Biofilm formation is a developmental process that involves the transition between planktonic (free-swimming) and surface-attached bacteria. This transition occurs in response to a variety of environmental cues including the nutritional status of the environment. A model for biofilm formation in Pseudomonas aeruginosa, an opportunistic pathogen, is shown below.

One goal of the lab is to dissect the developmental events leading up to the formation of the biofilm. We have used a simple genetic method to look for mutants unable to make a biofilm. Several years ago we showed that flagella, type IV pili, and the global carbon regulator Crc are required for P. aeruginosa biofilm development. Recently, we described the sadB locus and its role in the early development of biofilms and the sadARS locus and its role in the regulation of biofilm maturation and acute infection. We have also shown that rhamnolipid surfactants play a role in maintaining biofilm architecture. In addition to studying biofilm development in the lab, we are exploring the role of these functions in pathogenesis using a variety of model organisms.

Our recent studies have shown that biofilm formation is inversely regulated with swarming motility, indicating that Pseudomonas coordinates its group behaviors.