背景:自2019年以来,宁夏回族自治区的炭疽病发病率与往年相比明显增加,因此,在这种情况下,宁夏地区的炭疽病不仅对公共卫生产生了不利影响,但也造成了重大的经济影响。因此,我们对2019-2023年分离出的20株菌株进行了分子流行病学研究.本研究调查了炭疽芽孢杆菌的来源及其遗传多样性。
方法:我们基于提取的炭疽芽孢杆菌核酸进行了规范的单核苷酸多态性(CanSNPs)分型和全基因组测序。根据全基因组草案,我们研究了20个分离株的基因组特征.同时,我们使用MEGA的最大似然(ML)方法基于全基因组核心单核苷酸多态性(SNP)进行了系统发育研究,并使用BioNumerics最小生成树(MST)模型对这些菌株的核心基因组进行了基于核心基因组的多位点序列分型(cgMLST).
结果:将20株分离株归入亚谱系A.Br.001/002,与世界其他地区分离株的基因组比较分析表明,宁夏分离株与欧洲分离株具有相关性,印度尼西亚,格鲁吉亚(美国),北京(中国)。对于宁夏的20个分离株,从同一年份或地区分离的分离株的遗传关系相对接近。
结论:A.Br.001/002亚群是宁夏的优势特有菌株。宁夏分离株与欧洲和印度尼西亚分离株之间的遗传关系和系统发育表明,炭疽通过古老的贸易路线在全球传播。
BACKGROUND: Since 2019, the incidence of anthrax in the Ningxia Hui Autonomous Region has increased significantly compared with previous years, so in this situation the anthrax in the Ningxia region not only had a detrimental impact on public health, but also inflicted significant economic repercussions. Therefore, we conducted a molecular epidemiological study of 20 strains from 2019-2023 isolates. This study investigated the origin of Bacillus anthracis and its genetic diversity.
METHODS: We conducted canonical single-nucleotide polymorphisms (CanSNPs) typing and whole genome sequencing based on the extracted nucleic acid of Bacillus anthracis. Based on the whole genome drafts, we studied the genomic characteristics of 20 isolates. Meanwhile, we performed phylogenetic studies based on genome-wide core single-nucleotide polymorphisms (SNPs) using MEGA\'s Maximum Likelihood (ML) method and core-genome-based multilocus sequence typing (
cgMLST) of the core genomes of these strains using BioNumerics\' minimum spanning tree (MST) model.
RESULTS: The 20 isolates were categorized into sub-lineages A.Br.001/002, and comparative genomic analyses of these strains with other isolates from other parts of the world showed that the strains from Ningxia were correlated with isolates from Europe, Indonesia, Georgia (USA), and Beijing (China). For the 20 isolates in Ningxia, the genetic relationship of the isolates isolated from the same year or region was relatively close.
CONCLUSIONS: The A.Br.001/002 subgroup was the dominant endemic strain in Ningxia. The genetic relationship and phylogenesis between isolates from Ningxia and strains from Europe and Indonesia suggest that anthrax spread around the globe through ancient trade routes.