蛙源抗菌肽Magainin Ⅱ对畜禽常见病原菌抑菌活性与体外稳定性测定

抗菌肽MagaininⅡ是来源于非洲爪蟾体内的一种具有抗菌活性的小肽类物质。试验采用微量肉汤稀释法测定蛙源抗菌肽MagaininⅡ对几种常见畜禽致病菌的抑菌活性;在此基础上将抗菌肽MagaininⅡ在不同温度、pH值及人工胃蛋白酶与胰蛋白酶进行处理,进而评价其稳定性。试验结果表明,抗菌肽MagaininⅡ对革兰氏阳性菌不具有抑菌作用,但对几种革兰氏阴性菌表现出一定的抗菌活性,MIC值处于64~256μg/ml;由时间杀菌曲线可知,MagaininⅡ不能有效抑制金黄色葡萄球菌ATCC 25923菌落的形成,但能够在90 min内对大肠杆菌ATCC 25922发挥抑制作用;MagaininⅡ的稳定性测试结果表明,分别经不同温度、pH值以及人工胃蛋白酶与胰蛋白酶处理后的MagaininⅡ对金黄色葡萄球菌ATCC 29523和表皮葡萄球菌ATCC 12228始终没有发挥抑菌活性,在经50~70℃处理后能够对大肠杆菌K12和肠炎沙门氏菌CMCC 50041稳定发挥抗菌效果,MIC值始终为64μg/ml;经两种人工酶处理后的MagaininⅡ对两种试验革兰氏阴性菌不再具有抑菌作用;经pH值为2处理后,MagaininⅡ对大肠杆菌K12和肠炎沙门氏菌CMCC 50041的MIC均为256μg/ml,比未处理时明显增大,经pH值为8处理后,MagaininⅡ不能抑制大肠杆菌K12,对肠炎沙门氏菌CMCC50041的MIC为128μg/ml。基于试验结果可推断:MagaininⅡ对革兰氏阳性菌抗菌效果不明显,对革兰氏阴性菌具有一定的抗菌效果,经人工酶处理后性质不稳定,该研究为MagaininⅡ在畜禽生产上的应用提供参考。     

抗菌肽Cecropin D基因在毕赤酵母中的表达与抗菌活性分析

为使抗菌肽Cecropin D在巴斯德毕赤酵母中高效表达,本研究根据Cecropin D全基因序列和毕赤酵母的偏嗜性设计合成4条寡聚西核苷酸,SOEing-PCR技术法合成Cecropin D基因序列,并克隆至酵母表达载体pGAPZαA中,构建重组表达质粒,将其线性化后电击转化毕赤酵母菌株SMD1168,经高浓度博莱霉素筛选,获得高拷贝转化子,菌液PCR鉴定表明Cecropin D基因已整合到酵母基因组中.在GAP强启动子调控下,重组Cecropin D高效分泌表达,产物耐高温耐酸碱,并对部分革兰氏阳性菌和革兰氏阴性菌均有抑菌效果,对E.coliDH5 α和S.aureus Cowan I株的MIC值分别为2.17 μg/mL和4.55 μg/mL.     

庆大霉素与其他药物间的相互作用及其在使用中的注意事项

<正>庆大霉素(又名正泰霉素)属氨基糖苷类抗生素,与链霉素同属一类。1药物相互作用1.1庆大霉素与β-内酰胺类抗生素(如青霉素类或头孢菌素类)联用通常对多种革兰氏阴性菌,包括绿脓杆菌等有协同作用。对革兰氏阳性菌也有协同作用,例如,庆大霉素与青霉素联用     

小檗碱与氧氟沙星联合抗菌作用的试验研究

为评价盐酸小檗碱与氧氟沙星联用的体外抗菌作用,我们进行了该项试验。方法：将菌液稀释成0．5号麦氏标准管浊度,采用肉汤稀释法测定细菌对小檗碱和氧氟沙星的MIC;按棋盘法设计测定小檗碱和氧氟沙星联合抗菌的FIC。结果：小檗碱和氧氟沙星联合应用对金黄色葡萄球菌的FIC为0．375-0．5,对大肠杆菌为0．75-1。这说明两药联用对革兰氏阳性菌为协同作用,对革兰氏阴性菌为相加作用。     

蛇源抗菌肽C-BF和抗生素的抑菌活性比较及协同效应研究

研究旨在探讨蛇源抗菌肽C-BF的抗菌活性及其与抗生素和人源抗菌肽LL-37的抑菌协同作用。试验检测蛇源抗菌肽C-BF和2种畜禽常用抗生素对常见致病菌的最小抑菌浓度(MIC)与最小杀菌浓度(MBC);采用棋盘法分析蛇源抗菌肽C-BF与抗生素、人源抗菌肽LL-37联合使用效果,计算出部分抑菌浓度指数(FIC index)。结果表明:抗菌肽C-BF对革兰氏阴性菌和革兰氏阳性菌均有较强的抑菌效果;抗菌肽C-BF与抗生素联合使用对金黄色葡萄球菌表现出相加作用;与抗菌肽LL-37联合使用对大肠杆菌表现出协同效应。结果提示,蛇源抗菌肽C-BF具有成为新型饲用抗生素替代品的巨大潜力,试验可为C-BF在畜禽生产中的实际应用提供参考。     

硫酸头孢喹肟治疗猪细菌性呼吸道病的疗效试验

头孢喹肟属第4代头孢类抗生素,抗菌谱广,抗菌活性强,对临床分离的各种革兰氏阳性菌菌、革兰氏阴性菌的MIC50、MIC50值均较小[1].     

茶树油制剂对金黄色葡萄球菌和沙门氏菌的体外抑菌试验

确定茶树油制剂的最低抑菌浓度(MIC),为茶树油制剂作为饲料添加剂提供重要的参考依据,使茶树油有望被开发成为一种可缓解全球"抗菌药物危机"的天然抗菌剂。本试验以茶树油作为抑菌剂,以金黄色葡萄球菌和沙门氏菌分别作为革兰氏阳性菌和革兰氏阴性菌的代表,进行体外抑菌试验,测定混合抑制培养后的光密度值(OD600nm)并对其进行分析。研究发现茶树油制剂对金黄色葡萄球菌和沙门氏菌均具有显著的抑菌效果(P0.05),且对二者的抑菌效果一致,在二者浓度为106cfu/ml时的最低抑菌浓度(MIC)相同,均是0.1×2-1×2%,茶树油制剂对革兰氏阳性菌和革兰氏阴性菌都具有显著的抑菌效果(P0.05)。     

应用高效液相色谱测定饲料中金霉素方法探讨

金霉素是由美国氰胺公司于 1 949年开发的四环素类广谱抗生素 ,对革兰氏阳性菌、阴性菌、螺旋体、立克次氏体、大型病毒均有抑制作用。本试验应用高效液相色谱法对饲料中金霉素含量测定方法进行探讨。添加量在 4 96mg/kg时 ,回收率为 88 3 % ;添加量在 1 9 97mg/kg时 ,回收率为89 5 % ;添加量在 39 37mg/kg时 ,回收率为 95 9% ;添加量在 60 2 6mg/kg时 ,回收率为 96 4% ;添加量为 79 1 9mg/kg时 ,回收率为 97 9% ;平均回收率为 93 6 %。本试验回收率范围在 88 3 %～ 97 9%。1　仪器设备1 1　高效液相色谱仪　日立 65 5A型 ,65 5A— 2 2…     

生猪常用的抗生素及注意事项

1 常用的抗生素 普通青霉素(青霉素钾、钠、普鲁卡因)对革兰氏阳性菌特别有效,如金黄色葡萄球菌、链球菌、放线菌、芽胞杆菌、丹毒杆菌等.不能口服.肌肉注射1～2万单位/千克体重·次,每天2～3次. 氨苄青霉素为白色粉末或结晶,易溶于水.对大部分革兰氏阳性及阴性菌均有较强抗菌作用,但对绿脓杆菌无效.用于治疗猪胸膜肺炎、肠炎、子宫炎,可与链霉素等合用有协同作用.肌肉注射或静脉注射,4～15毫克/千克体重·次,每天2～4次.     

紫花地丁-芦荟紫花地丁-双花连翘提取物对大肠杆菌O_2的联合抑制作用研究

为了研究紫花地丁-芦荟、紫花地丁-双花连翘提取物两个药物对大肠杆菌的联合抑制作用,采用微量棋盘法对已知血清型大肠杆菌O_2进行了单独与联合抑菌对比试验。结果显示,紫花地丁、芦荟、双花连翘提取物,MIC分别为1/4原液、原液和1/4原液;当紫花地丁-芦荟、紫花地丁-双花连翘提取物两两相互配伍时,紫花地丁的MIC分别为单用时的1/16倍和1倍,芦荟和双花连翘提取物的MIC分别降为单用时的1/32倍和1/4。结论:紫花地丁与芦荟和双花连翘提取物分别联合应用时,FIC值分别为0.09375和1.25,相互作用分别为协同作用和无关作用。     

Disease and destiny-mystery and mastery

When early people made their appearance, zoonotic infectious diseases were already waiting, but epidemic diseases did not appear in human history until people began to live in large numbers under conditions of close contact, mainly during the last 10,000 years. Disease has decimated urban populations, conquered armies, and disrupted society. The focus here is on (1) the plague of Athens and the Black Death; (2) smallpox, influenza, and rabies; (3) avian influenza prion diseases, and foot & mouth disease; and (4) emerging and re-emerging diseases. All have veterinary public health associations. In Athens, Greece, in 430 BC, when the Spartans ravaged the countryside, hordes crowded into Athens so that orderly movements, space in which to live, and adequate supplies of food became impossible. Crowding of any population fosters disease transmission; chaos and disorder enhance it all the more. Out of northern Egypt came a terrible plague from across the Mediterranean Sea. The identity of the plague of Athens remains unsure, but the well-considered conclusion is Rift Valley Fever, a mosquito borne, viral zoonosis. The Black Death, also called the Plague, raged in Asia for centuries. In 1347, the Black Death was brought by a ship out of Asia to Sicily. The scenes of devastation were repeated throughout Europe, with 90% or more of the people dying in city after city. Influenza, too, has been a cause of periodic human epidemics, but the great pandemic of influenza occurred in the last months of World War I. In the years of highest occurrence, more than half the world's population became clinically infected. If veterinary public health had been born earlier, it could have led to elucidating the epidemiology of influenza and the plagues of Athens, Europe, and Asia. In turn, smallpox had also caused continual tragedy. In 1796, Edward Jenner began to harvest pustules of cowpox from children or infected cows and inject them into susceptible children. In 1980, the World Health Organization declared that smallpox had been eliminated from the world. Rabies, though, still strikes terror. A number of animal diseases, broadly termed emerging and re-emerging diseases, need surveillance because they have the potential to impact human health. From late in 2003 to 2007, the highly pathogenic H5N1 influenza virus in poultry infected at least 121 people and caused 62 deaths in four countries. The prion diseases, too, all have very high numbers in concentrated contacts. To control these diseases, veterinary public health is essential, with diagnosis, epidemiological surveillance, clinical manifestations, and prevention as primary measures.     

Foot and mouth disease and bluetongue: differences and similarities

On 26th of july 2007 a new case of bluetongue was notified in the Netherlands and on 2nd of august 2007 foot-and-mouth disease was diagnosed in Surrey, England, which raised the threat of having both infections simultaniously in one area. Bluetongue and foot-and-mouth disease have a different pathogenesis, but symptoms may resemble each other at a later stage of infection. The pathogenesis and possible clinical symptoms of both infections are discussed and illustrated with pictures.     

德国荷兰畜禽产品质量安全交流与启示

2018年岁末,笔者有幸赴德国和荷兰,就畜产品质量安全控制及检测技术等进行了短期交流,收获颇丰,现具体介绍如下。一、交流情况德国面积35.73万平方千米,人口约8175.2万,是欧盟人口最多的国家,农业发达,机械化程度很高。德国的畜牧业以猪、牛、羊和禽类为主,畜牧业产值占农业生产总值的61%。德国虽然农业比重很小,但却是有机农业运动最早的发起国,也是目前世界上有机农产品生产与消费大国。     

畜禽物种多样性及其保护和利用

文章就我国畜禽物种多样性资源的现状、保护和利用等方面进行阐述,为生态脆弱的喀斯特地区畜牧业可持续发展提供参考。     

马的咽气癖及其防制措施研究进展

在动物的异常行为中以刻板行为最为常见,而咽气癖又是马最常见的口部刻板行为之一。作者就咽气癖在生理方面和心智方面对马体产生的影响、行为基础、诱因的研究进展及常见的防治措施进行综述。     

奶牛肢蹄病及其防治

简介常见奶牛肢蹄病种类及其症状,从日粮营养、运动场地面结构、环境卫生、饲养管理、遗传育种、疾病管理等方面简析奶牛肢蹄病的病因,并提出相应的预防措施。     

牛羊焦虫病诊断与防治技术

近几年来,辽宁省牛羊饲养业迅速发展,焦虫病的危害越来越明显,已成为危害牛羊的主要疾病之一。为了提高牛羊焦虫病的防治水平,保证我省牛羊饲养业的健康发展,笔者在参阅文献和同行们诊疗经验的基础上,结合自己的治疗实践,详细阐述了我省牛羊焦虫病近几年的流行特点和诊断防治方法。     

国内外蛋氨酸与赖氨酸市场分析与展望

近几年,世界饲用添加剂市场增长较快,预计今后将进一步增长,据世界粮农组织(FAO)首领会议的倡议,到2015年,将使世界营养不良的人口削减一半,其间,肉制品将会以每年2％的速度增长,特别是加快猪肉和禽肉增长。这将促进世界添加剂,尤其是蛋氨酸和赖氨酸需求量的增加。