Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China.
Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Freie Universität Berlin, Berlin, Germany.
Emerg Microbes Infect. 2021 Dec;10(1):1481-1494. doi: 10.1080/22221751.2021.1951125.
Methicillin-resistant (MRSA) of sequence types ST398 and ST9 are dominant lineages among livestock in Europe and Asia, respectively. Although both STs were commonly found as colonizers of the skin and the mucosal membranes, MRSA ST398, rather than MRSA ST9, has been reported to cause infections in humans and animals. Herein, we comparatively analyzed the genomic characteristics, fitness and virulence of MRSA ST398 and ST9 isolated from pigs in both China (CHN) and Germany (GER) to explore the factors that lead to differences in their epidemics and pathogenicity. We observed that the CHN-MRSA ST9 and the GER-MRSA ST9 have evolved independently, whereas the CHN-MRSA ST398 and GER-MRSA ST398 had close evolutionary relationships. Resistance to antimicrobial agents commonly used in livestock, the enhanced ability of biofilm formation, and the resistance to desiccation contribute to the success of the dominant clones of CHN-MRSA ST9 and GER-MRSA ST398, and the gene on the genomic island might in part contribute to their colonization fitness in pigs. All MRSA ST398 strains revealed more diverse genome structures, higher tolerance to acids and high osmotic pressure, and greater competitive fitness in co-culture experiments. Notably, we identified and characterized a novel gene, which was located on the genomic island νSaβ of MRSA ST398 but was absent in MRSA ST9. The enhanced pathogenicity of the MRSA ST398 strains due to might in part explain why MRSA ST398 strains are more likely to cause infections.
耐甲氧西林金黄色葡萄球菌（MRSA）的序列类型 ST398 和 ST9 分别是欧洲和亚洲畜牧业中的主要谱系。尽管这两种 ST 都常见于皮肤和粘膜的定植，但据报道，MRSA ST398 而不是 MRSA ST9 会导致人类和动物感染。在此，我们比较分析了从中国（CHN）和德国（GER）猪中分离出的 MRSA ST398 和 ST9 的基因组特征、适应性和毒力，以探讨导致它们在流行和致病性方面存在差异的因素。我们观察到，CHN-MRSA ST9 和 GER-MRSA ST9 已经独立进化，而 CHN-MRSA ST398 和 GER-MRSA ST398 则具有密切的进化关系。对家畜中常用的抗菌药物的耐药性、增强的生物膜形成能力以及对干燥的抵抗力有助于 CHN-MRSA ST9 和 GER-MRSA ST398 的优势克隆的成功，而基因组岛上的 基因可能部分有助于它们在猪中的定植适应性。所有 MRSA ST398 株系均显示出更多样化的基因组结构、对酸和高渗透压的更高耐受性以及在共培养实验中的更强竞争适应性。值得注意的是，我们鉴定并表征了一个新型 基因，该基因位于 MRSA ST398 的基因组岛 νSaβ 上，但在 MRSA ST9 中不存在。MRSA ST398 株系由于 基因而增强的致病性在一定程度上可以解释为什么 MRSA ST398 株系更容易引起感染。
