Antibiotic Resistance Among Urinary Isolates from Female Outpatients in the United States in 2003 and 2012

A retrospective analysis was performed using The Surveillance Network, USA, to examine the prevalence of antibiotic resistance among urine isolates from U.S. female outpatients in 2012 and assessed trends in antibiotic resistance comparing data from 2003 and 2012. The most common pathogen identified in 2012 (n = 285,325) was Escherichia coli (64.9% of isolates). In 2012, E. coli resistance to nitrofurantoin was low (<3%) across all age groups. E. coli resistance to ciprofloxacin was high among adults (11.8%) and elderly outpatients (29.1%). When comparing the 2003 and 2012 data from isolates from adults, E. coli resistance to nitrofurantoin changed only slightly (from 0.7% to 0.9%), whereas increases in resistance to ciprofloxacin (3.6% to 11.8%) and trimethoprim-sulfamethoxazole (17.2% to 22.2%) changed substantially. In the United States, E. coli has become increasingly resistant to ciprofloxacin and trimethoprim-sulfamethoxazole (TMP-SMX) in adult female outpatients. Nitrofurantoin retains high levels of antibiotic activity against urinary E. coli.