Table 1.
Antimicrobial susceptibility testing results for isolates of Enterobacterales, NME and P. aeruginosa, including resistant isolate subsets, collected by the SMART global surveillance programme in the USA from 2019 to 2021
| Organism/phenotypea | n | Susceptible (%) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| C/T | IMI/REL | CZA | IMI | MEM | P/T | FEP | CAZ | ATM | LVXb | AMKc | ||
| Enterobacterales | 10 509 | 94.2 | NA | 99.8 | 88.4 | 99.0 | 87.8 | 89.0 | 85.2 | 85.0 | 79.9 | NA |
| CAZ-NS | 1552 | 62.5 | NA | 98.9 | 86.7 | 93.8 | 43.6 | 36.1 | 0 | 10.2 | 45.7 | NA |
| MEM-NS | 102 | 6.9 | NA | 90.2 | 4.9 | 0 | 2.9 | 7.8 | 5.9 | 5.9 | 25.5 | NA |
| NME | 9524 | 93.8 | 98.9 | 99.9 | 94.9 | 99.0 | 86.9 | 88.3 | 84.5 | 83.7 | 81.2 | NA |
| CAZ-NS | 1478 | 61.7 | 98.4 | 99.1 | 89.9 | 93.6 | 41.9 | 34.6 | 0 | 7.1 | 46.4 | NA |
| MEM-NS | 100 | 6.0 | 76.0 | 90.0 | 5.0 | 0 | 2.0 | 7.0 | 5.0 | 5.0 | 26.0 | NA |
| E. coli | 4154 | 98.3 | 99.9 | 100 | 99.5 | 99.8 | 92.7 | 86.2 | 86.3 | 85.1 | 71.5 | NA |
| CRO NS/non-CRE | 706 | 94.2 | 100 | 100 | 100 | 100 | 79.3 | 24.5 | 26.9 | 19.5 | 25.1 | NA |
| CAZ-NS | 571 | 88.1 | 99.6 | 99.8 | 97.7 | 98.4 | 71.8 | 16.6 | 0 | 6.7 | 22.6 | NA |
| K. pneumoniae | 1930 | 95.6 | 99.1 | 99.7 | 96.8 | 97.9 | 85.6 | 85.6 | 84.9 | 84.7 | 82.8 | NA |
| CRO NS/non-CRE | 274 | 88.7 | 99.6 | 100 | 98.9 | 100 | 60.9 | 19.3 | 16.8 | 13.1 | 39.1 | NA |
| CAZ-NS | 291 | 71.8 | 96.2 | 98.3 | 84.5 | 85.9 | 44.0 | 12.4 | 0 | 6.2 | 31.3 | NA |
| P. aeruginosa | 2524 | 96.6 | 90.7 | 94.8 | 65.1 | 79.4 | 78.6 | 82.3 | 80.7 | 71.1 | 67.0 | 97.0 |
| CAZ-NS | 487 | 83.0 | 73.1 | 73.1 | 37.6 | 47.2 | 12.9 | 21.8 | 0 | 14.6 | 42.8 | 91.6 |
| MEM-NS | 520 | 88.7 | 56.2 | 79.6 | 5.6 | 0 | 41.3 | 48.7 | 50.6 | 27.5 | 27.6 | 91.7 |
| MDR | 337 | 78.3 | 55.5 | 65.6 | 15.7 | 23.4 | 8.9 | 13.1 | 14.2 | 4.5 | 21.1 | 85.8 |
| DTR | 167 | 73.7 | 36.5 | 49.7 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 83.8 |
| Enterobacterales + P. aeruginosa | 13 033 | 94.7 | NA | 98.9 | 83.8 | 95.2 | 86.0 | 87.7 | 84.4 | 82.3 | 77.4 | NA |
| NME + P. aeruginosa | 12 048 | 94.4 | 97.2 | 98.8 | 88.7 | 94.9 | 85.1 | 87.1 | 83.7 | 81.1 | 78.2 | NA |
C/T, ceftolozane/tazobactam; IMI/REL, imipenem/relebactam; CZA, ceftazidime/avibactam; IMI, imipenem; MEM, meropenem; P/T, piperacillin/tazobactam; FEP, cefepime; CAZ, ceftazidime; ATM, aztreonam; LVX, levofloxacin; AMK, amikacin; NME, non-Morganellaceae Enterobacterales; CRO, ceftriaxone; CRE, carbapenem-resistant Enterobacterales; DTR, difficult-to-treat resistance; NA, not available; NS, non-susceptible.
aToo few isolates of E. coli (n = 10) and K. pneumoniae (n = 41) with a meropenem-non-susceptible phenotype were identified to be included in the table.
bSusceptibility to levofloxacin was not available for Salmonella spp. (n = 17) because the tested concentration range did not extend low enough for the Salmonella-specific CLSI susceptible breakpoint for that agent.
cSusceptibility to amikacin was not determinable for Enterobacterales because the tested concentration range did not extend low enough to include the revised 2023 CLSI susceptible breakpoint for that agent.