柔嫩艾美尔球虫野外株对3种聚醚类离子载体抗生素的敏感性试验

采用鸡体药效试验法测定了柔嫩艾美尔球虫对３种聚醚类离子载体抗生素的敏感性。试验证明，柔嫩艾美尔球虫野外分离株对盐霉素（６６×１０－６）、莫能菌素（１２０×１０－６）和拉沙菌素（１２５×１０－６）产生了耐药性。上述３种药物的抗球虫指数（ＡＣＩ）分别为１４９．３９、１３４．０４和１５６．１１。但这３种药物对柔嫩艾美尔球虫标准株仍然有效     

Preparation of Monoclonal Antibody Against Lasalocid and Deveopment of Indirect Competitive ELISA Detection Method

To prepare monoclonal antibodies (MAb) against lasalocid (LAS) and establish an indirect competitive ELISA (Ci-ELISA) detection method,conjuaction of LAS-BSA and LAS-OVA were synthetized as the immunogen and coating antigen by using active ester method in this experiment. After 6 times of immunization,the spleen cells of mice and myeloma cells were fused. Finally,a hybridoma cell line that could stably secrete specific MAb against LAS was screened.The immunological subtype of the MAb was identified as IgG1,and its light chain was κ type.The titer of the ascites was 1:16 000, which showed no cross activity with monensin sodium, salinomycin sodium,maduramycin,cefalotin sodium and streptomycin sulfate. Ci-ELISA method was established based on the MAb against LAS with the linear equation was y=0.376x-0.2374(R²=0.9914), and the linear range was 5 to 1 000 ng/mL and the IC₅₀ was 90.22 ng/mL. The method was used to detect LAS in spiked samples and the recovery rate was 81.76% to 102.41% within the detection range,indicating that the method was successfully established with good accuracy and high sensitivity. The preparation of MAb against LAS and the establishment of Ci-ELISA method laid the foundation for the development of LAS detection kit.     

鸡肝组织中拉沙洛西钠残留的高效液相色谱检测方法

建立了鸡肝组织中拉沙洛西钠残留的高效液相色谱检测方法.甲醇提取鸡肝组织样品中残留的拉沙洛西钠,硅胶柱净化,以磷酸盐缓冲液-乙腈-甲醇作为流动相,反相高效液相色谱-荧光检测法检测.方法平均回收率为82.1%,平均变异系数为7.75%,方法的检测限为0.02 mg/kg.     

三种药物防治奶牛球虫病试验

目的为考察现有抗球虫药物对奶牛球虫病的防治效果。方法选用应用较广的3种抗球虫药物(地克珠利、拉沙里菌素、莫能菌素)对1~6月龄球虫感染阳性奶牛进行防治试验。将34头球虫感染阳性奶牛分为4组,地克珠利组9头,按体重0.5 mg/kg.BW每天口服1次;拉沙里菌素组9头,按360 mg/头每天口服1次;莫能菌素组8头,按1 mg/kg.BW每天口服1次;不用药物对照组8头。连续用药10d,停药后再观测10 d,每3 d直肠采集粪便检测球虫1次,以每克粪便球虫卵囊数(OGP)为试验指标。结果用药9 d后的OPG与用药前相比,地克珠利组下降了78.9%,拉沙里菌素组下降了80.92%,莫能菌素组下降了98.81%。停药3~6 d后,地克珠利和拉沙里菌素组的OPG上升较快,而莫能菌素组的OPG保持较低水平。结论3种抗球虫药对奶牛球虫病均有防治效果,其中莫能菌素最好,拉沙里菌素和地克珠利次之。     

甜菜碱对聚醚类抗生素抗球虫药的增效作用

从中国广东分离的柔嫩艾美耳球虫（Ｅｉｍｅｒｉａｔｅｎｅｌｌａ）野外抗药株深圳（ＳＺ）株,分别对３种聚醚类抗生素－马杜拉霉素、盐霉素、拉萨里霉素及它们与甜菜碱同时使用的药效情况进行试验。结果发现,添加甜菜碱可提高聚醚类抗生素组的增重,特别是甜菜碱加马杜拉霉素组增重最明显,而对病变记分和卵囊数量无明显影响。     

拉沙里菌素对肉牛生产性能和血液指标的影响

试验旨在评价拉沙里菌素对西门塔尔牛生产性能和血液指标的影响。选取12月龄左右、体况良好、体重相近的西门塔尔牛48头,随机分为4组。对照组饲喂基础日粮(混合精料+玉米秸秆;精粗比45∶55);处理组分别在基础日粮中添加拉沙里菌素100mg/d、200mg/d和300mg/d。结果表明:日粮添加拉沙里菌素200mg/d和300mg/d时,干物质采食量、平均日增重,血液中血糖、白蛋白、总蛋白、尿素氮和谷草转氨酶的含量显著高于对照组(P0.05),饲料转化效率显著低于对照组(P0.05);日粮添加拉沙里菌素200mg/d和300mg/d时,增重收益和毛收益显著高于对照组(P0.05)。综合以上指标分析,日粮中拉沙里菌素的适宜添加量为200mg/d。     

拉沙里菌素单克隆抗体的研制及间接竞争ELISA检测方法的建立

为制备拉沙里菌素（LAS）单克隆抗体,建立针对LAS的间接竞争ELISA（Ci-ELISA）方法,试验采用了活性酯法将LAS分别与BSA和OVA偶联成LAS-BSA和LAS-OVA作为免疫原和检测原,6次免疫后,取小鼠脾细胞与骨髓瘤细胞融合,最终筛选出一株能稳定分泌抗LAS单克隆抗体的杂交瘤细胞株C11。经鉴定,C11的抗体类型为IgG1,轻链为κ链;所制腹水效价为1∶16 000,与莫能菌素钠、盐霉素钠、马杜霉素胺、头孢噻吩钠和硫酸链霉素均无交叉反应。用此单克隆抗体建立LAS Ci-ELISA检测方法显示,Ci-ELISA标准工作曲线为y=0.376x－0.2374（R²=0.9914）,LAS在5~1 000 ng/mL时,线性关系良好,IC₅₀为90.22 ng/mL,加标回收率为81.76%~102.41%,表明方法精确度好、灵敏度高。LAS单克隆抗体的制备和Ci-ELISA方法的建立为下一步试剂盒的研发奠定了基础。     

柔嫩艾美耳球虫对四种抗球虫药的交叉抗药性试验

为了测试柔嫩艾美耳球虫的４种抗药虫株（抗地克珠利、抗拉沙里菌素、抗盐霉素和抗克球粉虫株）对４种抗球虫药（地克珠利、拉沙里菌素、盐霉素和克球粉）的敏感性进行了本试验。结果表明：柔嫩艾美耳球虫地克珠利抗药虫株对拉沙里菌素、盐霉素和克球粉均表现敏感,拉沙里菌素抗药虫株、盐霉素抗药虫株和克球粉抗药虫株对地克珠利也表现为高度敏感,因此,柔嫩艾美耳球虫对地克珠利与拉沙里菌素、地克珠利与盐霉素、地克珠利与克球粉３组药物不存在交叉抗药性。