Prevalence of antibiotic resistance in Escherichia coli: overview of geographical, temporal, and methodological variations.

The increase in bacterial antibiotic resistance is of major concern worldwide, but pertinent epidemiologic studies have used strongly divergent approaches and are widely scattered in the literature. The aim of this study was to conduct a systematic review of studies reporting on the prevalence of antibiotic resistance in Escherichia coli in different parts of the world. Studies published from 1970 to 2006 on the prevalence of E. coli resistance were identified by a systematic Medline research and reviewed with respect to characteristics of the study design and study population, the method of resistance detection, and the prevalence of resistance. The prevalence of resistance to specific antibiotics was highly variable in different populations and in different countries and ranged from 0 to 100%. The prevalence of resistance reported in studies from Middle and South America, Spain, and Turkey was higher than that reported in the USA and Central Europe. Moreover, a tendency towards higher prevalence rates of resistance in recent years was observed. The findings indicate a need for regular monitoring of antimicrobial susceptibility rates in different human and animal populations by standardized sampling and measurement procedures. Such monitoring would help identify relevant factors that contribute to the spread of resistant pathogens and would support the prudent use of antibiotics.