Table 3.
Effects of efflux pump inhibitors on susceptibility of FQs and tigecycline
| Isolate | MIC (μg/ml)a |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CIP | CIP-NMP | CIP-PAβN | GAT | GAT-NMP | GAT-PAβN | LVX | LVX-NMP | LVX-PAβN | TIG | TIG-NMP | TIG-PAβN | |
| CCF-34A | >256 | 128 (>2×) | 64 (>4×) | 16 | 16 | 8 (2×) | 32 | 16 (2×) | 8 (4×) | |||
| CCF-40A | >256 | 128 (>2×) | 64 (>4×) | 256 | 16 (16×) | 8 (32×) | 32 | 16 (2×) | 8 (4×) | |||
| CCF-43A | 128 | 32 (4×) | 32 (4×) | 16 | 8 (2×) | 8 (2×) | 16 | 4 (4×) | 4 (4×) | |||
| CCF-45A | 256 | 128 (2×) | 64 (4×) | 16 | 16 | 16 | 16 | 16 | 8 (2×) | |||
| CCF-46A | 128 | 64 (2×) | 64 (2×) | 16 | 8 (2×) | 4 (4×) | 16 | 8 (2×) | 8 (2×) | |||
| CCF-55A | 64 | 4 (16×) | 8 (8×) | 32 | 2 (16×) | 2 (16×) | 64 | 4 (16×) | 2 (32×) | |||
| CCF-56A | >256 | 64 (>4×) | 64 (>4×) | >256 | 16 (>16×) | 8 (>32×) | >256 | 16 (>16×) | 8 (>32×) | 8 | 4 (2×) | 4 (2×) |
| CCF-63A | >256 | 64 (>4×) | 64 (>4×) | 128 | 16 (8×) | 16 (8×) | 64 | 16 (4×) | 8 (8×) | 8 | 4 (2×) | 4 (2×) |
| CCF-104A | 128 | 16 (8×) | 32 (4×) | 16 | 4 (4×) | 8 (2×) | 8 | 4 (2×) | 8 | |||
| CCF-8C | >256 | 128 (>2×) | 128 (>2×) | 128 | 32 (4×) | 16 (8×) | 128 | 32 (4×) | 16 (8×) | 16 | 8 (2×) | 4 (4×) |
| CCF-9C | >256 | 128 (>2×) | 128 (>2×) | 128 | 32 (4×) | 16 (8×) | 128 | 32 (4×) | 16 (8×) | 16 | 8 (2×) | 8 (2×) |
| CCF-54C | >256 | 256 | 128 (>2×) | 256 | 64 (4×) | 16 (16×) | 128 | 64 (2×) | 16 (8×) | 16 | 16 | 8 (2×) |
| CCF-59M | 128 | 128 | 64 (2×) | 32 | 16 (2×) | 8 (4×) | 32 | 16 (2×) | 8 (4×) | |||
| CCF-70M | 256 | 64 (4×) | 32 (8×) | >256 | 16 (>16×) | 8 (>32×) | >256 | 16 (>16×) | 4 (>64×) | |||
| CCF-93M | 128 | 64 (2×) | 64 (2×) | 8 | 8 | 8 | 16 | 16 | 8 (2×) | |||
| CCF-108M | >256 | 64 (>4×) | 128 (>2×) | 16 | 8 (2×) | 16 | 16 | 8 (2×) | 8 (2×) | |||
a
Values in parentheses are reductions (n-fold) in the MIC after the addition of the indicated efflux pump inhibitors. Antibiotic abbreviations: CIP, ciprofloxacin; GAT, gatifloxacin; TIG, tigecycline; LVX, levofloxacin; NMP, 1-(1-naphthylmethyl)-piperazine; PAβN, phe-arg-β-naphthylamide dihydrochloride.