title: Development and characterization of a strain of Babesia gibsoni resistant to diminazene aceturate in vitro.
abstract: We attempted to develop a strain of Babesia gibsoni resistant to diminazene aceturate (DA), an anti-babesial drug, in vitro. Since the DA-sensitive B. gibsoni strain could survive and proliferate in culture medium containing 1 ng/m l DA, the concentration of DA was gradually increased from 1 to 200 ng/ml. The results showed that the parasites could survive and proliferate in the medium containing 200 ng/m l DA, which was much higher than the 50% inhibitory concentration (IC(50)) of DA for B. gibsoni. Subsequently, these parasites were removed from erythrocytes and exposed directly to 200 ng/ml DA. They were able to survive and invade fresh erythrocytes, though the DA-sensitive B. gibsoni strain did not survive. Based on these results, the parasites cultured within 200 ng/ml DA were determined to be a DA-resistant B. gibsoni strain. In addition, the IC(50) levels of clindamycin, doxycycline and pentamidine for the DA-resistant B. gibsoni strain were determined. The IC(50) levels of clindamycin, doxycycline and pentamidine for the DA-resistant strain were higher than those for the DA-sensitive strain. The IC(50) of pentamidine for the resistant strain was much greater than that for the DA-sensitive strain. These results indicated that the DA-resistant B. gibsoni strain could have resistance not only to DA, but also to other anti-babesial drugs. In conclusion, we successfully developed a DA-resistant B. gibsoni strain in vitro.
authors.affiliation: Laboratory of Veterinary Internal Medicine, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Japan.
authors.forename: Shiang-Jyi
authors.initials: SJ
authors.lastname: Hwang
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamasaki
authors.forename: Kensuke
authors.initials: K
authors.lastname: Nakamura
authors.forename: Noboru
authors.initials: N
authors.lastname: Sasaki
authors.forename: Masahiro
authors.initials: M
authors.lastname: Murakami
authors.forename: Bandula Kumara
authors.initials: BK
authors.lastname: Wickramasekara Rajapakshage
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohta
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Maede
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Takiguchi
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001403:Babesia / Q000187:drug effects / Q000254:growth & development* / Q000302:isolation & purification; D001404:Babesiosis / Q000188:drug therapy / Q000662:veterinary*; D002455:Cell Division / Q000187:drug effects; D002981:Clindamycin / Q000627:therapeutic use; D004133:Diminazene / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D004283:Dog Diseases / Q000469:parasitology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004318:Doxycycline / Q000627:therapeutic use; D004351:Drug Resistance; D004912:Erythrocytes / Q000469:parasitology; D008795:Metronidazole / Q000627:therapeutic use; D010419:Pentamidine / Q000627:therapeutic use
chemical_list: D000981:Antiprotozoal Agents; D008795:Metronidazole; D002981:Clindamycin; D010419:Pentamidine; C003915:diminazene aceturate; D004318:Doxycycline; D004133:Diminazene