牛源、兔源及人源无乳链球菌分子分型特征分析

发布时间：2019-03-27 14:06

【摘要】：为了解人源、牛源及兔源无乳链球菌(S.agalactiae)的基因型差异及分子分型的总体结构特征,本实验对30株2012年~2015年分离于人、牛及兔的S.agalactiae在cfb基因鉴定的基础上,通过荚膜多糖分子血清分型(CPS)、多位点序列分型(MLST)和脉冲场凝胶电泳(PFGE)进行基因型的确定和分子特征差异性比较。CPS结果显示,牛源和兔源S.agalactiae均为Ia血清型,而人源无乳链球菌包括Ia和III型两种血清型,以Ia血清型为主要血清类型;MLST分型获得8个STs序列型(ST7、ST10、ST19、ST61、ST103、ST199、ST486、ST651)和6个克隆群(CC7、CC10、CC19、CC23、CC61、CC103),其中人源S.agalactiae拥有最多的STs和克隆群分型;PFGE聚类分析可以将其分为18个PFGE带型,且不同动物源性S.agalactiae之间基因分型差异性较大。血清分型、STs序列型、PFGE带型与宿主的来源之间无明显的相关性。不同来源菌株可以同属于血清型Ia,且所有Ia血清型菌株可以分布于不同的STs序列型和PFGE带型中。但分型为Ia/ST651的人源S.agalactiae在MLST的克隆分群中是分型为Ia/ST103牛源S.agalactiae的克隆衍生物,同属克隆群CC103,Ia/ST651只是Ia/ST103单一位点变化的产物,从分子水平的相似性推测二者存在交叉感染的可能性。本研究为奶牛乳房炎的有效预防和治疗提供依据。
[Abstract]:In order to understand the genotypic differences and the general structural characteristics of molecular typing of Streptococcus actinosus (S.agalactiae) from human, bovine and rabbit origin, 30 S.agalactiae isolated from human, bovine and rabbit from 2012 to 2015 were identified on the basis of cfb gene identification. The comparison of genotypes and molecular characteristics between capsular polysaccharide molecular serotype (CPS), (MLST) and pulsed field gel electrophoresis (PFGE) showed that both bovine and rabbit S.agalactiae were Ia serotypes, and the results showed that both bovine and rabbit S.agalactiae were Ia serotypes, and the results of PCR showed that both bovine and rabbit S.agalactiae were Ia serotypes. Human Streptococcus actinosus includes two serotypes, Ia and III, of which Ia serotype is the main serotype. Eight STs sequence types (ST7,ST10,ST19,ST61,ST103,ST199,ST486,ST651) and six clone groups (CC7,CC10,CC19,CC23,CC61,CC103) were obtained by MLST typing, among which human S.agalactiae had the most STs and clone group typing. It can be divided into 18 PFGE bands by PFGE cluster analysis, and there is great difference in genotyping among different animal-derived S.agalactiae. There was no significant correlation between serotype, STs sequence type, PFGE band type and host origin. The strains from different sources can belong to serotype Ia, and all Ia serotypes can be distributed in different STs sequence types and PFGE banding types. Human S.agalactiae, which was classified as Ia/ST651, was a clone derivative of Ia/ST103 bovine S.agalactiae in the clone cluster of MLST, and CC103,Ia/ST651 of the same clone group was only the product of the change of the single site of Ia/ST103, and the same clone group CC103,Ia/ST651 was the product of the variation of the single site of Ia/ST103. The possibility of cross-infection is deduced from the similarity of molecular level. This study provides evidence for the effective prevention and treatment of mastitis in dairy cows.
【作者单位】：四川农业大学动物医学院;
【基金】：四川省科技支撑计划(2016NZ0002)
【分类号】：S852.611

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