Surrogate testing of oral third-generation cephalosporin susceptibility to common uropathogens.

Cefazolin susceptibility of urine isolates of Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis predicts susceptibility to oral cephalosporins, but cefazolin-resistant isolates may be susceptible to oral third-generation cephalosporins. Among 194 urine isolates, we found >95% categorical agreement among oral third-generation cephalosporins. Surrogate testing of cefpodoxime for cefdinir, and vice versa, resulted in no major or very major errors, while combinations involving cefixime produced rare major and very major errors.