Lm. Dembry et al., IN-VITRO ACTIVITY OF TROVAFLOXACIN AGAINST SENSITIVE AND RESISTANT AEROBIC-BACTERIA USING THE STANDARD MICRODILUTION BROTH METHOD AND ETEST, Journal of antimicrobial chemotherapy, 39, 1997, pp. 35-42
A comparison of MICs of trovafloxacin (CP-99,219) determined by the st
andard microdilution broth method versus the Etest was performed for m
ultiple strains of Gram-positive and Gram-negative bacteria. A compari
son was also made of the in-vitro activity of trovafloxacin versus cip
rofloxacin and ofloxacin. The MIC50 and MIC90 were determined by both
methods for each species tested. The Etest resulted in MICs one to two
dilutions higher than the microdilution broth method. Trpvafloxacin w
as the most active agent against Gram-positive organisms. Ciprofloxaci
n was the most active agent against Citrobacter freundii, Proteus mira
bilis, Proteus vulgaris, Morganella morganii and Serratia marcescens,
while trovafloxacin had equal or greater activity compared with ciprof
loxacin and ofloxacin against the other Gram-negative organisms tested
. Overall, ofloxacin was the least active agent tested. In addition, t
he in-vitro activity of trovafloxacin or ciprofloxacin in combination
with ampicillin/sulbactam, gentamicin or vancomycin was evaluated. The
combination of trovafloxacin and gentamicin was synergic against two
of 20 Enterococcus faecium isolates, the combination of trovafloxacin
and ampicillin/sulbactam was synergic against two of 24 Enterococcus f
aecalis isolates, and the combination of ciprofloxacin and gentamicin
was synergic against one of 25 Stenotrophomonas maltophilia isolates.
All other antibiotic combinations resulted in an additive or indiffere
nt effect.