Abstract:
Requirement of Babesia spp maintenance for experiments in various aspects is crucial. In this study, a thai strain of Babesia bovis was inoculated to splencetomized calves. During a high parasitaemia, they were bled for cryopreservaton and in vitro cultvation. Parasitized erythrocytes have been cryopreserved for future use by mixing with 3 cryoprotectants and freezing at -70℃ in liquid ntrogen. The cryoprotectants are glyccrolyte (electrolyte-based balanced), sorbitol-based and glycerol in phosphate buffered soluton (PBS). After cryopreservation for 6 weeks, viability of the parasited were assessed by morphologically observatons of Giemsa stained smears. The results revealed that glycerol-PBS cryopreserved blood were recovered unsuccessfully in bovine erythrocytes and free exoerythrocytic babesial parasites. Glycerolyte and sorbitol-based cryoprotectants gave satsfactory results. Besides, glycerolyte provided a better cryopreserved property than sorbitol-based for exoerythrocytic Babesia. The babesial parasitized erythrocytes were also maintained and propagated in in vitro cultivation for a short term. However, unsatisfactory results has been shown in both under the conditions of 85-90% humidity, 37℃ and 5% CO₂ or 2%O₂, 5%CO₂ and 93%N₂ Attempts to develop a propered culture technique should be considered.