A Canadian National Surveillance Study of Urinary Tract Isolates from Outpatients: Comparison of the Activities of Trimethoprim-Sulfamethoxazole, Ampicillin, Mecillinam, Nitrofurantoin, and Ciprofloxacin

Abstract

Ampicillin, trimethoprim-sulfamethoxazole, mecillinam, nitrofurantoin, and ciprofloxacin mean resistance rates for 2,000 urinary tract isolates collected from outpatients across Canada in 1998 were 41.1, 19.2, 14.7, 5.0, and 1.8%, respectively. For Escherichia coli isolates alone (n ‫؍‬ 1,681) comparable rates were 41.0, 18.9, 7.4, 0.1, and 1.2%, respectively. The majority of E. coli isolates resistant to ampicillin, trimethoprim-sulfamethoxazole, or ciprofloxacin were susceptible (MIC, <16 g/ml) to mecillinam.Ampicillin and trimethoprim-sulfamethoxazole (SXT) resistance among urinary tract isolates has recently been reported with an increased frequency in Canada and the United States

Increased resistance to first-line agents among bacterial pathogens isolated from urinary tract infections in Latin America: time for local guidelines?

“…was the most common gram-positive uropathogen, responsible for 5.6% of all CA-UTI. These data are similar to those presented by other surveillance studies, in which gram-negative agents were the most common pathogens associated with CA-UTI (Zhanel et al 2000, Kahlmeter 2003.…”

Endemic and Epidemic Lineages ofEscherichia colithat Cause Urinary Tract Infections

“…Over the past decade, the prevalence of drug resistance in E. coli has increased dramatically, complicating management of these infections. Across the United States and Canada, urinary tract isolates of E. coli from outpatient clinics showed increased resistance to TMP-SMZ and ampicillin (4). A more serious concern has been the gradual increase in fl uoroquinolone (e.g., ciprofl oxacin) resistance among UTI isolates (5).…”

Clinical Risk Factors and Multi-Antimicrobial Resistance Pattern in Community-Acquired Outpatient Urinary Tract Isolates of Escherichia Coli

“…While previous retrospective studies that have inferred co-resistance of ciprofloxacin with other antimicrobials are unlikely in outpatient urinary E. coli isolates, our susceptibility data reported about 38% (n = 437/1160) of all MDR phenotypes which are resistant to ciprofloxacin were also resistant to 4 common antimicrobial phenotypes [6,15,18,19]. The co-resistance association between the ciprofloxacin resistant isolates with isolates resistant for TMP/SMX, nitrofurantoin, and cefazolins appeared to be significantly (P < 0.0001) strong ( Table 4 and Table 5).…”

“…In recent years overall use of fluoroquinolones, particularly ciprofloxacin in ambulatory care, has dramatically increased [8][9]. Clinicians and researchers already began to observe an increasing trend in E. coli resistance urinary isolates for quinolones in addition to ampicillin and TMP/SMX [5,6,10]. The focus of this study was to identify common risk factors as well as the distribution and characteristics of multi-antimicrobial resistance patterns of commonly prescribed antibiotics among E. coli infected UTI patients in community ED and outpatient clinics.…”

“…While resistance to amoxicillin has been established for years, trimethoprim/sulfamethoxazole (TMP/SMX) resistance became more prevalent in recent years. Studies have shown that TMP/SMX resistance rate varies by region ranging from 18% to 50% worldwide and from 18% to 25% in North America [3][4][5][6]. Recently revised published guidelines by the Infectious Disease Society of America (IDSA) recommended TMP/SMX therapy should not be used as empiric therapy in regions where the prevalence of TMP/SMX resistance rates exceed 20% [7].…”