Summary: Pseudomonas aeruginosa is recognised by the WHO as being a priority pathogen. It has acquired this dubious accolade as a consequence of its ubiquity in the built environment, its remarkable ability to rapidly degrade soft tissue, and the recalcitrance of many infections to be resolved using antibiotics. However, the organism rarely lives in “splendid isolation” and often shares the infection environment with a variety of other interlopers. In this talk – a series of vignettes – we examine how these co-habiting microbes influence the response to antibiotics, and how diversity within the local P. aeruginosa population affects this response. We’ll also take a look at how some unusual (but, nonetheless, very common) mutations affect the response of P. aeruginosa to antibiotic challenge, and examine the role of the biofilm matrix from a new angle.