Agarose gel electrophoresis of multiplex PCRs with DNAs containing several virulence genes (+) and DNAs without the genes (−). The genes and PCR primers in each lane, from left to right, were VT1, VT2, VT2e, and eaeA in the 1st lane; VT1, VT2, VT2e, eaeA, CNF2, and Einv in the 2nd and 3rd lanes; VT1, VT2, VT2e, eaeA, CNF1, and Eagg in the 4th and 5th lanes; VT1, VT2, VT2e, eaeA, LTI, and STI in the 6th and 7th lanes; VT1, VT2, VT2e, eaeA, CNF2, Einv, LTI, and STI in the 8th and 9th lanes; and VT1, VT2, VT2e, eaeA, CNF1, Eagg, LTI, and STI in the 10th and 11th lanes. Lane S, DNA standards.