TABLE 2 

Association of ST131 subclones with resistance traits among 261 recent clinical isolates of Escherichia coli ST131 from the United States and Germany

Resistance traitPrevalence of resistance trait, no. (%)
Total ST131 strains
(n = 261)
ST131 subclone(s)
Non-H30
(n = 87)
H30 (n = 174)
Non-H30-R
(n = 11)
H30-R (n = 165)
Non-H30-Rx
(n = 119)
H30-Rx
(n = 44)
FQ resistant163 (62)0 (0)0 (0)119 (100)44 (100)a
ESBL45 (17)3 (3)1 (9)7 (6)34 (77)b
blaCTX-M-1539 (15)3 (7)1 (9)2 (2)33 (75)c
  • a For the fluoroquinolone (FQ)-resistant fraction, H30-Rx compared to other ST131 isolates, P < 0.001 (Fisher’s exact test [FET]).

  • b For prevalence of extended-spectrum β-lactamase (ESBL) production, H30-Rx compared to other ST131 isolates, P < 0.001 (FET).

  • c For prevalence of blaCTX-M-15, H30-Rx compared to other ST131 isolates, P < 0.001 (FET).