TABLE 1

Antimicrobial activity of ceftolozane-tazobactam against isolates collected from hospitalized patients with pneumonia in U.S. hospitals

Organism or organism group (no. of isolates)No. of isolates at MIC (μg/ml) (cumulative %)MIC (μg/ml)
0.030.060.120.250.512481632>3250%90%
Pseudomonas aeruginosa (1,576)3 (0.2)4 (0.4)20 (1.7)164 (12.1)765 (60.7)385 (85.1)114 (92.3)62 (96.3)29 (98.1)9 (98.7)5 (99.0)16 (100.0)0.52
Enterobacteriaceae (2,362)1 (<0.1)21 (0.9)515 (22.7)790 (56.2)535 (78.8)192 (87.0)85 (90.6)47 (92.5)40 (94.2)30 (95.5)24 (96.5)82 (100.0)0.252
    Escherichia coli (441)7 (1.6)161 (38.1)188 (80.7)56 (93.4)15 (96.8)5 (98.0)4 (98.9)3 (99.5)1 (99.8)0 (99.8)1 (100.0)0.250.5
    Klebsiella pneumoniae (627)6 (1.0)141 (23.4)227 (59.6)101 (75.8)46 (83.1)17 (85.8)4 (86.4)5 (87.2)15 (89.6)14 (91.9)51 (100.0)0.2532
    Klebsiella oxytoca (190)3 (1.6)89 (48.4)55 (77.4)24 (90.0)8 (94.2)6 (97.4)1 (97.9)0 (97.9)0 (97.9)2 (98.9)2 (100.0)0.250.5
    Enterobacter cloacae (270)30 (11.1)129 (58.9)37 (72.6)12 (77.0)17 (83.3)13 (88.1)14 (93.3)8 (96.3)6 (98.5)4 (100.0)0.258
    Enterobacter aerogenes (161)32 (19.9)67 (61.5)22 (75.2)12 (82.6)12 (90.1)8 (95.0)6 (98.8)1 (99.4)0 (99.4)1 (100.0)0.252
    Citrobacter koseri (42)2 (4.8)16 (42.9)19 (88.1)5 (100.0)0.250.5
    Citrobacter freundii (32)4 (12.5)12 (50.0)4 (62.5)1 (65.6)1 (68.8))4 (81.2)2 (87.5)3 (96.9)0 (96.9)1 (100.0)0.2516
    Proteus mirabilis (90)3 (3.3)26 (32.2)53 (91.1)5 (96.7)2 (98.9)0 (98.9)0 (98.9)0 (98.9)0 (98.9)1 (100.0)0.50.5
    Indole-positive Proteeae (46)1 (2.2)6 (15.2)19 (6.5)14 (87.0)3 (93.5)1 (95.7)0 (95.7)2 (100.0)0.251
    Serratia spp. (354)2 (0.6)21 (6.5)205 (64.4)85 (88.4)21 (94.4)7 (96.3)2 (96.9)0 (96.9)1 (97.2)10 (100.0)0.52
    Isolates carrying ESBL genes (145)2 (1.4)11 (9.0)37 (34.5)35 (58.6)23 (74.5)12 (82.8)7 (87.6)4 (90.3)6 (94.5)1 (95.2)7 (100.0)0.58
        Isolates carrying blaCTX-M (111)1 (0.9)7 (7.2)30 (34.2)29 (60.4)22 (80.2)9 (88.3)4 (91.9)3 (94.6)3 (97.3)0 (97.3)3 (100.0)0.54
            Isolates carrying blaCTX-M-15-like genes (89)1 (1.1)5 (6.7)17 (25.8)24 (52.8)20 (75.3)9 (85.4)4 (89.9)3 (93.3)3 (96.6)0 (96.6)3 (100.0)0.58
            Isolates carrying blaCTX-M-14-like genes (22)2 (9.1)13 (68.2)5 (90.9)2 (100.0)0.250.5
        Isolates carrying blaSHV ESBL (31)1 (3.2)3 (12.9)6 (32.3)5 (48.4)1 (51.6)3 (61.3)3 (71.0)1 (74.2)3 (83.9)1 (87.1)4 (100.0)1>32
        Isolates carrying blaTEM ESBL (3)1 (33.3)1 (66.7)1 (100.0)0.25
    Isolates carrying blaKPC (70)1 (1.4)1 (2.9)2 (5.7)10 (20.0)13 (38.6)43 (100.0)>32>32
    Isolates carrying transferable AmpC genes (13)3 (23.1)4 (53.8)2 (69.2)2 (84.6)0 (84.6)1 (92.3)0 (92.3)0 (92.3)1 (100.0)0.58