TABLE 4

Ceftazidime-avibactam activity stratified by organism β-lactamase production

Organism/β-lactamase (no. of isolates)No. of isolates (cumulative %) inhibited at ceftazidime-avibactam MIC (μg/ml) of:MIC (μg/ml)
≤0.030.060.120.250.51248>8a50%90%
K. pneumoniae (371)23 (6.2)25 (12.9)76 (33.4)80 (55.0)84 (77.6)58 (93.3)21 (98.9)2 (99.5)0 (99.5)2 (100.0)0.251
    KPC-like (125)5 (4.0)5 (8.0)9 (15.2)19 (30.4)34 (57.6)40 (89.6)13 (100.0)0.52
    CTX-M-15 (105)7 (6.7)9 (15.2)29 (42.9)29 (70.5)18 (87.6)12 (99.0)1 (100.0)0.251
    SHV ESBL (59)9 (15.3)4 (22.0)18 (52.5)11 (71.2)14 (94.9)0 (94.9)3 (100.0)0.122
    Metallo-β-lactamases (2)b2 (100.0)1
    Others (17)c4 (23.5)3 (41.2)5 (70.6)3 (88.2)1 (94.1)0 (94.1)1 (100.0)0.251
    Negative (57)d2 (3.5)3 (8.8)15 (35.1)14 (59.7)13 (82.4)5 (91.2)4 (98.2)1 (100.0)0.251
E. coli (235)18 (7.7)32 (21.3)86 (57.9)71 (88.1)16 (94.9)9 (98.7)2 (99.6)0 (99.6)0 (99.6)1 (100.0)0.120.5
    CTX-M-15 (113)7 (6.2)14 (18.6)49 (61.9)28 (86.7)10 (95.6)5 (100.0)0.120.5
    CTX-M-14 (46)4 (8.7)9 (28.3)21 (73.9)10 (95.7)1 (97.8)1 (100.0)0.120.25
    CMY-2 (23)3 (13.0)3 (26.1)4 (43.5)12 (95.7)0 (95.7)1 (100.0)0.250.25
    TEM-ESBL (9)1 (11.1)1 (22.2)0 (22.2)6 (88.9)1 (100.0)0.25
    SHV-ESBL (6)2 (33.3)0 (33.3)3 (83.3)1 (100.0)0.25
    KPC-like (3)1 (33.3)2 (100.0)0.25
    NDM-1 (1)1 (100.0)
    Others (9)e2 (22.2)4 (66.7)2 (88.9)0 (88.9)1 (100.0)0.251
    Negative (25)d3 (12.0)3 (24.0)9 (60.0)6 (84.0)1 (8.0)2 (96.0)1 (100.0)0.120.25
  • a All three isolates are NDM-1 producers with ceftazidime-avibactam MIC values of >32 μg/ml.

  • b Includes two isolates with NDM-1 (12).

  • c Includes isolates with CTX-M-14 (6); CTX-M-14 and SHV-ESBL (4); CTX-M-15 and SHV-ESBL (4); CTX-M-15, SHV-ESBL, and OXA-1/30 (1); SHV-ESBL and DHA-like (1); and SVH-ESBL, TEM-ESBL, and CMY-2 (1).

  • d Negative results by Check-Points for the following genes: CTX-M groups 1, 2, 8 plus 25, and 9; TEM ESBL; SHV ESBL; ACC; ACT/MIR; CMYII; DHA; FOX; KPC; and NDM-1.

  • e Includes isolates with CTX-M-15 and CMY-2 (3); CTX-M-15 and CTX-M-14 (2); CTX-M-15, CMY-2, and OXA-1/30 (1); CTX-M-14 and TEM-ESBL (1); SHV-ESBL and CMY-2 (1); and FOX-like (1).