P. French et al., IN-VITRO ACTIVITY OF NOVOBIOCIN AGAINST MULTIRESISTANT STRAINS OF ENTEROCOCCUS-FAECIUM, Antimicrobial agents and chemotherapy, 37(12), 1993, pp. 2736-2739
Sixty strains of vancomycin- and ampicillin-resistant Enterococcus fae
cium 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 less than or equal to 2 mu g/ml and 40 of
60 strains when it was used at a concentration of less than or equal t
o 0.5 mu g/ml. MICs were 8- to 16-fold higher in 50% serum. Novobiocin
alone resulted in 2-log-unit killing at 24 h. Combinations of novobio
cin and a fluoroquinolone (either ciprofloxacin or ofloxacin) were add
itive and bactericidal for quinolone-susceptible strains in either bro
th or 50% serum. Gentamicin did not affect novobiocin activity, and ri
fampin and doxycycline were antagonistic.