益生素应用前景广阔

益生素(Probiotic)又称促生素、活菌制剂或微生态制剂,是近年来一种新兴的活菌饲料添加剂。饲喂动物后可以改善肠道中微生物菌群的平衡,从而对宿主动物产生有益的作用,益生素对动物具有多方面的功能,可以作为动物的生长促进剂、营养性生物调节剂和免疫刺激剂。益生素自问世以来,已显示了强大的生命力和广阔的应用前景,将来很有可能取代现行的抗生素而成为新一代的动物保健性饲料添加剂。     

六种可成功替代抗生素的饲料添加剂

从治疗目的上看,没有一种非药用性质的饲料添加剂可以替代抗生素的作用。在兽医护理中,需要抗生素治疗的患病动物应以合适的剂量接受适当的抗生素治疗,以确保其安全与健康。在无抗生素生产的背景下,饲养此类动物的情况与产品的业务营销或商业方面有关。这里关注的是某些非药用饲料添加剂在动物饲养中的预防和促进生长的作用,这些添加剂可以用来阻止细菌暴发,或至少有助于朝着这个方向发展,或增加动物整体免疫状态。这些添加剂所产生的促生长的效果可以替代过去使用的低剂量饲料用抗生素,而这种低剂量饲料抗生素目前在全世界都在以越来越快的速度被禁止使用。     

动物微生态制剂及应用

微生态制剂是根据微生态学原理研制,用于调节动物机体微生态平衡的一种活菌制剂,可作为动物治疗药物或饲料添加剂使用。人们通过对化学药品残留和细菌抗药性的深入研究,发现化学药品,特别是抗生素作为治疗剂和饲料添加剂的广泛应用,对畜牧业生产和人类产生了较大的副作用：首先是抗生素在灭杀致病菌的同时,也灭杀了对机体有益的生理性细菌,破坏了肠道微生物的生态平衡,出现菌群失调现象,导致幼畜对病原微生物的易感性增加。另外,长期饲喂抗生素致使动物体内产生具有抗药性的细菌,这些细菌对人富有害。而使用微生态制剂则无此忧虑…     

中草药饲料添加剂在畜禽生产中的应用

随着畜牧业集约化发展,化学合成药及抗生素等饲料添加剂在畜禽生产中的广泛应用,不仅造成其在畜禽体内残留和蓄积,产生毒副作用,还引起细菌耐药性产生、动物免疫力下降、环境污染等问题。中草药作为新型的饲料添加剂正引起国内外的广泛重视,被认为是解决以上问题的有效途径之一。为此,笔者对中草药饲料添加剂及其在畜禽生产中的应用进行了简单综述。     

葡糖酸可以替代抗生素促进断奶仔猪生长

3～4周龄断奶仔猪易受营养和环境的应激,导致仔猪营养吸收障碍、腹泻增加和增重降低。虽然在饲料中添加抗生素可以减少断奶后对仔猪产生的这些影响,但同时可引起细菌产生抗药性。这种风险和消费者对不含药物残留食品的需求,促使业界越来越严格的限制使用抗生素饲料添加剂,譬如欧盟,2006年1月起已全面禁止在饲料中使用抗生素作为生长促进剂。因此,必须寻找非药物性饲料添加剂以控制单胃动物胃肠道中的微生物活动,以保证不因禁用抗生素生长促进剂而降低生产性能。目前,主要的替代物是有机酸、原生素、植物性药物、前生素等。葡糖酸(GA)是用某…     

中草药添加剂在养猪生产上的应用

中草药饲料添加剂是一种资源丰富、应用前景十分广阔的天然优质饲料添加剂,含有多种结构成分,如多糖,甙类、酮类化合物等活性物质,实践证实中药作为饲料添加剂有促进动物食欲、增强机体抵抗力、提高饲料转化率、促进动物生长的作用,长期使用无污染、无残留,而且很少产生细菌耐药性、毒副作用,安全性较高。主要就中草药饲料添加剂的分类、生物功能及在养猪生产上的应用等问题进行了综述。     

中草药添加剂替代抗生素在断奶仔猪中的应用研究

<正>近年来,随着人们对抗生素、化学合成物作为饲料添加剂使用容易使动物产生抗药性和药物残留等用药弊端的认识加深,无公害的中草药饲料添加剂越来越多地受到关注。从2006年1月1日起,欧盟全面禁止食品动物使用抗生素促生长饲料添加剂。为了扩大饲料添加剂的来源,许多学者已经从植物药或其副产品中寻找新型添加剂。     

细菌素在饲料中的应用及展望

近年来细菌素由于其无毒无害，易分解，无残留等特点，成为人们关注的焦点。文中简要介绍了细菌素的定义，分类及作用机制；鉴于细菌素近年来在食品行业的广泛应用，着重阐述了细菌素作为一种高效安全的饲料添加剂可能性，并对其研究前景做了概括说明。     

枯草芽孢杆菌MA139类细菌素抑菌活性的研究

为测定枯草芽孢杆菌MA139产生的类细菌素的抑菌活性。本试验采用管碟法对枯草芽孢杆菌MA139产生的类细菌素对多株革兰氏阳性菌、革兰氏阴性菌和真菌的抑菌活性进行测定。结果表明:类细菌素不但对芽孢杆菌属的其他菌种有抗菌活性,对病原菌和霉菌也有拮抗作用;不同指示菌对类细菌素的敏感性不一样,其中金黄色葡萄球菌对其最敏感。该类细菌素具有广谱抗菌作用,有作为畜禽饲料添加剂的潜力。     

海狸保健素对海狸鼠增重试验

随着海狸鼠饲养业的兴起,海狸鼠的各种饲料添加剂也相继问世.目前多数养殖户是借用养貂的方法用土霉素作为海狸鼠的饲料添加剂.实践表明,长期应用土霉素作为该种动物的饲料添加剂不仅增重效果不明显,而且容易产生抗药性.为此我们研制了两种海狸鼠用保健素作为饲料添加剂,以期达到既增重,又防病的目的.现将试验情况报告如下.     

细菌素应用的理论与实践

细菌素是细菌在代谢过程中由核糖体合成基因编码的一类具有生物活性的多肽或蛋白质类物质,因其高效、无毒、耐高温、无残留、无抗药性以及良好的生物相容性等优点,得到国内外学者青睐。细菌素在饲料添加剂和生物药品的研发中有着广泛的应用价值和广阔的应用前景。文章就细菌素的理论研究及其在畜牧业、水产养殖业、医药保健中的应用价值和应用现状作一简要综述。     

细菌素应用的理论与实践

细菌素是细菌在代谢过程中由核糖体合成基因编码的一类具有生物活性的多肽或蛋白质类物质,因其高效、无毒、耐高温、无残留、无抗药性及良好的生物相容性等优点,得到国内外学者青睐。细菌素在生物饲料添加剂、生物兽药及人类医药保健和食品生物防腐剂的研发中有着广泛的应用价值和广阔的应用前景。作者就细菌素的理论研究及其在畜牧业、水产养殖业、医药保健中的应用价值和应用现状进行了综述。     

Predisposing factors and prevention of Clostridium perfringens-associated enteritis

Clostridium perfringens is one of the major causes of intestinal disease in humans and animals. Its pathogenicity is contributed to by the production of a variety of toxins. In addition, predisposing environmental factors are important for the induction of C. perfringens-associated enteritis as shown by infection models. Environmental contamination, gastric and intestinal pH, intestinal microflora, nutrition, concurrent infections, and medical interventions may influence the intestinal colonization, growth, and toxin production by C. perfringens. Prevention of C. perfringens-associated enteritis may be mediated by the use of feed additives like probiotics, prebiotics, organic acids, essential oils, bacteriophages, lysozymes, bacteriocins, and antimicrobial peptides. Here we summarize and discuss published data on the influence of different environmental predisposing factors and preventive measures. Further research should focus on feed composition and feed additives in order to prevent C. perfringens-associated enteritis.     

一株产细菌素植物乳酸杆菌YJG发酵液对蛋鸡生产性能以及蛋品质的影响

研究一株植物乳酸杆菌细菌素对蛋鸡生产性能和蛋品质的影响。选用232日龄产蛋率和体重相近、健康状况良好的海兰灰蛋鸡225只,试验期为34 d。结果表明:日粮中添加500 AU/kg植物乳酸杆菌细菌素对蛋鸡的产蛋率和平均蛋重的提升幅度最大,各细菌素添加组对降低料蛋比均有显著的效果(P<0.05),对平均日采食量、蛋黄色泽、哈氏单位、蛋壳强度和蛋形指数都有不同程度的改善。植物乳酸杆菌细菌素可以明显改善蛋鸡生产性能和蛋品质,可以为饲料添加剂的研发提供新的思路。     

Production of bacteriocins by coagulase-negative staphylococci involved in bovine mastitis

In the present study, 188 coagulase-negative Staphylococcus (CNS) strains were isolated from bovine mastitis cases from 56 different Brazilian dairy herds, located in the Southeast region of the country, and were tested for antimicrobial substance production. Twelve CNS strains (6.4%) exhibited antagonistic activity against a Corynebacterium fimi indicator strain. Most antimicrobial substances were sensitive to proteolytic enzymes suggesting that they might be bacteriocins (Bac). Amongst the CNS producers, six were identified as S. epidermidis, two as S. simulans, two as S. saprophyticus, one as S. hominis and one as S. arlettae. Plasmid profile analysis of these strains revealed the presence of at least one plasmid. The Bac(+) strains presented either no or few antibiotic resistance phenotypes. Three strains were shown to produce a bacteriocin either identical or similar to aureocin A70, a bacteriocin previously isolated from an S. aureus strain isolated from food. The remaining Bac(+) strains produce antimicrobial peptides that seem to be distinct from the best characterised staphylococcal bacteriocins described so far. Some of them were able to inhibit Listeria monocytogenes, an important food-borne pathogen, and several strains of Streptococcus agalactiae associated with bovine mastitis, suggesting a potential use of these bacteriocins either in the prevention or in the treatment of streptococcal mastitis.     

Establishment of canine and feline cells expressing canine signaling lymphocyte activation molecule for canine distemper virus study

Antimicrobial therapy is a useful tool to control bovine mastitis caused by Staphylococcus aureus, as consequence an increase in staphylococci resistant cases has been registered. Alternative strategies are desirable and bacteriocins represent attractive control agents to prevent bovine mastitis. The aim of this work was to evaluate the activity of five bacteriocins synthesized by Bacillus thuringiensis against S. aureus isolates associated to bovine mastitis. Fifty S. aureus isolates were recovered from milk composite samples of 26 Holstein lactating cows from one herd during September 2007 to February 2008 in México and susceptibility of those isolates to 12 antibiotics and 5 bacteriocins from B. thuringiensis was evaluated. S. aureus isolates were mainly resistant to penicillin (92%), dicloxacillin (86%), ampicillin (74%) and erythromycin (74%); whereas susceptibility to gentamicin, trimethoprim and tetracycline was detected at, respectively, 92%, 88%, and 72%. All S. aureus isolates showed susceptibility to the five bacteriocins synthesized by B. thuringiensis, mainly to morricin 269 and kurstacin 287 followed by kenyacin 404, entomocin 420 and tolworthcin 524. Our results showed that S. aureus isolates had differences in the antimicrobial resistance patterns and were susceptible to bacteriocins produced by B. thuringiensis, which could be useful as an alternative method to control bovine mastitis.     

细菌素及其应用的研究进展

细菌素是细菌自身生产的一类杀菌物质,由基因编码、核糖体合成,是自然界中细菌用于调节自身菌群结构的一类重要活性物质。细菌素的来源广泛、结构多样,对各种动物致病菌都具有高效抑杀作用,这些特点为细菌素开发成为一种新型抗菌药物提供了可能。作者对近年来在细菌素生物学特征的发展、分类更新及其应用研究等进行了综述,希望能为中国新型细菌素类动物药物的开发提供参考。     

抑制奶牛乳房炎源金黄色葡萄球菌的乳酸菌的筛选

为获得抑制奶牛乳房炎源金黄色葡萄球菌(S. aureus)的乳酸菌(LAB),本研究从新疆巴音布鲁克牧区鲜牛乳和哈萨克族乳制品奶疙瘩样品中分离培养LAB,通过传统的分离鉴定与16S rDNA基因序列测序相结合的方法鉴定LAB种类,同时以临床奶牛乳房炎源金黄色葡萄球菌S. aureus N2为指示菌,采用双层琼脂扩散法检测分离株的抑菌能力。通过测定生长曲线确定分离株的生长稳定期,进而利用硫酸铵沉淀法透析提取稳定期内分离株的细菌素,并检测其细菌素抑菌效价。结果显示:从样品中筛选获得5株能够抑制指示菌生长的LAB,分别为希氏乳杆菌、干酪乳杆菌、粪肠球菌、戊糖片球菌和乳酸乳球菌亚种。生长规律曲线表明20 h^30 h为5株LAB的稳定期,此期培养液pH值维持在3.8~4.5。从培养20 h的5株LAB上清液中提取到了细菌素,经检测其具有抑菌活性,抑菌效价分别为457 IU/mL、1 023 IU/mL、676 IU/mL、1 862 IU/mL和1 023 IU/mL。本研究结果表明5株LAB通过在生长稳定期内维持较低酸性环境(pH<4.5),代谢产生细菌素对乳房炎源S. aureus发挥抑制生长作用。本研究为S. aureus性奶牛乳房炎的生物防治提供了实验依据。     

Antimicrobials for foodborne pathogen reduction in organic and natural poultry production

Antimicrobials currently used in the conventional poultry industry include physical, chemical, and biological hurdles. However, there is a need for natural and organic antimicrobials to make the food safe and to retain its natural taste and texture. Potential natural or organic antimicrobials include bacteriophages, bacteriocins, antibody therapy, vaccination, and the use of natural plant compounds such as essential oils. Genomic methods applied to Salmonella responses to multiple interventions may offer opportunities to optimize combinations that are the most effective.     

Bacteriocin production of probiotic Lactobacillus gasseri LA39 isolated from human feces in milk-based media

The use of bacteriocins from Lactobacillus gasseri , a probiotic lactic acid bacterium, as bio-preservatives in the food industry and animal formulations has been limited because few strains of Lb. gasseri are cultivated and produce a bacteriocin in natural media such as milk and milk-based media. By the determination of the growth-supplements to milk among the 47 nutrients, Lb. gasseri JCM1131^T, LA39 and LA158 isolated from human feces were successfully cultured in reconstituted skim milk and cheese whey using proteose peptone as a nutrient supplement, where Lb. gasseri LA39 produced a useful bacteriocin, gassericin A, with effective growth-inhibiting activity against Gram-positive food-borne pathogens. The data suggest these developed low-cost safe media supporting enough production of bacteriocins by the probiotic Lb. gasseri LA39 could be used to improve the safe bio-preservation of foods and therapy of bovine mastitis, and extra cheese whey produced by cheese making industry is reused in the cultivation for probiotics effectively.