Antimicrobial activity of pyocins against antibiotic resistant small colony variants of Pseudomonas aeruginosa

Colonisation of the lungs of patients with cystic fibrosis by the bacterium Pseudomonas aeruginosa has been shown to be the main cause of mortality associated with this condition. The natural resistance of this pathogen to many commonly-used antibiotics and the acquisition of resistance to others can make P. aeruginosa infections very difficult to treat in some patients and there is an urgent need to develop new therapies. In people with cystic fibrosis P. aeruginosa can grow as a thin film in the lungs and in this state (biofilm) it is virtually impossible to eradicate with conventional antibiotics. Further, prolonged antimicrobial therapy leads to the development of highly resistant forms (known as small-colony variants) of the bacterium. The aim of this project is to test the ability of protein antibiotics (known as pyocins) to kill P. aeruginosa small-colony variants.