1 Department of Microbiology, University Hospital of Larissa, Larissa, Greece.
2 Veterinary Research Institute, Brno, Czech Republic.
Microb Drug Resist. 2019 May;25(4):543-550. doi: 10.1089/mdr.2018.0259. Epub 2018 Nov 7.
The aim of the present study was to determine the rate and mechanisms of resistance to macrolides, lincosamides, and streptogramin B (MLS) antibiotics of collected in Central Greece. Of the 2,893 collected during 2012-2017, 1,161 isolates (40.2%) exhibited resistance to at least one of the MLS agents. The rate of erythromycin resistance was statistically significantly higher in methicillin-resistant (MRSA) (58.6%) than in methicillin-sensitive (MSSA) isolates (20.7%) ( = 0.002). Two hundred seventy-five representative MLS-resistant , including 81 MSSA and 194 MRSA isolates, were further studied. Thirty-eight MSSA isolates carried , 26 MSSA were positive for , whereas 17 isolates carried gene. Among MRSA, the gene was identified in the majority of the isolates ( = 153). Thirty-seven MRSA isolates carried ; three isolates carried , whereas the remaining MRSA was positive for two genes ( and ). Phylogenetic analysis showed that ST225, which belongs to CC5, was the most prevalent, accounting for 137 MRSA isolates. Higher genetic diversity was found in the group of MSSA isolates, which comprised of 13 sequence types. Whole-genome sequencing data showed that all -positive , with the exception of one ST398 isolate, harbored the -carrying Tn transposon integrated into their chromosomes. Furthermore, Illumina sequencing followed by polymerase chain reaction screening identified that , which was identified in a polyclonal population of MSSA and MRSA isolates, was carried by small plasmids, like pNE131. These findings highlighted the important role of high-risk clones and of mobile elements carrying resistance genes in the successful dissemination of MLS-resistant staphylococci.
本研究旨在确定 2012 年至 2017 年期间在希腊中部收集的 对大环内酯类、林可酰胺类和链阳菌素 B（MLS）抗生素的耐药率和机制。在收集的 2893 株 中，有 1161 株（40.2%）至少对一种 MLS 药物表现出耐药性。耐甲氧西林金黄色葡萄球菌（MRSA）（58.6%）的红霉素耐药率明显高于甲氧西林敏感金黄色葡萄球菌（MSSA）（20.7%）（=0.002）。进一步研究了 275 株具有代表性的 MLS 耐药 ，包括 81 株 MSSA 和 194 株 MRSA 。38 株 MSSA 携带 ，26 株 MSSA 为 阳性，而 17 株携带 基因。在 MRSA 中，大多数分离株（=153）都鉴定出 基因。37 株 MRSA 携带 ；3 株携带 ，而其余的 MRSA 则为两个基因（ 和 ）阳性。系统发育分析显示，属于 CC5 的 ST225 是最常见的，占 137 株 MRSA 。MSSA 分离株的遗传多样性更高，包括 13 种序列类型。全基因组测序数据显示，除一株 ST398 分离株外，所有 -阳性分离株都携带携带 Tn 转座子的 基因整合到其染色体中。此外，Illumina 测序和聚合酶链反应筛选表明，在 MSSA 和 MRSA 分离株的多克隆群体中发现的 ，由小质粒携带，如 pNE131。这些发现强调了高风险克隆和携带耐药基因的移动元件在 MLS 耐药葡萄球菌成功传播中的重要作用。
