Transposon Tn1403 from a clinical Pseudomonas strain is composed of three transposons, including Tn5393c. A related transposon Tn1404* from a plant-associated Pseudomonas strain lacks Tn5393 but includes a transposon carrying the tet(C) tetracycline resistance determinant. These compound transposons illustrate the role of preexisting transposons in generating clusters of antibiotic resistance genes.
