The transition of bacterial infections from acute to chronic infections often involves the development of bacterial biofilm communities. Pseudomonas aeruginosa is a biofilm-producing, opportunistic pathogen critical to the pathogenesis of nosocomial infections like ventilator-associated pneumonia, as well as chronic lung diseases such as chronic obstructive pulmonary disease, bronchiectasis, and cystic fibrosis (CF). Little is known about the mechanism by which P. aeruginosa establishes biofilms in the host, but it has been reported that CF patients show a reduced ability to clear P. aeruginosa acquired during respiratory viral infections and 85 percent of new pseudomonal colonization in CF patients followed a respiratory viral infection within three weeks. Bomberger and colleagues hypothesized that virus co-infection promotes biofilm growth by P. aeruginosa. Using a novel live-cell imaging model, Bomberger demonstrated a dramatic increase in P. aeruginosa biofilm growth on airway cells in the presence of a viral co-infection.
Bomberger’s research provides evidence that respiratory viral infections can enhance the development of P. aeruginosa biofilms and provides a potential mechanism for the acquisition of chronic P. aeruginosa colonization associated with viral infections in CF patients. While it has been well-documented that viral infections are often accompanied by a secondary bacterial infection, this is the first study linking viral co-infection, and the immune response to that viral infection, to the establishment of chronic bacterial colonization.