Spread of a multiresistant strain of Pseudomonas aeruginosa in an adult cystic fibrosis clinic

We Initiated a prospective surveillance study to investigate possible Pseudomonas aeruginosa cross-infection In our cystic fibrosis centre. We characterised isolates by pyocin typing and pulsed-field gel electrophoresis. 22 (14%) of 154 patients with chronic P aeruginosa had Isolates with similar and new pyocin and pulsed-field gel electrophoresis types. The shared Isolates showed unusual phenotypic features: they were non-pigmented, non-motile, and resistant to a number of antipseudomonal antibiotics. Cross-infection by a multiresistant P aeruginosa strain has therefore occurred In patients attending our cystic fibrosis centre. We recommend microbiological surveillance in other cystic fibrosis centres.