IN-VITRO CULTIVATION OF BABESIA-EQUI - DETECTION OF CARRIER ANIMALS AND ISOLATION OF PARASITES

By means of an in vitro culture technique, 75 samples of horse blood w ere examined for Babesia equi, a causative agent of equine piroplasmos is. At the time of culture initiation, 15 samples were microscopically positive for B. equi, and this was subsequently confirmed by culture diagnosis. Sixty samples showed no parasites in Giemsa-stained thin bl ood smears. However, after the culturing process, parasites were found in blood smears of 36 of these samples. The sensitivity of the in vit ro culture method was such that 2,5 mu l (1/40 of the usual volume use d for the above-mentioned samples) of packed erythrocytes obtained fro m a carrier horse still yielded positive results after cultivation. Cu ltures were initiated from blood samples stored for up to 120 h at 8 d egrees C in vacuum tubes containing EDTA as anticoagulant. These resul ts show that the in vitro culture method is highly sensitive. It can b e used to identify B. equicarrier horses, to evaluate the effects of c hemotherapeutic intervention, and to isolate field strains of B. equi for further characterization.