基于16S rRNA基因测序技术分析猪链球菌2型感染BALB/c小鼠粪便样本中微生物的变化

Effects of Streptococcus suis type 2 on the fecal microflora of BALB/c mice based on 16S rRNA high-throughput sequencing

摘要:

[目的]通过研究粪便样本的微生物特点间接探讨猪链球菌2型感染BALB/c小鼠后肠道微生物的变化。[方法]本研究采用Illumina MiSeq测序技术，测定了健康小鼠和猪链球菌2型感染小鼠粪便中微生物16S rRNA V3-V4区序列，并对群落结构和多样性进行了比较分析。[结果]多样性分析表明，感染组和对照组小鼠的粪便中微生物多样性和群落组成均不相同，存在较大的差异，感染组展示了较高的物种丰度和种群差异性。在门水平上，相对于对照组，感染组增加厚壁菌门和拟杆菌门等有益微生物比例，以提高机体免疫力，但也同时增加了变形杆菌等条件致病菌的比例，增加了疾病发生的可能性。在科水平上，感染组和对照组优势菌均含有瘤胃菌科，但其所占细菌总序列的比例存在较大的差异，分别占感染组和对照组细菌总序列的36.58%和11.02%。在属水平上，感染组和对照组的优势菌属类别及占总微生物比例存在显著的差异。感染组主要以瘤胃菌科UCG-002和乳酸杆菌属为优势菌属，对照组以螺旋体科GWE2-31-10和密螺旋体属2为优势菌属。综上，BALB/c小鼠感染猪链球菌2型后存在肠道微生态失调。[结论]通过本研究，不仅对猪链球菌2型感染后小鼠的粪便微生物多样性和组成种类有了一定的认识，而且为今后筛选有益微生物、通过调整微生物治疗猪链球菌2型感染提供了依据。

Abstract:

[Objective] This study aims to explore the characteristics of intestinal microflora of BALB/c mice infected with Streptococcus suis (S. suis) type 2 by studying the characteristics of fecal microflora. [Methods] The V3-V4 region of 16S rRNA hypervariable genes in fecal samples of BALB/c mice infected with S. suis Type 2 and healthy controls were sequenced using the Illumina MiSeq platform. The microbiota composition and diversity of fecal samples were compared and analyzed. [Results] Alpha and Beta diversity showed that the fecal microflora diversity and community composition were different between the infection group and the control group. The infection group had higher bacterial diversity and microbial community richness than that of the control group. At the phylum level, compared with the control group, the infection group increased the proportion of Firmicutes and Bacteroidetes which were beneficial microorganisms to enhance the immunity of the body, but also increased the proportion of opportunistic pathogen such as Proteobacteria, which enhanced the likelihood of illness. At family level, Ruminococcaceae occurred in both groups with significantly different proportion, accounting for 36.58% and 11.02% respectively. At the genus level, Ruminococcaceae UCG-002 and Lactobacillus were dominant in the infection group, while Spirochaetaceae GWE 2-31-10 and Treponema 2 were dominant in the control group. [Conclusion] There were remarkable differences in the types and dominant bacteria between the infection group and the control group. Our results provide insights into the community and diversity of fecal microflora and foundation for screening beneficial microflora and adjusting microflora to treat S. suis type 2 infection in the future.