Table 3. The effect of PAβN on the susceptibility to cephalosporins of clinical isolates of ESβL-positive Enterobacteriaceae.
| Bacteria (No. of strains) | β-lactams | No. (%) of strains with ≥4-fold increase of antibiotic MICs in the presence of PAβN | |
|---|---|---|---|
| MH | MH+Mg | ||
| E. coli (n = 59) | cefepime | 5 (9) | 5 (9) |
| cefotaxime | 2 (3) | 2 (3) | |
| ceftriaxone | 3 (5) | 3 (5) | |
| cefepime and ceftriaxone | 1 (2) | 1 (2) | |
| cefepime and cefotaxime and ceftriaxone | 2 (3) | 2 (3) | |
| K.pneumoniae (n = 56) | cefepime | 15 (27) | 15 (27) |
| cefotaxime | 8 (14) | 4 (7) | |
| ceftriaxone | 2 (4) | 2 (4) | |
| cefepime and cefotaxime | 6 (11) | 6 (11) | |
| cefepime and cefotaxime and ceftriaxone | 2 (4) | 2 (4) | |
PAβN-efflux pump inhibitor Phe-Arg-β-naphthylamide at a concentration of 80 mg/L; MH-Mueller-Hinton II agar; MH+Mg-Mueller-Hinton II agar with 1mM MgSO4.