Table 3.
Activity of Ceftolozane/Tazobactam and Comparator Agents Tested Against the Main Organisms and Organism Groups
| Organism (No. Tested) Antimicrobial Agent | MIC (mg/L) | %S / %R | ||
|---|---|---|---|---|
| 50% | 90% | CLSIa | EUCASTa | |
| Pseudomonas aeruginosa (376) | ||||
| Ceftolozane/tazobactam | 0.5 | 4 | 91.0/7.7 | 91.0/9.0 |
| Amikacin | 4 | 16 | 92.0/5.6 | 92.0/8.0 |
| Cefepime | 2 | >16 | 83.5/10.1 | (83.5)c/16.5 |
| Ceftazidime | 2 | >32 | 80.3/16.0 | (80.3)c/19.7 |
| Colistin | 1 | 1 | (99.2)b/0.8 | 99.2/0.8 |
| Gentamicin | 2 | >8 | 85.4/10.9 | |
| Levofloxacin | 0.5 | >4 | 70.2/23.4 | (70.2)c/29.8 |
| Meropenem | 0.5 | 32 | 75.0/19.7 | 75.0/25.0 |
| Piperacillin/tazobactam | 4 | >64 | 79.0/10.9 | (79.0)c/21.0 |
| Ceftazidime-nonsusceptible (>8 mg/L) Pseudomonas aeruginosa (74) | ||||
| Ceftolozane/tazobactam | 4 | >32 | 56.8/39.2 | 56.8/43.2 |
| Amikacin | 8 | >32 | 64.9/24.3 | 64.9/35.1 |
| Cefepime | 16 | >16 | 24.3/48.6 | (24.3)c/75.7 |
| Colistin | 1 | 1 | (97.3)b/2.7 | 97.3/2.7 |
| Gentamicin | 8 | >8 | 41.9/44.6 | |
| Levofloxacin | >4 | >4 | 23.0/70.3 | (23.0)c/77.0 |
| Meropenem | 16 | >32 | 33.8/60.8 | 33.8/66.2 |
| Piperacillin/tazobactam | >64 | >64 | 14.9/51.4 | (14.9)c/85.1 |
| Meropenem-nonsusceptible (>2 mg/L) Pseudomonas aeruginosa (94) | ||||
| Ceftolozane/tazobactam | 1 | >32 | 66.0/28.7 | 66.0/34.0 |
| Amikacin | 8 | >32 | 71.3/20.2 | 71.3/28.7 |
| Cefepime | 16 | >16 | 45.7/38.3 | (45.7)c/54.3 |
| Ceftazidime | 16 | >32 | 47.9/42.6 | (47.9)c/52.1 |
| Colistin | 1 | 1 | (97.9)b/2.1 | 97.9/2.1 |
| Gentamicin | 4 | >8 | 54.3/38.3 | |
| Levofloxacin | >4 | >4 | 21.3/71.3 | (21.3)c/78.7 |
| Piperacillin/tazobactam | 32 | >64 | 46.8/31.9 | (46.8)c/53.2 |
| Piperacillin/tazobactam-NS (>16 mg/L) Pseudomonas aeruginosa (79) | ||||
| Ceftolozane/tazobactam | 2 | >32 | 67.1/26.6 | 67.1/32.9 |
| Amikacin | 8 | >32 | 73.4/22.8 | 73.4/26.6 |
| Cefepime | 16 | >16 | 35.4/39.2 | (35.4)c/64.6 |
| Ceftazidime | 32 | >32 | 20.3/65.8 | (20.3)c/79.7 |
| Colistin | 1 | 1 | (97.5)b/2.5 | 97.5/2.5 |
| Gentamicin | 8 | >8 | 49.4/39.2 | |
| Levofloxacin | >4 | >4 | 22.8/68.4 | (22.8)c/77.2 |
| Meropenem | 8 | >32 | 36.7/59.5 | 36.7/63.3 |
| MDR Pseudomonas aeruginosa (77) | ||||
| Ceftolozane/tazobactam | 4 | >32 | 55.8/37.7 | 55.8/44.2 |
| Amikacin | 16 | >32 | 61.0/27.3 | 61.0/39.0 |
| Cefepime | 16 | >16 | 23.4/48.1 | (23.4)c/76.6 |
| Ceftazidime | 32 | >32 | 19.5/64.9 | (19.5)c/80.5 |
| Colistin | 1 | 1 | (96.1)b/3.9 | 96.1/3.9 |
| Gentamicin | >8 | >8 | 33.8/53.2 | |
| Levofloxacin | >4 | >4 | 7.8/83.1 | (7.8)c/92.2 |
| Meropenem | 32 | >32 | 22.1/71.4 | 22.1/77.9 |
| Piperacillin/tazobactam | 64 | >64 | 15.6/48.1 | (15.6)c/84.4 |
| Enterobacterales (1662) | ||||
| Ceftolozane/tazobactam | 0.25 | 16 | 86.8 / 11.4 | 86.8 / 13.2 |
| Amikacin | 2 | 8 | 97.7/1.6 | 94.9/5.1 |
| Cefepime | ≤0.12 | >16 | 66.0/28.5 | 64.5/31.6 |
| Ceftazidime | 0.25 | >32 | 65.3/31.8 | 60.9/34.7 |
| Colistin | 0.12 | >8 | (87.6)b/12.4 | 87.6/12.4 |
| Gentamicin | 0.5 | >8 | 76.7/22.9 | 75.9/24.1 |
| Levofloxacin | 0.5 | >4 | 58.7/37.0 | 58.7/37.0 |
| Meropenem | 0.03 | 0.12 | 93.0/6.7 | 93.3/6.7 |
| Piperacillin/tazobactam | 2 | >64 | 81.5/12.0 | 77.7/22.3 |
| Presumptive ESBL non-CRE Enterobacterales (492) | ||||
| Ceftolozane/tazobactam | 0.5 | 8 | 84.8/10.6 | 84.8/15.2 |
| Amikacin | 2 | 8 | 96.7/2.2 | 91.5/8.5 |
| Cefepime | >16 | >16 | 17.1/67.9 | 14.4/77.8 |
| Ceftazidime | 32 | >32 | 22.2/69.3 | 8.5/77.8 |
| Colistin | 0.12 | 0.25 | (94.3b)/5.7 | 94.3/5.7 |
| Gentamicin | 2 | >8 | 52.6/46.7 | 51.6/48.4 |
| Levofloxacin | >4 | >4 | 22.0/71.7 | 22.0/71.7 |
| Meropenem | 0.03 | 0.12 | 99.2/0.0 | 100.0/0.0 |
| Piperacillin/tazobactam | 4 | >64 | 75.1/11.6 | 66.1/33.9 |
| Escherichia coli (716) | ||||
| Ceftolozane/tazobactam | 0.25 | 1 | 95.8/3.4 | 95.8/4.2 |
| Amikacin | 2 | 8 | 99.0/0.3 | 96.8/3.2 |
| Cefepime | ≤0.12 | >16 | 63.1/29.7 | 62.0/34.9 |
| Ceftazidime | 0.25 | >32 | 67.3/27.8 | 60.1/32.7 |
| Colistin | 0.12 | 0.25 | (99.3)b/ 0.7 | 99.3/0.7 |
| Gentamicin | 1 | >8 | 70.5/29.4 | 69.8/30.2 |
| Levofloxacin | 1 | >4 | 49.6/47.6 | 49.6/47.6 |
| Meropenem | ≤0.015 | 0.03 | 98.6/1.4 | 98.6/1.4 |
| Piperacillin/tazobactam | 2 | 16 | 91.6/4.3 | 88.2/11.8 |
| Presumptive ESBL non-CRE Escherichia coli (303) | ||||
| Ceftolozane/tazobactam | 0.5 | 2 | 93.7/4.3 | 93.7/6.3 |
| Amikacin | 4 | 8 | 99.0/0.0 | 94.7/5.3 |
| Cefepime | >16 | >16 | 16.5/67.0 | 14.2/79.2 |
| Ceftazidime | 16 | >32 | 26.4/62.0 | 9.2/73.6 |
| Colistin | 0.12 | 0.25 | (99.3)b/0.7 | 99.3/0.7 |
| Gentamicin | 2 | >8 | 52.1/47.9 | 51.5/48.5 |
| Levofloxacin | >4 | >4 | 21.1/74.9 | 21.1/74.9 |
| Meropenem | 0.03 | 0.06 | 100.0 / 0.0 | 100.0 / 0.0 |
| Piperacillin/tazobactam | 4 | 32 | 88.0/3.7 | 80.1/19.9 |
| Klebsiella spp. (610) | ||||
| Ceftolozane/tazobactam | 0.25 | >32 | 75.7/21.3 | 75.7/24.3 |
| Amikacin | 1 | 8 | 96.1/3.1 | 91.5/8.5 |
| Cefepime | ≤0.12 | >16 | 61.6/35.2 | 60.5/36.9 |
| Ceftazidime | 0.5 | >32 | 57.5/41.1 | 55.4/42.5 |
| Colistin | 0.12 | 0.25 | (94.6)b/5.4 | 94.6/5.4 |
| Gentamicin | 0.25 | >8 | 81.1/18.4 | 80.8/19.2 |
| Levofloxacin | 0.12 | >4 | 59.9/35.3 | 59.9/35.3 |
| Meropenem | 0.03 | 32 | 84.9/14.4 | 85.6/14.4 |
| Piperacillin/tazobactam | 4 | >64 | 69.1/22.5 | 64.5/35.5 |
| Klebsiella pneumoniae (547) | ||||
| Ceftolozane/tazobactam | 0.25 | >32 | 74.8/22.3 | 74.8/25.2 |
| Amikacin | 1 | 8 | 95.6/3.5 | 90.5/9.5 |
| Cefepime | ≤0.12 | >16 | 58.3/38.4 | 57.0/40.2 |
| Ceftazidime | 0.5 | >32 | 56.1/42.6 | 53.9/43.9 |
| Colistin | 0.12 | 0.25 | (94.3)b/5.7 | 94.3/5.7 |
| Gentamicin | 0.25 | >8 | 79.7/19.7 | 79.3/20.7 |
| Levofloxacin | 0.5 | >4 | 56.8/38.3 | 56.8/38.3 |
| Meropenem | 0.03 | 32 | 83.7/15.5 | 84.5/15.5 |
| Piperacillin/tazobactam | 4 | >64 | 68.4/24.2 | 64.2/35.8 |
| Presumptive ESBL non-CRE Klebsiella pneumoniae (175) | ||||
| Ceftolozane/tazobactam | 2 | >32 | 69.1/21.7 | 69.1/30.9 |
| Amikacin | 2 | 16 | 94.3/4.6 | 87.4/12.6 |
| Cefepime | >16 | >16 | 17.1/73.1 | 14.9/78.9 |
| Ceftazidime | >32 | >32 | 10.9/85.1 | 4.0/89.1 |
| Colistin | 0.12 | 0.25 | (93.1)b/6.9 | 93.1/6.9 |
| Gentamicin | 0.5 | >8 | 55.4/42.9 | 54.3/45.7 |
| Levofloxacin | >4 | >4 | 24.7/66.1 | 24.7/66.1 |
| Meropenem | 0.06 | 0.12 | 97.7/0.0 | 100.0 / 0.0 |
| Piperacillin/tazobactam | 16 | >64 | 51.4/26.3 | 40.0/60.0 |
| Klebsiella oxytoca (13) | ||||
| Ceftolozane/tazobactam | 0.25 | >32 | 84.6/15.4 | 84.6/15.4 |
| Amikacin | 1 | 4 | 100.0 / 0.0 | 100.0 / 0.0 |
| Cefepime | ≤0.12 | 128 | 84.6/15.4 | 84.6/15.4 |
| Ceftazidime | 0.25 | >32 | 84.6/15.4 | 84.6/15.4 |
| Colistin | 0.12 | 0.25 | (100.0)b/0.0 | 100.0/0.0 |
| Gentamicin | 0.5 | >16 | 84.6/15.4 | 84.6/15.4 |
| Levofloxacin | 0.06 | >32 | 76.9/15.4 | 76.9/15.4 |
| Meropenem | 0.03 | >32 | 84.6/15.4 | 84.6/15.4 |
| Piperacillin/tazobactam | 2 | >128 | 84.6/15.4 | 76.9/23.1 |
| Klebsiella aerogenes. (50) | ||||
| Ceftolozane/tazobactam | 0.25 | 8 | 84.0/12.0 | 84.0/16.0 |
| Amikacin | 1 | 4 | 100.0/0.0 | 100.0/0.0 |
| Cefepime | ≤0.12 | 1 | 92.0/6.0 | 92.0/6.0 |
| Ceftazidime | 0.5 | >32 | 66.0/32.0 | 64.0/34.0 |
| Colistin | 0.12 | 0.25 | (96.0)b/4.0 | 96.0/4.0 |
| Gentamicin | 0.25 | 1 | 96.0/4.0 | 96.0/4.0 |
| Levofloxacin | 0.06 | 0.5 | 90.0/8.0 | 90.0/8.0 |
| Meropenem | 0.06 | 0.06 | 98.0/2.0 | 98.0/2.0 |
| Piperacillin/tazobactam | 4 | 64 | 72.0/6.0 | 64.0/36.0 |
| Enterobacter cloacae species complex (152) | ||||
| Ceftolozane/tazobactam | 0.25 | 32 | 77.0/19.1 | 77.0/23.0 |
| Amikacin | 2 | 4 | 98.0/1.3 | 97.4/2.6 |
| Cefepime | ≤0.12 | >16 | 70.4/22.4 | 67.1/24.3 |
| Ceftazidime | 0.5 | >32 | 57.2/40.8 | 54.6/42.8 |
| Colistin | 0.25 | >8 | (72.6)b/ 27.4 | 72.6/27.4 |
| Gentamicin | 0.5 | >8 | 78.9/21.1 | 78.3/21.7 |
| Levofloxacin | 0.06 | >4 | 79.6/16.4 | 79.6/16.4 |
| Meropenem | 0.03 | 0.5 | 92.1/7.9 | 92.1/7.9 |
| Piperacillin/tazobactam | 4 | >64 | 69.7/17.8 | 66.4/33.6 |
| Ceftazidime-nonsusceptible (>4 mg/L) Enterobacter cloacae species complex . (65) | ||||
| Ceftolozane/tazobactam | 4 | >32 | 46.2/44.6 | 46.2/53.8 |
| Amikacin | 2 | 8 | 95.4/3.1 | 93.8/6.2 |
| Cefepime | 16 | >16 | 32.3/52.3 | 24.6/55.4 |
| Colistin | 0.25 | >8 | (88.9)b/11.1 | 88.9/11.1 |
| Gentamicin | 0.5 | >8 | 53.8/46.2 | 52.3/47.7 |
| Levofloxacin | 0.5 | >4 | 60.0/32.3 | 60.0/32.3 |
| Meropenem | 0.06 | 32 | 81.5/18.5 | 81.5/18.5 |
| Piperacillin/tazobactam | 64 | >64 | 30.8/41.5 | 23.1/76.9 |
| Citrobacter spp. (50) | ||||
| Ceftolozane/tazobactam | 0.25 | 0.5 | 92.0 / 8.0 | 92.0/8.0 |
| Amikacin | 2 | 4 | 98.0/2.0 | 98.0/2.0 |
| Cefepime | ≤0.12 | 1 | 94.0/6.0 | 90.0/6.0 |
| Ceftazidime | 0.25 | >32 | 82.0/16.0 | 80.0/18.0 |
| Colistin | 0.12 | 0.25 | (100.0)b/0.0 | 100.0/0.0 |
| Gentamicin | 0.5 | 1 | 90.0/10.0 | 90.0/10.0 |
| Levofloxacin | ≤0.03 | 2 | 80.0/16.0 | 80.0/16.0 |
| Meropenem | 0.03 | 0.03 | 100.0 / 0.0 | 100.0 / 0.0 |
| Piperacillin/tazobactam | 2 | 16 | 90.0/4.0 | 84.0/16.0 |
| Citrobacter koseri (25) | ||||
| Ceftolozane/tazobactam | 0.12 | 0.5 | 100.0 / 0.0 | 100.0/0.0 |
| Amikacin | 1 | 2 | 96.0/4.0 | 96.0/4.0 |
| Cefepime | ≤0.12 | ≤0.12 | 100.0 / 0.0 | 100.0 / 0.0 |
| Ceftazidime | 0.12 | 0.5 | 100.0/0.0 | 96.0/0.0 |
| Colistin | 0.12 | 0.12 | (100.0)b/0.0 | 100.0 / 0.0 |
| Gentamicin | 0.25 | 0.5 | 96.0/4.0 | 96.0/4.0 |
| Levofloxacin | ≤0.03 | 0.12 | 95.0/4.0 | 96.0/4.0 |
| Meropenem | ≤0.015 | 0.03 | 100.0 / 0.0 | 100.0 / 0.0 |
| Piperacillin/tazobactam | 2 | 4 | 100.0/0.0 | 96.0/4.0 |
| Citrobacter freundii species complex (25) | ||||
| Ceftolozane/tazobactam | 0.25 | 8 | 84.0/16.0 | 84.0/16.0 |
| Amikacin | 2 | 8 | 100.0 / 0.0 | 100.0/0.0 |
| Cefepime | ≤0.12 | >16 | 88.0/12.0 | 80.0/12.0 |
| Ceftazidime | 0.5 | >32 | 64.0/32.0 | 64.0/36.0 |
| Colistin | 0.25 | 0.25 | (100.0)b/0.0 | 100.0 / 0.0 |
| Gentamicin | 0.5 | >8 | 84.0/16.0 | 84.0/16.0 |
| Levofloxacin | 0.25 | 4 | 64.0/28.0 | 64.0/28.0 |
| Meropenem | 0.03 | 0.06 | 100.0 / 0.0 | 100.0 / 0.0 |
| Piperacillin/tazobactam | 2 | 32 | 80.0/8.0 | 72.0/28.0 |
| Serratia marcescens (53) | ||||
| Ceftolozane/tazobactam | 0.5 | 1 | 98.1/1.9 | 98.1/1.9 |
| Amikacin | 2 | 4 | 100.0 / 0.0 | 100.0 / 0.0 |
| Cefepime | ≤0.12 | 0.5 | 96.2/1.9 | 96.2/1.9 |
| Ceftazidime | 0.25 | 0.5 | 96.2/3.8 | 94.3/3.8 |
| Colistin | >8 | >8 | (1.9)b/98.1 | 1.9/98.1 |
| Gentamicin | 0.5 | 1 | 98.1/0.0 | 98.1/1.9 |
| Levofloxacin | 0.12 | 0.5 | 92.3/5.8 | 92.3/5.8 |
| Meropenem | 0.06 | 0.06 | 100.0 / 0.0 | 100.0 / 0.0 |
| Piperacillin/tazobactam | 2 | 8 | 94.3/1.9 | 92.5/7.5 |
| Proteus mirabilis (48) | ||||
| Ceftolozane/tazobactam | 0.5 | 1 | 95.8/2.1 | 95.8/4.2 |
| Amikacin | 4 | 8 | 93.8/6.2 | 91.7/8.3 |
| Cefepime | ≤0.12 | 8 | 82.9/8.3 | 66.7/14.6 |
| Ceftazidime | 0.06 | 4 | 91.7/8.3 | 85.4/8.3 |
| Colistin | >8 | >8 | (0.0)b/100.0 | 0.0/100.0 |
| Gentamicin | 1 | >8 | 62.5/35.4 | 56.2/43.8 |
| Levofloxacin | 0.5 | >4 | 50.0/37.5 | 50.0/37.5 |
| Meropenem | 0.06 | 0.12 | 97.9/2.1 | 97.9/2.1 |
| Piperacillin/tazobactam | ≤0.5 | 8 | 95.7/0.0 | 91.5/8.5 |
| Indole-positive Proteae (25) | ||||
| Ceftolozane/tazobactam | 0.25 | 0.5 | 100.0 / 0.0 | 100.0 / 0.0 |
| Amikacin | 2 | 4 | 100.0 / 0.0 | 100.0 / 0.0 |
| Cefepime | ≤0.12 | 4 | 88.0/8.0 | 88.0/4.0 |
| Ceftazidime | 0.25 | 1 | 92.0/4.0 | 92.0/8.0 |
| Colistin | >8 | >8 | (0.0)b/100.0 | 0.0/100.0 |
| Gentamicin | 0.5 | >8 | 84.0/12.0 | 76.0/24.0 |
| Levofloxacin | 0.12 | 2 | 60.0/16.0 | 60.0/16.0 |
| Meropenem | 0.06 | 0.12 | 100.0 / 0.0 | 100.0 / 0.0 |
| Piperacillin/tazobactam | ≤0.5 | 4 | 96.0/4.0 | 96.0/4.0 |
Notes: aCriteria published by CLSI29 and EUCAST.30 bIntermediate only, no susceptible category. cSusceptible, increased exposure.
Abbreviations: CLSI, Clinical and Laboratory Standards Institute; CRE, carbapenem-resistant Enterobacterales; ESBL, extended-spectrum β-lactamase; EUCAST, European Committee on Antimicrobial Susceptibility Testing; MDR, multidrug resistant; MIC, minimal inhibitory concentration; R, resistant; S, susceptible.