High rate of intestinal colonization with extended-spectrum-beta-lactamase-producing organisms in household contacts of infected community patients.

Fecal carriage of extended-spectrum-beta-lactamase (ESBL)-producing organisms was detected in 70% of index cases of patients (n = 40) with community-acquired infections due to ESBL producers and reached 16.7% in household contacts (n = 54). A total of 66% of ESBL-producing organisms from index cases were indistinguishable from isolates from household contacts by pulsed-field gel electrophoresis. Patients with community infections and members of their households represent a reservoir for ESBL producers, increasing dispersal of resistance in healthy people.