Antimicrobial resistance in E-Coli associated with urinary tract infection in the West of Ireland

Background Knowledge of antimicrobial resistance patterns in E. coli,the predominant pathogen associated with urinary tract infection (UTI) is important as a guide in selecting empirical antimicrobial therapy. Aims To describe the antimicrobial susceptibility of E. coli associated with UTI in a region in the West of Ireland. Methods A collection of 934 E. coli isolates associated with UTI were tested for susceptibility to a panel of antimicrobial agents by the disc diffusion method of the National Committee for Clinical Laboratory Standards. Results More than 50% of E. coli were resistant to ampicillin, more than 40% resistant to sulphonamide and more than 30% resistant to trimethoprim. From 7.9% (community) to 12.5% (hospital) are resistant to co-amoxiclav with approximately 20% of isolates of intermediate susceptibility. In general practice most E. coli remain susceptible to nitrofurantoin (96.7%), nalidixic acid (93.9%) and ciprofloxacin (94.7%). For all agents rates of resistance were higher in hospital as compared with general practice isolates. Three isolates with the phenotype of Extended Spectrum Beta-lactamase (ESBL) resistance were detected. Conclusions Ampicillin/amoxicillin are not suitable for empiric therapy of UTI in general practice or hospital patients in this region. There is doubt as to the role of trimethorpim or co-trimoxazole for empiric therapy of UTI. Nitrofurantoin, nalidixic acid and ciprofloxacin are active against the great majority of UTI associated E. coli.