TABLE 2.
Antibiotic susceptibilities of blaNDM-1-positive CRE and their transconjugants
| Isolatea | Antibioticb susceptibility (μg/ml) to: |
||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| SAM | TZP | CFZ | CTT | CAZ | FEP | IPM | ETP | CIP | LVX | GEN | AMK | SXT | ATM | CHL | TET | FOF | TGC | CST | |
| EC-01 | >256 | >256 | >256 | >256 | >256 | >256 | 8 | 16 | 2 | 2 | 64 | 16 | 40 | 8 | 256 | 256 | 8 | 0.75 | 0.5 |
| EC-03 | >256 | >256 | >256 | >256 | >256 | 256 | >32 | 32 | >32 | >32 | >256 | >256 | >320 | 256 | 256 | 256 | 512 | 0.5 | 0.5 |
| EC-13 | >256 | >256 | >256 | >256 | >256 | >256 | 4 | 16 | 8 | 2 | 32 | 16 | >320 | 64 | 256 | 256 | 8 | 0.38 | 1 |
| EC-24 | >256 | >256 | >256 | >256 | >256 | >256 | >32 | 32 | >32 | >32 | 32 | 8 | >320 | 128 | 256 | 256 | 512 | 3 | 1 |
| EC-SMX3 | >256 | >256 | >256 | >256 | >256 | >256 | 4 | 8 | >32 | >32 | 64 | 128 | >320 | 256 | 4 | 2 | 32 | 0.5 | 2 |
| EC-SMX5 | >256 | >256 | >256 | >256 | >256 | >256 | 32 | 16 | >32 | >32 | 32 | <2 | >320 | 128 | 256 | 256 | 8 | 0.5 | 2 |
| KP-07 | >256 | >256 | >256 | >256 | >256 | >256 | 8 | >32 | >32 | >32 | <1 | <2 | >320 | 256 | 128 | 2 | 8 | 3 | 1 |
| KP-09 | >256 | >256 | >256 | >256 | >256 | >256 | >32 | 4 | 1 | 1 | >256 | >256 | >320 | 32 | 256 | 256 | 32 | 3 | 1 |
| KP-40A | >256 | >256 | >256 | >256 | >256 | >256 | >32 | 16 | <0.25 | <0.25 | 64 | <2 | >320 | >256 | 256 | 256 | 32 | 6 | 1 |
| KP-41 | >256 | >256 | >256 | >256 | >256 | >256 | >32 | >32 | <0.25 | <0.25 | <1 | <2 | >320 | <1 | 6 | 2 | 8 | 3 | 0.5 |
| KO-ZMD8 | >256 | >256 | >256 | >256 | >256 | >256 | 8 | 16 | <0.25 | 0.5 | 32 | <2 | >320 | 128 | 256 | 256 | 32 | 0.5 | 0.5 |
| ECL-ZMD10 | ND | 64 | ND | ND | >256 | >256 | 8 | 32 | >32 | >32 | >256 | >256 | >320 | 256 | 256 | 256 | 128 | 1 | 1 |
| ECL-ZMD12 | ND | >256 | ND | ND | >256 | >256 | 8 | 32 | >32 | >32 | >256 | >256 | >320 | >256 | 256 | 256 | 32 | 3 | 2 |
| ECL-36 | ND | >256 | ND | ND | >256 | >256 | 32 | >32 | <0.25 | <0.25 | 32 | <2 | >320 | 256 | 8 | 4 | 8 | 2 | 1 |
| CF-SMX4 | ND | >256 | ND | ND | >256 | >256 | >32 | >32 | 8 | 4 | 16 | <2 | <20 | 256 | 6 | 128 | 8 | 1 | 1 |
| CF-25 | ND | >256 | ND | ND | >256 | >256 | >32 | >32 | >32 | >32 | >256 | >256 | >320 | 64 | 48 | 256 | 512 | 0.75 | 0.5 |
| E. coli transconjugant strains | |||||||||||||||||||
| EC-01-J53 | >256 | 64 | >256 | >256 | >256 | 32 | 8 | 16 | <0.25 | <0.25 | 32 | <2 | <20 | 4 | 256 | 256 | 8 | 1 | 0.5 |
| EC-03-J53 | >256 | 32 | >256 | >256 | >256 | 8 | >32 | 8 | <0.25 | <0.25 | >256 | >256 | >320 | 128 | 256 | 2 | 512 | 0.19 | 1 |
| EC-13-J53 | >256 | 64 | >256 | 32 | >256 | 4 | 4 | 4 | <0.25 | <0.25 | 16 | <2 | >320 | 32 | 128 | 128 | 8 | 0.25 | 1 |
| EC-24-J53 | >256 | >256 | >256 | >256 | >256 | >256 | 32 | 16 | <0.25 | <0.25 | 8 | <2 | <20 | 2 | 256 | 256 | 8 | 0.19 | 1 |
| EC-SMX3-J53 | >256 | >256 | >256 | >256 | >256 | >256 | 4 | 8 | 8 | 16 | 32 | 32 | >320 | 64 | 4 | 0.75 | 8 | 0.19 | 1 |
| EC-SMX5-J53 | >256 | 64 | >256 | >256 | >256 | 16 | 32 | 16 | <0.25 | <0.25 | 32 | <2 | <20 | <1 | 256 | 8 | 16 | 1 | 0.5 |
| KP-07-J53 | >256 | >256 | >256 | >256 | >256 | >256 | 8 | 16 | 8 | 16 | <1 | <2 | >320 | 128 | 24 | 2 | 8 | 0.5 | 1 |
| KP-09-J53 | >256 | 64 | >256 | 4 | >256 | 2 | 4 | 4 | <0.25 | <0.25 | <1 | <2 | <20 | <1 | 8 | 256 | 32 | 2 | 1 |
| KP-40A-J53 | >256 | >256 | >256 | 32 | >256 | 8 | 8 | 4 | <0.25 | <0.25 | 32 | <2 | >320 | 128 | 256 | 256 | 8 | 1 | 1 |
| KP-41-J53 | >256 | >256 | >256 | >256 | >256 | 8 | 8 | 16 | <0.25 | <0.25 | <1 | <2 | 40 | <1 | 4 | 2 | 8 | 0.75 | 1 |
| KO-ZMD8-J53 | >256 | >256 | >256 | >256 | >256 | >256 | 8 | 16 | <0.25 | <0.25 | 8 | <2 | >320 | 128 | 256 | 256 | 16 | 0.75 | 1 |
| ECL-ZMD10-J53 | >256 | 64 | >256 | >256 | >256 | >256 | 4 | 16 | 32 | 16 | >256 | >256 | >320 | 128 | 256 | 256 | 128 | 1.5 | 0.5 |
| ECL-ZMD12-J53 | >256 | >256 | >256 | >256 | >256 | >256 | 8 | 32 | 32 | 32 | >256 | 16 | <20 | >256 | 256 | 256 | 32 | 3 | 1 |
| ECL-36-J53 | >256 | 64 | >256 | >256 | >256 | >256 | 32 | >32 | <0.25 | <0.25 | 32 | <2 | >320 | <1 | 8 | 8 | 8 | 1.5 | 1 |
| CF-SMX4-J53 | >256 | 64 | >256 | 32 | >256 | >256 | 8 | 16 | <0.25 | <0.25 | 2 | <2 | <20 | 2 | 4 | 128 | 8 | 1 | 1 |
| CF-25-J53 | >256 | 64 | >256 | 16 | >256 | 2 | 8 | 4 | <0.25 | <0.25 | 32 | <2 | <20 | 4 | 48 | 128 | 128 | 0.25 | 1 |
| EC J53 | <2 | <4 | <4 | <4 | <1 | <1 | <1 | <0.5 | <0.25 | <0.25 | <1 | <2 | <20 | <1 | 8 | 2 | 2 | 0.25 | 0.5 |
All of the blaNDM-1-positive isolates were multidrug-resistant (MDR) strains, and the XDR isolates are highlighted in bold type. EC, E. coli strains; KP, K. pneumoniae strains; KO, K. oxytoca strains; ECL, E. cloacae strains; CF, C. freundii strains. For the transconjugants, all were E. coli J53 harboring plasmids from the respective clinical isolates.
SAM, ampicillin-sulbactam (1/0.5–256/128) (the numbers in parentheses indicate the test range [μg/ml] for each agent); TZP, piperacillin-tazobactam (0.5/4–256/4); CFZ, cefazolin (0.5–256); CTT, cefotetan (0.03–256); CAZ, ceftazidime (0.03–256); FEP, cefepime (0.015–256); IPM, imipenem (0.06–32); ETP, ertapenem (0.004–32); CIP, ciprofloxacin (0.004–32); LVX, levofloxacin (0.008–32); GEN, gentamicin (0.25–256); AMK, amikacin (0.5–256); ATM, aztreonam (0.06–256); CHL, chloramphenicol (0.016–256); TET, tetracycline (0.016–256); FOF, fosfomycin (0.25–512); TGC, tigecycline (0.016–256); CST, colistin (0.016–256). The MICs of trimethoprim-sulfamethoxazole (SXT) were obtained by the Vitek 2 system. ND, not determined (E. cloacae and C. freundii are intrinsically resistant to SAM, CFZ, and CTT).