Streptococcus pneumoniae killing rate and post-antibiotic effect of levofloxacin and ciprofloxacin.
In vitro killing rates for levofloxacin and ciprofloxacin for six strains of Streptococcus pneumoniae were determined by the time-kill method outlined by the NCCLS. Both drugs were bactericidal at concentrations of two and four times their respective minimum inhibitory concentrations (MICs). Levofloxacin achieved a 99.9% kill on average in 1 hour more rapidly than ciprofloxacin. Post-antibiotic effect was also determined for both drugs against the same six strains. A post-antibiotic effect for a mean of 1.2 and 1.0 hours was observed for levofloxacin and ciprofloxacin, respectively. The latter means were not considered significantly different.
Fuchs
P C
PC
The Clinical Microbiology Institute, Wilsonville, Oregon 97070, USA.
Barry
A L
AL
Brown
S D
SD
D000890:Anti-Infective Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology*; D015169:Colony Count, Microbial; D064704:Levofloxacin; D008826:Microbial Sensitivity Tests; D015242:Ofloxacin / Q000494:pharmacology*; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D013997:Time Factors
D000890:Anti-Infective Agents; D002939:Ciprofloxacin; D064704:Levofloxacin; D015242:Ofloxacin