53 Non-tuberculous mycobacteria in cystic fibrosis: A single centre study of prevalence, sampling and microbiological outcomes

Abstract

Background The rise in non tuberculous mycobacteria (NTM) from cystic fibrosis patients is of concern. Discerning pathogenicity from colonisation increases difficulty in treatment. Objective The aims of the study were to evaluate the impact of NTM's by calculating prevalence and species distribution. Macrolide use in the context of NTM sampling was analyzed as were microbiological outcomes of patients who received treatment with those not considered for therapy. Methods This was a single centre study of cystic fibrosis patients in Glasgow. Electronic databases and written case notes were used to gain microbiological and clinical information. Data was collected from patients who had at least one NTM screen processed. Results The prevalence of NTMs was 14.9%, the majority species was the Mycobacterium abscessus group (MABSC) followed by Mycobacterium avium complex (MAC). The majority received macrolides prior (58%) and equal figures after first positive culture (50%), predominantly within the MAC group. Despite treatment, microbiological eradication rates (57%) were similar to untreated transient colonisation (61%). Data showed MABSC equally likely to be eradicated or persistent post treatment (50% vs 50%). Conclusion The data showed an increasing prevalence of NTMs with predominance of MABSC. A potential link between macrolide monotherapy and increasing, persisting NTMs is a concern. This requires more research and judicial use of macrolides. The emergence of MABSC highlights that further studies are required regarding subspecies and transmission. These increasing numbers mandate a multidisciplinary approach for management.