Fig. 1

Schematic presentation of conjugation and mobilization. Conjugation refers to transfer of a conjugative plasmid from donor to recipient (a), whereas mobilization refers to mobilization of a mobilizable plasmid from donor to recipient mediated by the helper function of a co-resident conjugative plasmid (b). Large light circle, conjugative plasmid; small bold circle, mobilizable plasmid; light rounded rectangle, donor cell; and bold rounded rectangle, recipient cell