<p>(<b>A</b>) <b>Sensitivity analysis using the bacterial genomic DNA.</b> The detection limit was determined as 10 pg of bacterial DNA for <i>E. coli</i> serotypes O2 and O18 strains, and 500 pg of bacterial DNA for <i>E. coli</i> serotypes O1 and O78 strains, respectively. (<b>B</b>) <b>Sensitivity analysis using the bacterial culture.</b> The detection limit was determined as 10 CFUs of <i>E. coli</i> serotypes O2 and O18 strains, and 1,000 CFUs of <i>E. coli</i> serotypes O1 and O78 strains, respectively. Lane M: DL2000 Marker.</p