Prevalence of iron transport gene on pathogenicity-associated island of uropathogenic Escherichia coli in E-coli O157 : H7 containing Shiga toxin gene

Uropathogenc Escherichia coli (UPEC) CFT073 has a pathogenicity-associated island (PAI(CFT073)), which causes pyelonephritis and cystitis, Using PCR m ethod, we found the prrA gene of PAI(CFT073) in E. coli O157:H7 EDL933. Fur ther detailed PCR screening of 38 open reading frames, the right and left j unction sequences of PAI(CFT073), revealed that it is the prrA-modD-yc73-fe pC gene cluster but not the PAI(CFT073) present in E. coli O157:H7 EDL933, A rapid preliminary analysis suggested that the prrA-modD-yc73-fepC gene cl uster of the PAI(CFT073), is present in 43 strains off. coli O157:H7 contai ning Shiga toxin (Stx) gene but absent in 19 strains of E. coli O157:H7 wit hout Stx gene. A strict co-occurrence of the prrA-modD-yc73-fepC gene clust er and Stx genes was observed, regardless of their origin, The prrA-modD-yc 73-fepC gene cluster encode proteins probably involved in iron uptake syste m, which strongly suggests the importance of iron metabolism in the Stx-med iated virulence, In addition, the prrA-modD-yc73-fepC gene cluster may be u sed as a diagnostic marker to distinguish E. coli O157:H7 strains containin g Stx gene from that without Stx gene, and possibly to quickly detect other pathogenic gram-negative bacteria containing the Stx gene.