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.

中文翻译：

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蜡状芽孢杆菌群分离株的毒力相关基因的基于全基因组序列的比较和概况分析，来自日本的各种来源。

背景技术分析了从日本不同来源收集的44种蜡状芽孢杆菌群分离株的完整基因组序列，以确定它们在日本的遗传背景和多样性水平。分析了来自全基因组序列的多基因座序列分型（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。与毒力相关的基因图谱也用于评估遗传背景和分离株之间的关系。结果通过MLST和核心基因组SNP分型对44种蜡状芽孢杆菌组分离株，包括土壤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进行基因分型。通过MLST和核心基因组SNP系统发育与日本以外国家参考菌株的比较，鉴定出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）分析用于评估分离株之间的遗传相似性，使用基因存在和缺失信息以及分离株起源作为元数据。在主要成分与蜡状芽孢杆菌中编码溶血素BL和催吐基因决定簇的基因与炭疽芽孢杆菌中的胶囊蛋白之间存在显着相关性。NMDS显示，土壤分离物群与动物衍生和临床分离物群重叠。结论乙型肝炎的分子和流行病学分析。在日本的蜡样菌群分离株表明，我们研究中的土壤和动物来源细菌对人类健康没有重大危险。但是，由于一些临床分离株与环境分离株有着密切的遗传关系，因此分子和流行病学监测研究都可以有效地用于估计这些重要病原体的毒力。