基于16S rDNA测序分析柔嫩艾美耳球虫感染对鸡盲肠菌群的影响

Analysis of cecal microbiota in chickens infected with Eimeria tenella based on the 16S rDNA sequencing technology

为探究柔嫩艾美耳球虫感染对鸡盲肠菌群的影响,采集对照组和球虫感染组雏鸡盲肠内容物,提取DNA,16S rDNA测序分析鸡盲肠菌群丰度、多样性的变化,采用粪菌移植验证正常鸡肠道菌群对柔嫩艾美耳球虫感染的保护作用。16S rDNA测序结果显示,柔嫩艾美耳球虫感染后盲肠内菌群丰度、多样性显著降低。在门水平上,感染前,两组雏鸡盲肠的优势菌门均为厚壁菌、变形菌、放线菌;感染后厚壁菌门丰度下降,变形菌门、放线菌门的丰度上升,差异显著(P<0.05),感染组出现了拟杆菌门。在属水平上,与对照组相比,感染组鸡盲肠微生物菌群中乳杆菌属、埃希菌-志贺菌属、拟杆菌属、罗姆布茨菌属、棒状杆菌属、肠球菌属、变形杆菌属丰度增加但差异不显著(P>0.05),毛螺菌科未定属、瘤胃球菌属、梭菌UCG-014、瘤胃球菌科未定属丰度显著下降(P<0.05),GCA-900066575丰度降低但差异不显著(P>0.05)。粪菌移植结果显示,与生理盐水移植组相比,盲肠内容物移植组和粪便菌移植组能显著减轻柔嫩艾美耳球虫感染后鸡增重降低的影响,减轻盲肠损伤,卵囊产量显著下降(P<0.05)。盲肠内容物移植组和粪便菌移植组的抗球虫指数分别为173.12和164.38,可以抵抗柔嫩艾美耳球虫的感染。以上结果表明,柔嫩艾美耳球虫感染破坏了原始肠道菌群,鸡盲肠的组成和结构被改变,促进了以埃希菌-志贺菌为代表的致病菌快速生长和定殖,而正常鸡肠道内存在益生菌,可保护机体对抗柔嫩艾美耳球虫感染。

To explore the effect of Eimeria tenella infection on the cecal flora of chickens,the cecal contents in chickens in the control group and the infected group were collected and their DNA was extracted.16S rDNA sequencing was used to analyze the changes in the abun-dance and diversity of the cecal flora.The 16S rDNA sequencing results showed that,compared with the control group,the abundance and diversity of bacteria in the cecum of the treated group were significantly reduced.At the phylum level,the dominant microbiota in the control group and the treat group were Firmicutes,Proteobacteria,and Actinobacteriota.After Eimeria tenella infection,the abundance of Firmicutes decreased,and those of Proteobacteria and Actinobacteriota were increased,the difference was significant(P<005).At the same time,the dominant Bacteroidot appeared in the treated group.At the genus level,the abundances of Lactobacillus,Escherichia-Shigella,Bacteroides,Rombutes,Corynebacterium,Enterococcus and Proteus in the cecal microflora of the chickens in the treated group was increased,compared with that of the control group,but the difference was not significant(P>005).The abundances of f-Lachnospiraceae_unclassified,the[Ru-minococcus]_torques_group,Clostridia_UCG-014,f-Ruminococcaceae_unclassified were decreased significantly(P<005).GCA-900066575 was also decreased but not significantly(P>005).The results of the fecal microbiota transplantation showed that the cecal content transplantation group and the fecal bacteria transplantation group significantly reduced the weight gain of the chickens infected with Eimeria tenella,alleviated the cecal injury and OPG significantly,as compared with the saline transplantation group.The anticoccidial inde-xes of the cecal contents transplantation group and the fecal microbiota transplantation group were 17312 and 16438,respectively.The a-bove results indicated that Eimeria tenella infection destroyed the original intestinal flora,changed the composition and structure of the chick-en cecum,and promoted the rapid growth and colonization of pathogenic bacteria represented by Escherichia-Shigella,while the presence of probiotics in intestines of normal chickens intestines protect them against Eimeria tenella infection.