Widespread antibiotic resistance has been recognized in Escherichia coli isolates from human, animal and environmental sources. Although prevalence rates for resistant E coli strains are significantly distinct for various populations and environments, the impact of resistance to antimicrobial drugs is ubiquitous. This article provides information about the epidemiology, mechanisms and molecular principles of resistance, shows consequences for the antiinfective treatment of selected infections and describes measures to control the spread of antibiotic-resistant E coli. (c) 2005 Elsevier GmbH. All rights reserved.