Department of Laboratory Medicine, College of Health Science and Technology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Department of Animal Health and Food Safety, School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Department of Laboratory Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Vet Microbiol. 2024 Jul;294:110129. doi: 10.1016/j.vetmic.2024.110129. Epub 2024 May 27.
To conduct molecular prevalence and genetic polymorphism analysis of 24 Swine Farm associated C. difficile ST11 strains, in addition to other representative sequenced ST strains.
The collected C. difficile strains underwent whole genome sequencing and bioinformatic analysis using the illumina NovaSeq platform, SPAdes, Prokka, MOB-suite, and FastTree. Virulence and antibiotic resistance genes were identified through NCBI Pathogen Database. Cytotoxicity tests were conducted on HT-29 cells and Vero cells to verify the function of toxin A and toxin B.
The most prevalent resistance genes in ST11 were found to be against β-lactamases, aminoglycosides, and tetracycline. A C. difficile isolate (strain 27) with tcdA deletion and high antibiotic resistance genes was far apart from other swine farm associated ST11 isolates in the phylogenetic branch. The remarkable genetic similarity between animal and human C. difficile strains suggests potential transmission of ST11 strains between animals and humans. The plasmid replicon sequences repUS43 were identified in all ST11 strains except one variant (strain 27), and 91.67% (22/24) of these were assessed by MOB-typer as having mobilizable plasmids.
Swine farm associated C. difficile ST11 carried fewer virulence genes than ST11 strains collected from NCBI database. It is critical to monitor the evolution of C. difficile strains to understand their changing characteristics, host-switching, and develop effective control and prevention strategies.
对 24 株猪源关联的艰难梭菌 ST11 菌株以及其他代表性测序 ST 菌株进行分子流行率和遗传多态性分析。
采集的艰难梭菌菌株进行全基因组测序，并使用 illumina NovaSeq 平台、SPAdes、Prokka、MOB-suite 和 FastTree 进行生物信息学分析。通过 NCBI 病原体数据库识别毒力和抗生素耐药基因。通过 HT-29 细胞和 Vero 细胞进行细胞毒性试验，以验证毒素 A 和毒素 B 的功能。
在 ST11 中最常见的耐药基因是针对β-内酰胺类、氨基糖苷类和四环素类的耐药基因。一株艰难梭菌分离株（菌株 27）缺失 tcdA 且携带大量抗生素耐药基因，在系统发育分支中与其他猪源关联的 ST11 分离株相距较远。动物和人类艰难梭菌菌株之间存在显著的遗传相似性，表明 ST11 菌株可能在动物和人类之间传播。除一个变体（菌株 27）外，所有 ST11 菌株均鉴定出质粒复制子序列 repUS43，MOB-typer 评估其中 91.67%（22/24）具有可移动质粒。
与从 NCBI 数据库中收集的 ST11 菌株相比，猪源关联的艰难梭菌 ST11 携带的毒力基因较少。监测艰难梭菌菌株的进化对于了解其特征变化、宿主转换以及制定有效的控制和预防策略至关重要。
