Sharon Belle M, Hulyalkar Neha V, Zimmern Philippe E, Palmer Kelli L, De Nisco Nicole J
Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA.
Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
Access Microbiol. 2023 Jun 12;5(6). doi: 10.1099/acmi.0.000508.v3. eCollection 2023.
is an understudied member of its genus possessing a characteristic megaplasmid contributing to a large genome size. Although less commonly associated with human infection compared to other enterococci, this species can cause disease and persist in diverse niches such as the gut, urinary tract, blood and environment. Few complete genome assemblies have been published to date for . In this study, we report the complete assembly of the first clinical urinary strain, Er676, isolated from a postmenopausal woman with history of recurrent urinary tract infection. We additionally completed the assembly of clinical type strain ATCC49464. Comparative genomic analyses reveal inter-species diversity driven by large accessory genomes. The presence of a conserved megaplasmid indicates it is a ubiquitous and vital genetic feature of . We find that the chromosome is enriched for DNA replication and protein biosynthesis genes while the megaplasmid is enriched for transcription and carbohydrate metabolism genes. Prophage analysis suggests that diversity in the chromosome and megaplasmid sequences arises, in part, from horizontal gene transfer. Er676 demonstrated the largest genome size reported to date for and the highest probability of human pathogenicity. Er676 also possesses multiple antimicrobial resistance genes, of which all but one are encoded on the chromosome, and has the most complete prophage sequences. Complete assembly and comparative analyses of the Er676 and ATCC49464 genomes provide important insight into the inter-species diversity of that gives it its ability to colonize and persist in the human body. Investigating genetic factors that contribute to the pathogenicity of this species will provide valuable tools to combat diseases caused by this opportunistic pathogen.
是其属中研究较少的成员，拥有一个特征性的大质粒，导致基因组较大。与其他肠球菌相比，该物种与人类感染的关联较少，但可引起疾病并在多种生态位中持续存在，如肠道、泌尿道、血液和环境。迄今为止，针对该物种的完整基因组组装报道较少。在本研究中，我们报告了从一名有复发性尿路感染病史的绝经后妇女中分离出的第一株临床泌尿道菌株Er676的完整组装。我们还完成了临床模式菌株ATCC49464的组装。比较基因组分析揭示了由大型辅助基因组驱动的种间多样性。保守大质粒的存在表明它是该物种普遍存在且至关重要的遗传特征。我们发现该物种的染色体富含DNA复制和蛋白质生物合成基因，而大质粒富含转录和碳水化合物代谢基因。原噬菌体分析表明，染色体和大质粒序列的多样性部分源于水平基因转移。Er676展示了迄今为止报道的该物种最大的基因组大小和最高的人类致病可能性。Er676还拥有多个抗菌抗性基因，其中除一个外均编码在染色体上，并且具有最完整的原噬菌体序列。Er676和ATCC49464基因组的完整组装和比较分析为该物种的种间多样性提供了重要见解，使其能够在人体中定殖和持续存在。研究导致该物种致病性的遗传因素将为对抗由这种机会性病原体引起的疾病提供有价值的工具。
