Positive Signature-Tagged Mutagenesis in Pseudomonas aeruginosa: Tracking Patho-Adaptive Mutations Promoting Airways Chronic Infection

• DOI: 10.1371/journal.ppat.1001270
• Publication Date: 2011-02-03T21:37:45Z
• Authors: Irene Bianconi; Andrea Milani; Cristina Cigana; Moira Paroni; Roger C. Levesque; Giovanni Bertoni; Alessandra Bragonzi
• Keywords: Pyocyanin; Chronic infection

The opportunistic pathogen Pseudomonas aeruginosa can establish life-long chronic infections in the airways of cystic fibrosis (CF) patients. Persistent lifestyle is established with P. patho-adaptive variants, which are clonal initially-acquired strains. Several reports indicated that adapts by loss-of-function mutations enhance fitness CF and sustain its expansion during infection. To validate this model adaptation to identify novel genes involved microevolution, we designed a approach positive-selection screening PCR-based signature-tagged mutagenesis (Pos-STM) murine A systematic scheme using sequential rounds vivo screenings for bacterial maintenance, as opposed elimination, generated list whose inactivation increased colonization persistence phenotypes associated these Pos-STM reflect alterations diverse aspects biology include lack swimming twitching motility, production virulence factors such pyocyanin, biofilm formation, metabolic functions. In addition, mutants showed altered invasion stimulation immune response when tested human respiratory epithelial cells, indicating prone revise interaction host persistent lifestyle. Finally, sequence analysis longitudinally isolates from patients identified signs within genome. This functions have important clinical implications disease progression airway