TABLE 1.
Plasmids used in this study
| Plasmid | Relevant markersa | Function(s)b | Source or reference |
|---|---|---|---|
| pBP507 | Mob+ Amir | Vector control | 22 |
| pBP517 | Mob+ AmirgyrAs | gyrA+ dominance test | 22 |
| pBP567 | Mob+ AmirparCs | parC+ dominance test | 20 |
| pMAK705 | Clmr Repts | Cloning | 19 |
| pMAK705gyrA3 | Clmr ReptsgyrA(S83L, D87G) | Mutagenesis | This study |
| pMAK705gyrA3.1 | Clmr ReptsgyrA(S83L) | Mutagenesis | This study |
| pMAK705gyrA3.2 | Clmr ReptsgyrA(D87G) | Mutagenesis | This study |
| pMAK705parC4 | Clmr ReptsparC(S80I) | Mutagenesis | This study |
| pBR322 | Ampr Tetr | Template for bla gene cloning, topoisomer distribution | 5 |
| pBR328 | Ampr Tetr | Control for Qsc determination | Boehringer |
| pBP523 | Mob+ Amir Ampr pgyrA-bla | Qsc determination | This study |
| pBP524 | Mob+ Amir Ampr ptopA-bla | Qsc determination | This study |
a
Relevant markers include determinants mediating resistance to amikacin (Amir), ampicillin (Ampr), chloramphenicol (Clmr), and tetracycline (Tetr); sequences required for mobilization transfer (Mob+) and thermosensitive replication (Repts); quinolone resistance mutations in genes gyrA and parC leading to amino acid exchanges of serine-83 to leucine and aspartate-87 to glycine (gyrAS83L and gyrD87G), as well as serine-80 to isoleucine (parCS80I), respectively; and reporter gene fusions of the bla gene coding for TEM-1 β-lactamase to promoters pgyrA and ptopA.
b
Qsc, measure of the relative degree of supercoiling (for a definition, see the text).