TABLE 1

Contribution of ST131, non-ST131, and stool E. coli isolates to overall antimicrobial resistance rates

Resistance traitOverall prevalence of resistant phenotype in population (%)Estimated fraction due to:
ST131 clinical isolatesNon- ST131 clinical isolatesStool non-ST131 isolates
Quinolone or fluoroquinolone
    Ciprofloxacin760.400.250.34
    Nalidixic acid950.380.230.38
Sulfonamide-trimethoprim, co-trimoxazole680.330.230.43
Aminoglycosides, gentamicin450.470.210.31
Phenicols, chloramphenicol280.510.170.31
Tetracyclines, tetracycline670.350.270.37
ESBL phenotype870.330.300.35
MBL phenotypea200.480.520.00
Multidrug resistance920.330.320.33
  • a Fisher's exact test did not identify any significant differences between the three groups of strains for the different traits analyzed, except for the MBL phenotype, in which the P value for ST131 and non-ST131 isolates was <0.05 in comparison with stool E. coli isolates.