In vitro activity of novobiocin against multiresistant strains of Enterococcus faecium.
Sixty strains of vancomycin- and ampicillin-resistant Enterococcus faecium were evaluated for their susceptibilities to novobiocin in vitro. In Mueller-Hinton broth, novobiocin inhibited all strains when it was used at a concentration of < or = 2 microgram/ml and 40 of 60 strains when it was used at a concentration of < or = 0.5 micrograms/ml. MICs were 8- to 16-fold higher in 50% serum. Novobiocin alone resulted in 2-log-unit killing at 24 h. Combinations of novobiocin and a fluoroquinolone (either ciprofloxacin or ofloxacin) were additive and bactericidal for quinolone-susceptible strains in either broth or 50% serum. Gentamicin did not affect novobiocin activity, and rifampin and doxycycline were antagonistic.
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Dorrance H. Hamilton Laboratories, Department of Medicine, Jefferson Medical College, Philadelphia, Pennsylvania 19107.
Venuti
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Fraimow
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D000890:Anti-Infective Agents / Q000494:pharmacology; D002939:Ciprofloxacin / Q000494:pharmacology; D004347:Drug Interactions; D004352:Drug Resistance, Microbial / Q000235:genetics; D016984:Enterococcus faecium / Q000187:drug effects* / Q000235:genetics; D009675:Novobiocin / Q000494:pharmacology*; D015242:Ofloxacin / Q000494:pharmacology
D000890:Anti-Infective Agents; D009675:Novobiocin; D002939:Ciprofloxacin; D015242:Ofloxacin