The bacterial strains used in this study were part of a research collection of E. coli isolated from UTI cultures during the years of 2007–2008. There were 80 isolates selected from this collection that represented a wide spectrum of antimicrobial susceptibility patterns; in addition, two control strains that were susceptible to all the clinically tested (prior to this study) antimicrobials were selected. Table 1 shows the antimicrobial agents tested and frequency of the strains that were resistance to each drug.