杆菌肽类饲料添加剂在畜禽养殖中的应用

杆菌肽作为抗菌饲料添加剂使用已经有50多年的历史了,本文主要杆菌肽锌和亚甲基水杨酸抗生素类饲料添加剂的药理作用、毒性安全、动物保健效果、国内外生产使用情况等方面进行了综述。     

Replacing bacitracin methylene disalicylate by crushed Nigella sativa seeds in broiler rations and its effects on growth, blood constituents and immunity

The effect of using crushed Nigella sativa seeds (NSS) as a natural growth promoter instead of the antibiotic growth promoter bacitracin methylene disalicylate (BMD) in broiler rations that contain one of two types of anticoccidials (either lasalocid Na or 3-nitro) on growth performance, blood constituents and some selected antibody titers was studied. An experiment was conducted on five dietary groups with two different growth promoter's supplementation from one to 42 days of age. The statistical findings of this experiment prove that replacing BMD by crushed NSS significantly improve growth performance. The serum levels of cholesterol, triglyceride were significantly decreased, while, high density lipoprotein (HDL) was significantly increased. Concerning the findings that pertain to immunity, antibody titer against Newcastle and infectious bursal diseases were significantly improved by replacing BMD by crushed NSS, but no significant effects were noticed in antibody titer against infectious bronchitis. In conclusion, from the results of the current study it could be speculated that crushed NSS could be of value to replace BMD in broiler diets. Further studies must be performed to detect the proper level of NSS before field application.     

八角抽提油和蚯蚓粉对肉鸡肠道发育和养分利用率的影响

本试验旨在研究八角抽提油(八角油)和蚯蚓粉对肉鸡肠道发育和养分利用率的影响。试验一选用1日龄爱拔益加肉鸡384只,随机分为4个处理,每个处理12个重复,对照组饲喂基础日粮,八角油组、蚯蚓粉组和杆菌肽锌组分别在基础日粮中添加50 mg/kg八角油、100 mg/kg蚯蚓粉和20 mg/kg杆菌肽锌;试验二选用21日龄爱拔益加肉鸡120只,随机分为5个处理(处理1~4同试验一,处理5为内源组),每个处理12个重复。结果表明:与对照组相比,其余各组均能显著改善肉鸡21 d小肠各段的相对长度和相对重量(P0.05);与对照组相比,八角油和蚯蚓粉均显著提高肉鸡部分肠段的绒毛高度(P0.05);与对照组相比,其余各组均显著提高部分肠段绒腺比(P0.05);与对照组相比,其余各组均极显著提高肉鸡氮的表观和真利用率(P0.001);与对照组和杆菌肽锌组相比,八角油组和蚯蚓粉组肉鸡蛋氨酸的表观和真利用率均显著提高(P0.001)。由此可见,八角油和蚯蚓粉作为饲料添加剂均可以一定程度上改善肉鸡肠道发育,提高养分利用率。     

原生质体诱变结合复合抗性筛选杆菌肽高产菌株

[目的]筛选杆菌肽的高产菌株。[方法]将原始菌株经活化后制备原生质体,采用紫外照射75s后再用终浓度为100μg／ml的NTG诱变通过硫酸链霉素＋杆菌肽复合抗性平板筛选杆菌肽的高产菌株。[结果]经过7轮诱变,一共分离了1000个菌株（筛选过的所有菌株）;最终获得C-67号高产菌株,其杆菌肽效价达到963．2957U／ml,相比原始菌株提高22．34％。C-67连续传代5次后,产量仍稳定,表明其遗传稳定性较高。[结论]原生质体诱变结合复合抗性筛选是一种简单高效的微生物育种及筛选方法。     

牛奶中粘菌素和杆菌肽残留的固相萃取超高效液相色谱-串联质谱法测定

建立了牛奶中粘菌素和杆菌肽药物残留的固相萃取-超高效液相色谱-串联质谱测定方法,样品用4%三氯乙酸乙腈溶液提取,经乙醚除脂,HLB固相萃取柱净化,相色谱-串联质谱法分析,外标法定量。结果表明：粘菌素和杆菌肽在20~2 000μg/L浓度范围内呈现良好线性,R2均大于0.998;方法检出限为5μg/kg,定量限为10μg/kg;粘菌素和杆菌肽分别在10~100μg/kg和10~1 000μg/kg浓度添加范围内的平均回收率为84%~110%,批内、批间RSD均小于20%。该方法具有简便快捷、灵敏度高、定性准确等优点,能够满足牛奶中其残留检测有关法规的要求。     

Effect of bacitracin on tetracycline resistance in Escherichia coli and Salmonella

Tetracyclines and bacitracin are used extensively as a growth promotant and a therapeutic, respectively in livestock. In this study, we test whether there is an interaction between bacitracin and tetracycline that can select for an increase in microbial tetracycline sensitivity, using Escherichia coli and Salmonella as a model. We found via in vitro studies that bacitracin at sublethal concentrations preferentially selects for outgrowth of tetracycline-sensitive bacteria from among a population of tetracycline-resistant and tetracycline-sensitive E. coli and Salmonella strains. Most of the bacterial strains employed in our study were shown by PCR to possess the tetracycline resistance gene tet(A) or tet(C), either of whose activity is associated with tetracycline efflux. Bacitracin could be substituted for the lipophylic chelator, fusaric acid, used as a positive selective agent for tetracycline sensitivity. Together, these observations suggest that bacitracin-mediated selection for tetracycline sensitivity alters the function of tetracycline efflux proteins. Using bacitracin and tetracycline simultaneously may improve the effectiveness of the antibiotics, while decreasing the risk of selecting for a population of tetracycline-resistant microorganisms.     

杆菌肽锌与硫酸抗敌素配伍对异育银鲫增重率和耐低氧力的影响

144尾异育银鲫随机分成3组,Ⅰ组对照组,投喂基础日粮,Ⅱ、Ⅲ组为试验组,分别投喂基础日粮含30ppm杆菌肽锌、基础日粮含30ppm杆菌肽锌和6ppm硫酸抗敌素,探讨杆菌肽锌与硫酸抗敌素配伍对异育银鲫增重率和耐低氧力的影响.经39天饲养试验,结果表明加药的Ⅱ、Ⅲ组增重率分别高于对照组9.8%和24.5%,且差异都显著(P＜0.05).杆菌肽锌和硫酸抗敌素配合使用比单独使用杆菌肽锌增重率提高13.4%,抗低氧能力为Ⅰ＞Ⅱ＞Ⅲ,且Ⅰ与Ⅲ组差异显著(P＜0.05).