【作者】 刘文进；

【导师】 陈创夫；

【作者基本信息】 石河子大学 ， 预防兽医学， 2005， 硕士

【摘要】 本项研究对北疆垦区7个牛场的泌乳奶牛，根据临床症状和乳房炎诊断试剂检测，采集奶牛乳房炎患牛的奶样。经过增菌、分离和选择培养，进行了病原学研究。继而进行体外药物敏感性试验和生化试验进行鉴定，选出优势致病菌。利用PCR扩增技术，研究致病菌的分子鉴定和奶牛乳房炎的致病菌诊断。将奶牛乳房炎主要致病菌株进行获得培养，制成灭活菌苗，按照基础免疫和高度免疫相结合的免疫程序接种3只绵羊和2头牛，以150～350亿和100～170亿个菌数，分别给实验牛和羊肌肉、皮下部位分点免疫金色葡萄球菌灭活苗，制备高效价的抗血清。最后，从由主要致病菌株感染的患奶牛乳房炎的奶牛中，选择个体种属等均相近临床型奶牛乳房炎患牛2头(牛乳pH值均在7.3左右，乳体细胞在500万／ml左右，有轻度炎性水肿)，以及亚临床型奶牛乳房炎患牛3头(牛乳pH值均在7.1左右，乳体细胞在250～300万／ml，无临床症状)，以20～50ml／头的剂量和皮下、乳房肌肉和乳静脉等免疫方式，给5头患乳房炎的奶牛进行抗血清治疗试验的研究。 结果显示如下： 1．经对北疆垦区部分地区的泌乳奶牛进行乳房炎的诊断显示，经临床调查显示，患奶牛临床型乳房炎的平均检出率为16.7％；从随机选取的604头泌乳奶牛中，检出奶牛亚临床型乳房炎奶牛219头，检出率为36.3％。 2．经牛乳pH值、乳体细胞含量和酒精阳性乳测定显示，牛乳酒精阳性与奶牛亚临床型乳房炎之间无直接关系；牛乳pH值的变化与奶牛乳房炎的发病和发病程度呈正相关，是奶牛乳房炎的一项更为重要的诊断指标之一。 3．经本研究病原分离鉴定显示，检出金色葡萄球菌、停乳链球菌、蜡样芽孢杆菌、大肠杆菌、沙门氏菌、绿脓杆菌和假丝酵母菌等。选出奶牛乳房炎最为主要致病菌——金色葡萄球菌，进行菌落PCR鉴定，从而建立了从病原学快速诊断奶牛乳房炎的方法。 4．免疫抗血清，牛的混合血清(效价为1:32)和羊的混合血清(效价在1:64)等体积混合进行抗血清治疗。临床抗血清治疗试验显示，患亚临床型乳房炎的奶牛用20～27ml的抗血清治疗，7天后，牛乳pH值由7.1降到6.6，乳体细胞含量由200万／ml降到50万／ml以下；患临床型乳房炎的奶牛以50ml血清剂量治疗，在10天后pH值和乳体细胞含量基本恢复正常，牛乳pH值由7.3降到6.7，乳体细胞含量由500万／ml降到70万/ml。更多还原

【Abstract】 In the study, we sample positive milk from the cattle with mastitis of various breeds at 7 ranches in north reclamation area of Xinjiang, based on the test results by clinical observation and reagent diagnosis. After increment and elective culture in laboratory, the pathogens inducing to mastitis are primarily separated and further identified through drug sensitivity tests in vitro and biochemical tests. We design primers by the use of PCR techniques to identify the dominant pathogen firstly, then culture the pathogen to make inactivated bacterin, and inoculate them to 3 sheep and 2 cattle according to immune program to prepare the high active antiserum through centrifugation. Finally, we choose 2 cattle with clinic-mastitis (average pH-value of their milk is about 7.3, somatic cells amount to 5,000,000 per ml. approximately and the cattle catch a slight inflammatory edema) and 3 cattle with sub-clinic mastitis (average pH-value of their milk is about 7.1, somatic cells count between 2,500,000 and 3,000,000 million per ml.) from the head of sick cattle which are infected by the dominant pathogen, then inject antiserum to them with different dose and different times.The result shows as follow:a. clinic mastitis’s average detectable rate is 16.7% and sub-clinic rate is 36.3%.there are 219 cattle with sub-clinic mastitis in the random samples of 604 lactating cattle.b. we test pH-value, the quantity of somatic cells and alcohol positive milk and find that, there is no direct correlation between pH-value and alcohol positive milk; pH-value is a more important factor to examine mastitis and there is positive correlation between pH-value and the incidence and the magnitude of mastitis.c. we separate staphylococcus aureus, Streptococcus dysgalactiae, Salmonella, Escherichia coli, Pseudomonas sp and Prototheca. Staphylococcus aureus is the dominant pathogen causing mastitis based on the identification by PCR. We establish a new quick diagnosis technology of mastitis by the use of PCR techniques.d. to treat cattle by equally mixing the cattle’s mixed antiserum (titer is 1:32) and the sheep’s mixed antiserum (titer is 1:64), the pH-value and the quantity of somatic cells of the cattle with sub-clinic mastitis decline from 7.1 to 6.6 and from 2,000,000 to 500,000 per ml after 7 days, but the cattle with clinic mastitis decline from 7.3 to 6.7 and from 5,000,000 to 700,000 per ml after 10 days.更多还原