Direct Evaluation of Pseudomonas aeruginosa Biofilm Mediators in a Chronic Infection Model

Biofilms contribute to persistence in a variety of diseases, including cystic fibrosis, burn wounds, and chronic suppurative otitis media. However, few studies have directly addressed biofilms . We used a chinchilla model of otitis media, which has previously been used to study persistent and infections, to show that structures formed are biofilms of bacterial and host origin within a matrix that includes Psl, a biofilm polysaccharide. We evaluated three biofilm and/or virulence mediators of known to affect biofilm formation and pathogenesis —bis-(3′,5′)-cyclic dimeric GMP (c-di-GMP), flagella, and quorum sensing—in a chinchilla model. We show that c-di-GMP overproduction has a positive impact on bacterial persistence, while quorum sensing increases virulence. We found no difference in persistence attributed to flagella. We conclude from these studies that a chinchilla otitis media model provides a means to evaluate pathogenic mediators of and that phenotypes should be examined in multiple infection systems to fully understand their role in disease.

Duke Scholars

Author Kristin E.D. Weimer Pediatrics, Neonatology