Table 1.
TEM-1 mutants and the minimum inhibitory concentrations (MIC) of CTZ and CAZ. Mutants were constructed using site-directed mutagenesis. Bold underlined values represent the peak(s) in each two-locus fitness landscape; landscapes with reciprocal sign epistasis have two peaks. Mutations E104K, M182T, and T265M do not influence the occurrence of sign epistasis on CAZ, but do change the occurrence of reciprocal sign epistasis on CTX
| Mutant | MIC CTX (μg/mL) | MIC CAZ (μg/mL) |
|---|---|---|
| TEM-1 | 0.125 | 1 |
| G238S | 4 | 2 |
| G238S + R164S | 0.25 | 8 |
| R164S | 1 | 32 |
| TEM-1 | 0.125 | 1 |
| G238S + E104K | 64 | 64 |
| G238S + R164S + E104K | 8 | 256 |
| R164S + E104K | 16 | 1024 |
| TEM-1 | 0.125 | 1 |
| G238S + M182T | 32 | 4 |
| G238S + R164S + M182T | 4 | 32 |
| R164S + M182T | 1 | 64 |
| TEM-1 | 0.125 | 1 |
| G238S + E104K + M182T | 512 | 256 |
| G238S + R164S + E104K + M182T | 32 | 512 |
| R164S + E104K + M182T | 16 | 4096 |
| TEM-1 | 0.125 | 1 |
| G238S + T265M | 16 | 4 |
| G238S + R164S + T265M | 1 | 8 |
| R164S + T265M | 2 | 32 |
| TEM-1 | 0.125 | 1 |
| G238S + E104K + T265M | 256 | 64 |
| G238S + R164S + E104K + T265M | 32 | 256 |
| R164S + E104K + T265M | 16 | 2048 |