The antimicrobial resistance of urinary Escherichia coli (E. coli) isolates to ciprofloxacin and trimethoprim-sulfamethoxazole (TMP-SMX) increased substantially from 2000 to 2010, according to a study published in the April issue of Antimicrobial Agents and Chemotherapy.
Guillermo V. Sanchez, MD, of George Washington University in Washington D.C., and colleagues assessed trends in antimicrobial resistance from E. coli isolates for 12,253,679 urine samples from U.S. outpatients obtained between 2000 and 2010. The researchers found that ciprofloxacin resistance of E. coli from urine samples increased from 3% to 17.1%, and TMP-SMX resistance increased from 17.9% to 24.2%. There was little change in resistance to nitrofurantoin (0.8% to 1.6%) and ceftriaxone (0.2% to 2.3%).
“In summary, our study shows that from 2000 to 2010, antimicrobial resistance of urinary E. coli isolates to ciprofloxacin and TMP-SMX increased substantially but that resistance to nitrofurantoin and ceftriaxone remained low,” the authors wrote. “Given the frequency with which urinary tract infections are treated empirically, compounded with the speed that E. coli acquires resistance, prudent use of antimicrobial agents remains crucial.”