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《黑龙江畜牧兽医》2017,(22)
为了筛选出既具有高抗氧化活性又能耐酸、耐胆盐、耐胰蛋白酶的优良菌株,试验以东北地区传统手工奶酪为分离源,采用常规微生物学方法分离纯化乳酸菌,并结合镜检观察、生化试验以及16S r DNA基因序列分析对菌株进行鉴定,筛选出产酸性能良好的乳酸菌,并对其进行耐酸、耐胆盐、耐胰蛋白酶、抑菌、抗氧化等特性试验。结果表明:筛选出的59株产酸性能良好的乳酸菌中,有19株耐酸、耐胆盐、耐胰蛋白酶且对金黄色葡萄球菌、粪肠球菌、沙门氏菌、绿脓杆菌和李氏杆菌均有抑制作用,其中筛选出的植物乳杆菌B5-1-1-1和干酪乳杆菌B4-2-11-5不仅具有还原性,而且在清除羟基和自由基方面均具有较高能力,有望成为具有益生特性的乳酸菌资源,从而为东北地区奶酪选育优良乳酸菌奠定基础。 相似文献
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本研究对从腊肉中分离得到的13株芽孢杆菌进行筛选，选择对大肠杆菌K88、K99具有最强抑制效果的一株菌，进行下一步的耐酸耐胆盐的试验，结果表明，筛选得到的这株芽孢菌能够很好地耐酸耐胆盐，用16SDNA基因片断的PCR扩增与序列分析，该菌株YB6与地衣芽孢杆菌的同源性为98％。本试验为动物饲用益生菌产品的开发和推广应用打下基础。 相似文献
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<正>一、起源由猪只肠道筛选出15株菌,其中一株耐酸、耐胆盐能力最佳之菌株外观呈长杆状。LA=Lactobacillus acidophilus,外观长杆状P=frompig,5=当时试验菌株编号。二、LAP5具通过、定殖消化道、排除沙门氏菌能力LAP5可耐酸耐胆盐能力佳→存活于消化道;可吸附与 相似文献
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《黑龙江畜牧兽医》2017,(23)
为了筛选对肠炎沙门氏菌具有抑制作用的益生菌,并对其耐酸、耐胆盐、表现疏水性及抗生素敏感性进行评价,试验采用平板倾注法分离,双层琼脂法初筛和牛津杯法复筛对肠炎沙门氏菌(Salmonella enteritidis)有颉颃作用的益生菌株,并进行生理生化试验和16S r DNA序列鉴定。结果表明:从健康鸡粪便中共分离出41株菌株,并从中筛选出有较强颉颃作用的菌株4株,其中W22菌株同时具有较强的耐酸、耐胆盐特性和较好的疏水性能,经形态、生理生化试验和16S rDNA序列鉴定确定其为卷曲乳杆菌(Lactobacillus crispatus)。说明从鸡粪中筛选得到了能有效抑制肠炎沙门氏菌的益生菌株,有望作为潜在的颉颃性饲用益生菌用于控制鸡的肠炎沙门氏菌感染。 相似文献
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《饲料研究》2016,(13)
试验旨在通过逐步提高培养基酸度及胆盐质量分数的方法,选育出耐酸及耐胆盐效果较强的菌株。以菌珠L102为原始菌株逐步选育出耐性菌株L102b。该耐性菌株在p H 2.0及p H 2.5酸度条件下,存活率较原始菌株提高45.0%以上,在p H 1.5的极低酸度条件下,亦有20.3%的存活率;胆盐质量分数为0.1%~0.3%存活率均在85.0%以上,胆盐质量分数为0.5%时仍有46.2%的存活率。对比原始菌株L102耐酸性能及耐胆盐性能均有明显提高。通过研究单因素及正交试验对选育的耐性菌株L102b的发酵条件,得出菌株L102b的最佳培养条件:转速100 r/min,培养温度35℃,初始p H 6.4,装液量300 m L。 相似文献
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本实验对戊糖片球菌进行耐酸、耐胆盐能力表征及模拟胃液和模拟肠液实验.结果表明,在pH 2.5、3.5条件下培养4h后,戊糖片球菌PP的活菌数分别能达到108 cfu/mL和1010 cfu/mL以上.在胆盐质量分数为0.1％、0.2％和0.3％的MRS培养基中培养4h后,戊糖片球菌PP生长良好,活菌数均在106cfu/mL以上,其中胆盐质量分数为0.1％时,戊糖片球菌PP存活率能达到133.3％.模拟胃液和模拟肠液实验结果表明,该菌株能够有效通过胃环境,能在肠道中繁殖.结果可见,戊糖片球菌PP具有较强的耐酸耐胆盐能力,符合微生态制剂和乳酸菌发酵功能食品菌种的要求. 相似文献
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将90羽健康蛋雏鸡随机分成9组,每组10羽,其中Ⅰ组为对照组,Ⅱ～Ⅸ为试验组.用中草药黄芪多糖、淫羊藿多糖、当归多糖、生物制剂犊牛胸腺肽、化学合成药左旋咪唑、脂质体、维生素E和亚硒酸钠8种具有免疫增强作用的药物,配合鸡新城疫(ND-lasota)疫苗注射使用,采用β-微量血凝抑制试验(ND-HI),α-醋酸萘酯酶染色(ANAE)及试验各组免疫器官相对重量的变化,检测了参试雏鸡的三项免疫指标.结果表明,所选用的药物都不同程度的增强了鸡的免疫功能,并依据其自然特性、免疫增强机理及其特异性,从中筛选出了5种免疫增强剂药物,为下一步筛选高效、经济、实用的复合免疫增强剂的研究提供依据. 相似文献
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猪细小病毒BQ株灭活疫苗免疫剂量及免疫持续期的初步研究 总被引：1，自引：0，他引：1
为确定猪细小病毒(PPV)BQ株灭活疫苗(PPV-BQ)的免疫剂量及免疫持续期,本研究与市场上销售的2种PPV灭活疫苗A和B进行了比较。试验分6组,每组免疫3头PPV抗体阴性猪,1组～3组分别免疫BQ株灭活疫苗1mL、2mL、4mL,4组～5组按照说明书免疫A、B两种PPV灭活疫苗,6组为阴性对照组(免疫油佐剂)。两周后进行二免,定期检测血清抗体水平。结果表明,注射疫苗组均产生了PPV抗体,都能持续到免疫后24周。免疫不同剂量PPV-BQ各组间抗体水平差异不显著(p0.05),PPV-BQ与PPV-A抗体水平差异不显著(p0.05),与PPV-B抗体水平差异极显著(p0.01),显著优于PPV-B。PPV-BQ1mL免疫剂量即可达到或超过同类产品的免疫效果,是较为理想的PPV灭活疫苗。 相似文献
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A I Hurvitz 《Journal of the American Veterinary Medical Association》1982,181(10):1080-1082
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FIV/HIV infections are associated with an early robust humoral and cellular anti-viral immune response followed by a progressive immune suppression that eventually results in AIDS. Several mechanisms responsible for this immune dysfunction have been proposed including cytokine dysregulation, immunologic anergy and apoptosis, and inappropriate activation of immune regulatory cells. Studies on FIV infection provide evidence for all three. Cytokine alterations include decreases in IL2 and IL12 production and increases in IFNγ and IL10 in FIV+ cats compared to normal cats. The elevated IL10:IL12 ratio is associated with the inability of FIV+ cats to mount a successful immune response to secondary pathogens. Additionally, chronic antigenic (FIV) stimulation results in an increase in the percent of activated T cells expressing B7 and CTLA4 co-stimulatory molecules in infected cats. The expression of these molecules is associated with T cells that are undergoing apoptosis in the lymph nodes. As ligation of CTLA4 by B7 transduces a signal for induction of anergy, one can speculate that the activated T cells are capable of T cell–T cell interactions resulting in anergy and apoptosis. The inability of CD4+ cells from FIV+ cats to produce IL2 in response to recall antigens and the gradual loss of CD4+ cell numbers could be due to B7–CTLA4 interactions. The chronic antigenemia may also lead to activation of CD4+CD25+ T regulatory cells. Treg cells from FIV+ cats are chronically activated and inhibit the mitogen-induced proliferative response of CD4+CD25− by down-regulating IL2 production. Although Treg cell activation can be antigen-specific, the suppressor function is not, and thus activated Treg cells would suppress responses to secondary pathogens as well as to FIV. Concomitant with the well-known virus-induced immune suppression is a progressive immune hyper-activation. Evidence for immune hyper-activation includes polyclonal B cell responses, gradual replacement of naïve CD4+ and CD8+ T cell phenotypes with activation phenotypes (CD62L−, B7+, CTLA4+), and the chronic activation of CD4+CD25+ Treg cells. Thus lentivirus infections lead to severe immune dysregulation manifested as both chronic immune suppression and chronic immune activation. FIV infection of cats provides a number of advantages over other lentivirus infections as a model to study this immune dysregulation. It is a natural infection that has existed in balance with the cat's immune system for thousands of years. As such, the natural history and pathogenesis provides an excellent model to study the long-term relationships between AIDS lentivirus and host immune system function/dysregulation. 相似文献
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African trypanosomosis: from immune escape and immunopathology to immune intervention 总被引：2，自引：0，他引：2
Stijlemans B Guilliams M Raes G Beschin A Magez S De Baetselier P 《Veterinary parasitology》2007,148(1):3-13
African trypanosomes can cause prolonged chronic infections through a mechanism of antigen variation whereby they manipulate the humoral immune system of their hosts. However, besides antigenic variation these extracellular parasites exert other immunoregulatory activities mainly mediated by innate cells in particular macrophage-like (M) cells. In this review, the modulation of M cells through parasite factors and host cytokines as well as their role in parasite control and immunopathology will be examined. The concept of M cell polarization into distinct activation states (M1, M2) that may contribute to trypanosusceptibility or resistance will be discussed. Finally, the possibility to interfere with such activation states hereby providing new therapeutical modalities in the treatment of this infectious disease will be illustrated. 相似文献
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多不饱和脂肪酸(PUFA)对家禽免疫功能的影响及其作用机制研究进展 总被引：1，自引：0，他引：1
随着家禽生产集约化程度提高,养殖密度加大,造成养殖环境恶化。各种环境因子的刺激及传染病的影响,使家禽长期处于应激和免疫失调状态,机体代谢紊乱,从而影响家禽的生产性能和产品品质。如何改善家禽的亚健康或应激状态,充分发挥其生产潜力,成为家禽营养研究的热点之一。多不饱 相似文献
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一 发生情况
秦皇岛市昌黎县于某饲养的4000只肉鸡，按常规饲养并免疫了新城疫、传染性支气管炎、法氏囊炎疫苗，但未进行新城疫二价油苗的免疫。饲养到26日龄，鸡群中有个别鸡出现呼吸道症状，并陆续有鸡只死亡，发病率达30％，且每天死亡由几十只增加到100多只，病鸡出现神经症状。鸡群发病后曾用过泰乐菌素、红霉素、双黄连口服液等药物治疗，效果甚微。2009年2月10日来我处就诊，经剖检、诊断为鸡新城疫。 相似文献