TABLE 3

PCR hybridization and real-time PCR of IncF, IncI1, and IncI2 plasmids and intI1 and tet(A) from TC-DNA extracted from produce before and after enrichmenta

ProduceDNA isolationTime point
(day)
IncF IncI1 IncI2 intI1tet(A)
RT-PCRBlotRT-PCRBlotRT-PCRBlotRT-PCRBlotRT-PCRBlot
Mixed saladDirect extraction0++++(+++)(++)1
7++++(+++)(+++)2
Enrichment0+(+++)+(++)+++++(+++)+(++)2
7+(+++)+(++)+++++(+++)++++
ArugulaDirect extraction0(++)3+(++)(+++)2
7(++)1+(++)(+++)1
Enrichment0+(+++)+++++(++)++++
7+(+++)+++++(++)++++
CilantroDirect extraction0(+)1(++)(+)1(+++)3
7(+)1(++)2(+)3(+++)(+)2(+++)3
Enrichment0(+)2(+++)2(+)1(++)2(+)3(+++)(+)2(+++)3
7(+)2(+++)2(+)2(++)2(+)3(+++)3(+)3(+++)3
  • a Superscript numbers indicate number of positive replicates; −, not detected or no signal; (+), positive (RT-PCR); (++), medium signal; (+++), strong signal.