In-vitro susceptibility of Streptococcus pneumoniae to the d- and l-isomers of ofloxacin: interpretive criteria and quality control limits.
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.
Barry
A L
AL
Clinical Microbiology Institute, Tualatin, Oregon 97062, USA.
Fuchs
P C
PC
Allen
S D
SD
Brown
S D
SD
Jorgensen
J H
JH
Tenover
F C
FC
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*
D000890:Anti-Infective Agents; D064704:Levofloxacin; D015242:Ofloxacin