Consequences of changing resistance patterns in urinary tract infections

Escherichia coli is responsible for the majority of uncomplicated urinary tract infections in healthy women. The rate of resistance to cotrimoxazole (trimethoprim-sulfamethoxazole) among E. coli urinary isolates from outpatients is approaching and even exceeding 20% in some regions of the USA. Evidence linking in vitro resistance with poorer clinical outcome in cystitis and pyelonephritis is accumulating. Recent prior or current use of antibacterials, recent hospitalisation and comorbidity, e.g. diabetes mellitus, are associated with a greater likelihood of antibacterial resistance. In areas of high resistance to cotrimoxazole, depending upon the risks associated with treatment failure, empirical therapy may have to be altered. This article reviews recent literature on the prevalence of resistance, clinical outcomes associated with in vitro resistance, and management of community-acquired urinary tract infections in the era of increased uropathogen resistance.