Treatment Efficiency of Combination Therapy With Diminazene Aceturate and Quinapyramine Sulfate in a Horse With Dourine.

Dourine is a lethal protozoan disease of equids, and it is caused by Trypanosoma equiperdum infection via coitus. To date, treatment strategies against the dourine are not recommended because of the frequent relapses; therefore, the World Organisation for Animal Health recommends the stamping-out policy for the control of dourine. Our previous studies have revealed a number of horses with dourine in Mongolia that is the fifth largest horse-breeding country. It is difficult to apply the stamping-out policy for cases of dourine in Mongolia because of an inadequate livestock guarantee system. Therefore, the development of effective treatment measures is an urgent need. In this study, an 8-year-old stallion was definitely diagnosed with dourine based on clinical signs, molecular analysis, and microscopic examination of trypanosomes. Combination therapy with diminazene aceturate and quinapyramine sulfate was applied. Before the treatment, the characteristic clinical signs of dourine were observed, and trypanosomes were detected in the urogenital tract mucosal swab samples by microscopic examination and polymerase chain reaction (PCR). Moreover, positive serological results were obtained. After the treatment, we observed an improvement in the health of the treated horse and no trypanosome infection in its urogenital tract by microscopic examination and PCR. Moreover, serological tests showed seronegative results. The horse has showed no relapse for at least 2.5 years after the treatment, and its reproductive ability has improved. Our result suggests that trypanosomes did not invade cerebrospinal fluid when we started the therapy. In conclusion, the combination therapy has therapeutic potential against dourine at an early phase.

Immunological characterization of Neospora caninum cyclophilin.

Neospora caninum is an intracellular parasite that poses a unique ability to infect a variety of cell types by causing host cell migration. Although previous studies demonstrated that parasite-derived proteins could trigger host cell migration, the related molecules have yet to be determined. Our study aimed to investigate the relationship between Neospora-derived molecules and host cell migration using recombinant protein of N. caninum cyclophilin (NcCyp). Indirect fluorescent antibody test revealed that NcCyp was expressed in the tachyzoite cytosol. Furthermore, NcCyp release from extracellular parasites was detected by sandwich enzyme-linked immunosorbent assay in a time-dependent manner. Recombinant NcCyp caused the cysteine-cysteine chemokine receptor 5-dependent migration of murine and bovine cells. Furthermore, immunohistochemistry indicated that NcCyp was consistently detected in tachyzoites distributed within or around the brain lesions. In conclusion, N. caninum-derived cyclophilin appears to contribute to host cell migration, thereby maintaining parasite/host interactions.