TABLE 5.
MICs of LK-157 in combination with cefotaxime, ceftriaxone, cefepime, ceftazidime, cefpirome, and aztreonam against CTX-M-producing E. colia
| Microorganism | Strain | β-Lactamase
|
MIC (μg/ml)
|
||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CTX
|
CRO
|
FEP
|
Cefpirome
|
CAZ
|
ATM
|
LK-157 alone | TZB-LK-157 | ||||||||||||||||
| Type | Class | Alone | LK-157 | TZB | Alone | LK-157 | TZB | Alone | LK-157 | TZB | Alone | LK-157 | TZB | Alone | LK-157 | TZB | Alone | LK-157 | TZB | ||||
| E. coli | B 1147 | CTX-M-1 | A | >25.6 | >25.6 | 1.6 | >25.6 | >25.6 | 1.6 | >25.6 | 12.8 | 0.8 | >25.6 | 25.6 | 1.6 | 25.6 | >25.6 | 0.4 | >25.6 | >25.6 | 0.8 | >25.6 | >25.6 |
| E. coli | B 1094 | CTX-M-2 | A | >25.6 | >25.6 | 0.8 | >25.6 | >25.6 | 0.2 | 12.8 | 12.8 | 0.05 | 12.8 | 12.8 | 0.05 | 1.6 | 1.6 | 0.2 | 12.8 | 12.8 | 0.1 | >25.6 | >25.6 |
| E. coli | B 1095 | CTX-M-14 | A | >25.6 | >25.6 | 6.4 | >25.6 | >25.6 | 3.2 | 6.4 | 6.4 | 0.1 | >25.6 | 12.8 | 0.1 | 12.8 | 12.8 | 12.8 | 12.8 | 12.8 | 6.4 | >25.6 | >25.6 |
| E. coli | B 1096 | CTX-M-9 | A | 25.6 | 3.2 | 0.4 | >25.6 | 6.4 | 0.4 | 6.4 | 0.4 | 0.2 | 12.8 | 1.6 | 0.2 | 1.6 | 0.4 | 0.4 | 6.4 | 1.6 | 0.2 | >25.6 | >25.6 |
| E. coli | B 1097 | CTX-M-15 | A | >25.6 | >25.6 | 0.1 | >25.6 | >25.6 | 0.4 | 6.4 | 3.2 | 0.05 | 25.6 | 3.2 | 0.2 | 12.8 | 6.4 | 0.2 | >25.6 | 25.6 | 0.1 | 25.6 | >25.6 |
| E. coli | B 1098 | CTX-M-15 | A | >25.6 | >25.6 | 12.8 | >25.6 | >25.6 | 1.6 | 25.6 | 12.8 | 0.2 | >25.6 | 25.6 | 0.4 | 25.6 | 25.6 | 0.8 | >25.6 | >25.6 | 1.6 | >25.6 | >25.6 |
| C. freundii | B 1099 | CTX-M-15 (strain E) | A | >25.6 | 12.8 | 0.1 | >25.6 | 25.6 | 0.2 | 3.2 | 0.8 | 0.1 | 25.6 | 1.6 | 0.2 | 6.4 | 3.2 | 0.2 | >25.6 | 6.4 | 0.1 | 12.8 | >25.6 |
| E. coli | B 1100 | CTX-M-15 (strain D) | A | >25.6 | >25.6 | 1.6 | >25.6 | >25.6 | 12.8 | 25.6 | 12.8 | 0.4 | >25.6 | >25.6 | 0.4 | >25.6 | >25.6 | 0.8 | >25.6 | >25.6 | 0.8 | 25.6 | >25.6 |
| E. coli | B 1101 | CTX-M-3 (strain C) | A | >25.6 | 25.6 | 0.2 | >25.6 | >25.6 | 1.6 | 6.4 | 6.4 | 0.1 | 12.8 | 6.4 | 0.05 | 1.6 | 1.6 | 0.2 | 12.8 | 12.8 | 0.2 | >25.6 | >25.6 |
| E. coli | B 1102 | CTX-M-15 (strain B) | A | >25.6 | >25.6 | 1.6 | >25.6 | >25.6 | 1.6 | 25.6 | 12.8 | 0.2 | >25.6 | 25.6 | 0.8 | >25.6 | 25.6 | 0.4 | >25.6 | >25.6 | 1.6 | >25.6 | >25.6 |
| E. coli | B 1103 | CTX-M-15 (strain A) | A | 25.6 | 0.8 | 0.4 | 12.8 | 0.8 | 0.1 | 0.8 | 0.05 | 0.2 | 3.2 | 0.1 | 0.1 | 1.6 | 0.8 | 0.2 | 6.4 | 1.6 | 0.2 | 25.6 | >25.6 |
| E. coli | B 1146 | CTX-M-15 | A | >25.6 | >25.6 | 0.8 | >25.6 | >25.6 | 1.6 | >25.6 | 12.8 | 0.8 | >25.6 | >25.6 | 0.8 | >25.6 | 25.6 | 0.8 | >25.6 | >25.6 | 0.8 | >25.6 | >25.6 |
a
The MICs of various cephalosporins in the presence of a constant concentration (4 μg/ml) of the β-lactamase inhibitors LK-157 and tazobactam (TZB) were determined by a microdilution test. CTX, cefotaxime; CRO, ceftriaxone; FEP, cefepime; CAZ, ceftazidime; ATM, aztreonam.