抗生素工业化生产中一级种子罐染菌原因及解决方法

抗生素工业化生产中,菌种往往需要扩大繁殖到一定的数量后再进入发酵罐.在一级种子制备过程中,引起染菌的因素很多,极大地影响了抗生素生产的产量和质量.解决一级种子罐染菌的方法,除制定科学的岗位SOP并不断提高操作者的技能外,更重要的是要加强工艺管理,树立以预防为主的思想,根据微生物特性,强化环境清洁,加强设备清洁、维修,操作时实行定人、定操作.     

滨梅茎段组培污染率控制方法的研究

以当年生滨梅茎段为试材,针对在组培过程中滨梅茎段易感染外生菌和内生菌的问题进行了污染率控制方法的探索。研究结果表明：（1）不同的消毒试剂中,0.1%的升汞消毒效果最好;（2）不同消毒试剂最优组合为75%的酒精 0.1%的升汞,可以有效控制外生菌染菌率在8.25%,死亡率在18.20%;（3）最优消毒试剂组合的最佳消毒时间为先用75%酒精消毒30秒,再用0.1%的升汞消毒5分钟;（4）抗生素添加试验中,添加浓度为5‰的制霉菌素可使内生菌染菌率减少到3.2%,死亡率减少到9.2%,无菌苗获得率为81.3%。     

向染菌作斗争

1971年6月份我们发酵12罐土霉素,染菌率达91％以上,1972年7月份大罐染菌率也达到75％,染菌的罐批多数滤速不好,严重影响产量,如何解决染菌问题,是当前抗菌素生产中的重要问题。造成染菌的原因很多,如水、电、空气、蒸汽、设备维修、工艺操作等等,但是,根据我们的经验,首先要抓路线、抓政治思想。     

寡聚糖研究与应用

为了克服抗生素类生长促进剂的弱点,营养学家开发了第一代抗生素替代品益生素。益生素是指对动物有益的微生物活菌制剂,能竞争性地抑制有害微生物的生长,维持肠道正常的微生物平衡区系,发挥类似抗生素的作用。然而益生素的使用目前仍受到许多限制,主要表现在3个方面:1)动物消化道中原生菌的优生作用使活菌制剂很难在短时间内定植、完成续生或大量繁殖。2)活菌制剂均有其特定的微生态环境,如果动物肠道中无法长久供应这些外源活菌制剂的营养素,它也将死亡而失效。3)活菌制剂必需耐受饲料制粒过程中的高温以及胃肠道中消化酶、酸、碱环境。因…     

硫酸粘杆菌素抗生素效价测定中应注意的事项

对兽药抗生素药品硫酸粘杆菌素在效价测定过程中经常出现的问题,在培养基的制备、样品的提取菌悬液的制备、双碟的制备抗生素溶液的浓度范围等几个方面做了综述。     

猪霉形体体外药物敏感性试验

探讨体外培养条件下,强力霉素等8种抗生素对猪霉形体的杀灭效果。将感染猪霉形体(Mycoplasma suis,M.suis)的猪红细胞接种到培养基内体外培养,在培养基内添加不同种类和不同浓度的抗生素,结果发现,强力霉素和土霉素杀灭和抑制M.suis的效果明显高于其他抗生素,可明显减小M.suis的染虫率(p0.05)。泰乐菌素对M.suis的染虫率无明显影响,但可明显减小M.suis的染虫强度。     

益生素作用机理及其在现代畜牧生产中的应用

目前由细菌引起的疾病一般都通过抗生素来治疗,但是抗生素的滥用使得大部分细菌对其产生了不同程度的抗性,给疾病治疗及人类健康带来隐患。寻找有益的抗生素替代品已成为亟待解决的问题,而以菌治菌的方法正日益被人们接受。实践证明益生素是一种可直接饲喂动物并能促进动物肠道菌群平衡的微生态制剂,可部分替换抗生素作为饲料添加剂,有望解决抗生素残留问题及动物耐药问题,对畜牧业发展具有不可估量的作用。作者将就益生素菌种的选择、作用机理及提高其作用效果的措施等方面展开综述。     

大肠埃希菌多重耐药调节子研究进展

大肠埃希菌多重抗生素耐药主要是由多重耐药调节基因和外输泵共同作用产生的。大肠埃希菌多重耐药调节子是广泛存在于肠杆菌科细菌染色体上的抗生素多重耐药调节中心,是大肠埃希菌耐药的主要组成部分。为解决多重抗生素耐药问题,很多专家和学者对大肠埃希菌多重耐药调节子和外输泵的耐药机制进行了深入的研究,研究开发多重抗生素耐药基因消除剂和外输泵抑制剂,或增加外输泵抑制基因的表达,将成为从根本上解决多重抗生素耐药问题的最好方法。文章对大肠埃希菌AcrAB、AcrAB-Tolc,Mar和膜孔蛋白Ompf、Ompc等多重抗生素耐药调节子的组成、功能及其影响因素进行了综述。     

中药代替抗生素防治蛋鸡疾病的研究

随着抗生素残留、耐药菌的不断增加,天然、绿色的蛋鸡产品已经成为人们的基本需求,中药具有医用食用的双重效果,而且是自然界自然存在生长的,代替抗生素成为现在的研究热点。本文对目前中药替代抗生素在蛋鸡健脾促消化、促生长、治未病、抗病毒、抗菌和抗寄生虫等方面进行综述,为更好地开发利用中药和临床使用中药代替抗生素提供参考。     

抗菌肽的生理功能和作用机制及其在断奶仔猪上的应用研究进展

全球耐药菌的增加和抗生素生长促进剂的禁用使得寻找新型预防细菌感染和促生长性能的替代物刻不容缓.抗菌肽的抗菌谱广,对多重耐药菌具有良好的杀伤作用,因此被认为是抗生素的理想替代品.本文综述了抗菌肽的生理功能、作用机制及其在断奶仔猪生长性能、肠道健康和免疫功能等方面的应用,为抗菌肽在断奶仔猪生产中的研究与科学应用提供参考依据...     

乳酸菌发酵中药制剂防制鸡球虫病条件的优化及应用

本试验旨在摸索乳酸菌发酵抗鸡球虫中药制剂的最佳制备条件,研究其对鸡球虫病的防制效果。首先对乳酸菌发酵中药制剂的最佳菌株、接菌量、时间、温度、pH条件进行摸索,制得乳酸菌发酵中药制剂,然后选取150只AA+肉鸡进行效果试验。试验随机分为对照组、感染组、乳酸菌发酵组、西药组和纯中药组,21日龄时计算各试验组鸡生长性能及免疫细胞因子IgG、IL-12、IFN-γ、IL-10的含量。结果显示,3.0%戊糖片球菌PP培养于浓度1.0 g/mL的中药培养基,在pH 6.0、37℃的温度下培养12 h,戊糖片球菌PP的活性最高,生长良好;且乳酸菌发酵组鸡的平均日增重显著高于感染组(P<0.05),高于纯中药组及西药组,但差异不显著(P>0.05),与对照组增重效果相当(P>0.05);其料重比(F/G)显著低于感染组(P<0.05),低于纯中药组、西药组,但差异不显著(P>0.05);其IL-12、IFN-γ的表达均显著高于感染组(P<0.05),高于纯中药组和西药组,但差异不显著(P>0.05);其IL-10、IgG显著高于感染组(P<0.05),稍高于纯中药组及西药组(P>0.05)。结果表明经优化的乳酸菌发酵中药制剂可提高感染球虫鸡的生长性能,且能增强机体免疫水平。     

桑树病原原核生物及其病害的研究进展(Ⅰ)

侵染桑树的病原原核生物有细菌、菌原体、螺原体、立克次体等,其中由病原细菌引发的桑树细菌病害对蚕桑生产的危害极大。主要介绍原核生物界薄壁菌门的病原细菌侵染桑树导致的桑疫病、桑青枯病、桑枝软腐病、桑枯萎病和桑叶斑病等重要桑树细菌病害,从病原及其侵染循环,桑树发病规律、发病症状,病害防治方法几个方面概述其研究进展。     

The behaviour of mixed bacterial infections in the shell membranes of the hen's egg

The selection of Gram‐negative bacteria from a heterogenous flora on the shell membranes of the hen's egg occurred during two phases of the infection process. When the infection was confined to the shell membranes, the Gram‐negative bacteria achieved dominance over the Gram‐positive organisms. This dominance was accentuated when the albumen was invaded and it was noted, moreover, that a particular strain of Gram‐negative bacteria predominated whereas several strains co‐existed in the shell membranes.     

The epidemiology of bacterial infection of the genitalia in rams

The interrelationship between the various bacteria isolated from the genital tract of rams and their host animals was studied. The pathogenicity of the different isolates varied. Several of these bacteria could be cultured in a medium consisting of a suspension of pen floor debris solidified with agar, while many organisms survived in the suspension for 10 days. Epidemiological investigations showed that rams kept under intensive systems were subjected to large-scale invasion of their genitalia by bacteria which led to infection of the accessory glands and orchitis and epididymitis. Apart from the preputial cavity, some rams kept on open range were entirely free of bacterial infection of their genitalia, and those that did have bacteria in the deeper parts of their genitalia had a very significantly lower incidence of pathological lesions of their genitalia. Finding bacteria and neutrophils in semen is consistent with the epidemiological findings.     

A practical method of reducing spread of disease by hypodermic needles

Transmission of infection between animals is possible when using multidose syringes. The possibility of infection spreading can be reduced by using a telescopic device which fits the syringe barrel and is topped by a cap containing plastic foam impregnated with biocide. Under laboratory conditions, and continually contaminating the needle with various bacteria, infection could not be cultured in broth until after at least 25 injections and in most cases contamination did not occur after 50 injections. When culture was undertaken on solid media breakdowns occurred more frequently, possibly because the agar became lodged in the needle and shielded the bacteria from the biocide.     

Fish oil-induced yellow fat disease in rats. IV. Functional studies of the reticuloendothelial system.

In rats with "stage S/E" yellow fat disease an injection of colloidal carbon resulted in a marked reduction in the number of circulating platelets. The death rate of rats with experimental Listeria monocytogenes infection, the number of bacteria in their spleens and the decrease of bacteria in their spleens on the days after infection were the same in rats with yellow fat disease as in controls. The fact that the rats died during the first few days after infection also may indicate that their immunological resistance to L. monocytogenes was not altered by yellow fat disease.     

中药有效成分对细菌溶血素的抑制作用

在防制细菌性疾病方面,抗菌药物起着非常重要的作用,但是随着抗菌药物在临床上的广泛应用,细菌的耐药问题日益突出,给临床治疗带来极大困难。近年来,以中药抑制细菌毒力因子控制细菌感染的治疗策略已引起国内外学者的广泛关注。细菌溶血素是细菌产生的主要毒力因子之一,随着研究的不断深入,开发溶血素抑制剂成为解决细菌感染问题的关键。现针对中药对细菌溶血素的抑制作用进行综述,以期为临床治疗细菌性疾病提供理论依据。     

Review on the Prohibitive Effect of Gradients in Chinese Traditional Herbs on Hemolysin in Bacteria

Antimicrobial agents play a crucial role in the prevention and treatment of bacterial diseases. However, the widely clinical use of antibiotics makes the bacteria antibiotic-resistance problem much more severe, which could increase the difficulty of clinical treatment. Recently, the method of using traditional Chinese herbs to control bacterial infection by suppressing the bacterial virulence factors has got researchers'attention around the world. Hemolysin is one of the crucial virulence factors in many kinds of bacteria, therefore hemolysin is an ideal target to combat the infection caused by bacteria. The suppressing effect of Chinese herbs to the hemolysin is synthesized and reviewed here to lay theoretical foundation for the clinical treatment of bacterial diseases.     

一株血清7型致病性猪链球菌的分离鉴定

为确定2007年11月黑龙江省五常市某猪场发病猪的病原,本研究将病猪迫杀,采取脑和关节液在血平板培养基上划线进行细菌分离培养,结果显示在血平板培养基上形成灰色、半透明、边缘整齐的有草绿色狭窄溶血环的光滑型圆形小菌落,镜检观察到散在排列的革兰氏阳性短链球菌,经生化反应、PCR反应及血清学试验鉴定为7型猪链球菌,并命名为07WC11株,其毒力基因型为cps7H+、gdh+、mrp+、ef和sly.以纯化的该分离菌株对斑马鱼和仔猪进行动物感染试验均能够导致斑马鱼和仔猪发病,表明该菌株具有一定的致病性,其毒力比国际标准菌株R735株和8074株更强.     

大菱鲆(Scophthalmus maximus L.)鳗利斯顿氏菌(Listonella anguillarum)感染症及其病原特性

对一养殖场所发生的大菱鲆（Scophthalmus maximus L．）病害进行了发病情况、临床表现、病理变化及病原等方面的检验，结果表明为细菌性败血感染症。通过对15尾病（死）大菱鲆病变组织中细菌检查、细菌分离与鉴定，以及人工感染试验的致病作用等，表明所检出的细菌为利斯顿氏菌属（Listonella MaeDonell and Colwell 1986）的鳗利斯顿氏菌[L．anguillarum（Bergeman 1909）MacDonell and Colwell 1986]，系该病例的病原菌。