TABLE 3

Summary of activity of cefepime-tazobactam with tazobactam at fixed 8 μg/ml stratified by geographic region

Organisms (no. of isolates for all regions combined)bMIC50/MIC90 (μg/ml) of cefepime-tazobactam with tazobactam at fixed 8 μg/ml (% isolates inhibited at ≤8 µg/ml)a
United StatesEuropeLatin AmericaAPACbChinaAll regions
Enterobacteriaceae (6,219)≤0.03/0.25 (98.3)≤0.03/0.5 (95.8)0.06/1 (94.4)≤0.03/0.25 (98.7)0.06/0.5 (93.8)≤0.03/0.25 (96.9)
E. coli (2,211)≤0.03/0.12 (99.9)≤0.03/0.12 (100.0)0.06/0.25 (100.0)≤0.03/0.06 (99.7)0.06/0.25 (96.2)≤0.03/0.12 (99.7)
    ESBL phenotype (471)0.12/0.25 (99.0)0.12/1 (100.0)0.12/0.25 (100.0)0.06/0.25 (98.4)0.06/0.25 (94.2)0.12/0.5 (98.7)
Klebsiella spp. (2,138)≤0.03/0.25 (95.9)0.06/32 (87.4)0.06/64 (85.0)≤0.03/0.25 (96.5)0.06/64 (86.1)≤00.03/4 (91.9)
    ESBL phenotype (661)0.5/32 (78.8)0.5/>64 (71.8)1/>64 (72.2)0.12/64 (87.9)0.12/64 (66.7)0.5/64 (73.7)
K. pneumoniae (1,788)≤0.03/0.25 (94.9)0.06/64 (85.0)0.06/64 (83.3)≤0.03/0.5 (96.2)0.06/64 (85.1)0.06/8 (90.3)
    MEM-non-susceptible (183)16/>64 (20.0)64/>64 (14.6)64/>64 (20.8)>64/— (0.0)64/>64 (0.0)64/>64 (15.3)
Klebsiella oxytoca (345)≤0.03/0.12 (100.0)≤0.03/1 (99.2)≤0.03/1 (100.0)≤0.03/0.12 (100.0)≤0.03/— (100.0)≤0.03/0.25 (99.7)
    ESBL-phenotype (59)0.5/4 (100.0)1/8 (96.4)1/— (100.0)0.12/— (100.0)0.5/4 (98.3)
P. mirabilis (228)0.06/0.12 (100.0)0.06/0.12 (100.0)0.06/0.12 (100.0)0.06/0.06 (100.0)0.06/— (100.0)0.06/0.12 (100.0)
    ESBL phenotype (19)0.12/— (100.0)0.12/0.25 (100.0)0.25 (100.0)0.06/— (100.0)0.12/0.25 (100.0)
Enterobacter spp. (629)0.06/0.25 (99.2)0.06/0.5 (98.7)0.06/1 (98.2)0.06/1 (100.0)0.06/1 (97.4)0.06/0.5 (98.9)
    CAZ nonsusceptible (179)0.25/2 (96.2)0.25/2 (95.5)0.25/2 (95.2)0.25/2 (100.0)0.25/8 (93.3)0.25/2 (96.1)
Morganella morganii (165)≤0.03/0.06 (100.0)≤0.03/0.06 (100.0)≤0.03/— (100.0)≤0.03/≤0.03 (100.0)≤0.03/— (100.0)≤0.03/0.06 (100.0)
Citrobacter spp. (311)≤0.03/0.12 (100.0)≤0.03/0.25 (99.2)0.06/— (100.0)≤0.03/0.25 (100.0)0.12/— (100.0)≤0.03/0.25 (99.7)
Serratia marcescens (245)0.06/0.25 (100.0)0.06/0.25 (100.0)0.06/0.12 (100.0)0.06/0.12 (100.0)0.06/0.25 (100.0)0.06/0.25 (100.0)
Proteus vulgaris (144)0.06/0.12 (100.0)0.06/0.12 (100.0)≤0.03/— (100.0)0.06/— (100.0)0.06/— (100.0)0.06/0.12 (100.0)
Providencia spp. (148)≤0.03/0.12 (98.9)≤0.03/0.06 (98.1)≤0.03/— (100.0)≤0.03/— (100.0)≤0.03/0.06 (98.6)
P. aeruginosa (1,171)2/16 (85.9)4/16 (79.8)4/32 (79.8)2/16 (85.8)4/32 (73.8)2/16 (82.4)
    CAZ nonsusceptible (252)16/64 (22.0)16/32 (31.4)16/>64 (37.5)16/>64 (35.0)32/>64 (20.0)16/64 (29.8)
    MEM nonsusceptible (244)16/64 (37.5)16/32 (42.2)16/>64 (44.4)16/>64 (39.4)32/>64 (15.6)16/64 (40.6)
A. baumannii (591)4/>64 (53.9)64/>64 (18.5)>64/>64 (9.7)>64/>64 (18.3)>64/>64 (15.6)64/>64 (26.1)
  • a According to the breakpoint for cefepime susceptibility for a high dosage (2 g every 8 h) published in CLSI document M100-S26 (7). —, there were too few isolates (<10) with which to calculate the MIC90.

  • b Abbreviations: APAC, Asia-Pacific region excluding China; ESBL phenotype, extended-spectrum β-lactamase (ESBL)-screen-positive phenotype, defined as an MIC of ≥2 μg/ml for ceftriaxone, ceftazidime, and/or aztreonam; CAZ nonsusceptible, ceftazidime nonsusceptible (MICs, ≥8 μg/ml for Enterobacteriaceae and ≥16 μg/ml for P. aeruginosa); MEM nonsusceptible, meropenem nonsusceptible (MICs, ≥2 μg/ml for Enterobacteriaceae and ≥4 μg/ml for P. aeruginosa) (7).