Five-year survey of changing patterns of susceptibility of bacterial uropathogens to trimethoprim-sulfamethoxazole and other antimicrobial agents

Abstract

We analyzed the antibiotic susceptibility of 5,348 urinary isolates of Escherichia coli, "Klebsiella aerogenes," and Proteus mirabilis grown in three laboratories from 1980 to 1985. A continuous rise in resistance to trimethoprim-sulfamethoxazole was observed; 63% of the strains from inpatients in 1984 and 51% of those from outpatients in 1985 were resistant to this drug. Isolates from outpatients in 1985 were mostly susceptible to nitrofurantoin (mean susceptibility, 92%) and to oral cephalosporins (mean susceptibility, 84%). As for isolates from inpatients, none of the antimicrobial agents now used was satisfactory for initial chemotherapy, indicating a need for new antibacterial strategies.