title: In-vitro susceptibility of Streptococcus pneumoniae to the d- and l-isomers of ofloxacin: interpretive criteria and quality control limits.
abstract: The l-isomer of ofloxacin (levofloxacin) was twice as active as ofloxacin and the d-isomer was inactive against 654 Streptococcus pneumoniae isolates. For disc susceptibility tests of pneumococci, 5 micrograms levofloxacin discs can be used with interpretive criteria of < or = 12 mm for resistant (MIC > or = 8.0 mg/L) and > or = 16 mm for susceptible (MIC < or = 2.0 mg/L). For quality control of levofloxacin tests, S. pneumoniae ATCC 49619 should give zones 20-25 mm in diameter and MICs 0.5-2.0 mg/L.
authors.affiliation: Clinical Microbiology Institute, Tualatin, Oregon 97062, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Barry
authors.forename: P C
authors.initials: PC
authors.lastname: Fuchs
authors.forename: S D
authors.initials: SD
authors.lastname: Allen
authors.forename: S D
authors.initials: SD
authors.lastname: Brown
authors.forename: J H
authors.initials: JH
authors.lastname: Jorgensen
authors.forename: F C
authors.initials: FC
authors.lastname: Tenover
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D003627:Data Interpretation, Statistical; D064704:Levofloxacin; D008826:Microbial Sensitivity Tests; D015242:Ofloxacin / Q000494:pharmacology*; D011786:Quality Control; D015203:Reproducibility of Results; D013237:Stereoisomerism; D013296:Streptococcus pneumoniae / Q000187:drug effects*
chemical_list: D000890:Anti-Infective Agents; D064704:Levofloxacin; D015242:Ofloxacin