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

• Published in: Diagnostic microbiology and infectious disease Vol. 99; no. 4; p. 115299
• Main Authors: Watson, Joshua R., Burch, Cynthia, Leber, Amy L.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-04-2021
• Subjects: Cefazolin; Cefdinir; Cefixime; Cefpodoxime; Susceptibility testing; Uropathogen; CLSI; Cefazolin; Uropathogen; BMD; Susceptibility testing; Cefdinir; UTI; Cefixime; Cefpodoxime; 3GC
• ISSN: 0732-8893; 1879-0070
• DOI: 10.1016/j.diagmicrobio.2020.115299

•Oral third-generation cephalosporins may treat cefazolin-resistant uropathogens.•We evaluated surrogate susceptibility testing of cefpodoxime, cefdinir, and cefixime.•Escherichia coli susceptibility results for cefpodoxime predicted cefdinir, and vice versa.•Similar results for Klebsiella pneumoniae and Proteus mirabilis, but fewer isolates tested.•Surrogate testing involving cefixime produced rare major and very major errors.
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.