3.4.7. Peptide Transport

A single mutation in peptide antibiotic transport gene *sbmA* was observed on days 24–30 for biofilm population 3, with a 256–1024-fold increase in MIC (Table 4). SbmA is an inner membrane transporter that facilitates the transport of antimicrobial peptides, especially those that are proline-rich, into the cell [39]. It has recently been observed that mutations in *sbmA* confer resistance to certain peptide conjugates [40]. Biofilm KP mutations in *sbmA* occurred following LPS biosynthesis modifications, in accordance with two mutations having roles in fatty-acid biosynthesis (Figure 4).
