Maximum-likelihood phylogenetic reconstruction for 63 P. aeruginosa LES isolates. All were isolated from CF patient sputa: 40 were isolated from a single sample obtained at a clinic in Liverpool, UK in 2009 (ERR953477–ERR953516) and 22 were isolated from a single sample obtained at a clinic in Nottingham, UK in approximately 2014 (ERR453458–ERR453479). The remaining outgroup isolate, LESB58, was isolated in 1988 in Liverpool, UK. The coloured circles indicate branches that imported DNA by homologous recombination as inferred by ClonalFrameML. The positions in the key correspond to the LESB58 genome sequence.