Effects of oral orbifloxacin on fecal coliforms in healthy cats: a pilot
study |
| |
| Authors: | Kazuki HARADA Atsushi SASAKI Takae SHIMIZU |
| |
| Institution: | 1)Department of Veterinary Internal Medicine, Tottori University, 4–101 Minami, Koyama-Cho, Tottori-Shi, Tottori 680–8553, Japan |
| |
| Abstract: | The study objective was to determine the effect of oral orbifloxacin (ORB) on
antimicrobial susceptibility and composition of fecal coliforms in cats. Nine cats were
randomized to two groups administered a daily oral dose of 2.5 and 5.0 mg ORB/kg for 7
days and a control group (three cats per group). Coliforms were isolated from stool
samples and were tested for susceptibilities to ORB and 5 other drugs. ORB concentration
in feces was measured using high-performance liquid chromatography (HPLC). The coliforms
were undetectable after 2 days of ORB administration, and their number increased in most
cats after termination of the administration. Furthermore, only isolates of
Escherichia coli were detected in all cats before administration, and
those of Citrobacter freundii were detected after termination of the
administration. E. coli isolates exhibited high ORB susceptibility
Minimum inhibitory concentration (MIC), ≤0.125 µg/ml]
or relatively low susceptibility (MIC, 1−2 µg/ml) with a
single gyrA mutation. C. freundii isolates largely
exhibited intermediate ORB susceptibility (MIC, 4
µg/ml), in addition to resistance to ampicillin and
cefazolin, and harbored qnrB, but not a gyrA mutation.
HPLC revealed that the peaks of mean concentration were 61.3 and 141.0
µg/g in groups receiving 2.5 and 5.0 mg/kg, respectively. Our findings
suggest that oral ORB may alter the total counts and composition of fecal coliform, but is
unlikely to yield highly fluoroquinolone-resistant mutants of E. coli and
C. freundii in cats, possibly because of the high drug concentration in
feces. |
| |
| Keywords: | antimicrobial resistance fecal coliforms feline orbifloxacin |
|
|
