CP inhibits Fe uptake by P. aeruginosa, A. baumannii, and S. aureus, and various Fe starvation responses have been observed in each organism. For P. aeruginosa, a decrease in intracellular Fe levels has been observed as well as the upregulation of siderophore production and the downregulation of phenazine production. The downregulation of PrrF signaling in the form of repression of antR was also observed. For A. baumannii a decrease in cellular Fe and bacterioferritins accompanied by the upregulation of genes involved in siderophore production and utilization were observed. For S. aureus, lower cellular Fe levels, the upregulation of siderophore production, and the upregulation of genes involved in siderophore biosynthesis, siderophore transport, and heme uptake were observed.