Carol Yu Center for Infection and Department of Microbiology, University of Hong Kong, Hong Kong SAR.
Department of Clinical Pathology, Kwong Wah Hospital, Hospital Authority, Hong Kong SAR.
J Med Microbiol. 2019 Sep;68(9):1367-1372. doi: 10.1099/jmm.0.001013.
Methicillin-resistant (MRSL) is increasingly recognized in healthcare and community settings. To obtain a better understanding of the emergence of MRSL, this study characterized the structure and content of the SCC elements harboured by 36 MRSL isolates obtained from diverse sources in Hong Kong from 2008 to 2017. The isolates were investigated by whole-genome sequencing. SCC types and subtypes were assigned according to the guidelines from the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements. The sequence type (ST)-SCC combinations in the 36 MRSL isolates were as follows: ST3-SCC IV (=2), ST3-SCC V (=28), ST27-SCC V (=5) and ST42-SCC V (=1). The two SCC IV elements were highly similar to the SCC IV element harboured by the community-associated methicillin-resistant (CA-MRSA) strain, JCSC6668. The J3 complex-J2 regions in the SCC V elements were highly similar to the corresponding regions in the CA-MRSA strains PM1 (=13) or WIS (=21). Based on the J1 to J3 sequences, the SCC V elements can be categorized into nine different subtypes. Our findings highlight the diversified structures of SCC elements among MRSL strains and their close relationship with SCC elements harboured by CA-MRSA.
耐甲氧西林金黄色葡萄球菌（MRSL）在医疗保健和社区环境中日益受到关注。为了更好地了解 MRSL 的出现情况，本研究对 2008 年至 2017 年期间从香港不同来源获得的 36 株 MRSL 分离株中携带的 SCC 元件的结构和内容进行了特征描述。通过全基因组测序对这些分离株进行了研究。根据国际葡萄球菌盒式染色体元件分类工作组的指南，对 SCC 类型和亚型进行了分配。36 株 MRSL 分离株中的 ST-SCC 组合如下：ST3-SCC IV（=2）、ST3-SCC V（=28）、ST27-SCC V（=5）和 ST42-SCC V（=1）。两个 SCC IV 元件与社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）菌株 JCSC6668 携带的 SCC IV 元件高度相似。SCC V 元件中的 J3 复合体-J2 区域与 CA-MRSA 菌株 PM1（=13）或 WIS（=21）的相应区域高度相似。根据 J1 到 J3 序列，SCC V 元件可分为九个不同的亚型。我们的研究结果强调了 MRSL 菌株中 SCC 元件的多样化结构及其与 CA-MRSA 菌株携带的 SCC 元件的密切关系。
