The purpose of this study is to review patients with E. coli infections at UPMC from January 1, 2004 to December 31, 2005 to determine if these infections have arisen in the community rather than in hospitals or nursing homes. The occurrence of such resistant isolates could be devastating if they were associated with bloodstream infection, such as sometimes accompanies urinary tract infection, since antibiotic resistant E. coli is not suspected in isolates coming from the community.

The following variables will be followed: age, sex, hospital location at the time of positive culture (ER, medical ward, ICU etc), prior hospitalization or nursing home admission, receipt of outpatient dialysis or other regular medical care (eg, outpatient chemotherapy), presence of invasive devices, receipt of antibiotics, including their type and whether they were adequate for the resistance profile of the organism, prior positive microbiologic cultures.

Inclusion Criteria:

• ll patients with E. coli infections during the time period of the study will be reviewed. A community-associated E. coli isolate will be defined as one which was recovered from a clinical culture from a patient at UPMC-P who had no established risk factors for infection with an antibiotic resistant organism.

Established risk factors are defined as:

• Isolation of the organism two or more days after admission for hospitalization OR A history of hospitalization, surgery, dialysis, or residence in a long-term care facility within one year before the culture date
• OR The presence of an indwelling catheter or percutaneous medical device (eg, tracheostomy tube, gastrostomy tube, or Foley catheter) at the time of the culture
• OR Previous isolation of an antibiotic resistant organism