Predominance of a single restriction endonuclease analysis group with intrahospital subgroup diversity among Clostridium difficile isolates at two Chicago hospitals.

Objective: To determine the epidemiology and relatedness of Clostridium difficile isolates in two geographically separated hospitals in a large metropolitan area, each with unique patients and personneL DESIGN: Observational descriptive molecular epidemiology of clinical C. difficile isolates.

Setting: Two tertiary-care hospitals in Chicago.