Secular Trend and Risk Factors for Antimicrobial Resistance in Escherichia coli Isolates in Switzerland 1997–2007

Abstract

Background: Antibacterial resistance in Escherichia coli isolates of urinary infections, mainly to fluoroquinolones, is emerging. The aim of our study was to identify the secular trend of resistant E. coli isolates and to characterize the population at risk for colonization or infections with these organisms. Patients and Methods: Retrospective analysis of 3,430 E.coli first isolates of urine specimens from patients admitted to the University Hospital Basel in 1997Basel in , 2000Basel in , 2003Basel in , and 2007. Results: Resistance to ciprofloxacin, trimethoprim/sulfamethoxazole, and amoxicillin/clavulanate has increased over the 10-year study period (from 1.8% to 15.9%, 17.4% to 21.3%, and 9.5% to 14.5%, respectively). A detailed analysis of the 2007 data revealed that independent risk factors for ciprofloxacin resistance were age (5.3% < 35 years of age to 21.9% in patients > 75 years; odds ratio [OR] 1.29 per 10 years, 95% confidence interval [CI] 1.15-1.45, p < 0.001) and male gender (OR 1.59, 95% CI 1.05-2.41, p = 0.04). In contrast, nosocomial E. coli isolates were associated with lower odds of ciprofloxacin resistance (OR 0.51, 95% CI 0.28-0.67, p < 0.001). The frequency of resistant isolate rates was not influenced by the clinical significance (i.e., colonization vs urinary tract infection, UTI) or by whether the urine was taken from a urinary catheter. Importantly, the increase in ciprofloxacin resistance paralleled the increase in ciprofloxacin consumption in Switzerland (Pearson's correlation test R 2 = 0.998, p = 0.002). Of note, resistance was less frequent in isolates sent in by general practitioners. However, after adjustment for age and gender, only resistance against amoxicillin/clavulanate was found to be less frequent (OR 0.34, p = 0.03). Conclusion: Our study reveals that resistance rates have been increasing during the last decade. Published resistance rates may lack information due to important differences regarding age, gender, and probable origin of the isolates. Empirical therapy for UTI should be guided more on individual risk profile and local resistance data than on resistance data banks.

Prevalence of Antimicrobial-Resistant Pathogens in Canadian Hospitals: Results of the Canadian Ward Surveillance Study (CANWARD 2008)

“…For Gram-negative bacilli, resistance was more likely to occur in isolates obtained from inpatients and men. These data support the current literature, which indicates that antimicrobial resistance generally increases with increasing age and among inpatients (4,34). Especially among urinary tract isolates of E. coli, it has been established that resistance is higher in men than in women and increases with age (4).…”

Factores asociados al desarrollo de infección urinaria de origen comunitario causada por Escherichia coli resistente a fluoroquinolonas

“…A pesar que varios trabajos analizan los factores de riesgo asociados al desarrollo de ITU por bacilos gramnegativos resistente a FQ 13,[25][26][27][28][29][30] pocos analizan, exclusivamente, infecciones de origen comunitario 14,15,29 y ninguno analizó, como lo hizo nuestro estudio, pacientes con ITU de origen comunitario identificados en forma prospectiva como tampoco excluyeron aquellos que pudieran tener factores de confusión tales como portación de catéter vesical y/o institucionalizados.…”

Incidence of Antibiotic Resistance Bacteria in Jeddah's Ministry of Health Hospitals, Saudi Arabia

“…In contrast, E. coli collected during 1997-2007 from urine specimens showed increasing resistance to ciprofloxacin, trimethoprim/sulfamethoxazole, and amoxicillin/clavulanic acid [8]. In a 30-year (1979-2009) follow-up study in Sweden, E. coli showed an increasing resistance towards ampicillin, sulfonamide, trimethoprim, and gentamicin [9] and this yet was a great concern.…”