Integron-mediated ESBL resistance in rare serotypes of Escherichia coli causing infections in an elderly population of Israel.

Objectives: To identify and characterize the aetiology of an outbreak of extra-intestinal multidrug-resistant Escherichia coli infections in elderly patients in Israel.

Methods: Extended-spectrum beta-lactamase (ESBL)-producing clinical isolates of E. coli from extra-intestinal sources were tested for susceptibility to non-beta-lactam drugs, and their serotypes were determined.

Endemic occurrence of infections by multidrug-resistant Escherichia coli of four unique serotypes in the elderly population of Israel.

During a period of four years, multidrug-resistant Escherichia coli of particular serotypes have been isolated from 255 elderly (>65 years) patients from four hospitals in central Israel. 83% of the isolates belonged to one of four predominant serotypes (O153:H31, O101:H-, O2:H42, and O102:H6). All isolates were producers of extended spectrum beta-lactamases and resistant to ciprofloxacin.