Genotyping and investigating capsular polysaccharide synthesis gene loci of non-serotypeable Streptococcus suis isolated from diseased pigs in Canada.
Genotyping and investigating capsular polysaccharide synthesis gene loci of non-serotypeable Streptococcus suis isolated from diseased pigs in Canada.
复制标题
加拿大病猪分离的非血清型猪链球菌的基因分型和荚膜多糖合成基因位点研究
DOI：
10.1186/s13567-017-0417-6
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发表时间：
2017-02-20
影响因子：
4.4
通讯作者：
Gottschalk M
中科院分区：
文献类型：
--
作者：
Zheng H;Qiu X;Roy D;Segura M;Du P;Xu J;Gottschalk M
猪链球菌（S. suis）是一种重要的猪病原体，也是一种新兴的人畜共患病病原体。大多数临床猪链球菌菌株表达荚膜多糖（CPS），可以使用凝血试验通过抗血清对其进行分型。在这项研究中，从加拿大病猪中回收的 79 株猪链球菌菌株，无法使用抗血清进行分型，并通过荚膜基因分型和测序进一步表征。观察到 cps 位点的四种模式：(1) 15 个菌株被分为先前报道的血清型，但与参考菌株的可用数据相比，它们的 cps 位点出现了一些突变； (2) 7株菌株cps位点完全缺失，导致无法合成荚膜； (3) 47 个菌株被分类为最近描述的新 cps 位点 (NCL)； (4) 10 个菌株携带以前未描述过的新型 NCL。在这些非血清型菌株中观察到不同的毒力基因谱（基于 mrp、epf 和/或 sly 的存在）。这项研究为了解从患病动物中回收的非血清型猪链球菌菌株中 cps 位点的遗传特征提供了进一步的见解。当结合使用先前描述的 35 种血清型和完整的 NCL 系统时，从加拿大患病动物中回收的未分型菌株的数量将显着减少。
Streptococcus suis (S. suis) is an important swine pathogen and an emerging zoonotic agent. Most clinical S. suis strains express capsular polysaccharides (CPS), which can be typed by antisera using the coagglutination test. In this study, 79 S. suis strains recovered from diseased pigs in Canada and which could not be typed using antisera were further characterized by capsular gene typing and sequencing. Four patterns of cps locus were observed: (1) fifteen strains were grouped into previously reported serotypes but presented several mutations in their cps loci, when compared to available data from reference strains; (2) seven strains presented a complete deletion of the cps locus, which would result in an inability to synthesize capsule; (3) forty-seven strains were classified in recently described novel cps loci (NCLs); and (4) ten strains carried novel NCLs not previously described. Different virulence gene profiles (based on the presence of mrp, epf, and/or sly) were observed in these non-serotypeable strains. This study provides further insight in understanding the genetic characteristics of cps loci in non-serotypeable S. suis strains recovered from diseased animals. When using a combination of the previously described 35 serotypes and the complete NCL system, the number of untypeable strains recovered from diseased animals in Canada would be significantly reduced.