Schematic illustration of the different genomic loci of subAB . A) plasmid locus of subAB1 of E. coli O113:H21 strain 98NK2 (GenBank Acc. No. AY258503) with three putative genes located upstream of the subAB operon and primer binding sites 202 bp upstream and 194 bp downstream of the operon. B) genomic locus of subAB
of E. coli O78:H- strain ED32 (Acc. No. JQ994271) with the tia gene of the SE-PAI located 789 bp upstream of the operon and primer binding sites 1336 bp upstream and 316 bp downstream of the operon. C) locus of the new (subAB
) operon of E. coli O76:H- strain 1.2264 (Acc. No. AEZO02000020.1) with an outer membrane efflux protein as part of a type 1 secretion system located 1496 bp upstream of the subAB operon and primer binding sites 1235 bp upstream and 65 bp downstream of the operon. Primers subA-L and subAB2-3′out (Table 1) were used to generate a template for sequencing.