Xie Xiaolei, Hu Yachen, Xu Yaohui, Yin Kequan, Li Yang, Chen Yun, Xia Jie, Xu Lijuan, Liu Zijian, Geng Shizhong, Li Qiuchun, Jiao Xinan, Chen Xiang, Pan Zhiming
Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China.
College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Henan, China.
Vet Microbiol. 2017 May;203:81-87. doi: 10.1016/j.vetmic.2017.02.010. Epub 2017 Feb 27.
Salmonella enterica serovar Gallinarum biovar Pullorum (S. Pullorum) is the cause of pullorum disease, characterized by white diarrhea, which leads to high mortality in poultry. In this study, we aimed to assess the genetic diversity of 655 S. Pullorum strains from 1962 to 2015 in China, Europe, and South America. A sequence typing scheme based on clustered regularly interspaced short palindromic repeats (CRISPR) was used to reveal the genetic relationships among these strains in this study. Overall, a total of 20 Pullorum sequence types (PSTs) of CRISPR were identified in the 655 isolates with PST7 (74%, 486/655) and PST3 (13%, 86/655) to be the most two frequent PSTs belonging to two different lineages, which confirmed the genetic conservation of S. Pullorum strains isolated from six provinces and two direct-controlled municipalities (Beijing and Shanghai) in China. However, the identification of seven new PSTs distributed in strains isolated since 2001 implied that genetic variation continues to develop in S. Pullorum. Interestingly, the whole-genome single-nucleotide polymorphism typing (WGST) of 96 strains out of the 655 isolates divided them into four lineages based on SNP analysis of core genomic sequence and exhibit good correspondence with the CRISPR subtyping method. Notably, 22 out of 26 isolates from Europe and South America were distributed in five distinctive PSTs (with no Chinese strains). Additionally, CRISPR data of spacers and their arrangement exhibit subtle but distinct specificity between different strains, and the dynamic adaptive nature of CRISPR loci provides critical insights into the evolution of S. Pullorum as the bacteria are influenced by their environment.
鸡伤寒沙门氏菌鸡白痢变种（鸡白痢沙门氏菌）是鸡白痢病的病原体，其特征为白色腹泻，可导致家禽的高死亡率。在本研究中，我们旨在评估1962年至2015年间来自中国、欧洲和南美洲的655株鸡白痢沙门氏菌的遗传多样性。本研究采用基于成簇规律间隔短回文重复序列（CRISPR）的序列分型方案来揭示这些菌株之间的遗传关系。总体而言，在655株分离株中总共鉴定出20种鸡白痢序列类型（PSTs），其中PST7（74%，486/655）和PST3（13%，86/655）是属于两个不同谱系的最常见的两种PSTs，这证实了从中国六个省份和两个直辖市（北京和上海）分离的鸡白痢沙门氏菌菌株的遗传保守性。然而，2001年以来分离的菌株中发现了七种新的PSTs，这意味着鸡白痢沙门氏菌的遗传变异仍在继续发展。有趣的是，655株分离株中的96株的全基因组单核苷酸多态性分型（WGST）基于核心基因组序列的SNP分析将它们分为四个谱系，并且与CRISPR分型方法表现出良好的对应关系。值得注意的是，来自欧洲和南美洲的26株分离株中有22株分布在五种不同的PSTs中（无中国菌株）。此外，间隔序列及其排列的CRISPR数据在不同菌株之间表现出细微但明显的特异性，并且CRISPR位点的动态适应性本质为鸡白痢沙门氏菌的进化提供了关键见解，因为细菌受到其环境的影响。
