Figure 2.

First AmpC β-lactamase–producing Escherichia coli isolates per 1,000 E. coli isolates per year. Calgary Health Region, 2000–2003. Community isolates were those obtained from outpatients or admitted patients who had their first cultures obtained within 2 days of hospital admission. First cultures from other hospitalized patients obtained after 2 days of admission were deemed to represent hospital-onset isolates.