Research Article

Self-Conjugation of the Enteropathogenic Escherichia coli Adherence Factor Plasmid of Four Typical EPEC Isolates

Figure 1

Schematic and plasmid profile representation of the first- and second-generation conjugation experiments. (a) A donor (D) tEPEC/pEAF::km strain was challenged for conjugation with recipient (R1) and aEPEC or E. coli DH5α (Table 1). Subsequently, the pEAF::km plasmid from a transconjugant colony (Tc1) was purified and transformed by electroporation into E. coli DH5α. The transformant (TfD) DH5α/pEAF::km was used as donor for conjugation with recipient strain DH5αRN (R2), from which transconjugant colonies (Tc2) were derived. (b) Plasmid preparations of donor (D) strain D0131/pD0131::km (1), recipient (R1) strain D3264RN (2), transconjugant (Tc1) strain D3264RN/pD0131::km, obtained from the first-generation conjugation (3), transformant (TfD) DH5α harboring the transconjugant pD0131::km, used as donor in the second-generation conjugation experiment (4), and transconjugant strain D3264RN harboring the pD0131::km (Tc2), obtained in the second-generation conjugation experiment (5).