Detection of conversion to mucoidy in Pseudomonas aeruginosa infecting cystic fibrosis patients involving the algu gene

摘要

Compositions and methods for detecting the conversion to mucoidy in Pseudomonas aeruginosa are disclosed. Mucoidy is a critical P. aeruginosa virulence factor in cystic fibrosis that has been associated with biofilm develoment and resistance to phagocytosis. The present invention provides for detecting the switch from nonmucoid to mucoid state as caused by the interaction of the algU gene product, algU, with RNA polymerase. Inactivation of algU results in a loss of expression of genes, such as algD, dependent on algU for transcription. Also disclosed is a novel alginate biosynthesis heterologous expression system for use in screening candidate substances that inhibit conversion to mucoidy by inhibiting the interaction of algU with the RNA polymerase holoenzyme.