Table 1

Prevalence of antimicrobial drug resistance among 953 E. coli isolates from reproductive-age women with cystitis or pyelonephritis and healthy fecal controls

Resistance parameteraIsolate sourceP value by isolate sourceb
Fecal (n = 330)Cystitis (n = 322)Pyelonephritis (n = 301)Fecal vs cystitisFecal vs pyelonephritisCystitis vs pyelonephritis
No. (%) of isolates resistant to the following antibiotics
    Ampicillin59 (18)135 (42)160 (53)<0.001<0.0010.006
    Amoxicillin-clavulanate33 (10)84 (26)102 (34)<0.001<0.0010.036
    Cephalothin33 (10)129 (40)157 (52)<0.001<0.0010.003
    TMP-SMZ17 (5)64 (20)87 (29)<0.001<0.0010.009
    Nitrofurantoin3 (1)10 (3)9 (3)0.050.05NS
    Gentamicin3 (1)19 (6)21 (7)<0.001<0.001NS
    Amikacin0 (0)6 (2)6 (2)0.0100.010NS
    Norfloxacin10 (3)40 (12)42 (14)<0.001<0.001NS
    Ciprofloxacin10 (3)41 (13)41 (14)<0.001<0.001NS
    Imipenem0 (0)2 (0.5)2 (0.5)NSNSNS
    Nalidixic acid13 (4)68 (21)72 (24)<0.001<0.001NS
    Tetracycline76 (23)182 (57)196 (65)<0.001<0.0010.033
    Ceftriaxone3 (1)13 (4)18 (6)0.011NSNS
    Ceftazidime0 (0)3 (1)12 (4)0.016<0.0010.017
No. (%) of isolates that were ESBL producers3 (1)16 (5)27 (9)0.002<0.0010.04
No. (%) of isolates resistant to >1 agent79 (24)203 (63)201 (67)<0.001<0.001NS
Resistance score (median [range])3 (0–9)5 (0–11)7 (0–13)<0.001<0.001<0.001
  • a TMP-SMZ, trimethoprim-sulfamethoxazole; ESBL, extended-spectrum β-lactamase.

  • b P values are shown where P < 0.05, as calculated by Fisher's exact test; in the last row, the Mann-Whitney U test was used. NS, nonsignificant.