Better treatment options through a better understanding of Pseudomonas aeruginosa biofilm formation and biofilm-mediated resistance

Bacteria living in biofilms tolerate much higher antibiotic concentrations compared to planktonic bacteria and can cause chronic infections. Among the most difficult pathogens to treat, Pseudomonas aeruginosa is responsible for many biofilm-related infections and for much of the mortality associated with airway infections in cystic fibrosis. We speculated that there are specific genes responsible for increased antibiotic resistance in biofilms and aimed to identify them in P. aeruginosa. By doing so, a better understanding of biofilm-mediated resistance can be achieved and new bacterial targets can be identified. A P. aeruginosa transposon mutant library was screened to assess the impact on biofilm formation and the biofilm resistance toward antibiotics. Briefly, the biofilm resistance was estimated by following the re-growth of biofilm cells exposed to different concentrations of antibiotics. A few candidates, e. g. the response regulator CbrB, involved in nutrient uptake, have been identified as crucial for biofilm formation and resistance towards antibiotics. Further characterization of these interesting genes has been carried out to explore the underlying mechanism of resistance. Such knowledge can lead to the identification of susceptibility of P. aeruginosa biofilm and help to develop tools to treat persistent infections.