乳酸菌调节的雏鸡呼吸道菌群变化及免疫调节作用研究

发布时间：2018-06-03 00:23

本文选题：乳酸菌 + 雏鸡　；参考：《吉林农业大学》2015年硕士论文

【摘要】：近年来,随着我国畜牧业的飞速发展以及人们生活水平的不断提高,微生态制剂也得到了越来越为广泛的应用。乳酸菌是一类能够利用碳水化合物生成50%以上乳酸的革兰氏阳性菌。乳酸菌作为使用最广泛,效果最理想的益生菌,可以通过占位作用、产生抑菌物质等来抑制病原菌生长,还可以刺激机体免疫系统,提高机体免疫力,是最早应用于微生态制剂的菌种。目前已被公认为安全的食品级微生物应用于畜牧业和食品加工行业中。本试验将乳酸菌制作成细菌悬液,对雏鸡1~7日龄时进行喷雾,并在7日龄时免疫ND弱毒苗,研究其对雏鸡呼吸系统菌群多样性、雏鸡免疫功能以及对ND弱毒苗保护率的影响作用,明确乳酸菌与雏鸡呼吸道菌群多样性以及免疫机能的相关性,进而为揭示乳酸菌与雏鸡呼吸道菌群及免疫机能的相互关系以及呼吸道益生菌在养鸡业中的应用提供理论依据。本试验选取600只一日龄健康非免疫海兰褐蛋鸡雏,随机分成四组,A组为对照组,正常饮水,饲喂基础日粮;B组为乳酸菌组,1~7日龄喷雾乳酸菌活菌,7日龄滴鼻点眼生理盐水;C组为ND弱毒疫苗组,1~7日龄喷雾生理盐水,7日龄滴鼻点眼ND弱毒疫苗;D组为乳酸菌+弱毒疫苗组,1~7日龄喷雾乳酸菌,7日龄滴鼻点眼免疫ND弱毒苗。试验期为42d。不同时间采集样本,研究乳酸菌对雏鸡呼吸道菌群多样性、雏鸡免疫功能及其对ND疫苗免疫保护影响作用。试验结果如下:(1)通过PCR-DGGE结果显示乳酸菌对雏鸡呼吸道菌群多样性影响不明显,但是可以抑制呼吸道内的大肠杆菌的定殖;对7个差异明显的目的条带测序分别为4株假单胞菌属、1株大肠杆菌、1株Robinsoniella sp和1株不动杆菌。(2)间接ELISA试验结果表明,相对于对照组,1~7日龄雏鸡进行喷雾乳酸菌后于7日龄滴鼻点眼ND弱毒苗,血清、喉头洗脱液、气管洗脱液、肺脏洗脱液的IgA、IgG抗体水平均有不同水平的提高;石蜡切片HE染色结果表明,D组雏鸡假复层上皮内黏液泡状腺体数量明显高于其它组(P0.05),A组假复层上皮较薄且泡状腺体数量较少;A组雏鸡肺脏中淋巴组织较少,而相对于A组,B、C组雏鸡肺脏中的淋巴组织更为密集,D组雏鸡肺脏中的淋巴组织明显高于其他组,分布十分密集。乳酸菌能够增加雏鸡呼吸道内泡状黏液腺的分泌、增加上皮纤毛的黏附性,喷雾乳酸菌的雏鸡肺脏有较多的淋巴细胞识别抗原成分,从而增强了其抗NDV免疫能力。(3)攻毒试验结果表明,乳酸菌能够增强雏鸡呼吸系统的免疫功能,促进ND弱毒苗免疫效果,提高攻毒保护率。以上结果表明,乳酸菌能够调节雏鸡呼吸道菌群多样性,对雏鸡呼吸系统免疫功能以及ND疫苗免疫保护率均有促进作用。
[Abstract]:In recent years, with the rapid development of animal husbandry in China and the continuous improvement of people's living standards, microecological agents have been more and more widely used. Lactic acid bacteria are a group of Gram-positive bacteria that can produce more than 50% lactic acid from carbohydrates. As the most widely used and ideal probiotics, lactic acid bacteria can inhibit the growth of pathogenic bacteria by occupying space, producing bacteriostatic substances, and can stimulate the body's immune system and improve the body's immunity. It is the first strain used in microecological preparation. Food-grade microbes, which have been recognized as safe, are used in animal husbandry and food processing industries. In this experiment, lactic acid bacteria were prepared into bacterial suspensions, then sprayed on chicks at 1 and 7 days old, and ND attenuated vaccine was immunized at 7 days old to study the diversity of respiratory bacteria in chicks. The immune function of chicks and the protective effect on ND attenuated vaccine were studied. The relationship between lactic acid bacteria and respiratory microflora diversity and immune function of chicks was clarified. It provides a theoretical basis for revealing the relationship between lactic acid bacteria and respiratory tract bacteria and immune function of chicks and the application of respiratory probiotics in chicken industry. In this experiment, 600 unimmunized Hailan brown laying hens of one day old were randomly divided into four groups: control group A, normal drinking water. Group B was fed with lactobacillus group 1 and 7 days old live lactobacillus, 7 day old nasal drip eye normal saline and C group was ND attenuated vaccine group 1 and 7 days old spray normal saline and 7 days old eye ND attenuated vaccine D group was lactic acid bacteria. The attenuated vaccine group was immunized with ND attenuated vaccine. The experimental period is 42 days. The effects of lactic acid bacteria on the diversity of respiratory tract flora, immune function of chicks and their protective effects on ND vaccine were studied. The results were as follows: (1) the results of PCR-DGGE showed that lactic acid bacteria had no obvious effect on the diversity of respiratory tract bacteria, but could inhibit the colonization of Escherichia coli in the respiratory tract. The results of indirect ELISA test showed that four strains of Pseudomonas, one strain of Escherichia coli, one strain of Robinsoniella sp, and one strain of Acinetobacter sp. The IgG antibody levels of ND attenuated vaccine, serum, larynx eluate, trachea eluate and lung eluate in 7-day-old chicks treated with spraying lactic acid bacteria were higher than those in the control group. The results of HE staining in paraffin sections showed that the number of mucous vesicular glands in pseudostratified epithelium in group D was significantly higher than that in group A (P 0.05), and the number of alveolar glands in group A was less than that in group A. The number of lymphoid tissue in lung of group A was lower than that of group A. Compared with group A, the lymphoid tissue in the lung of group D was higher than that of other groups, and the distribution of lymphoid tissue in the lung of group D was denser than that of other groups. Lactic acid bacteria could increase the secretion of bubbly mucous glands and the adhesion of epithelial cilia in the respiratory tract of chicks. The results showed that lactic acid bacteria could enhance the immune function of chicken respiratory system, promote the immune effect of ND attenuated vaccine, and improve the protection rate. The results showed that lactic acid bacteria could regulate the diversity of respiratory tract bacteria in chicks and promote the immune function of respiratory system and the protective rate of ND vaccine.
【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S831;S852.4

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