Moxifloxacin superior to vancomycin for treatment of bone infections--a study in rats.
BACKGROUND
Increasing resistance rates towards conventional antibiotics necessitate investigations of the efficacy of newly developed antibiotics. Thus, in a rat study, we compared the efficacy of moxifloxacin and vancomycin in the treatment of a local Staphylococcus aureus bone infection.


METHODS
The femoral medullary cavities of 36 Wistar rats were contaminated with 100 muL of an oxacillin-sensitive Staphylococcus aureus strain (ATCC 29213) at 10(8) cfu/mL. On the seventh day, antibiotic treatment with moxifloxacin (10 mg/kg twice daily i.p.) or vancomycin (15 mg/kg twice daily i.p.) was commenced in 12 animals each. 12 control animals were left untreated. After 21 days, the infected femurs were explanted and the bacterial counts (cfu/g) were determined.


RESULTS
In the control group, a median of 3.42 x 10(6) cfu/g (LQ/UQ 1.09 x 10(6)/ 1.55 x 10(7)) was cultured, with a median of 2.53 x 10(6) cfu/g (LQ/UQ 1.95 x 10(6)/ 4.25 x 10(6)) in the vancomycin group and a median of 2.49 x 10(5) cfu/g (LQ/UQ 2.84 x 10(4)/ 3.75 x 10(5)) in the moxifloxacin group. The bacterial count was reduced by treatment with moxifloxacin both in comparison with the control group (p < 0.001), and in comparison with treatment with vancomycin (p < 0.001). There was no statistically significant difference between the vancomycin group and the control group (p = 0.53).


CONCLUSIONS
In contrast to vancomycin, moxifloxacin proved to be an effective antibiotic for the treatment of bone infections due to Staphylococcus aureus in our animal model.
Kalteis
Thomas
T
Department of Orthopaedic Surgery, University of Regensburg, Germany. thomas.kalteis@klinik.uni-regensburg.de
Beckmann
Johannes
J
Schröder
Hans-Jürgen
HJ
Handel
Martin
M
Grifka
Joachim
J
Lehn
Norbert
N
Lerch
Klaus
K
D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001372:Aza Compounds / Q000627:therapeutic use*; D024881:Drug Resistance, Bacterial; D005269:Femur / Q000382:microbiology; D024841:Fluoroquinolones; D008297:Male; D000077266:Moxifloxacin; D010019:Osteomyelitis / Q000188:drug therapy* / Q000382:microbiology; D011804:Quinolines / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D013203:Staphylococcal Infections / Q000188:drug therapy*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D014640:Vancomycin / Q000627:therapeutic use*
D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D011804:Quinolines; D014640:Vancomycin; D000077266:Moxifloxacin