TABLE 2.
In vitro potencies of additional oral beta-lactams in combination with QPX7728 at 4 μg/mL against isogenic strains of Klebsiella pneumoniae expressing cloned beta-lactamasesa
| Strain | Beta-lactamase | MIC (μg/mL) |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| Amdinocillin | Amdinocillin + QPX7728 | Cefaclor | Cefaclor + QPX7728 | Cefuroxime | Cefuroxime + QPX7728 | Cephalexin | Cephalexin + QPX7728 | ||
| KPM1116 | None | 0.25 | 0.25 | 0.5 | 0.25 | 2 | 0.5 | 4 | 2 |
| KPM1113 | KPC-2 | 64 | 0.25 | >64 | 0.25 | 64 | 0.5 | 128 | 2 |
| KPM1031 | CTX-M-14 | 0.5 | 0.125 | 256 | 0.125 | >256 | 0.5 | 256 | 2 |
| KPM1114 | CTX-M-15 | 1 | 0.25 | 256 | 0.25 | >256 | 1 | 256 | 2 |
| KPM1115 | SHV-12 | 8 | 0.25 | 256 | 0.25 | 32 | 0.5 | 64 | 2 |
| KPM3258 | SHV-5 | 16 | 0.25 | 128 | 0.25 | 64 | 1 | 64 | 8 |
| KPM1112 | TEM-10 | 64 | 0.25 | 4 | 0.25 | 4 | 1 | 8 | 4 |
| KPM3736 | PER-2 | 64 | 0.25 | 128 | 0.25 | >64 | 1 | 256 | 4 |
| KPM3812 | VEB-2 | 16 | 0.25 | 64 | 0.25 | 64 | 0.5 | 64 | 2 |
| KPM1956 | P99-like AmpC | 0.5 | 0.25 | >256 | 0.5 | 128 | 1 | >256 | 4 |
| KPM1030 | DHA-1 | 0.25 | 0.25 | 64 | 0.25 | 32 | 2 | >64 | 4 |
| KPM1045 | CMY-2 | 8 | 0.25 | 256 | 0.25 | 32 | 1 | 128 | 2 |
| KPM3352 | MIR-1 | 1 | 0.5 | >64 | 0.5 | >64 | 1 | >64 | 4 |
| KPM1939 | OXA-48 | 0.5 | 0.25 | 32 | 0.25 | 4 | 1 | 8 | 2 |
| KPM1932 | NDM-1 | 8 | 0.25 | >256 | 8 (32) | >256 | 32 (64) | >256 | 32 (16) |
| KPM1935 | VIM-1 | >256 | 0.5 | >256 | 0.5 | >256 | 2 (4) | 256 | 4 |
| KPM1996 | IMP-1 | 16 | 0.25 | 128 | 1 (4) | 256 | 2 (4) | 128 | 8 (4) |
a
Bold numbers in parentheses indicate MIC ratios between the beta-lactamase-producing strains and the vector-alone strain that are equal to or higher than 4.