Evaluation of The In Vitro And In Vivo Inhibitory Effects of Enrofloxacin On the Growth of Babesia Species and Theileria Equi

Objectives: Enrofloxacin, a fluoroquinolone antibiotic, is an inhibitor of prokaryotic topoisomerase II with antibacterial and antiparasitic activities. The study aimed to evaluate the inhibitory effect of enrofloxacin on Babesia species and Theileria equi in vitro and in vivo. Methods: The inhibitory effects of enrofloxacin were evaluated in vitro cultures using in vitro inhibition assay of three Babesia species and Theileria equi; furthermore, the in vivo inhibitory effect of enrofloxacin was evaluated in the mice model of Babesia microti. Results: The IC50 values of enrofloxacin were 4.9, 4.5, 4, and 3.9 nM for B. bovis, B. bigemina, B. caballi, and B. equi, respectively. Enrofloxacin at a dose rate of 10 mg/kg resulted in a 92.9 % inhibition of Babesia microti growth in BALB/c mice. Combination therapy of enrofloxacin at a dose rate of 5 mg/kg with diminazene aceturate at a dose rate of 12.5 mg/kg resulted in 93.83 % inhibition of Babesia microti growth in BALB/c mice. Conclusions: Enrofloxacin might be used for drug therapy in babesiosis.