猪链球菌新cps基因簇分析及其高通量检测方法的建立

发布时间：2018-02-10 06:45

本文关键词： 猪链球菌血清未分型荚膜多糖基因簇新cps型 Luminex wzy　出处：《中国疾病预防控制中心》2017年硕士论文　论文类型：学位论文

【摘要】：猪链球菌(Streptococcus sus)是一种重要的人兽共患病病原体。荚膜多糖(CPS)是猪链球菌的重要致病因子,在猪链球菌抗吞噬的过程中起关键作用,由基因组中的荚膜多糖基因簇(cps cluster)编码。根据CPS抗原性不同,猪链球菌可分为33个血清型。凝集试验和协同凝集试验是猪链球菌传统的血清分型方法。然而大量研究表明仍有一部分猪链球菌无法用传统血清分型方法区分,即血清未分型菌株。在基因组时代,随着高通量测序技术的普及,猪链球菌33种血清型标准菌株的基因组草图完成测序。序列比对结果证实猪链球菌CPS的合成为Wzx/Wzy决定途径,wzy基因是决定血清型别的关键基因。近年来,通过wzy基因的比较分析,11种新cps型别(NCL1～NCL10,Chz)的猪链球菌陆续被发现。在本研究的第一部分,我们对来自中国和加拿大的部分血清未分型猪链球菌进行了 Illumina高通量测序,并分析了其cps基因簇,由此发现了 10种新cps型别(NCL11～NCL20)。基于以前的研究结果,我们认为这些新cps型别极有可能代表新的猪链球菌血清型。除此之外,我们也对部分无法用传统血清凝集方法区分,但经分子血清分型方法鉴定为已知血清型的菌株进行了 Illumina高通量测序。通过对其cps基因簇的分析发现这些菌株的cps基因簇发生了不同程度的变异,例如基因的插入、缺失、替换,基因内部的点突变以及cps基因簇的缺失等。我们的研究结果对揭示这部分菌株无法用抗血清分型的原因提供了线索。Luminex xMAP系统是基于多重微球的悬浮阵列平台。32重Luminex体系已被建立用于同时检测33种猪链球菌血清型。在本研究的第二部分,我们建立了一个可以同时检测目前已发现的全部21种新cps型别猪链球菌的高通量检测方法,即22重Luminex体系。该方法灵敏度高、特异性好,为检测血清未分型猪链球菌提供了一种快速、有效、便捷的工具。
[Abstract]:Streptococcus sus is an important zoonotic pathogen. CPS is an important pathogenic factor of Streptococcus sus, which plays a key role in the anti-phagocytosis process of Streptococcus sus. Encoded by the capsule polysaccharide gene cluster in the genome, cps cluster.According to the antigenicity of CPS, Streptococcus suis can be divided into 33 serotypes. Agglutination test and co-agglutination test are the traditional serotyping methods of Streptococcus suis. In the genome era, with the popularity of high-throughput sequencing technology, The genomic sketches of 33 standard strains of Streptococcus suis serotype were sequenced. The results of sequence alignment confirmed that the synthesis of CPS from Streptococcus suis was the key gene to determine the Wzx/Wzy pathway. In the first part of this study, Illumina high-throughput sequencing of some untyped Streptococcus suis from China and Canada was carried out. The cps gene cluster was analyzed and 10 new cps types were found. Based on the previous research results, we think that these new cps types are very likely to represent new serotypes of Streptococcus suis. We also can't distinguish some of them with traditional seroagglutination. But the strains identified by molecular serotyping as known serotypes were sequenced by high throughput Illumina. By analyzing the cps gene cluster of these strains, it was found that the cps gene cluster of these strains had varying degrees of variation, such as gene insertion and deletion. Replace, Point mutation within the gene and deletion of cps gene cluster. Our results provide clues to the reason why these strains can not be typed with antiserum. Luminex xMAP system is based on multiple microspheres suspended array platform .32 heavy. Luminex system has been established for simultaneous detection of 33 serotypes of Streptococcus suis. We have established a high throughput detection method for all 21 new cps strains of Streptococcus suis, I. e., 22 Luminex system, which can simultaneously detect all the new strains of Streptococcus suis, which has high sensitivity and specificity. It provides a rapid, effective and convenient tool for the detection of untyped Streptococcus suis.
【学位授予单位】：中国疾病预防控制中心
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R378

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