TABLE 3

Arbekacin MIC distributions when tested against antimicrobial resistant organism subsets

Organism or phenotype (no. of isolates tested)aNo. of isolates (cumulative %) inhibited at an arbekacin MIC (μg/ml) of:
≤0.250.51248163264≥128
ESBL E. coli (33)b2 (6.1)5 (21.2)8 (45.5)4 (57.6)4 (69.7)3 (78.8)2 (84.8)3 (93.9)1 (97.0)1 (100.0)
    Gentamicin resistantc (15)1 (6.7)2 (20.0)2 (33.3)3 (53.3)1 (60.0)1 (66.7)1 (73.3)2 (86.7)1 (93.3)1 (100.0)
ESBL/KPC K. pneumoniae (78)8 (10.3)18 (33.3)1 (34.6)4 (39.7)4 (44.9)13 (61.5)26 (94.9)0 (94.9)0 (94.9)4 (100.0)
    ESBL producing (38)d6 (15.8)14 (52.4)1 (55.3)2 (60.5)1 (63.2)3 (71.1)8 (92.1)0 (92.1)0 (92.1)3 (100.0)
    KPC-2/3 producing (40)2 (5.0)4 (15.0)0 (15.0)2 (20.0)3 (27.5)10 (52.5)18 (97.5)0 (97.5)0 (97.5)1 (100.0)
    Gentamicin resistantc (37)2 (5.4)8 (27.0)0 (27.0)0 (27.0)3 (35.1)9 (59.5)11 (89.2)0 (89.2)0 (89.2)4 (100.0)
CAZ-R E. cloacae (21)2 (9.5)13 (71.4)6 (100.0)
CAZ-R C. freundii (20)14 (70.0)4 (90.0)0 (90.0)0 (90.0)1 (95.0)1 (100.0)
IMI-R P. aeruginosa (31)1 (3.2)5 (19.4)6 (38.7)6 (58.1)2 (64.5)4 (77.4)2 (83.9)3 (93.5)2 (100.0)
    MBL producinge (13)1 (7.7)2 (23.1)3 (46.2)3 (69.2)1 (76.9)1 (84.6)2 (100.0)
    Gentamicin resistant (19)1 (5.3)3 (21.1)4 (42.1)3 (57.9)1 (63.2)2 (73.7)2 (84.2)2 (94.7)1 (100.0)
    Tobramycin resistant (17)1 (5.9)2 (17.6)4 (41.2)3 (58.8)1 (64.7)2 (76.5)2 (88.2)2 (100.0)
    AMK, GEN and TOB-NSf (9)1 (11.1)2 (33.3)3 (66.7)1 (77.8)1 (88.9)1 (100.0)
IMI-R A. baumannii (50)1 (2.0)5 (12.0)6 (24.0)8 (40.0)9 (58.0)10 (78.0)8 (94.0)1 (96.0)2 (100.0)
    Gentamicin resistant (42)5 (11.9)4 (21.4)4 (31.0)8 (50.0)10 (73.8)8 (92.2)1 (95.2)2 (100.0)
MRSA (70)5 (7.1)27 (45.7)34 (94.3)3 (98.6)1 (100.0)
    hVISA (20)4 (20.0)6 (50.0)9 (95.0)0 (95.0)1 (100.0)
    CA-MRSA (30)1 (3.3)14 (50.0)15 (100.0)
    Gentamicin-resistant (22)7 (31.8)11 (81.8)3 (95.5)1 (100.0)
  • a ESBL, extended-spectrum β-lactamase producing; KPC, Klebsiella pneumoniae carbapenemase; CAZ-R, ceftazidime-resistant (MIC, ≥16 μg/ml); IMI-R, imipenem-resistant (MIC, ≥8 μg/ml); hVISA, heterogeneous vancomycin-intermediate S. aureus; CA-MRSA, community-acquired MRSA.

  • b Includes CTX-M-type (19 isolates), SHV-type (8 isolates), and TEM-type (5 isolates) ESBLs, as well as one strain with OXA-1.

  • c Gentamicin MIC ≥16 μg/ml (CLSI 2014 [14]).

  • d Includes CTX-M-type (16 isolates) and SHV-type (22 isolates) ESBLs.

  • e Include VIM-type (6 isolates), IMP-type (5 isolates), GIM-1 (1 isolate), and SPM-1 (1 isolate).

  • f Isolates that were nonsusceptible to amikacin (MIC, ≥32 μg/ml), gentamicin (MIC, ≥8 μg/ml), and tobramycin (MIC, ≥8 μg/ml) (14).