Population biology of Pseudomonas aeruginosa in chronic CF and COPD airway infections

To analyse the population structure of Pseudomonas aeruginosa, more than 1400 independent isolates from diverse environmental and clinical habitats and geographic origins were investigated by SNP- typing of core genome and markers of the accessory genome. More than 50% of all isolates belonged to less than 25 dominant clones widespread in disease and environmental habitats. Moreover, most clones group in only a few clonal complexes. These complexes seem to be phylogenetically ancient and related to specific sets of genomic islands, e.g. exoU islands. This implies that recombinations between strains of different…