TABLE 1.
Susceptibility test results of the parental K. pneumoniae isolates, VA367 and VA375, and the corresponding E. coli J53 transconjugants, VA367-J53 and VA375-J53a
| Antimicrobial drug | VA367 [blaKPC-3qnrB19 blaTEM-1blaSHV-11blaSHV-12aac(6′)-Ib]
|
VA367-J53 [blaKPC-3qnrB19 blaTEM-1blaSHV-11aac(6′)-Ib]
|
VA375 (blaKPC-3qnrA1 blaTEM-1blaSHV-11)
|
VA375-J53 (qnrA1 blaTEM-1blaSHV-11)
|
E. coli J53
|
|||||
|---|---|---|---|---|---|---|---|---|---|---|
| MIC (μg/ml) | Susceptibilityc | MIC (μg/ml) | Susceptibility | MIC (μg/ml) | Susceptibility | MIC (μg/ml) | Susceptibility | MIC (μg/ml) | Susceptibility | |
| Levofloxacin | ≥8 (≥32) | R | 1 (0.75) | S | 1 (0.75) | S | 1 (1.5) | S | ≤0.25 (0.25) | S |
| Ciprofloxacin | ≥4 (≥32) | R | 1 (1) | S | 1 (0.75) | S | 1 (2) | S | ≤0.25 (0.25) | S |
| Gentamicin | 4 | S | ≤1 | S | ≥16 | R | 4 | S | ≤1 | S |
| Amikacin | ≥64 | R | 16 | S | ≤2 | S | ≤2 | S | ≤2 | S |
| Tobramycin | ≥16 | R | ≥16 | R | ≥16 | R | 4 | S | ≤1 | S |
| Trimethoprim-sulfamethoxazole | ≥320 | R | ≤20 | S | ≥320 | R | ≥320 | R | ≤20 | S |
| Nitrofurantoin | ≥512 | R | ≤16 | S | 64 | I | ≤16 | S | ≤16 | S |
| Tigecyclineb | (3) | (0.5) | (1.5) | (0.5) | (0.5) | |||||
| Colistinb | (1.5) | (0.38) | (1) | (0.38) | (0.38) | |||||
| Piperacillin | ≥128 | R | ≥128 | R | ≥128 | R | ≥128 | R | ≤4 | S |
| Piperacillin-tazobactam | ≥128 | R | 64 | I | ≥128 | R | 64 | I | ≤4 | S |
| Ampicillin-sulbactam | ≥32 | R | ≥32 | R | ≥32 | R | ≥32 | R | 4 | S |
| Cefazolin | ≥64 | R | ≥64 | R | ≥64 | R | ≥64 | R | ≤4 | S |
| Cefuroxime | ≥64 | R | ≥64 | R | ≥64 | R | ≥64 | R | 16 | I |
| Ceftazidime | ≥64 | R | 32 | R | ≥64 | R | ≥64 | R | ≤1 | S |
| Ceftriaxone | ≥64 | R | 8 | S | 32 | I | 8 | S | ≤1 | S |
| Cefepime | ≥64 | R | 2 | S | ≥64 | R | ≤1 | S | ≤1 | S |
| Aztreonam | ≥64 | R | ≥64 | R | ≥64 | R | 2 | S | ≤1 | S |
| Meropenem | 2 (8) | S (I) | 1 (4) | S (S) | 1 (4) | S (S) | ≤0.25 (0.38) | S | ≤0.25 (0.047) | S |
| Imipenem | 2 (16) | S (R) | 4 (4) | S (S) | 2 (8) | S (I) | ≤1 (0.38) | S | ≤1 (0.25) | S |
| Ertapenem | (16) | (R) | (2) | (S) | (8) | (I) | (0.125) | (S) | (0.023) | (S) |
a
The antimicrobial susceptibility tests were performed with the Vitek 2 system, using AST-GN09 cards (bioMérieux, Durham, NC). The results were interpreted according to the Clinical and Laboratory Standards Institute (CLSI; formerly NCCLS) criteria (4). All MIC and susceptibility data given in parentheses were obtained by the Etest method (AB Biodisk, Solna, Sweden) on Mueller-Hinton agar.
b
Interpretative criteria for this drug have not yet been released by the CLSI (4).
c
S, susceptible; I, intermediate; R, resistant.