Stenotrophomonas maltophilia and achromobacter xylosoxidans in cystic fibrosis patients

Introduction: In recent years there has been an increasing number of recognized emerging pathogens like Stenotrophomonas maltophilia (SM) and Achromobacter xylosoxidans (AX) but their effect in CF lung disease is yet unknown. Aims: 1) to assess the prevalence of SM and AX and 2) to compare the lung function, clinical symptoms at first isolation, CT scan and colonization with Pseudomonas aeruginosa (PA) between the two groups. Methods: Retrospective cohort study using the CF Database of the CF Center of Catalonia (Spain). Data were collected at first isolation and after one year. Results: 130 patients were included in this study, 44 of whom (33,8%) had a positive culture to SM and 11 (8.4%) to AX at some time. Mean age at acquisition of SM was 6±4.6 years and of AX was 6.5±3 years. In the SM group 36% of patients were under 4 years in comparison with 9% in the AX group. No significant difference in symptoms at acquisition (56% and 63% respectively), FEV1 (75% and 84%), bronchiectasis (47% and 36%) and PA colonization (79% and 91%) were found between the SM and AX groups. After specific ATB therapy, chronic colonization was higher in AX (36%) in comparison with the SM group (9%). Conclusions: The prevalence of SM colonisation was higher than AX. Patients colonized with SM were younger but chronic infection was more associated with AX.