**15. Other microbial organisms in cystic fibrosis**

*Aspergillus Fumigatus* (AspF) is a common airway fungus found in the CF lung. Previous treatment was aimed largely at patients meeting criteria for diagnosis of Allergic Broncho‐ pulmonary Aspergillosis (ABPA). More recent evidence, however, suggests that AspF carriage correlates with more severe changes on HRCT [78] and can predict greater rate of FEV1 decline in patients who are a) colonised but not sensitised, b) sensitised but do not meet ABPA diagnostic criteria, and c) those with a diagnosis of ABPA [79]. Suitable studies assessing the value of AspF eradication in patients with CF not meeting ABPA criteria are lacking.

*Stenotrophomonas Maltophilia (*SM*)* and its relevance has been a point of debate for some time. Previously regarded as a bystander in the CF microbiome there is growing belief that it represents a true pathogen with potentially significant impact of mortality [80]. Antibiotic options for the treatment of SM are limited and dedicated studies assessing treatment effec‐ tiveness are lacking [81].

*Candida Species* are highly prevalent in CF airway culture [82]. Difficulty arises in differentiat‐ ing oropharyngeal contamination from bronchial colonisation without bronchoscopic sam‐ pling. Data from 2010 suggests that colonisation with *Candida Albicans* is associated with increased exacerbation rate and significant decline in FEV1 [83]. There is a paucity of data relating to the benefits of treating *Candida Species* routinely in CF.
