Table 2.
Resistance phenotypes, distribution of carbapenenmase, ESBLs, AMEs encoding genes and 16sRNA methylase genes, sequence typing, and biofilm formation ability in amikacin-heteroresistant K. pneumoniae strains.
| Strains | MIC (μg/ml) | Carbapenenmase, ESBLs, 16sRNA methylase genes and AMEs encoding genes | Sequence type | Biofilm formation ability | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| AMK | IMP | MEM | CIP | KAN | CHL | CTX | ||||
| S38 | 32 (Ia) | 64 (Rb) | 128 (R) | 128 (R) | 2048 (R) | 1,024 (R) | 128 (R) | blaKPC-2, blaOXA-1, blaSHV-182, blaTEM-1B, blaCTX-M-15, aac (6')-Ib-cr, aph (3’)-Ia | ST11 | Moderate |
| S33* | 4 (Sc) | 64 (R) | 256 (R) | 16 (R) | 128 (R) | 4 (S) | 64 (R) | blaCTX-M-65, blaTEM-1B, blaSHV-12, aac (3)-IId, aac (6')-Ib-cr | ST2324 | Weak |
| S30* | 4 (S) | 4 (R) | 2 (I) | 8 (R) | 64 (R) | 32 (R) | 64 (R) | blaCTX-M-3, blaTEM-1B, blaSHV-27, blaVIM-2, aac (6')-Ib3, aac (3)-IId | ST11 | Weak |
| S28* | 4 (S) | 4 (R) | 2 (I) | 4 (R) | 128 (R) | 32 (R) | 64 (R) | blaCTX-M-15, blaTEM-1B, blaSHV-11, blaVIM-4, aac (3)-IIa, aac (6')-Ib3 | ST307 | Moderate |
| S9 | 2 (S) | 32 (R) | 16 (R) | 32 (R) | 2048 (R) | 64 (R) | 64 (R) | blaKPC-2, blaNDM-5, blaCTX-M-27, blaTEM-1B, blaIMP-4, blaSHV-18, aac (3)-IIa, aac (6')-Ib-cr | ST11 | Moderate |
| F48 | 2 (S) | 32 (R) | 64 (R) | 64 (R) | 8 (S) | 128 (R) | 64 (R) | blaKPC-2, blaCTX-M-15, blaTEM-116, blaSHV-29, blaVIM-1, aph (3')-Ia, aac (3)-IIa | ST11 | Weak |
| F50 | 2 (S) | 16 (R) | 2 (I) | 0.25 (S) | 8 (S) | 4 (S) | 32 (R) | blaNDM-5, blaCTX-M-1, blaTEM-1B, blaSHV-182, aph (3')-Ia | ST11 | Moderate |
| F35 | 8 (S) | 16 (R) | 8 (R) | 8 (R) | 256 (R) | 32 (R) | 128 (R) | blaCTX-M-3, blaTEM-1B, blaSHV-33, blaIMP-4, aph (3')-Ia, aac (3)-IId, aac (6')-Ib-cr | ST2637 | Moderate |
| H28 | 4 (S) | 64 (R) | 4 (R) | 0.25 (S) | 8 (S) | 4 (S) | 64 (R) | blaCTX-M-15, blaTEM-1B, blaSHV-144, blaIMP-2, aph (3')-Ia, aac (3)-IIa | ST2637 | Weak |
| H628* | 16 (S) | 64 (R) | 8 (R) | 128 (R) | 2048 (R) | 256 (R) | 64 (R) | blaCTX-M-65, blaTEM-1B, blaSHV-27, blaVIM-4, aph (3')-Ia, aac (3)-IIa, aac (6')-Ib-cr | ST11 | Weak |
| 17-3 | 2 (S) | 64 (R) | 128 (R) | 32 (R) | 16 (S) | 4 (S) | 32 (R) | blaKPC-2, blaTEM-1B, blaSHV-55, blaVIM-4, blaIMP-4, aac (3)-IIa, aph (3')-Ia | ST11 | Moderate |
| 17-4 | 8 (S) | 64 (R) | 128 (R) | 16 (R) | 8 (S) | 128 (R) | 64 (R) | blaKPC-2, blaNDM-5, blaCTX-M-1, blaTEM-1B, blaSHV-2, blaVIM-2, aac (3)-IId, aph (3')-Ia | ST11 | Moderate |
| 17-10* | 8 (S) | 64 (R) | 2 (I) | 128 (R) | 64 (R) | 16 (I) | 64 (R) | blaCTX-M-1, blaTEM-1B, blaSHV-48, aac (3)-IIa, aac (6')-Ib-cr | ST761 | Moderate |
IMP, imipenem; MEM, meropenem; CTX, cefotaxime; CIP, ciprofloxacin; CHL, chloramphenicol; and KAN, kanamycin.
a
I: K. pneumoniae strains were intermediately resistant to antibiotics.
b
R: K. pneumoniae strains were resistant to antibiotics.
c
S: K. pneumoniae strains were susceptible to antibiotics.
*
K. pneumoniae isolates which do not have carbapenemases but are resistant to imipenem or meropenem. It is speculated that the reduced susceptibility to imipenem or meropenem might be due to porins, which is already established.