Whole-genome sequence-based comparison and profiling of virulence-associated genes of Bacillus cereus group isolates from diverse sources in Japan
Whole-genome sequence-based comparison and profiling of virulence-associated genes of Bacillus cereus group isolates from diverse sources in Japan
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DOI：
10.1186/s12866-019-1678-1
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发表时间：
2019-12-16
期刊：
影响因子：
4.2
通讯作者：
Morikawa, Shigeru
中科院分区：
文献类型：
--
作者：
Okutani, Akiko;Inoue, Satoshi;Morikawa, Shigeru
背景资料：分析了从日本不同来源收集的44株蜡样芽孢杆菌群菌株的全基因组序列，以确定其在日本的遗传背景和多样性水平。分析来自全基因组序列的多位点序列分型（MLST）和核心基因组单核苷酸多态性（SNP）分型数据，以确定遗传多样性水平。结果：44株B。采用MLST和核心基因组SNP分型方法对蜡样芽胞杆菌群分离株进行基因分型，包括土壤来源和动物来源的分离株，以及从住院患者和食物中毒病例中回收的分离株。通过MLST和核心基因组SNP同源性比较与日本以外国家的参考菌株鉴定分离株之间的遗传变异。探索性主成分分析和非度量多维标度（NMDS）分析被用来评估分离株之间的遗传相似性，使用基因的存在和不存在的信息和分离源作为元数据。在B中，主成分与编码溶血素BL和呕吐遗传决定因子的基因之间存在显著相关性。蜡状芽孢杆菌和B中的荚膜蛋白。炭疽病NMDS分析表明，土壤分离株与动物源性分离株和临床分离株组成的聚类重叠。日本蜡样芽胞杆菌群分离株表明，我们研究中的土壤和动物源性细菌对人类健康没有重大风险。然而，由于一些临床分离株与环境分离株有着密切的遗传关系，分子和流行病学监测研究可以有效地用于估计这些重要病原体的毒力。
Background: The complete genome sequences of 44 Bacillus cereus group isolates collected from diverse sources in Japan were analyzed to determine their genetic backgrounds and diversity levels in Japan. Multilocus sequence typing (MLST) and core-genome single-nucleotide polymorphism (SNP) typing data from whole-genome sequences were analyzed to determine genetic diversity levels. Virulence-associated gene profiles were also used to evaluate the genetic backgrounds and relationships among the isolates.Results: The 44 B. cereus group isolates, including soil- and animal-derived isolates and isolates recovered from hospitalized patients and food poisoning cases, were genotyped by MLST and core-genome SNP typing. Genetic variation among the isolates was identified by the MLST and core-genome SNP phylogeny comparison against reference strains from countries outside of Japan. Exploratory principal component analysis and nonmetric multidimensional scaling (NMDS) analyses were used to assess the genetic similarities among the isolates using gene presence and absence information and isolate origins as the metadata. A significant correlation was seen between the principal components and the presence of genes encoding hemolysin BL and emetic genetic determinants in B. cereus, and the capsule proteins in B. anthracis. NMDS showed that the cluster of soil isolates overlapped with the cluster comprising animal-derived and clinical isolates.Conclusions: Molecular and epidemiological analyses of B. cereus group isolates in Japan suggest that the soil- and animal-derived bacteria from our study are not a significant risk to human health. However, because several of the clinical isolates share close genetic relationships with the environmental isolates, both molecular and epidemiological surveillance studies could be used effectively to estimate virulence in these important pathogens.