水牛牛巴贝斯虫低温保存和复苏后的致病力研究

STUDIES ON THE FATHOGENICITY OF BABESIA BOVIS IN WATER BUFFALOS AFTER CBYOPRESERVATION AND RESUSCITATION

将含水牛牛巴贝斯虫的压积红细胞与等量的１６％二甲基亚砜阿氏液混合后分装于冷冻管内，于液氮（－１９６℃）中保存。保存２６ｄ、７８ｄ、１４２ｄ和１４９ｄ后，在３８℃温水中复苏，经皮下、静脉和静脉皮下同时感染摘脾小牛获得成功。水牛感染后，外周血液出现虫体时间短的为５ｄ，其余的为８ｄ和９ｄ。血液涂片中发现典型的牛巴贝斯虫，最高染虫率（ＰＰＥ）为１５％。由低温保存的含虫血与新鲜虫血和蜱感染一样使水牛发病，出现高温稽留（最高体温达４１．３℃贫血、黄疸和血红蛋白尿等典型的症状，未经治疗均以死亡告终。本研究的成功为长期保存水牛巴贝斯虫株提供了简便而可靠的方法。

The Packed erythrocytes infected with Babesia bovis were mixed with an equalvolume of 16% dimethyl sulphoxide (DMSO) in Alsever's solution and dispensed in 1.5or 5 ml cryotubes. The vials were kept in liquid N2 (-196℃) for 26 days, 78 days,142 days and 149 days. The samples were removed from the liquid N2 container andrapidly thawed in a 38℃ water bath. The thawed samples successfully infected thesplenectomized buffalo calves by subcutaneous, vein or vein and subcutaneous routes.The parasites, typical Babesia bovis, were discovered in the red blood cells 5 days, 8days and 9 days after inoculation. The highest Percent of Parasitized erythrocytes (PPE)was 15%. The babesiosis resulting from frozen parasites was the same as that resultingfrom fresh parasites from ticks, Typical clinical signs were found, such as continuousfever (the highest teinperature was 41.3℃), anaemia, icterus and haemoglobinuria.Infected calves without treatment died. The cryopreservation is a simple and reliablemethod for long preservation of Babesia bovis of water buffaloes.