Table 5.
Interplay of mechanisms of resistance to several antibiotics of the strains of clones PFGE-ROC-1 and PFGE-HUI-1 under study
| Antibiotic(s) | Mechanism of resistance |
||
|---|---|---|---|
| PFGE-ROC-1OXA-58 | PFGE-ROC-1OXA-24 | PFGE-HUI-1 | |
| Tigecycline | Overexpression of AdeIJK | Overexpression of AdeABC | New RND efflux system/TetA(39) efflux pumpc |
| Gentamicin | Overexpression of AdeABC/acetylases (aacC1, aphA1, aadB) | Overexpression of AdeABC/acetylases (aacC1, aphA1, aadB) | Acetylases (aacC1, aphA1, aadB) |
| Minocycline | Overexpression of AdeIJK/TetB efflux pumps | Overexpression of AdeABCb | |
| Netilmicin, tobramycin, and amikacin | Acetylases (aacC1, aphA1, aadB) | Acetylases (aacC1, aphA1, aadB) | Acetylases (aacC1, aphA1, aadB) |
| Imipenem, meropenem, and doripenem | OXA-58 β-lactamase | OXA-24 β-lactamase | |
| Ciprofloxacin | Mutations in gyrA and parC | Mutations in gyrA and parC | Mutations in gyrA and parC |
| Doxycycline | Overexpression of AdeIJKa/TetB efflux pumps | TetB efflux pump | TetA(39) efflux pumpc |
| Tetracyclines | TetB efflux pump | TetB efflux pump | TetA(39) efflux pumpc |
a
Nonsignificantly increased expression relative to strains with doxycycline resistance.
b
Only three isolates, 61, 74, and 75.
c
Except for strains 421, 422, 423, 424, and 426.