Department of Laboratory Medicine, Linkou Chang Gung Memorial Hospitalgrid.413801.f, Taoyuan, Taiwan.
Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
Antimicrob Agents Chemother. 2022 Aug 16;66(8):e0019722. doi: 10.1128/aac.00197-22. Epub 2022 Jul 25.
Methicillin-resistant Staphylococcus lugdunensis (MRSL) strains showing resistance to several common antibiotics have been reported recently. Sequence type (ST) 3 MRSL carrying SCC types IV, V, or Vt is the major lineage associated with health care-associated infections. We aimed to investigate the distribution and dissemination of antimicrobial resistance determinants in this lineage. Two representative ST3-MRSL strains, CGMH-SL131 (SCC V) and CGMH-SL138 (SCC IV), were subjected to whole-genome sequencing. Detection of antibiotic resistance genes and screening of susceptibility patterns were performed for 30 ST3-MRSL and 16 ST6-MRSL strains via PCR and standard methods. Except for and , antimicrobial resistance genes were located within two plasmids: a 28.6 kb (A)-carrying plasmid (pCGMH_SL138) in CGMH-SL138 and a 26 kb plasmid carrying non-(A) resistance genes (pCGMH_SL131) in CGMH-SL131. Both plasmids shared common genetic features with multiple copies of IS flanked by genes conferring resistance to aminoglycoside ( and ), TET (), and cadmium () and tolerance to chlorhexidine (/); however, only pCGMH_SL138 harbored (A) that conferred resistance to lincomycin and that encodes a replication initiation protein. Unlike ST6-MRSL, none of the ST3-MRSL isolates contained the gene. Instead, most isolates harbored (A) (20/30, 66.7%), and several other resistance genes found on pCGMH_SL138. These isolates and transformants containing pCGMH_SL138 exhibited susceptibility to ERY and higher MICs for lincomycin and aforementioned antibiotics. A novel (A)-carrying plasmid, pCGMH_SL138, that harbored a multiresistance gene cluster, was identified in ST3-MRSL strains and may contribute to the dissemination of antibiotic resistance in staphylococci.
耐甲氧西林金黄色葡萄球菌（MRSL）对几种常见抗生素表现出耐药性的菌株最近已有报道。携带 SCC 类型 IV、V 或 Vt 的 ST3 MRSL 是与医疗保健相关感染相关的主要谱系。我们旨在研究该谱系中抗菌药物耐药决定因素的分布和传播。两个代表性的 ST3-MRSL 菌株，CGMH-SL131（SCC V）和 CGMH-SL138（SCC IV），进行了全基因组测序。通过 PCR 和标准方法对 30 株 ST3-MRSL 和 16 株 ST6-MRSL 菌株进行抗生素耐药基因检测和药敏模式筛选。除了 和 外，抗菌药物耐药基因位于两个质粒中：CGMH-SL138 中的一个 28.6kb（A）携带质粒（pCGMH_SL138）和 CGMH-SL131 中携带非（A）耐药基因的 26kb 质粒（pCGMH_SL131）。两个质粒都具有相同的遗传特征，具有多个被氨基糖苷（和）、TET（）和镉（）赋予耐药性的基因，以及对氯己定（/）的耐受性；然而，只有 pCGMH_SL138 携带（A），它赋予了林可霉素和 编码复制起始蛋白的耐药性。与 ST6-MRSL 不同，没有 ST3-MRSL 分离株携带 基因。相反，大多数分离株携带（A）（20/30，66.7%），以及其他一些在 pCGMH_SL138 上发现的耐药基因。这些分离株和含有 pCGMH_SL138 的转化子对 ERY 表现出敏感性，对林可霉素和上述抗生素的 MIC 更高。在 ST3-MRSL 菌株中发现了一种携带新型（A）的质粒，pCGMH_SL138，它携带一个多耐药基因簇，可能有助于葡萄球菌的抗生素耐药性传播。
