Volume 19, Number 1—January 2013
Letter
Carbapenem-hydrolyzing Oxacillinase-48 and Oxacillinase-181 in Canada, 2011
Table
Patient data and antimicrobial drug susceptibility profiles for isolates of Klebsiella pneumoniae and Escherichia coli harboring OXA-type carbapenemases, Canada, 2011*
| Variable | Bacterial isolate, strain no., OXA-type |
E. coli DH10B† | |||||||
|---|---|---|---|---|---|---|---|---|---|
| K. pneumoniae |
E. coli |
Plasmid |
|||||||
| 11-882, OXA-48 | 11-2568, OXA-181 | 11-2720, OXA-48 | 11-1498, OXA-48 | p48-11-882 | p181-11-2568 | ||||
| Patient data | NA | NA | NA | ||||||
| Recent travel | NK | India | Lebanon | Dubai | NA | NA | NA | ||
| Site of bacterial isolation | Urine | Perirectal | Urine | Skin swab | NA | NA | NA | ||
| Infection/colonization | NK | Colonization | Infection | Colonization | NA | NA | NA | ||
| Hospitalization |
NK |
General ward |
Outpatient |
ICU |
NA |
NA |
NA |
||
| Bacterial isolate data | |||||||||
| β-lactamase | TEM-1, SHV-11 | TEM-1, SHV-11, CTX-M-15, OXA-1 | SHV-11, OXA-1 | TEM-1, CTX-M-24 | TEM-1 | Neg | NA | ||
| Sequence type |
395 |
147 |
831 |
38 |
NA |
NA |
NA |
||
| Antimicrobial drug susceptibility test, drug‡ | |||||||||
| Vitek2,§ MIC μg/mL | |||||||||
| Amikacin | <2.0 | 4.0 | <2.0 | <2.0 | <2.0 | <2.0 | <2.0 | ||
| Aztreonam | <1.0 | >64.0 | <1.0 | 32.0 | <1.0 | <1.0 | <1.0 | ||
| Cefazolin | 32.0 | >64.0 | 16.0 | >64.0 | >64.0 | 32.0 | <4.0 | ||
| Cefepime | <1.0 | >64.0 | <1.0 | <1.0 | <1.0 | <1.0 | <1.0 | ||
| Ceftriaxone | <1.0 | >64.0 | <1.0 | >64.0 | <1.0 | <1.0 | <1.0 | ||
| Ciprofloxacin | >4.0 | >4.0 | <0.25 | <0.25 | <0.25 | <0.25 | <0.25 | ||
| Ertapenem | >8.0 | >8.0 | 4.0 | 4.0 | >8.0 | 4.0 | <0.5 | ||
| Gentamicin | <1.0 | >16.0 | <1.0 | >16.0 | <1.0 | <1.0 | <1.0 | ||
| Imipenem | 4.0 | >16.0 | <1.0 | <1.0 | 8.0 | 2.0 | <1.0 | ||
| Meropenem | 1.0 | >16.0 | <0.25 | 0.5 | 8.0 | <0.25 | <0.25 | ||
| Tigecycline¶ | 1.0 | 2.0 | <0.5 | <0.5 | <0.5 | <0.5 | <0.5 | ||
| TMP/SXT | >320.0 | >320.0 | <20.0 | >320.0 | >320 | <20 | <20.0 | ||
| Etest,§ MIC μg/mL | |||||||||
| Imipenem | 1.0 | 24.0 | 0.38 | 0.38 | 0.5 | 0.5 | 0.19 | ||
| Meropenem | 0.5 | 24.0 | 0.19 | 0.38 | 0.125 | 0.19 | 0.032 | ||
| Ertapenem | 2.0 | >32.0 | 0.5 | 2.0 | 0.38 | 0.75 | 0.008 | ||
| Colistin# | 0.38 | 0.5 | 0.5 | 0.5 | 0.125 | 0.125 | ND | ||
| Disk diffusion,** zone diameter, mm | |||||||||
| Imipenem | 20 | 8 | 23 | 22 | 24 | 25 | 33 | ||
| Meropenem | 20 | 7 | 23 | 22 | 22 | 28 | 35 | ||
| Ertapenem | 16 | 6 | 19 | 16 | 23 | 22 | 35 | ||
*NK, not known; NA, not applicable; ICU, intensive care unit; Neg, negative; TMP/SXT, trimethoprim/sulfamethoxazole; ND, not done.
†OXA-48–type plasmids were electroporated into E. coli DH10B cells.
‡Additional antimicrobial drugs on panel: ampicillin, ampicillin/sulbactam, nitrofurantoin, piperacillin/tazobactam, tobramycin.
§Test from bioMérieux Canada Inc., St. Laurent, Quebec, Canada.
¶MIC breakpoints for tigecycline were based on the US Food and Drug Administration criteria for Enterobacteriaceae: susceptible, <2 μg/mL; intermediate, 4 μg/mL; resistant, >8 μg/mL.
#MIC breakpoints for colistin followed Clinical Laboratory Standards Institute breakpoint criteria for Acinetobacter spp.: susceptible, MIC <2 μg/mL; resistant, MIC >4 μg/mL.
**Test from Clinical Laboratory Standards Institute (www.clsi.org/source/orders/free/m100-s22.pdf).