P052 Late impact of early chronic methicillin-sensitive Staphylococcus aureus (MSSA) infection in children with cystic fibrosis F. Galode, M. Fayon, S. Bui. CHU de Bordeaux Hôpital Pellegrin-Enfants, CRCM Pédiatrique, Centre d’Investigation Clinique (CIC 1401), Bordeaux, France Objectives: To determine if early chronic MSSA infection is correlated with poorer prognosis at the age of six years. Methods: We conducted a retrospective study in pediatric cystic fibrosis patient screened in Bordeaux CF center between 2002 and 2011, to evaluate the impact of early chronic MSSA infection at the age of one year (Y1). The primary endpoint was the severity of bronchiectasis on CT-scan at the age of six years (Y6). Other end-points included clinical status (clubbing, crackles, nutritional status), lung function tests, and serum IgG. Results: Forty patients were included. Ten patients had early chronic MSSA infection at Y1 and in 30 patients MSSA infection occurred at a later date. Early chronic Y1 MSSA infection had no impact on any clinical symptom or sign, or nutritional status, at any age. In contrast, early chronic Y1 MSSA infection (vs. after Y1) had a significant negative impact on Y6 CT-scan bronchiectasis severity (4.7 ± 0.8 vs 2.3 ± 0.4, p < 0.05) and Bhalla score (7.3 ± 1.1 vs 4.2 ± 0.6, p < 0.05). Y6 lung function was no significantly worsened by early chronic Y1 MSSA infection (FEV1: 83.7 ± 6 vs 92.8 ± 3.4, p = 0.26; FEF25-75: 67.8 ± 8.9 vs 78.2 ± 5.1, p = 0.21). Finally, the Y6 serum IgG, a marker of chronic inflammation was significantly elevated in the early chronic Y1 MSSA infection group vs. later MSSA infection group (11.3 ± 0.7 vs 8.7 ± 0.4, p < 0.05). Conclusion: Early chronic Y1 MSSA in pediatric patients with cystic fibrosis is associated with more severe lung disease at six years. From the time of screening, prophylactic and/or curative anti-Staphylococcal antibiotic treatment should be discussed. P053 Use of extended-quantitative culture does not predict an imminent pulmonary exacerbation L. Sherrard 1 , G. Einarsson 1 , E. Johnston 1 , K. O’neill 1 , L. Mcilreavey 1 , S. Mcgrath 1 , D. Gilpin 1 , M. Murray 2 , G. Lavelle 2 , G. Mcelvaney 2 , R. Boucher 3 , M. Muchlebach 3 , J.S. Elborn 1,4 , M. Tunney 1 . 1 Queen’s University Belfast, Belfast, United Kingdom; 2 Royal College of Surgeons in Ireland, Dublin, Ireland; 3 University of North Carolina, Chapel Hill, United States; 4 Imperial College and Royal Brompton Hospital and Harefield NHS Foundation Trust, London, United Kingdom Objectives: To determine if extended-quantitative culture, clinical or inflammatory markers could be used to predict an imminent PEx. Methods: Consecutive sputa (n = ≥2) were collected from 56 CF patients. Extended-quantitative bacterial culture was performed under aerobic, microaerophilic and anaerobic atmospheric conditions and total viable counts [TVCs] and ecological indexes were calculated. Patient metadata was recorded. Patients were stratified into groups: (1) those who remained clinically stable for >4 months (n = 37) and (2) those who experienced a PEx (n= 19) within 4 months of baseline. Logistic regression was performed to identify factors associated with a PEx. Results: Neither TVCs nor ecological indexes (e.g. community diversity) were independent predictors of an imminent PEx. However, in a univariable logistic regression, higher lung function (OR, 0.95; 95%CI, 0.91–0.98; P = 0.002) and BMI (OR, 0.80; 95%CI, 0.66–0.98; P = 0.03) at baseline were significantly associated with a reduced risk of a PEx. Higher CRP (OR, 6.3; 95%CI, 1.38–28.91; P = 0.02) and chronic azithromycin (OR, 3.96; 95%CI, 1.10–14.2; P = 0.04) at baseline were significantly associated with an elevated risk. Being female was associated with an elevated risk (OR, 3.0; 95%CI, 0.94–9.54; P = 0.06) and a higher CFQ-R respiratory symptom score at baseline was associated with a lower risk (OR, 0.96; 95% CI, 0.93–1.01; P = 0.09). The results of the multivariable logistic regression are shown in the Table. Conclusion: Baseline clinical parameters were better PEx predictors than sputum cultures, even when detailed microbiota were cultured and quantified. Funding: HSC R&D, Public Health Agency (Northern Ireland), the MRC and the US NIH (HL092964, HL084934, 5R01 HL092964-04) through a US-Ireland Partnership Grant. Table. Multivariable logistic regression Multivariable model Odds ratio (95% CI) P-value FEV1% predicted (per % predicted increase) 0.72 (0.55–0.95) 0.02 BMI (per kg/m 2 increase) 0.19 (0.04–0.89) 0.04 Respiratory symptoms (CFQ- R, per point increase) 0.82 (0.68–1.00) 0.05 P054 Human reservoirs of pathogens colonising the airways of cystic fibrosis patients A. Sandri 1 , C. Cazzarolli 2 , G. Burlacchini 1 , P. Melotti 2 , S. Volpi 2 , C. D’orazio 2 , M.M. Lleò 1 , C. Signoretto 1 . 1 University of Verona, Diagnostics and Public Health, Verona, Italy; 2 Azienda Ospedaliera Universitaria Integrata di Verona, Cystic Fibrosis Center, Verona, Italy Background: Recent findings indicate that the sinuses act as a bacterial reservoir for transmitting pathogens to the lower airways. Thus, control of upper airways infections might allow early therapeutic regimens, prevent the establishment of chronic infection and improve pulmonary outcomes. Objectives: This study aims to elucidate the role of sinonasal and oral sites in the outcome of lung disease by evaluating the presence of CF pathogens in the different airway sites. Here, we present results regarding sinonasal infections, while investigation on oral microflora is still ongoing. Methods: Sputum and nasal lavage were collected from 60 patients followed at the Cystic Fibrosis Center of Verona, Italy. Pseudomonas aeruginosa, Staphylococcus aureus, Stenotrophomonas maltophilia and Achromobacter xylosoxidans were identified and collected. Results: At least one of the investigated pathogens was isolated from both sputum and nasal lavage in 57% of patients and from only nasal lavage in 10% of patients. Considering patients with occasional or no infection by P. aeruginosa (n = 50), in 44% of cases the same species was present in both samples and in 12% only in nasal lavage. In all patients chronically infected by P. aeruginosa (n = 9) the pathogen was isolated from both upper and lower airways, while in occasionally-infected patients (n= 10) the number drops to 17%. During the screening, we identified 3 children at their first infection with P. aeruginosa; none of them was infected in both sites. Conclusions: The high percentage of patients carrying the same pathogens in upper and lower airways, especially in presence of chronic P. aeruginosa infection, support the transmission of microorganisms within the respiratory system. Follow-up of patients with sinonasal and/or early- stage lung infections, as well as with oral infections, will possibly further elucidate this scenario. This study is supported by the Italian Cystic Fibrosis Research Foundation (project #22/2016). P055 A cross-sectional analysis of cough swabs from non-expectorating CF patients and healthy control participants G.G. Einarsson 1 , L.J. Sherrard 1 , E. Johnston 1 , K. O’neill 1 , L. MCllreavey 1 , S.J. MCGrath 1 , D.F. Gilpin 1 , M. Murray 2 , G. Lavelle 2 , G. MCElvaney 2 , M. Muhlebach 3 , J.S. Elborn 1 , M.M. Tunney 1 . 1 Queen’s University Belfast, Belfast, United Kingdom; 2 Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland; 3 University of North Carolina, Chapel Hill, United States Objectives: To determine and compare microbial community structures using cough swabs collected from non-expectorating CF patients and healthy control (HC) participants. Methods: Cough swabs were collected during outpatient appointments at the adult and paediatric CF Centres of the Belfast Health and Social Care Trust (Belfast City Hospital and Royal Belfast Hospital for Sick Children). Healthy, age matched, control (HC) subjects were invited to attend a single study visit by means of e-mail circulation among work colleagues at Queen’s University Belfast and Belfast Health and Social Care Trust. Extended qualitative microbial culture (absence/presence) was performed Poster Sessions / Journal of Cystic Fibrosis 17S3 (2018) S59–S138 S74