Infection and inflammation in non-cystic fibrosis bronchiectasis

This thesis comprises three studies. The first investigates non-cystic fibrosis ( non-CF) bronchiectasis patients in a stable stage of their disease. The relationship between bacteria found on sputum culture and systemic and airway inflammatory mediators has been characterised here. It has been shown that, even in a clinically stable state, the airways of this heterogeneous group of patients have multiple different species of bacteria growing therein which elicit a low grade inflammation in the airways but little systemic response. The second looks at non-CF bronchiectasis patients and the relationship between bacteria and inflammatory markers during and after antibiotic treatment for an infective exacerbation. Results show that the bacterial load within the sputum does not change significantly following ng antibiotic therapy. The composition of the microbiome alters with a primary pathogen suppressed but total viable count remains similar with commensals increasing in number. Inflammation is transiently decreased, returning to pre-treatment levels b) 4 weeks after stopping antibiotics. The third study is a pilot study to investigate the pulsed-field gel electrophoresis genotype profiles of Pseudomonas aeruginosa isolates from the sputum of non-CF bronchiectasis patients. The results suggest that there is a clonal strain of Pseudomonas aeruginosa present in the sputum of the bronchiectasis population in Northern Ireland. Continued typing of the clinical population would be required to determine whether the strains are transmitted between patients.EThOS - Electronic Theses Online ServiceGBUnited Kingdo