TABLE 2

MIC distributions for the 139 carbapenem-nonsusceptible Enterobacteriaceae clinical isolates, with cumulative percentages

Organism (no. of strains)Agent(s)aMIC (μg/ml) (cumulative %)MIC50MIC90
≤0.060.1250.250.5124816≥32
E. cloacae (104)CAZ2 (2)3 (5)99 (100)≥32≥32
CAZ-AVI9 (9)21 (29)58 (85)12 (96)4 (100)0.51
ATM2 (2)3 (5)14 (18)85 (100)≥32≥32
ATM-AVI14 (13)23 (36)63 (96)4 (100)0.50.5
ERTA82 (79)12 (90)5 (93)5 (100)12
IMP5 (5)8 (13)76 (86)10 (95)4 (99)b1 (100)c0.51
MERO11 (11)79 (87)9 (95)4 (99)b1 (100)c0.51
DORI18 (17)71 (86)9 (94)1 (95)4 (99)b1 (100)c0.251
K. pneumoniae (16)CAZ1 (6)15 (100)≥32≥32
CAZ-AVI3 (19)8 (69)1 (75)4 (100)0.254
ATM1 (6)15 (100)≥32≥32
ATM-AVI1 (6)9 (63)2 (75)4 (100)0.1254
ERTA7 (44)3 (63)2 (75)5 (100)b2≥32
IMP2 (13)8 (63)1 (69)1 (75)b4 (100)b0.5≥32
MERO2 (13)9 (69)1 (75)b4 (100)b1≥32
DORI2 (13)7 (56)2 (69)1 (75)b4 (100)b0.516
E. aerogenes (5)CAZ1 (20)4 (100)≥32≥32
CAZ-AVI2 (40)2 (80)1 (100)0.52
ATM1 (20)1 (40)3 (100)≥32≥32
ATM-AVI3 (60)1 (80)1 (100)0.251
ERTA4 (80)1 (100)b2≥32
IMP4 (80)1 (100)b18
MERO4 (80%)1 (100)b18
DORI1 (20%)3 (80%)1 (100%)b0.54
E. coli (3)CAZ2 (67)1 (100)2≥32
CAZ-AVI1 (33)2 (100)0.250.25
ATM2 (66)1 (100)8≥32
ATM-AVI1 (33)1 (67)1 (100)0.1250.25
ERTA2 (67)1 (100)12
IMP3 (100)0.250.25
MERO3 (100)0.250.25
DORI1 (33)2 (100)0.250.25
C. freundii (5)CAZ5 (100)≥32≥32
CAZ-AVI2 (40)3 (100)0.50.5
ATM4 (80)1 (100)16≥32
ATM-AVI4 (80)1 (100)0.250.5
ERTA1 (20)3 (80)1 (100)24
IMP1 (20)2 (60)2 (100)0.51
MERO3 (60)2 (100)0.51
DORI3 (60)1 (80)1 (100)0.251
S. marcescens (2)CAZ2 (100)≥32≥32
CAZ-AVI1 (50)1 (100)0.51
ATM2 (100)≥32≥32
ATM-AVI1 (50)1 (100)0.251
ERTA1 (50)1 (100)b1≥32
IMP1 (50)1 (100)b0.5≥32
MERO1 (50)1 (100)b0.25≥32
DORI1 (50)1 (100)b0.254
P. mirabilis (1)CAZ1 (100)≤0.06≤0.06
CAZ-AVI1 (100)≤0.06≤0.06
ATM1 (100)≤0.06≤0.06
ATM-AVI1 (100)≤0.06≤0.06
ERTA1 (100)≤0.06≤0.06
IMP1 (100)88
MERO1 (100)≤0.06≤0.06
DORI1 (100)≤0.06≤0.06
M. morganii (3)CAZ1 (33)1 (67)1 (100)8≥32
CAZ-AVI1 (33)1 (67)1 (100)0.1250.25
ATM1 (33)1 (67)1 (100)0.1251
ATM-AVI3 (100)≤0.06≤0.06
ERTA3 (100)≤0.06≤0.06
IMP2 (67)1 (100)816
MERO3 (100)≤0.06≤0.06
DORI3 (100)≤0.06≤0.06
  • a CAZ, ceftazidime; CAZ-AVI, ceftazidime-avibactam; ATM, aztreonam; ATM-AVI, aztreonam-avibactam; ERTA, ertapenem; IMP, imipenem; MERO, meropenem; DORI, doripenem.

  • b CNSE isolates with a complete loss of OmpC and OmpF porins.

  • c True carbapenemase producers.