CAD and abscess: Mechanistic analyses revealed that the peptide interferes with CPS biosynthesis and alters the structure and expression of type 1 fimbriae (<i>fimA</i>) and type 3 fimbriae (<i>mrkA</i>, <i>mrkD</i>, <i>mrkH</i>), which are associated with reduced bacterial tissue invasion and attenuated virulence in a murine abscess model.