TABLE 2

MIC distributions of S-649266, cefepime, and meropenem against various β-lactamase-producing strainsa

Species and β-lactamase (no. of isolates)Test compoundNo. of strains inhibited at test compound MIC (μg/ml):R%b
≤0.1250.250.5124816>16
Escherichia coli
    KPC typesc (7)S-64926661
Cefepime321128.6
Meropenem33157.1
    NDM-1 (19)S-649266165214
Cefepime19100
Meropenem1216100
    ESBLd (49)S-64926641341
Cefepime12353242967.3
Meropenem4810
    Othere (3)S-6492663
Cefepime1110
Meropenem120
Klebsiella pneumoniae
    KPC typesf (20)S-64926615311
Cefepime1121690.0
Meropenem14411100
    NDM-1 (24)S-64926627771
Cefepime24100
Meropenem1151795.8
    VIM-1 (4)S-6492664
Cefepime11275.0
Meropenem2250.0
    ESBLg (24)S-64926617241
Cefepime1133311254.2
Meropenem2011118.3
    Otherh (9)S-649266621
Cefepime111111333.3
Meropenem71111.1
Serratia marcescens, Citrobacter freundii, and Enterobacter cloacae
    KPC typesi(20)S-649266152111
Cefepime12341070.0
Meropenem22562380.0
    NDM-1 (6)S-649266222
Cefepime15100
Meropenem121283.3
    VIM typesj (8)S-649266611
Cefepime112475.0
Meropenem123262.5
    IMP typesk (8)S-64926632111
Cefepime11687.5
Meropenem1123187.5
    ESBLl (19)S-649266131113
Cefepime32412747.4
Meropenem152115.3
    Otherm (13)S-6492661111
Cefepime6122215.4
Meropenem3111769.2
  • a Cation-adjusted Mueller-Hinton broth was used as a medium but was supplemented with 20 μM human apo-transferrin for S-649266 to obtain free iron-deficient condition.

  • b Resistance rate (%) based on CLSI resistance breakpoints: 16 μg/ml for cefepime and 4 μg/ml for meropenem (23).

  • c 4 KPC-2, 2 KPC-3, and 1 KPC-like.

  • d 1 CTX-M-2, 4 CTX-M-3, 14 CTX-M-14, 20 CTX-M-15, 2 CTX-M-24, 1 CTX-M-28, 1 SHV-5, 2 SHV-12, 1 SHV-30, 1 TEM-10, 1 TEM-12, and 1 TEM-26.

  • e 2 OXA-48 and 1 OXA-1.

  • f 13 KPC-2 and 7 KPC-3.

  • g 2 CTX-M-2, 1 CTX-M-3, 3 CTX-M-14, 4 CTX-M-15, 1 CTX-M-24, 3 SHV-5, 2 SHV-7, 3 SHV-12, 1 SHV-27, 2 SHV-30, 1 SHV-31, and 1 SHV-40.

  • h 1 OXA-1, 1 OXA-2, 1 OXA-2-like, 1 OXA-10, 2 OXA-10-like, and 3 OXA-48.

  • i 8 KPC-2, 11 KPC-3, and 1 KPC-4.

  • j 5 VIM-1, 2 VIM-2, and 1 VIM-23.

  • k 7 IMP-1 and 1 IMP-21.

  • l 1 CTX-M-2, 3 CTX-M-3, 2 CTX-M-14, 1 CTX-M-15, 1 CTX-M-24, 1 CTX-M-like, 2 SHV-5, 2 SHV-7, 1 SHV-12, 3 SHV-30, 1 PER-2, and 1 GES-1.

  • m 1 SME-1, 5 SME-2, 1 NMC-A, 4 OXA-2, 1 OXA-10-like, and 1 OXA-48.