环境源蜡样芽孢杆菌全基因组测序分析及生物学特性研究
Genomic Sequencing Analysis and Biological Characterization Study of Bacillus cereus Isolated from Environmental Sources

对此前医院环境中分离筛选得到的一株蜡样芽孢杆菌进行全基因组测序分析。对其基因组进行COG、GO、KEGG通路分析、CAZy、TCDB、CARD对比分析，获得相应注释基因。结果表明该株蜡样芽孢杆菌(ZJ4)基因组大小为584,719,145 bp，编码DNA序列(CDS) 6063个，含有107个tRNA基因，45个rRNA基因。基因平均长度为809.19 bp，质粒数量有6个，遗传间区GC含量是16.09%。拥有14个基因组岛，10个位于染色体上，4个位于质粒上。通过CAZy数据库的比对共获得ZJ4碳水化合物酶基因数量共为124个；TCDB数据库比对转运蛋白共有七类，948个基因。CARD软件对ZJ4进行抗生素耐药基因预测ZJ4耐药基因共计353个，分为11类，在KEGG数据库中ZJ4共检测出13个基因，其中位于Sec-SRP分泌系统的居多，属于Tat分泌系统相对较少。结论：医疗环境中分离的蜡样芽孢杆菌活性强适应性好，具有溶血活性和较为复杂的蛋白质表达调控、耐药基因也相对较多，容易引起医院二次感染。
Whole genome sequencing analysis was performed on a previously isolated Bacillus cereus strain from a hospital environment. Comparative genomic analyses including COG, GO, KEGG pathway annotation, CAZy, TCDB, and CARD were conducted to annotate functional genes. Results showed that the genome size of this B. cereus strain (ZJ4) is 584,719,145 bp, containing 6063 coding DNA sequences (CDS), 107 tRNA genes, and 45 rRNA genes. The average gene length was 809.19 bp, with six plasmids identified. The GC content of intergenic regions was 16.09%. 14 genomic islands were detected, 10 located on the chromosome and 4 on plasmids. 124 carbohydrate-active enzyme genes were revealed through CAZy database analysis. TCDB annotation identified 948 transporter genes classified into seven categories. 353 antibiotic resistance genes across 11 classes were predicted by CARD software. KEGG pathway analysis detected 13 secretion system-related genes, predominantly in the Sec-SRP pathway, with fewer in the Tat pathway. Conclusion: The Bacillus cereus strain isolated from the medical environment exhibits strong adaptability, hemolytic activity, complex protein expression regulation mechanisms, and a high abundance of antibiotic resistance genes, making them prone to causing nosocomial secondary infections.