FIGURE 2.

Multiplex PCR to analyze a 294-member library of UPEC and fecal/commensal isolates for the presence of papX, focX, and nonspecific 17-kDa family genes. A, three primer sets were designed to amplify a 607-bp fragment of papX and flanking region, a 449-bp fragment of focX and flanking region, and a 249-bp region common to all papX homologs. All primer sets shared a common reverse primer (supplemental Table 2, papXMltplxRev) with a unique forward primer (supplemental Table 2, papXMltPlxfwd, focXMltPlxfwd, and XMltPlxfwd). papX and focX contain nearly identical nucleotide sequence, so unique primers for each originated in the sequence flanking each gene. Fragments were sequenced to confirm their composition. Each fragment was generated from extracted, pooled CFT073 WT genomic DNA and separated on 2% agarose gel. The prevalence of papX (B) and focX (C) within the library was scored by the appearance of their respective amplicon during multiplex PCR within each strain type. The percentage of papX-containing (D) or focX-containing (E) strains within papG- or focH-containing strains, respectively, is shown.