Genetic relatedness of multidrug-resistant Escherichia coli cultured from geographically diverse outpatient, midstream urine specimens

Genomic DNA from 70 demographically matched geographically diverse pairs of urinary isolates of antimicrobial-susceptible and multidrug-resistant Escherichia coli was restricted using XbaI and analyzed by pulsed-field gel electrophoresis. Antimicrobial-susceptible isolates demonstrated limited genetic relatedness, whereas 2 epidemiologic clusters containing a total of 40 isolates (57.1%) were identified among the multidrug-resistant isolates.