TABLE 1

Demographic and clinical information of patients with resistant versus control isolates

CharacteristicNo. (%) unless otherwise noted
All patients (n = 1,204)ESBL cases (n = 210)AmpC cases (n = 94)Controls (n = 900)P valuea
Hospital0.91
    West417 (35)73 (35)32 (34)312 (35)
    Midwest 1306 (25)51 (24)27 (29)228 (25)
    Midwest 2168 (14)27 (13)15 (16)126 (14)
    East313 (26)59 (28)20 (21)234 (26)
Species0.38
    E. coli1,058 (88)178 (85)89 (95)791 (88)
    K. pneumoniae146 (12)32 (15)5 (5)109 (12)
Median age (range) (yr)5.2 (0.1–21.9)4.3 (0.1–20.4)7.7 (0.1–20.6)5.2 (0.1–21.9)0.02
IQR1.4, 12.20.9, 10.51.9, 13.51.4, 12.5
Female976 (81)154 (73)73 (78)749 (83)0.006
Hispanic ethnicity165 (14)25 (13)20 (21)120 (14)0.18
Race<0.001
    Caucasian740 (64)110 (56)65 (70)565 (66)
    African-American270 (23)29 (15)19 (20)222 (26)
    Asian101 (9)50 (25)3 (3)48 (6)
    Native American14 (1)6 (3)0 (0)8 (1)
    Pacific Islander15 (1)3 (2)5 (5)7 (1)
    More than one race13 (1)0 (0)1 (1)12 (1)
Site of culture<0.001
    Urine1,110 (92)186 (89)84 (89)840 (93)
    Blood77 (6)15 (7)7 (7)55 (6)
    Otherb17 (1)9 (4)3 (3)5 (1)
Onsetc<0.001
    Community associated573 (48)67 (32)25 (26)481 (53)
    Healthcare associated503 (42)107 (51)58 (62)338 (38)
    Hospital associated128 (10)36 (17)11 (12)81 (9)
Hospitalization (in last yr)357 (30)91 (43)48 (51)218 (24)<0.001
Medical condition category<0.001
    Urologicd317 (26)72 (34)40 (43)205 (23)
    Malignancy53 (4)17 (8)4 (4)32 (3)
    Other condition197 (16)44 (21)20 (22)133 (15)
    No condition634 (53)77 (37)29 (31)528 (59)
History of Transplantation62 (5)18 (9)9 (10)35 (4)<0.001
Immunosuppression (in last yr)e137 (11)36 (17)17 (18)84 (9)<0.001
Device type<0.001
    Central venous catheter135 (11)40 (19)11 (12)84 (9)
    Foley catheter26 (2)9 (4)2 (2)15 (2)
    Other device120 (10)32 (16)18 (19)70 (8)
    No device922 (77)128 (61)63 (67)731 (81)
Other antibiotic susceptibilitiesf
    Nonsusceptible to cip231 (19)150 (71)18 (19)63 (7)<0.001
    Nonsusceptible to gent172 (14)103 (49)26 (28)43 (5)<0.001
    Nonsusceptible to TMP-SMX434 (36)151 (72)46 (49)237 (26)<0.001
    Nonsusceptible to TMP-SMX and cip171 (14)115 (55)16 (17)40 (4)<0.001
    Nonsusceptible to all three79 (7)61 (29)7 (7)11 (1)<0.001
    Susceptible to all three685 (57)15 (7)41 (44)629 (70)<0.001
  • a Generated comparing 3 categories of outcome for case status: ESBL producing, AmpC producing, and susceptible (controls).

  • b Other sites of infection include the following: in ESBL cases, peritoneal fluid (n = 4), bone (n = 3), and surgical wound (n = 2); in AmpC cases, peritoneal fluid (n = 2) and cerebrospinal fluid (CSF) (n = 1); and in controls, peritoneal fluid (n = 4) and CSF (n = 1).

  • c Definitions of onset are as follows: community associated, culture obtained in an outpatient setting or ≤48 h after hospital admission from an otherwise healthy patient without hospitalization in the previous year; healthcare associated, culture obtained in an outpatient setting or ≤48 h after hospital admission from a patient who had been hospitalized in the previous year and/or had a chronic medical condition requiring frequent health care or prolonged/recurrent antibiotic courses; and hospital associated, culture obtained >48 h after hospital admission or <48 h after hospital discharge from a patient without signs or symptoms of infection on admission.

  • d Diagnoses included in the urologic category are congenital urological abnormality, neurogenic bladder, and vesicoureteral reflux.

  • e Immunosuppressants included antineoplastic agents, high-dose glucocorticoids (≥2mg/kg of body weight), tumor necrosis factor inhibitors, calcineurin inhibitors, and mycophenolate mofetil.

  • f cip, ciprofloxacin; gent, gentamicin; TMP-SMX, trimethoprim-sulfamethoxazole.