TABLE 1

Univariate comparison between patients with breakthrough Acinetobacter bacteremia during carbapenem therapy and nonbreakthrough Acinetobacter bacteremia caused by carbapenem-resistant strains

CharacteristicaBreakthrough carbapenem resistant (n = 87)Nonbreakthrough carbapenem resistant (n = 265)P value
Demographic characteristics
    Age (median [IQR]) (yr)69 (53–80)72 (58–81)0.192
    Male sex51 (58.6)186 (70.2)0.062
    Recent ICU stay49 (56.3)124 (46.8)0.156
    Bacteremia acquired in ICU60 (69.0)120 (45.3)<0.001
    Length of hospitalization before bacteremia (median [IQR]) (days)21 (13–34)22 (10–39)0.624
Comorbid conditions
    Alcoholism3 (3.4)13 (4.9)0.770
    Liver cirrhosis8 (9.2)44 (16.6)0.130
    Chronic obstructive pulmonary disease28 (32.2)48 (18.1)0.009
    Chronic kidney disease32 (36.8)101 (38.1)0.924
    Type 2 diabetes mellitus31 (35.6)97 (36.6)0.972
    Hypertension37 (42.5)108 (40.8)0.868
    Coronary artery disease14 (16.1)31 (11.7)0.379
    Congestive heart failure21 (24.1)50 (18.9)0.363
    Cerebrovascular accident18 (20.7)51 (19.2)0.890
    Collagen vascular disease3 (3.4)8 (3.0)0.737
    Immunosuppressant therapy11 (12.6)26 (9.8)0.585
    Solid tumor13 (14.9)71 (26.8)0.035
    Hematological malignancy8 (9.2)8 (3.0)0.032
    Chemotherapy7 (8.0)14 (5.3)0.494
    Neutropenia7 (8.0)11 (4.2)0.165
    Trauma4 (4.6)9 (3.4)0.743
    Burn1 (1.1)5 (1.9)1.000
    Recent surgery21 (24.1)57 (21.5)0.716
Charlson comorbidity index (median [IQR])4 (2–6)4 (2–6)0.919
Invasive procedures
    Arterial catheter40 (46.0)108 (40.8)0.465
    Central venous catheter49 (56.3)139 (52.5)0.614
    Ventilator use70 (80.5)163 (61.5)0.002
    Hemodialysis18 (20.7)58 (21.9)0.932
    Thoracic drain10 (11.5)18 (6.8)0.239
    Abdominal drain11 (12.6)25 (9.4)0.514
Sources of bacteremia
    Pneumonia42 (48.3)99 (37.4)0.094
    Catheter18 (20.7)46 (17.4)0.590
    Urinary tract infection1 (1.1)10 (3.8)0.305
    Intra-abdominal infection6 (6.9)16 (6.0)0.975
    Wound2 (2.3)11 (4.2)0.532
    Primary bacteremia18 (20.7)83 (31.3)0.077
Antimicrobial therapy after bacteremia onset
    Appropriate antimicrobial therapy32 (36.8)56 (21.1)0.005
    Effective regimensb
        Colistin18 (56.3)43 (75.4)0.102
        Tigecycline12 (37.5)15 (26.3)0.389
        Fluoroquinolone7 (21.9)9 (15.8)0.667
        Sulbactam2 (6.3)4 (7.0)1.000
        Carbapenem + colistin16 (50.0)11 (19.3)0.005
        Carbapenem + tigecycline6 (18.8)2 (3.5)0.023
        Carbapenem + sulbactam2 (6.3)1 (1.8)0.293
        Colistin + tigecycline4 (12.5)12 (21.1)0.471
Outcome
    Shock29 (33.3)89 (33.6)1.000
    APACHE II score (median [IQR])26 (19–32)24 (17–30)0.023
    14-day mortality45 (51.7)99 (37.4)0.025
    30-day mortality54 (62.1)132 (49.8)0.062
Species causing bacteremia
    A. baumannii52 (59.8)184 (69.4)0.125
    A. nosocomialis24 (27.6)66 (24.9)0.722
    A. pittii10 (11.5)8 (3.0)0.004
    A. soli0 (0.0)4 (1.5)0.576
Microbiological characteristics of causative microorganisms
    Nonsusceptibility to:
        Amikacin46 (52.9)117 (44.2)0.196
        Ampicillin-sulbactam52 (59.8)192 (72.3)0.036
        Cefepime75 (86.2)246 (92.9)0.094
        Ceftazidime78 (89.7)250 (94.3)0.208
        Piperacillin-tazobactam83 (95.4)258 (97.4)0.475
        Ciprofloxacin67 (77.0)223 (84.2)0.176
        Levofloxacin70 (80.5)221 (83.4)0.642
        Colistin0 (0.0)6 (2.3)0.343
        Tigecycline31 (35.6)94 (35.5)1.000
    Isolates harboring ISAba1-blaOXA-51-like20 (23.0)38 (14.3)0.085
        A. baumannii isolates harboring ISAba1-blaOXA-51-like/total no. of isolates harboring ISAba1-blaOXA-51-like (%)18/52 (36.7)32/184 (17.4)0.013
    Isolates harboring ISAba1-blaOXA-23-like37 (42.5)168 (63.4)0.001
        A. baumannii isolates harboring ISAba1-blaOXA-23-like/total no. of isolates harboring ISAba1-blaOXA-23-like (%)21/52 (40.4)147/184 (79.9)<0.001
    Isolates harboring IS1008 (or IS1006)-ΔISAba3-blaOXA-58-like6 (6.9)8 (3.0)0.120
    Isolates harboring blaOXA-24-like11 (12.6)16 (6.0)0.076
    Isolates harboring blaIMP-like5 (5.7)5 (1.9)0.072
    Isolates harboring blaVIM-like3 (3.4)5 (1.9)0.414
  • a Data are presented as the number (%), unless otherwise indicated. IQR, interquartile range; ICU, intensive care unit; APACHE II, Acute Physiology and Chronic Health Evaluation II.

  • b Each item denotes the corresponding antimicrobial agent alone or in combination with other antimicrobial agent(s). For example, “colistin” denotes “colistin alone or in combination with other antimicrobial agent(s).” The numbers in parentheses denote the percentage of patients who received the corresponding antimicrobial agent alone or in combination with other antimicrobial agent(s) among the patients who received appropriate antimicrobial therapy.