Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.
The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.
Front Cell Infect Microbiol. 2020 Jun 12;10:274. doi: 10.3389/fcimb.2020.00274. eCollection 2020.
, and belong to the "Epidermidis Cluster Group" (ECG) and are generally opportunistic pathogens. In this work, whole genome sequencing, molecular cloning and pan-genome analysis were performed to investigate the genetic characteristics of the resistance, virulence and genome structures of 69 ECG strains, including a clinical isolate ( SY333) obtained in this work. Two resistance genes ( and ) encoded on the plasmids pSY333-41 and pSY333-45 of SY333 were confirmed to be functional. The region in ECG exhibited three distinct structures, and these chromosome- and plasmid-encoded operons seemed to follow two different evolutionary paths. Pan-genome analysis revealed their pan-genomes tend to be "open." For the virulence-related factors, the genes involved in primary attachment were observed almost exclusively in , while the genes associated with intercellular aggregation were observed more frequently in and . The type VII secretion system was present in all strains of and some of but not in . Moreover, the locus (iron regulated surface determinant) was first found to be encoded on the genomes of and . These findings suggested that the plasmid and chromosome encoded operons of ECG species underwent different evolution paths, as well as they differed in the abundance of virulence genes associated with adherence, invasion, secretion system and immune evasion. Identification of loci in and indicated their ability to acquire heme as nutrient iron during infection.
和 属于“表皮葡萄球菌群”（ECG），通常是机会致病菌。在这项工作中，我们进行了全基因组测序、分子克隆和泛基因组分析，以研究 69 株 ECG 菌株（包括本工作中获得的临床分离株 SY333）的耐药性、毒力和基因组结构的遗传特征。质粒 pSY333-41 和 pSY333-45 编码的两个耐药基因（ 和 ）被证实具有功能。ECG 中的 区有三种不同的结构，这些染色体和质粒编码的 操纵子似乎遵循两种不同的进化途径。泛基因组分析表明，它们的泛基因组倾向于“开放”。对于与毒力相关的因素，我们观察到参与初始附着的基因几乎只存在于 中，而与细胞间聚集相关的基因则更频繁地存在于 和 中。所有 和部分 菌株都存在 VII 型分泌系统，但 中不存在。此外， 基因座（铁调节表面决定因子）首次被发现编码在 和 的基因组中。这些发现表明，ECG 种属的质粒和染色体编码的 操纵子经历了不同的进化途径，与附着、入侵、分泌系统和免疫逃避相关的毒力基因的丰度也不同。在 和 中鉴定出 基因座表明它们在感染过程中能够作为营养铁获取血红素。
