Transcript poster_1 - Cairo University Scholars

Evaluation of in vitro inhibitory effect of Enoxacin on Babesia and Theileria parasites
Mosaab A. Omara,b, Mohmed A. Rizka,c, Shimaa M. Elsayeda,d, Ahmed ElSifya, e, Akram A. Salamaa, e,
Sherein S. AbdElgayedf, Naoaki Yokoyamaa, Ikuo Igarashia
a
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-Cho, Obihiro, Hokkaido 080-8555, Japan
b Department of Parasitology, Faculty of Veterinary Medicine, SouthValley University, Qena, 83523 Egypt
c Department of Internal Medicine and Infectious Diseases, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
d Department of Biochemistry, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
e Department of Animal Medicine and Infectious Diseases, Faculty of Veterinary Medicine, Sadat City University, Sadat City 32897, Minoufiya, Egypt
f Department of Veterinary Pathology, Cairo university, Egypt.
Abstract: Enoxacin is a broad-spectrum 6-fluoronaphthyridinone antibacterial agent (fluoroquinolones) structurally related to nalidixic acid used
mainly in the treatment of urinary tract infections and gonorrhea. Also it has been shown recently that it may have cancer inhibiting effect. The
primary antibabesial effect of Enoxacin is due to inhibition of DNA gyrase subunit A, and DNA topoisomerase. In the present study, enoxacin was
tested as a potent inhibitor against the in vitro growth of bovine and equine Piroplasms. The in vitro growth of five Babesia species that were tested
was significantly inhibited (P < 0.05) by micro molar concentrations of enoxacin (IC50 values = 13.5, 7.2, 7.5 and 24.2 µM for Babesia bovis, Babesia
bigemina, Babesia caballi, and Theileria equi, respectively). Enoxacin IC50 values for Babesia and Theileria parasites were satisfactory as the drug is
potent antibacterial drug with minimum side effects. Therefore, enoxacin might be used for treatment of Babesiosis and Theileriosis especially in case
of mixed infections with bacterial diseases or incase of animal sensitivity against diminazin toxicity.
Materials and methods:
Parasites: The Texas strain of B. bovis, the Argentine strain of B. bigemina the USDA strain of B. caballi , Theileria equi, and the Munich strain of B.
microti were used in this study.
Culture conditions: The Babesia parasites used in this study were maintained in bovine or equine red blood cells (RBCs) using a microaerophilic
stationary-phase culture system. Briefly, Medium 199 was used for B. bovis, B. bigemina, and T. equi, while RPMI-1640 was used for B. caballi (both
from Sigma-Aldrich, Tokyo, Japan).
Chemicals reagents: Enoxacin was purchased from Sigma–Aldrich, Tokyo, Japan and used as a test drug. A working stock solution of 100 µM
Enoxacin dissolved in (DMSO)
In vitro growth inhibition assay: The inhibitory effect of enoxacin on the growth of Babesia parasites was tested using an assay previously described
with slight modification. Parasite-infected RBCs will be diluted with uninfected RBCs to obtain an RBC stock supply with 1% parasitemia. Twenty μl
of RBCs with 1% parasitemia will be dispensed into a 96-well microtiter plate (Nunc, Roskilde, Denmark) with 200 μl of the culture medium
containing the indicated concentration of Enoxacin (0.1, 1, 10, 15, 25 and 50 μM) for B. bovis and (0.1, 1, 0.5, 10, 15, 25 and 50 μM) for other Babesia
species, and then incubated at 37 °C in a humidified multi-gas water-jacketed incubator.
Viability test: After the 4th day of treatment, 6 μl of each of the control and drug-treated (at the various indicated concentrations) RBCs will be mixed
with 14 μl of parasite free RBCs and suspended in fresh growth medium without Enoxacin supplementation. The plates will be incubated at 37 °C for
the next 10 days.
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Fig 3. In vitro inhibitory effect of different concentrations of enoxacin on the growth of B. bovis
Fig.1. In vitro inhibitory effect of different concentrations of enoxacin on the growth of B. bigemina
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Fig.1. In vitro inhibitory effect of different concentrations of enoxacin on the growth of B. caballi
Light micrographs of enoxacin treated bovine Babesia parasites in an in vitro
culture. Micrographs were
Taken on day 3 of the experiment. B.bigemina (A) control and (B) 25 uM Enoxacin.
Light micrographs of enoxacin treated bovine Babesia parasites in an in vitro
culture. Micrographs were
Taken on day 3 of the experiment. B.bovis (A) control and (B) 25 uM Enoxacin.
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Fig.1. In vitro inhibitory effect of different concentrations of enoxacin on the growth of Th. equi
Light micrographs of enoxacin treated equine Babesia parasites in an in vitro
culture. Micrographs were
Taken on day 3 of the experiment. B.caballi (A) control and (B) 25 uM Enoxacin.
Light micrographs of Enoxacin treated Theileria equi in an in vitro culture.
Micrographs were taken on day 3 of the experiment.
Theileria equi (A) control and (B) 50 uM Enoxacin.