用牛环形泰勒虫裂殖体胶冻细胞苗防制牛泰勒虫病

牛泰勒虫病在我省流行已久,主要用药物治疗。1972—1976年,中国农科院兰州兽研所和宁夏兽研所共同研制成功牛环形泰勒虫裂殖体胶冻细胞苗(以下简称细胞苗),经试验,免疫效果可靠,较好地解决了该病的免疫     

牛环形泰勒虫病的防治

新疆呼图壁种牛场奶业公司是以养奶牛为主的畜牧场 ,1999年年底存栏黑白花牛 142 2头 ,其中生产母牛 879头 ,黑白花母牛平均年单产 75 0 0ｋｇ以上 ,牛群质量、奶牛平均年单产在全国名列前茅。但牛泰勒虫病在历史上曾给该场养牛业造成过较大的威胁 ,多年来经过全场兽医人员不懈努力和上级科研单位协助取得了一定的成效和防治经验 ,该病现已基本控制。1　流行情况呼图壁种牛场总面积约为 15 0ｋｍ2 ,解放前误认为是炭疽疫区 ,后经确诊为焦虫病区。 195 5年建场以来 ,陆续从培城、乌鲁木齐市南山 ,昭苏调进土杂种牛 ,以后又引进了阿拉托夫 ,西…     

牛环形泰勒虫病3种检测方法对比分析

本研究利用血液涂片染色、间接酶联免疫吸附试验(ELISA)、聚合酶链式反应(PCR)3种方法,对潍坊市104头奶牛血液样品进行了牛环形泰勒虫病的检测。结果显示血液涂片染色阳性率为15.4%,血清阳性率为51.9%,PCR检测阳性率20.2%。结果表明,这三种方法都可用于检测牛环形泰勒虫病。血液涂片染色法查找红细胞中的虫体,PCR检测的是虫体,反映奶牛当前感染情况;ELISA检测的是抗体水平,反映了近阶段感染情况。     

牛环形泰勒虫病的诊治

1993年7月份，我县有两个村先后发现牛环形泰勒虫病，经综合诊治，病情得到控制。l流行情况：据资料记载，我县小作镇于1982年从尚义县购进53头草原红杂交牛，多为两岁左右。翌年7月月发本病，诊治不及时，全部死亡，此后呈零星散发．1993年7月5日和17日，我县北孤台村集体牛场     

牛环形泰勒虫病的诊断及防治

曲靖市麒麟区西山奶牛场寄养于郎目山的后备奶牛 4 0头于 2 0 0 1年 7月 19日至 2 0 0 1年 7月 2 5日全部发病 ,死亡 5头 ,致死率为 12 5 %。经流行病学、临床症状、病理剖检及实验室检验诊断为牛环形泰勒虫病。1　临床症状消瘦 ,呼吸困难 ,眼结膜苍白 ,流泪 ,视力减退 ,有的眼角膜变为灰色 ,体温 39 5～ 4 1 3℃ ,为稽留热。鼻镜干燥 ,鼻孔流出清白粘液 ,流清口水。肌肉震颤 ,垂头耷耳 ,肷下陷 ,弓腰缩腹 ,精神萎顿 ,食欲减少或废绝 ,体表淋巴结肿大 ,压迫有痛感。血液稀薄呈淡红色。检查牛体 ,发现有硬蜱。2　病理剖检胸腹两侧皮下有很多…     

酶联免疫吸附试验诊断环形泰勒虫感染牛的研究

用层析法制备的牛环形泰勒虫抗原用于ＥＬＩＳＡ试验，检测６２头份带虫牛血清，阳性符合率９６．６７％；在疫区检测１５０头份牛血清，阳性率８０．４３％；在瑟氏泰勒虫流行区检测４５４头份牛血清，有交叉反应，阳性率２８．１９％；检测８９头份安全区牛血阴性符合率１００％。用正常红细胞抗原和环形泰勒虫抗原分别对人工感染和自然感染牛作了特异性试验，结果ＥＬＩＳＡ前者ＯＤ值为阴性，后者ＯＤ值来阳性。２头人工感染牛于     

Investigation of lectin activity in Theileria annulata piroplasms

Adhesion to target cells is an essential step in the pathogenesis of many protozoal infections. Some protozoa have been reported to have a lectin activity involved in their attachment to the cell surface. The ligand-receptor interaction involved in Theileria annulata infection is unclear at present, in spite of the fact that some aspects of the process have been investigated. To this end, T. annulata piroplasms have been screened for lectin activity. Blood taken from infected cattle was first depleted of leukocytes and then subjected to ammonium chloride lysis in order to isolate the piroplasms. The piroplasms were homogenised and a crude membrane extract was prepared by centrifugation. To investigate lectin activity in piroplasm proteins, a simple screening procedure was employed for analysing piroplasm proteins binding to various lectin ligands. Numerous immobilised lectin ligands (L-fucose-sepharose, N-acetyl-neuraminic acid-sepharose, N-acetyl-D-galactosamine-agarose, N-acetyl-D-glucosamine-agarose, D-mannose-agarose, beta-D-glucose-agarose, alpha-methyl-D-mannoside-agarose) were incubated with T. annulata piroplasm crude membrane extract. The ligand-bound proteins were eluted and separated by a brief centrifugation and determined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The present study suggests that a 32 kDa protein of piroplasm binds to D-galactosyl residues of the agarose matrix and that the binding is inhibited by galactose and not by the other monosaccharides tested.     

Treatment of Theileria annulata infection in calves with parvaquone

Fifteen calves were infected by the injection of stabilate of a suspension of Hyalomma anatolicum anatolicum ticks infected with the Ankara strain of Theileria annulata. Three were kept untreated, as controls, and they all died of theileriosis. Three groups of four calves were treated intramuscularly with parvaquone (Clexon; Wellcome) when early signs of theileriosis were clinically apparent. One group received 20 mg (kg bodyweight)-1 of parvaquone 10 days after infection. Two of these calves were clinically cured and two died of theileriosis. The remaining two groups of four calves received two doses of parvaquone, each of 10 mg (kg bodyweight)-1, either on days 10 and 11 or days 10 and 12. Three calves in each group were clinically cured while one in each group died of theileriosis. Total parasitological cure was not achieved in any of the calves. No symptoms of toxicity due to parvaquone treatment were observed.     

Efficacy of parvaquone and long-acting oxytetracycline in Theileria annulata infection

Therapeutic and prophylactic efficacies of parvaquone and long-acting oxytetracycline were tested against Theileria annulata infection, induced by injecting a suspension of infected ground tick tissues (GUTS) into groups of 4 or 5 calves. This infection killed two of four control calves, while all the animals given a single intramuscular dose of 20 mg kg-1 parvaquone or long-acting oxytetracycline on the day of infection underwent mild reactions and recovered. Two separate doses of parvaquone of 10 mg kg-1 administered on the first and second days of fever protected four out of five calves. All the recovered animals from both treated and control groups resisted a homologous challenge with GUTS on Day 45 post-infection which killed three out of four susceptible unimmunized control calves.     

Haematological and biochemical studies on experimental Theileria annulata infection in crossbred calves

Administration of ground-up tick tissue stabilate (0.75 tick equivalent) by the subcutaneous route to crossbred calves aged 1 week to 1 month led to the development of acute theileriosis. Haematological studies revealed significant progressive decreases in haemoglobin concentration, packed cell volume and red blood cell count, whereas the total leukocyte count showed an initial non-significant leukocytosis followed by a significant leukopenia. Analysis of serum revealed significant increases in levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, creatinine kinase and -glutamyltransferase, and in the concentrations of uric acid, blood urea nitrogen and bilirubin. The concentrations of total protein, albumin, glucose, cholesterol and calcium showed non-significant decreases, while phosphorus decreased significantly during the terminal stages of the disease.     

Presence of Theileria annulata in Mauritania

A fatal case of bovine theileriosis by Theileria annulata is reported from Mauritania in a Friesian cow born in a dairy farm in Nouakchott. The farm was originally established with cattle imported from France. Specific diagnosis was based on piroplasm morphology and on high specific antibody titres in some of the animals. The only tick found in the herd was Hyalomma dromedarii. Four of 49 local zebus sampled at random in the south of the country had high specific antibody titres to T. annulata, while 14 had lower or doubtful titres. The infection therefore appears to be autochthonous.     

Prophylactic efficacy of buparvaquone in experimentally induced Theileria annulata infection in calves

The antitheilerial activity of buparvaquone (BW 720C) was evaluated in experimentally induced Theileria annulata infections in cross-bred male calves. T. annulata infections were induced by injecting a suspension of infected ground tick tissue suspension (GUTTS) equivalent to two ticks subcutaneously into each calf. Buparvaquone at a dose of 2.5 mg kg-1 body weight was given as a single injection (intramuscularly) on Day 0 (Group 1), Day 8 (Group 2) and Day 12 (Group 3) post-infection. The animals in Groups 4 and 5 were untreated and challenged controls, respectively. All of the recovered animals from Groups 1-4 were challenged with a lethal dose of T. annulata at 6 weeks post-infection. The immunized animals were resistant to the homologous challenge, which killed three of four control animals (Group 5); the controls showed typical antemortem and post-mortem lesions of theileriosis.