Disk diffusion interpretive zone size criteria for use with Haemophilus test medium are proposed for five extended-spectrum cephalosporins. With cefuroxime, zones ≤24 mm in diameter indicated susceptibility, while zones ≤20 mm implied resistance. With cefotaxime, ceftazidime, ceftizoxime, and ceftriaxone, a single susceptible-zone size, ≥26 mm, is proposed.
ASJC Scopus subject areas
- Microbiology (medical)