In vitro activity of moxifloxacin, a new 8-methoxyquinolone, against gram-positive bacteria

Kumthorn Malathum, Kavindra V. Singh, Barbara E. Murray

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


The in vitro activity of moxifloxacin, formerly BAY 12-8039, against gram-positive bacteria was tested by the agar dilution method. A total of 189 isolates that included Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, streptococci, rhodococci, leuconostocs, pediococci, lactobacilli, and diphtheroids were tested. Moxifloxacin showed greater potency than ciprofloxacin against S. aureus, streptococci, and enterococci, having Minimal Inhibitory Concentrations (MICs) lower than those of ciprofloxacin by 2- to 64-fold. This improved activity was most prominent for S. aureus. Moxifloxacin was active against Leuconostoc and Rhodococcus species. Time-kill studies using moxifloxacin at a concentration of 3 μg/mL against one isolate each of methicillin-resistant S. aureus (MSSA) (MIC, 0.031 μg/mL), MRSA (MIC, 1 μg/mL), two isolates of E. faecalis (MICs, 0.25 and 2 μg/mL), and two isolates of vancomycin-resistant E. faecium (MICs, 0.25 and 2 μg/mL) revealed an average decrease in colony forming unit (CFU) by 3.8, 0.4, 4.0, 2.0, 4.2, and 1.8 log10 CFU/mL at 24 h, respectively. Moxifloxacin is a new 8-methoxyquinolone with improved in vitro activity against gram-positive bacteria. Further studies of the in vivo activity of this compound appear warranted. Copyright (C) 1999 Elsevier Science Inc.

Original languageEnglish (US)
Pages (from-to)127-133
Number of pages7
JournalDiagnostic Microbiology and Infectious Disease
Issue number2
StatePublished - Oct 1999

ASJC Scopus subject areas

  • Microbiology (medical)
  • Infectious Diseases


Dive into the research topics of 'In vitro activity of moxifloxacin, a new 8-methoxyquinolone, against gram-positive bacteria'. Together they form a unique fingerprint.

Cite this