对源自中国市售奶粉的一株枯草芽孢杆菌菌株的基因组研究揭示了潜在风险因素。

Genomic Investigation of a Bacillus subtilis Strain Sourced from Commercially Available Milk Powder in China Reveals Potential Risk Factors.

作者信息

Zhu Ling, Chen Keyu, Xu Liu, Wang Afeng, Gan Haojian, Sun Junhong, Wu Yujie, Li Yutong, Guo Yingying, Yi Yanfeng, Qiang Xinhua, He Jie, Zhou Hongchang, Lin Yibin

机构信息

Clinical Laboratory, First People's Hospital Affiliated to Huzhou University, Huzhou, 313000, People's Republic of China.

School of Medicine, Huzhou University, Huzhou, 313000, China.

出版信息

Infect Drug Resist. 2025 Aug 25;18:4311-4328. doi: 10.2147/IDR.S544153. eCollection 2025.

BACKGROUND

Milk powder is a key food source, especially for infants and vulnerable groups. However, Bacillus contamination during production, storage, or handling can cause spoilage, quality issues, or health risks. This study identified and isolated from commercially available Chinese milk powder.

METHODS

A pure colony of was isolated from an LB agar plate supplemented with milk powder and identified using mass spectrometry. The genome of this strain was sequenced using third-generation sequencing technology. Following assembly, the genome was functionally annotated and subjected to comprehensive bioinformatic analysis.

RESULTS

Genomic analysis classified the strain as via MALDI-TOF and ANI (98.82% with AMR1). Its genome features a 4.26 Mbp chromosome and 97.6 kbp plasmid encoding 4,539 genes, including virulence factors (209 genes), antibiotic resistance genes (19 genes), and carbohydrate-active enzymes (253 genes). Key virulence mechanisms include immune modulation, stress adaptation, toxin production, and biofilm formation. Antibiotic resistance involves efflux pumps (eg, ), enzymatic inactivation (eg, ), and target modification (eg, cluster, ). Phylogenetically (LIN78), the strain clusters with foodborne isolates (eg, from Korean gochujang and soybean), diverging from and environmental clades. Comparative genomics revealed 53 LIN78-specific genes, encompassing defense mechanisms and mobile elements, and synteny in all homologs except ATCC 11774. Genomic islands, CRISPR arrays, and recombination-associated repeats indicate adaptive evolution.

CONCLUSION

This study characterizes LIN78, a genomically plastic strain isolated from Chinese milk powder. It exhibits adaptation to food environments via horizontal gene transfer, stress tolerance, and spoilage traits, while carrying antimicrobial resistance risks and potential biotechnological applications. The findings necessitate genomic monitoring to manage food safety, resistance spread, and leverage its dual role as both a spoilage organism and source of bioactive compounds..

背景

奶粉是一种关键的食物来源，尤其对于婴儿和弱势群体而言。然而，在生产、储存或处理过程中，芽孢杆菌污染会导致变质、质量问题或健康风险。本研究从市售中国奶粉中鉴定并分离出[具体菌种名称未给出]。

方法

从添加了奶粉的LB琼脂平板上分离出[具体菌种名称未给出]的纯菌落，并使用质谱法进行鉴定。使用第三代测序技术对该菌株的基因组进行测序。组装后，对基因组进行功能注释并进行全面的生物信息学分析。

结果

基因组分析通过基质辅助激光解吸电离飞行时间质谱（MALDI-TOF）和平均核苷酸一致性（ANI，与[具体参照菌株名称未给出]AMR1的ANI为98.82%）将该菌株归类为[具体菌种名称未给出]。其基因组具有一条4.26兆碱基对的染色体和一个97.6千碱基对的质粒，编码4539个基因，包括毒力因子（209个基因）、抗生素抗性基因（19个基因）和碳水化合物活性酶（253个基因）。关键的毒力机制包括免疫调节、应激适应、毒素产生和生物膜形成。抗生素抗性涉及外排泵（例如，[具体外排泵名称未给出]）、酶失活（例如，[具体酶名称未给出]）和靶点修饰（例如，[具体基因簇名称未给出]簇、[具体基因名称未给出]）。在系统发育上（LIN78），该菌株与食源性[具体菌种名称未给出]分离株（例如，来自韩国辣椒酱和大豆的分离株）聚类，与[具体菌种名称未给出]和环境[具体菌种名称未给出]分支不同。比较基因组学揭示了53个LIN78特异性基因，包括防御机制和移动元件，并且除了[具体参照菌株名称未给出]ATCC 11774外，所有同源物中都存在共线性。基因组岛、CRISPR阵列和与重组相关的重复序列表明了适应性进化。