牛血清白蛋白泡沫法提取庆大霉素产物快速检测方法的研究

采用醋酸纤维薄膜电泳法分离庆大霉素与牛血清白蛋白,再用紫外分光光度法测定蛋白质泡沫法提取庆大霉素含量的方法.该方法中,选择620 nm作定量峰,庆大霉素和氨基黑10B的结合物浓度在1.25～10μg/mL范围内,吸收度与浓度的线性关系良好,相关系数为0.999 6,回收率为100.59%.     

rboGM-CSF结合庆大霉素治疗奶牛隐性乳房炎试验

利用rboGM-CSF(500μg/15mL)结合庆大霉素(15mL)进行奶牛隐性乳房炎治疗试验。乳内同时灌注rboGM-CSF与庆大霉素,治疗期为8d。试验结果显示,单独使用rboGM-CSF对轻度隐性乳房炎有一定疗效,但对重度隐性乳房炎效果不佳;联合庆大霉素灌注后,能明显提高二者单独使用的治愈率。说明rboGM-CSF具有潜在的治疗轻度奶牛乳房炎的功效。     

庆大霉素发酵液检测方法研究

在庆大霉素微生物发酵过程中,探索发酵液中庆大霉素效价的快速测定方法。在优化的发酵工艺条件下发酵生产庆大霉素,分别运用旋光法、紫外分光光度法和高效液相色谱法(HPLC)对庆大霉素发酵液的效价进行测定。结果最佳发酵条件为:种瓶接种量2 cm2,种龄24 h,发酵瓶接种量12%,发酵周期5 d。优化后的庆大霉素发酵液效价相较于优化前提高70%左右。紫外分光光度法、HPLC法和旋光法测定的庆大霉素发酵液效价产生的误差均小于3%。三种检测方法均能运用在庆大霉素发酵液效价的快速检测中。旋光法操作简单但对标准品需求量大,紫外分光光度法耗时短但只能测定庆大霉素总体效价,HPLC法需要出峰时间。因此,在庆大霉素发酵液效价测定中需根据自己的需求选择最佳检测方法。     

牛奶中庆大霉素半定量胶体金试纸条的研制

先将庆大霉素与载体蛋白偶联形成完全抗原,再与庆大霉素单克隆抗体反应制备试剂条。通过抗原抗体之间的免疫反应,采用胶体金检测方法,将抗原按不同浓度喷制两条检测线,使牛奶中庆大霉素检测灵敏度分别为20μg/kg和100μg/kg,该检测限满足我国及欧盟对庆大霉素检测的要求,并且能够实现牛奶样品中庆大霉素现场快速检测。     

庆大霉素诱发鸡肠源性大肠杆菌易位的研究

实验选择庆大霉素作为诱发因子,制备含pUC118质粒DNA的大肠杆菌作为易位示踪菌,将45只20日龄肉仔鸡随机分成3组,庆大霉素诱发组、大肠杆菌感染对照组和空白对照组.比较庆大霉素诱发组不同时间和不同组织的大肠杆菌易位率,测定分泌型免疫球蛋白A(SIgA)的含量,并与易位率进行相关性分析.结果表明4×104U/kg的庆大霉素可引起鸡肠源性大肠杆菌易位,48h易位率达80%,SIgA水平与E.coli易位率呈负强相关关系,可作为肠道细菌易位的敏感指标.肝脏的易位率最高.免疫器官脾脏、法氏囊、胸腺易位率较低可能与庆大霉素直接毒性较弱及鸡全身性炎症反应滞后有关.     

The Use of Cefquinome in Equine Semen Extender

Antibiotics are commonly used in equine semen extender for conservation, if semen has to be stored cooled for a maximum of 48 hours or frozen, to eliminate pathogenic or potentially pathogenic bacteria from semen and reduce the risk of postmating endometritis. Little is known about the effect of antibiotics on spermatozoa when semen is stored over a longer period. Cefquinome, a broad spectrum antibiotic and fourth-generation cephalosporin, has been proven to be a powerful drug for the treatment of endometritis and mastitis in different species. Recently in equine studies, it was found to localize in high concentrations in the endometrium. Therefore, cefquinome was used as the antibiotic in semen extender and compared with a commercial semen extender containing gentamicin for effects on motility and membrane integrity of spermatozoa. During the breeding season, ejaculates from nine light horse stallions were collected and half of each ejaculate was stored for 48 hours in modified Kenney type semen extender containing either cefquinome or gentamicin. At 0, 24, and 48 hours, aliquots (20 μL) of the stored semen were evaluated for (progressive) motility and membrane integrity, as well as for various motility parameters by computer assisted sperm analysis. No differences (P > .05) were found in total motility or progressive motility between extenders at any time point. However, there were differences (P < .05) in velocity parameters, although the effect of velocity parameters on fertility is not clear. In general, semen parameters after storage in non-fat dried skim milk semen extender containing cefquinome are comparable with those after storage in semen extender containing gentamicin. The wider spectrum of bactericidal activity possessed by cefquinome may prove to be beneficial in some cases.     

庆大霉素标准品制备中效价测定及原材料选择的研究

在近期庆大霉素标准品制备过程中遇到两个问题——双圈与可靠性测验不符合规定。通过调整菌悬液浓度、抗生素浓度及上层菌液加入量使双圈现象得以抑制,以保证测量结果准确可靠。C组分测定结果显示原料药与标准品C组分差异较大,容易导致二者剂量反应直线不平行,进而影响可靠性测验结果。通过更换与标准品C组分更为相近的原料药使可靠性测验符合规定。上述改进措施保证了国家标准品赋值的准确性,以期为同业人员效价测定遇到类似问题提供借鉴。     

庆大霉素在猪肉和鸡肉组织中残留的微生物学检测方法研究

以表皮葡萄球菌 2 6 0 6 9型 (Staphylococcusepidermidis,ATCC12 2 2 8)为测试菌 ,用微生物学杯碟法定量测定庆大霉素在猪肉和鸡肉组织中的残留。庆大霉素在磷酸盐缓冲液、鸡和猪的肌肉组织中的最低检测限分别为 0 .0 2 5 μg/ml、0 .0 5 μg/g和 0 .0 5 μg/ g ,在磷酸盐缓冲液中标准曲线的线性范围为 2 .5× 10-2 ～ 0 .8μg/ml。庆大霉素浓度为 0 .0 5、0 .10、0 .2 0 μg/g时 ,鸡肉组织中的回收率分别为 (85 .8± 4 .5 ) %、(90 .1± 5 .9) %和 (88.8± 5 .3) % ,猪肉组织中的回收率分别为 (83.5± 7.1) %、(85 .2± 5 .4 ) %和 (86 .9± 6 .7) % ,日内和日间变异系数均小于 10 %。结果表明 ,本法快速、灵敏、简便 ,适用于庆大霉素在猪和鸡肌肉中残留的定量检测     

The occurrence of bioactive micromonosporae in aquatic habitats of the Sunshine Coast in Australia

Screening strategies based on the ecological knowledge of antibiotic producing microorganisms and their roles in the natural environment are being increasingly employed in the search for novel antibiotic agents. Micromonosporae are common inhabitants of aquatic habitats and have proved to be a continuing source of novel bioactive compounds including antibacterial and antitumor agents. The ecological distribution and frequency of bioactive micromonosporae in Sunshine Coast region aquatic habitats were studied through a range of selective isolation procedures designed to negatively select against the isolation of unwanted microbial taxa commonly associated with marine environments. It was revealed that bioactive compound producing species of micromonosporae were present in the aquatic habitats of the Sunshine Coast region in Australia.