TY - JOUR T1 - Serum bactericidal activity in non cystic fibrosis bronchiectasis in patients with <em>pseudomonas aeruginosa</em> colonisation JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - p2540 AU - Deborah Whitters AU - Timothy Wells AU - Robert Stockley Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/p2540.abstract N2 - Background: Pseudomonas aeruginosa (PA) colonisation is commonly encountered and problematic in patients with nonCF bronchiectasis. Inhibitory factors in the serum of patients with CF and chronic PA infection which impair phagocytosis of PA have previously been identified with IgG2 proposed to act as a blocking antibody.We have investigated this concept further in patients with non CF bronchiectasis.Methods: Stable state serum and sputum collected from 11 patients with non CF bronchiectasis colonised with PA. 33 morphological strains of PA identified from this group.Control serum was obtained from healthy individuals for comparison.Stationary phase bacterial cultures were prepared and 10μL innoculum added to 90μL of healthy control and patient serum and incubated at 37°C.At 3 time intervals (45,90,180 mins) the serum/innoculum mixture underwent serial dilution and a miles+misra plate prepared for each strain at every time point at 4 dilutions.This was incubated overnight at 37°C and colonies analysed to observe the serum killing trend.Results: Serum from 2 patients was demonstrated to have blocking activity against 4 strains of PA isolated from these patients.Conclusion: The concept of blocking activity in the serum of patients with non CF bronchiectasis may provide some explanation for the mechanism of establishment of PA colonisation in the airways of some patients and requires further investigation. ER -