【作者】 于曦；

【导师】 牛淑玲；

【作者基本信息】 吉林大学 ， 动物营养与饲料科学， 2019， 硕士

【摘要】 本研究前期发现鲎素抗菌肽(Tachyplesin I,TP I)可以提高SPF鸡的生长性能,促进炎症与免疫抑制因子产生,增强机体免疫机能,以及提高产短链脂肪酸相关细菌Butyricicoccus和Blautia的丰度。鸡白痢是由鸡白痢沙门菌引起的细菌性传染疾病,雏鸡感染后常出现急性败血症,感染鸡白痢雏鸡的肠道组织结构受到严重损害。受损肠道内微生态结构失调,导致肠道菌群生态平衡被打破,因此通过鲎素抗菌肽调节肠道菌群结构对未来防治沙门菌感染具有研究价值。本实验研究了鸡白痢沙门菌感染雏鸡后对肠道菌群变化的影响,鲎素抗菌肽对感染雏鸡肠道菌群的调节作用,以及鸡源性乳酸菌对肠道微生态失调的调整。通过Illumina Miseq平台对感染雏鸡的盲肠内细菌的16S rDNA进行测序分析,揭示沙门菌对肠道菌群的影响方式,为丰富人为调控肠道菌群理论提供数据支持。鸡白痢沙门菌感染雏鸡后会显著降低雏鸡生长性能(P<0.05),肠道组织与结构如肠黏膜、肠绒毛受到严重破坏,此外肝脏与肺脏出现了不同程度的病变。对感染雏鸡的肠道菌群进行分析,鸡白痢沙门菌感染会显著降低肠道内细菌的丰度水平,降低厚壁菌门(Firmicutes)(P<0.05)并提高变形菌门(Proteobacteria)(P<0.05)的丰度水平,在属水平上沙门菌会降低乳酸菌属(Lactobacillus)(P<0.05)和粪杆菌属(Faecalibacterium)(P<0.05)的丰度,并提高肠杆菌科(Enterobacteriaceae)(P<0.05)与颤螺旋菌属(Oscillospira)(P<0.05)的丰度水平。向感染沙门菌的雏鸡饮水中补充鲎素抗菌肽,能够提高感染雏鸡生长性能(P>0.05),同时可以减缓鸡白痢感染对肝脏与肠道的损伤情况。鲎素抗菌肽可以提高感染雏鸡属水平的物种多样性,同时能够抑制沙门菌感染后毛螺菌科(Lachnospiraceae)、瘤胃球菌属(Ruminococcus)、粪芽孢菌属(Coprobacillus)、肠杆菌科(Enterobacteriaceae)、梭菌目(Clostridiales)等细菌的变化趋势,维持肠道内环境的稳定。向感染鸡白痢雏鸡补充鸡源性乳酸菌制剂,发现乳酸菌-抗菌肽制剂比乳酸菌单独使用更能提高肠道内微生物的多样性。鸡源性乳酸菌可恢复沙门菌感染形成的差异菌属毛螺菌科(Lachnospiraceae)、梭菌目(Clostridiales)的丰度水平,增加丰度较低的Erysipelotrichaceae,Christensenellaceae,Peptostreptococaceae菌属的丰度水平,并使肠道菌群的结构在4周龄前达到稳定状态。综上,本研究验证了鲎素抗菌肽可以促进感染鸡白痢沙门菌雏鸡的生长状况,以及减少肠道和肝脏的炎症情况和损伤,并减缓毛螺菌科(Lachnospiraceae)、瘤胃球菌属(Ruminococcus)、粪芽孢菌属(Coprobacillus)、肠杆菌科(Enterobacteriaceae)、梭菌目(Clostridiales)等细菌增加或减少的趋势。通过补充鸡源性乳酸菌与抗菌肽制剂可以增加肠道内细菌的丰富度与多样性水平,恢复感染造成差异菌属的毛螺菌科(Lachnospiraceae)、梭菌目(Clostridiales)的丰度水平,但完全恢复肠道微生态原始结构需要进一步验证。本研究丰富了鸡白痢沙门菌感染,以及鲎素抗菌肽对感染雏鸡肠道菌群变化的数据理论,为鲎素抗菌肽调节肠道菌群稳态提供理论基础。更多还原

【Abstract】 Our previous research found that Tachyplesin I(TP I)could improve the growth performance of SPF chickens,promote the production of inflammation and immunosuppressive factors,enhance the body`s immune function,and increase the abundance of short-chain fatty acid-related bacteria,Butyricicoccus and Blautia.Pullorosis disease is a bacterial infection caused by Salmonella pullorum.The chicks often develop acute sepsis after infection.The intestinal structure of chickens infected with Salmonella pullorum is seriously damaged,the microbial micro-ecological structure in the intestinal tract is imbalanced,and the ecological balance of intestinal flora is upset.Regulation of Tachyplesin I on the intestinal flora of Salmonella infection is of great significance for the prevention and purification of Salmonella infection through the intestinal flora.This study investigated the effects of Salmonella pullorum on chicks after intestinal infection,the regulation of Tachyplesin I on the intestinal flora of infected chicks,and the regulation of intestinal microcological disorders by chicken-derived Lactobacillus.The 16 S rDNA of cecal bacteria in infected chicks was sequenced by Illumina Miseq platform which provided data support for enriching the theory of artificial regulation of intestinal flora.The infection of chicks with Salmonella pullorum significantly reduced the growth performance of chicks(P<0.05).Intestinal tissues and structures such as intestinal mucosa and intestinal villi were severely damaged.In addition,liver and lung showed different degrees of lesions.Analysis of the intestinal flora of infected chicks,Salmonella pullorum infection significantly reduced the abundance of bacteria in the intestine,reduced the Firmicutes(P <0.05)and increased Proteobacteria abundance(P<0.05),at the genus level,reduced the abundance of Lactobacillus(P<0.05)and Faecalibacterium(P<0.05)and increased Enterobacteriaceae(P<0.05)abundance level with Oscillospira(P < 0.05).The addition of TachyplesinI to the drinking water of chicken infected with Salmonella was found to increase the growth performance of infected chicks(P>0.05),and it could slow down the damage to the liver and intestines.Tachyplesin I canincrease the species diversity at the level of infected chicks,and can inhibit Lachnospiraceae,Ruminococcus,Coprobacillus,Enterobacteriaceae after Salmonella infection.The trend of bacteria such as Enterobacteriaceae and Clostridiales maintains the stability of the intestinal environment.By adding the chicken-derived Lactobacillus preparation to the infected chicks,it is found that the Lactobacillus-TachyplesinI preparation can improve the microbial diversity in the intestinal tract more than the Lactobacillus alone.Chicken-derived Lactobacillus can restore the abundance of the differential genus Lachnospiraceae and Clostridiales formed by Salmonella infection,but increase the abundance of the abundance of Erysipelotrichaceae,Christensenellaceae,and Peptostreptococaceae.The structure of the intestinal flora was stabilized before 4 weeks of age.In summary,this study demonstrates that Tachyplesin I can promote the growth of chickens infected with Salmonella typhimurium,inflammation and damage in the intestines and liver,and slow the increase and decrease of bacteria such as Lachnospiraceae,Ruminococcus,Coprobacillus,Enterobacteriaceae,and Clostridiales.By supplementing chicken-derived Lactobacillus and Tachyplesin I preparations,the abundance of bacteria in the intestine can be increased,and the abundance level of Lachnospiraceae and Clostridiales of the differential genus can be restored.However,complete restoration of the original structure of the intestinal micro-ecology requires further verification.The data of this study enriched the Salmonella infection and the data theory of the changes of intestinal microflora in infected chicks by the Tachyplesin I,providing a theoretical basis for regulating the intestinal flora stability by Tachyplesin I.更多还原