(Difco, Detroit, MI, USA) is sufficient to relieve PCR inhibition (not shown) suggests that DPCR would provide a rapid means to confirm the presence of STEC in enrichment cultures. With optimized primer design and PCR condi- tions, DPCR could be used to detect other virulence genes of E. coli O157:H7 and distinguish E. coli O157:H7 from other STEC.