Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Goldbelt C6, LLC, Chesapeake, Virginia, USA.
Antimicrob Agents Chemother. 2024 Nov 6;68(11):e0059124. doi: 10.1128/aac.00591-24. Epub 2024 Oct 15.
and are frequent causes of healthcare-associated infections. Antimicrobial-resistant enterococci pose a serious public health threat, particularly vancomycin-resistant enterococci (VRE), for which treatment options are limited. The Centers for Disease Control and Prevention's Division of Healthcare Quality Promotion Sentinel Surveillance system conducted surveillance from 2018 to 2019 to evaluate antimicrobial susceptibility profiles and molecular epidemiology of 205 and 180 clinical isolates collected from nine geographically diverse sites in the United States. Whole genome sequencing revealed diverse genetic lineages, with no single sequence type accounting for more than 15% of or . Phylogenetic analysis distinguished from 19 (previously known as clade B). Resistance to vancomycin was 78.3% among , 7.8% among , and did not occur among isolates. Resistance to daptomycin and linezolid was rare: (5.6%, 0.6%, respectively), (2%, 2%), and (5.3%, 0%). All VRE harbored the gene. Three of the seven isolates that were not susceptible to linezolid harbored , one chromosomally located and two on linear plasmids that shared a conserved backbone with other multidrug-resistant conjugative linear plasmids. One of these isolates contained and co-localized on the linear plasmid. By screening all enterococci, 20% of were predicted to harbor linear plasmids, whereas none were predicted among or . Continued surveillance is needed to assess the future emergence and spread of antimicrobial resistance by linear plasmids and other mechanisms.IMPORTANCEThis work confirms prior reports of showing higher levels of resistance to more antibiotics than and identifies that diverse sequence types are contributing to enterococcal infections in the United States. All VRE harbored the gene. We present the first report of the linezolid resistance gene on linear plasmids in the United States, one of which co-carried a cassette. Additional studies integrating epidemiological, antimicrobial susceptibility, and genomic methods to characterize mechanisms of resistance, including the role of linear plasmids, will be critical to understanding the changing landscape of enterococci in the United States.
和 是导致医疗保健相关感染的常见原因。耐抗生素肠球菌对公共健康构成严重威胁，特别是耐万古霉素肠球菌（VRE），其治疗选择有限。疾病控制与预防中心的医疗保健质量促进监测系统从 2018 年至 2019 年进行监测，以评估从美国九个地理位置不同的地点收集的 205 株 和 180 株 临床分离株的抗生素敏感性谱和分子流行病学。全基因组测序显示出多样化的遗传谱系，没有单一的序列类型占 或 的 15%以上。系统发育分析将 与 19 株（以前称为 群 B）区分开来。 对万古霉素的耐药率为 78.3%， 对 为 7.8%，而 对 则没有耐药性。对达托霉素和利奈唑胺的耐药性罕见： （分别为 5.6%和 0.6%）， （分别为 2%和 2%）， （5.3%）。所有 VRE 均携带 基因。在 7 株对利奈唑胺不敏感的分离株中，有 3 株携带 ，其中 1 株位于染色体上，另外 2 株位于与其他多药耐药性可转移线性质粒共享保守骨架的线性质粒上。其中一个分离株携带 和 ，它们共同位于线性质粒上。通过筛选所有肠球菌，预计 20%的 携带线性质粒，而 或 则没有。需要继续监测，以评估线性质粒和其他机制引起的抗生素耐药性的未来出现和传播。
重要性
这项工作证实了先前的报告，即 显示出比 更高水平的抗生素耐药性，并确定了不同的序列类型在美国导致肠球菌感染。所有 VRE 均携带 基因。我们首次在美国报告了耐万古霉素基因 在线性质粒上的存在，其中一个携带 盒。整合流行病学、抗生素敏感性和基因组方法来描述耐药机制的额外研究，包括线性质粒的作用，对于了解美国肠球菌不断变化的格局至关重要。
