A Canadian national surveillance study of urinary tract isolates from outpatients: Comparison of the activities of trimethoprim-sulfamethoxazole, ampicillin, mecillinam, nitrofurantoin, and ciprofloxacin

Ampicillin, trimethoprim-sulfamethoxazole, mecillinam, nitrofurantoin, and ciprofloxacin mean resistance rates for 2,000 urinary tract isolates collected from outpatients across Canada in 1998 were 41.1, 19.2, 14.7, 5.0, and 1.8%, respectively. For Escherichia coli isolates alone (n = 1,681) comparable rates were 41.0, 18.9, 7.4, 0.1, and 1.2%, respectively. The majority off. coli isolates resistant to ampicillin, trimethoprim-sulfamethoxazole, or ciprofloxacin were susceptible (MIC, <16 mu g/ml) to mecillinam.