Table 1

Spectrum of activity and MIC distribution of AN3365 tested against Enterobacteriaceae and nonfermentative Gram-negative clinical isolates

Organism and group (no. of strains tested)MIC (μg/ml)No. of strains (cumulative %)a inhibited at MIC (μg/ml) of:
50%90%0.250.51248163264
Enterobacteriaceae (2,029)0.5184 (4.1)1,342 (70.3)544 (97.1)58 (>99.9)1 (100.0)
    E. coli (252)0.510 (0.0)131 (52.0)112 (96.4)9 (100.0)
        Wild type (214)0.510 (0.0)108 (50.5)98 (96.3)8 (100.0)
        pAmpCk (11)b0.510 (0.0)8 (72.7)3 (100.0)
        ESBLl (27)c0.510 (0.0)15 (55.6)11 (96.3)1 (100.0)
    K. pneumoniae (261)0.511 (0.4)151 (58.2)94 (94.2)15 (100.0)
        Wild type (159)0.510 (0.0)96 (60.4)57 (96.2)6 (100.0)
        pAmpC (5)d0.5m0 (0.0)3 (60.0)1 (80.0)1 (100.0)
        ESBL (71)e0.510 (0.0)43 (60.6)24 (94.4)4 (100.0)
        KPC (26)121 (3.8)9 (38.5)12 (84.6)4 (100.0)
    P. mirabilis (250)f110 (0.0)78 (31.2)163 (96.4)9 (100.0)
    E. aerogenes (250)0.515 (2.0)200 (82.0)40 (98.0)5 (100.0)
        Wild type (199)0.511 (0.5)163 (82.4)31 (98.0)4 (100.0)
        Non-wild typeg (51)0.514 (7.8)37 (80.4)9 (98.0)1 (100.0)
    E. cloacae (252)0.517 (2.8)194 (79.8)46 (98.0)5 (100.0)
        Wild type (201)0.512 (1.0)152 (76.7)42 (97.5)5 (100.0)
        Non-wild typeg (51)0.50.55 (9.8)42 (92.2)4 (100.0)
    C. freundii (253)0.517 (2.8)208 (85.0)36 (99.2)2 (100.0)
        Wild type (188)0.516 (3.2)155 (85.6)26 (99.5)1 (100.0)
        Non-wild typeg (65)0.511 (1.5)53 (81.5)10 (98.5)1 (100.0)
    Indole-positive Proteeaeh (259)0.5123 (8.9)184 (79.9)39 (95.0)12 (99.6)1 (100.0)
        Wild type (202)0.5123 (11.4)145 (83.2)28 (97.0)5 (99.5)1 (100.0)
        Non-wild typeg (57)0.520 (0.0)39 (68.4)11 (88.0)7 (100.0)
    S. marcescens (252)0.50.541 (16.3)196 (94.1)14 (99.6)1 (100.0)
        Wild type (192)0.50.536 (18.8)148 (95.8)8 (100.0)
        Non-wild typeg (60)0.515 (11.5)48 (88.5)6 (100.0)1 (100.0)
Nonfermentative Gram negative
    P. aeruginosa (101)480 (0.0)0 (0.0)6 (5.9)28 (33.7)41 (74.3)21 (95.0)5 (100.0)
        Wild type (50)280 (0.0)0 (0.0)4 (8.0)24 (56.0)16 (88.0)5 (98.0)1 (100.0)
        Carbapenem resistant480 (0.0)0 (0.0)2 (4.0)4 (11.8)25 (60.8)16 (92.2)4 (100.0)
            MBL negative (32)480 (0.0)0 (0.0)2 (6.3)1 (9.4)15 (53.1)12 (93.8)2 (100.0)
            MBL positivei (19)4160 (0.0)0 (0.0)0 (0.0)3 (15.8)10 (68.4)4 (89.5)2 (100.0)
    A. baumannii (51)480 (0.0)1 (2.0)1 (3.9)12 (27.5)16 (58.8)17 (92.2)3 (98.0)1 (100.0)
        Wild type (25)280 (0.0)1 (4.0)1 (8.0)12 (56.0)8 (88.0)3 (100.0)
        Multidrug resistant (26)8160 (0.0)0 (0.0)0 (0.0)0 (0.0)7 (30.8)10 (84.6)3 (96.2)1 (100.0)
    S. maltophilia (50)240 (0.0)4 (8.0)15 (38.0)14 (66.0)15 (96.0)2 (100.0)
    B. cepaciaj (50)8320 (0.0)1 (2.0)1 (4.0)4 (12.0)15 (42.0)12 (66.0)8 (82.0)7 (96.0)1 (98.0)
  • a Modal MICs are in boldface.

  • b All CMY-2 producers.

  • c Includes one OXA-2-like strain, one CTX-M-3 strain, five CTX-M-14 strains, 19 CTX-M-15 strains, and one KPC-3 producer.

  • d Includes two CMY-2 strains and three FOX-5 strains.

  • e All have a positive confirmatory ESBL result. When available, genotypic results were as follows: eight CTX-M-like strains, two OXA-2-like strains, two OXA-10-like strains, two OXA-48-like strains, five SHV-5 strains, one SHV-7 strain, three SHV-12 strains, one SHV-30 strain, four SHV-31 strains, and one SHV-40 strain.

  • f Fifteen ESBL-positive strains.

  • g Non-wild type represents isolates with elevated MICs for ceftazidime (>4 μg/ml) and/or ceftriaxone (>1 μg/ml) with or without a positive confirmatory ESBL result.

  • h Includes Morganella morganii (150 strains), Proteus vulgaris (41 strains), Providencia rettgeri (14 strains), Providencia stuartii (43 strains), and Providencia spp. (11 strains).

  • i Includes 14 VIM-like strains, three SPM-1 strains, one GIM-1 strain, and one IMP-15 producer.

  • j One strain with an AN3365 MIC of 128 μg/ml.

  • k pAmpC, AmpC encoded by a plasmid-borne AmpC gene.

  • l ESBL, extended-spectrum β-lactamase.

  • m —, MIC90 value not available.