KRCC1 and pyelonephritis: Three main virulence determinants of UPEC isolates are involved in biofilm formation: type 1 fimbriae (fim), coded by the fim gene cluster: the P-fimbriae (pap), coded by the pap (pyelonephritis-associated pili) gene; and α-hemolysin (hly), a member of the RTX toxin family on the basis of a common nonapeptide repeat in the C-terminal part of the protein, that were investigated in the present study [16], [17].