)-1alpha and IL-8 , tumour necrosis factor-alpha , or leukotriene B4 . The results of this pilot study show that low-dose erythromycin improves lung function and sputum volume in bronchiectasis . Further studies are indicated to evaluate the efficacy of long-term erythromycin therapy in bronchiectasis There is minimal published longitudinal data about pathogenic microorganisms in adults with bronchiectasis . Therefore a study was undertaken to assess the microbiologic profile over time in bronchiectasis . A prospect i ve study of clinical and microbiologic outcomes was performed . Subjects were assessed by a respiratory physician  and sputum sample were collected for analysis . Subjects were followed up and had repeat assessment performed . Eighty-nine subjects were followed up for a period of 5.7+/-3.6 years . On initial assessment the two most common pathogens isolated were Haemophilus influenzae ( 47 % ) and Pseudomonas aeruginosa ( 12 % ) whilst 21 % had no pathogens isolated . On follow-up review results were similar ( 40 % H. influenzae , 18 % P. aeruginosa and 26 % no pathogens ) . The prevalence of antibiotic resistance of isolates increased from 13 % to 30 % . Analysis of a series of H. influenzae isolates showed they were nearly all nontypeable and all were different subtypes . Subjects with no pathogens isolated from their sputum had the mildest disease , while subjects with P. aeruginosa had the most severe bronchiectasis . Many subjects with bronchiectasis are colonized with the same bacterium over an average 
    Output:
    
Conclusions : H. influenzae accounted for the highest percentage in different methodology .