title: Comparison of Etest, agar dilution, broth microdilution and disk diffusion methods for testing in vitro activity of levofloxacin against Staphylococcus spp. isolated from neutropenic cancer patients.
abstract: The susceptibility to levofloxacin of 194 consecutive staphylococcal (45 Staphylococcus aureus and 149 coagulase-negative staphylococci) isolates from neutropenic patients was determined by Etest and the results compared with those obtained using NCCLS-methods (broth microdilution, agar dilution and disk diffusion). Overall agreement at +/- 1log(2) dilution for Etest compared with broth microdilution and agar dilution was 99.0 and 83.5%, respectively. The Etest category agreement with broth microdilution and disk diffusion was 95.9 and 89.7%, respectively. Comparison of categories with Etest and agar dilution method gave only 67.0% absolute categorical agreement, with 29.9% minor errors and 10.7% major errors. No very major errors occurred by the four methods tested. Our results show that Etest is a valid alternative to the reference NCCLS-methods for monitoring the clinical usefulness of levofloxacin against staphylococci isolates from neutropenic patients.
authors.affiliation: Department of Biomedical Sciences, Laboratory of Clinical Microbiology, G. D'Annunzio University, Via dei Vestini 31, I-66100, Chieti, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Di Bonaventura
authors.forename: Domenico
authors.initials: D
authors.lastname: D'Antonio
authors.forename: Giovanni
authors.initials: G
authors.lastname: Catamo
authors.forename: Enzo
authors.initials: E
authors.lastname: Ballone
authors.forename: Raffaele
authors.initials: R
authors.lastname: Piccolomini
mesh_terms: D000362:Agar; D000890:Anti-Infective Agents / Q000494:pharmacology; D003470:Culture Media; D004058:Diffusion; D004352:Drug Resistance, Microbial; D006801:Humans; D064704:Levofloxacin; D008826:Microbial Sensitivity Tests / Q000379:methods*; D009369:Neoplasms / Q000150:complications / Q000382:microbiology*; D009503:Neutropenia / Q000150:complications / Q000382:microbiology*; D015242:Ofloxacin / Q000494:pharmacology*; D013210:Staphylococcus / Q000187:drug effects*
chemical_list: D000890:Anti-Infective Agents; D003470:Culture Media; D064704:Levofloxacin; D000362:Agar; D015242:Ofloxacin