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

Abstract

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. Antibiotic use is the single most important modifiable risk factor for antibiotic resistance (1). Urinary tract infection (UTI), accounting for Ͼ8 million office visits and 1 million emergency department visits annually in the United States, is one of the most frequent indications for antibiotic use in ambulatory care (2). For the treatment of uncomplicated UTIs, or cystitis, clinical practice guidelines recommend the empirical use of nitrofurantoin or trimethoprim-sulfamethoxazole (TMP-SMX) as first-line therapy (3, 4). Fluoroquinolones, including ciprofloxacin and levofloxacin, are considered alternative agents for the treatment of uncomplicated UTIs (3).An important consideration for the appropriate empirical treatment of UTIs is antibiotic susceptibility among uropathogens isolated from urine cultures (3). Urine cultures are often obtained for outpatients with UTIs, including those with recurrent infections, previous treatment failures, or complicated infections (5). Few investigations have explored national trends of outpatient antibiotic resistance among uropathogens in women. The objectives of this study were to examine the recent prevalence of in vitro antibiotic resistance among common bacteria isolated from urine cultures collected from U.S. female outpatients and to assess trends in antibiotic resistance by comparing data from 2003 and 2012. MATERIALS AND METHODSWe performed a retrospective analysis of antibiotic susceptibility test results from urine cultures collected from female outpatients in the United States comparing 2003 with 2012 data from The Surveillance Network (TSN) (Eurofins Medinet, Chantilly, VA). More than 200 institutions in the United States collected and submitted susceptibility data and corresponding demographic information (age, sex, and site of infection) to TSN during these years. Outpatients were defined as individuals who visited any ambulatory care setting, such as an emergency department, hospital-based outpatient clinic, or...

Antimicrobial Resistance of Escherichia coli Urinary Isolates in the Veterans Affairs Health Care System

“…Trimethoprimsulfamethoxazole should not be used for empirical treatment of acute cystitis when local antibiograms reveal Ն20% resistance, according to Infectious Diseases Society of America (IDSA) guidelines (2). Similar to previous findings, we demonstrated that rates of resistance to nitrofurantoin remain low, and this is an appropriate option for patients with uncomplicated cystitis (15,16). For empirical inpatient treatment options, our data suggest that antipseudomonal penicillin/␤-lactamase inhibitors and carbapenems remain among the most active agents, similar to recent nationwide surveillance data (6,13).…”

“…We identified high rates of antimicrobial resistance to several commonly used E. coli UTI treatment options. The overall rate of fluoroquinolone resistance using NHSN methods was 34%, with resistance reaching almost 50% among inpatients and being 30% for outpatients, similar to previous studies (6,(13)(14)(15)(16). These findings are concerning, as fluoroquinolones are frequently used empirically to treat UTIs, especially complicated infections.…”

“…Several studies with E. coli urinary isolates from U.S. outpatients have reported Ͼ20% resistance to trimethoprim-sulfamethoxazole (15,16). Trimethoprimsulfamethoxazole should not be used for empirical treatment of acute cystitis when local antibiograms reveal Ն20% resistance, according to Infectious Diseases Society of America (IDSA) guidelines (2).…”

Reply to “Nitrofurantoin, an Excellent Empiric Choice for Outpatient Cystitis”

“…; Centers for Disease Control and Prevention, Atlanta, Georgia, USA b W e read the letter from Cortes-Penfield and Trautner (1) and thank them for their interest in our recent paper (2). In our paper, we demonstrated increasing resistance of Escherichia coli to ciprofloxacin and trimethoprim-sulfamethoxazole (TMP-SMX) in urinary isolates obtained from adult female outpatients, with the isolates retaining high levels of susceptibility to nitrofurantoin.…”

Nitrofurantoin, an Excellent Empiric Choice for Outpatient Cystitis

“…e read with interest the report by Sanchez et al describing antibiotic resistance among the 10 most common pathogens isolated from urine cultures in women in the outpatient setting (1). Resistance rates reflected in the over 1.6 million isolates reported may exceed the prevalence of resistance in cases of uncomplicated cystitis in which a urine culture is not collected (2).…”