Table 4.
Multilocus sequence types, beta-lactamase genes identified, and antimicrobial resistance profiles of community-associated Carbapenem-resistant Enterobacterales isolates that underwent whole genome sequencing analysis at CDC, 2012-2015, n = 12
| Organism type* | Carbapenemase gene variants | MLST | Non-carbapenemase beta-lactamase gene variants | Antimicrobial resistance profile‡ |
|---|---|---|---|---|
| Enterobacter cloacae complex (n = 6) | None | Novel† | ACT-70 | AMC, AMP, ATM, CFZ, FOX, TZP |
| None | 108 | ACT-55 | AMP, ATM, CFZ, FOX, TZP§ | |
| KPC-3 | 171 | ACT-45, OXA-9, SHV-12, TEM-1A | AMC, AMP, ATM, CFZ, FEP, FOX, CIP, LVX, TZP, SXT, TOB | |
| None | 45 | TEM-1B | AMC, AMP, ATM, CFZ, FOX, CST, TZP, PMB, SXT | |
| None | 365 | None | AMC, AMP, ATM, CFZ, FOX, CST, TZP, PMB | |
| None | 125 | ACT-28 | AMC, AMP, ATM, CFZ, FOX, CST, TZP, PMB | |
| Escherichia coli (n = 3) | NDM-1 | 5498 | TEM-1A | AMP, CFZ, FEP, FOX, CIP, GEN, LVX, TZP, TET, SXT, TOB§ |
| None | 167 | CTX-M-15, OXA-1 | AMP, ATM, CFZ, FEP, FOX, CIP, GEN, LVX, TET, SXT | |
| None | 131 | CTX-M-15, OXA-1, TEM-1B | AMC, AMP, ATM, CFZ, FEP, FOX, CIP, LVX, TZP, SXT, TOB | |
| Klebsiella pneumoniae (n = 3) | KPC-3 | 258 | SHV-11 | AMC, AMP, ATM, CFZ, CIP, LVX, TZP, SXT, TOB |
| KPC-3 | 1737 | LEN-17 | AMC, AMP, ATM, CFZ, FEP, CIP, LVX, TZP, SXT, TOB | |
| KPC-3 | 485 | SHV-27 | AMC, AMP, ATM, CFZ, FEP, CIP, LVX, TZP, SXT |
None of the identified community-associated- K. aerogenes isolates that were sequenced met the phenotypic case definition after testing at CDC.
Novel: This MLST sequence type is not in the Pasteur MLST database.
Isolate not tested against amoxicillin-clavulanic acid.
Antimicrobials reported if the isolate tested resistant based on reference broth microdilution testing performed at CDC. Isolates were tested against the following unless noted: AMK, amikacin; AMC, amoxicillin-clavulanic acid; AMP, ampicillin; ATM, aztreonam; CFZ, cefazolin; FEP, cefepime; CTX, cefotaxime; CAZ, ceftazidime; FOX, cefoxitin; CRO, ceftriaxone; CIP, ciprofloxacin; CST, colistin; DOR, doripenem; ETP, ertapenem; GEN, gentamicin; IPM, imipenem; LVX, levofloxacin; MEM, meropenem; TZP, piperacillin-tazobactam; PMB, polymyxin B; TET, tetracycline; TGC, tigecycline; SXT, trimethoprim-sulfamethoxazole; TOB, tobramycin. Interpretations are based on the 2019 Clinical and Laboratory Standards Institute; CLSI, interpretative criteria. Performance standards for antimicrobial susceptibility testing: twenty-ninth informational supplement, M100-S29. Wayne [PA]: The Institute; 2019).