Approximately 85% of antibiotics in Spain are prescribed to outpatients, but information available on the antibiotic resistance profile is nearly exclusively based on specimens from hospitalised patients, mainly those with severe and invasive infectious diseases [1]. It is well established that the prevalence of resistance to antibiotics greatly depends on their use since increased consumption of these drugs may not only produce higher resistance at the individual patient level but may also spur greater resistance at the community level, which can harm individual patients. The relationship between antibiotic consumption and the emergence of resistant pathogenic germs is well established [1,2], but evidence about previous antibiotic use regarding the isolation of resistant commensal germs in otherwise healthy individuals is scarce.