(362f) Metabolic Modeling of Interactions Between Pseudomonas aeruginosa and Staphylococcus aureus in Cystic Fibrosis Biofilm Infections
In this study, we developed a multispecies biofilm metabolic model to further investigate the hypothesis that P. aeruginosa can exert its influence on S. aureus at a distance via secreted factors. Simulations were performed by supplying glucose, amino acids and oxygen at the top of the biofilm to mimic the in vivo CF environment. P. aeruginosa was forced to secrete HQNO, which diffused through the biofilm and inhibited S. aureus ETC through cytochrome b. Lactate synthesized by S. aureus was modeled to be the preferred carbon source for P. aeruginosa, as has been shown experimentally. The multispecies biofilm model was shown to reproduce experimentally observed behavior, including dominance of P. aeruginosa, upregulation of S. aureus fermentative metabolism and enhanced P. aeruginosa growth due to lactate cross feeding. These results represent the first step towards integrating laboratory experiments with clinically isolated bacterial strains and in silico modeling of biofilm metabolism to unravel the enhanced pathogenicity of this CF coinfection.