Rampelotto R F, Faria N A, Hörner R, Miragaia M
Laboratory of Bacteriology, Department of Clinical and Toxicological Analysis, Health Sciences Center, Federal University of Santa Maria, Santa Maria, RS, Brazil; Laboratory of Bacterial Evolution and Molecular Epidemiology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Portugal.
Laboratory of Bacterial Evolution and Molecular Epidemiology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Portugal.
J Hosp Infect. 2025 Jul;161:148-158. doi: 10.1016/j.jhin.2025.04.011. Epub 2025 Apr 25.
Bloodstream infections caused by Staphylococcus epidermidis are among the most frequent and serious infections in neonatal intensive care units (NICU), being responsible for high rates of morbidity and mortality. However, how S. epidermidis prevails, disseminates and evolves to cause outbreaks in NICU is poorly understood. We aimed to understand what is the genomic basis of S. epidermidis outbreaks in NICU to provide guidelines for a better infection control. We collected all S. epidermidis isolated from newborn blood cultures admitted to a hospital NICU in Brazil over one-year and compared their genomes. The S. epidermidis infection incidence rate was 1.17 per baby-year. 83,64% of S. epidermidis were resistant to methicillin (MRSE) and 84,5% belonged to sequence type 2 (ST2) or related, carrying the staphylococcal cassette chromosome mec (SCCmec) type III or IVa. Single nucleotide polymorphisms (SNPs) analysis showed that S. epidermidis infections resulted from the co-existence of three ST2 transmission chains originating from distinct endemic sources (<50 SNPs). Each transmission chain was characterized by specific antibiotic resistance and virulence profile and content in staphylococcal cassette chromosome elements (SCCmec, SCC non-mec and ACME). During transmission, other mobile genetic elements were acquired/lost and mutations emerged in genes involved in adhesion, signal transduction, general metabolism, replication, recombination and repair. Tracking S. epidermidis transmission chains in the NICU will require a deep genomic analysis, combining bacterial genetic background and accessory genome. This study highlighted the need for the integration of whole genome sequencing as a key surveillance tool for infection control in NICUs.
由表皮葡萄球菌引起的血流感染是新生儿重症监护病房（NICU）中最常见且严重的感染之一，导致高发病率和死亡率。然而，表皮葡萄球菌如何在NICU中盛行、传播并演变成暴发，目前了解甚少。我们旨在了解NICU中表皮葡萄球菌暴发的基因组基础，以提供更好的感染控制指南。我们收集了巴西一家医院NICU一年内从新生儿血培养中分离出的所有表皮葡萄球菌，并比较了它们的基因组。表皮葡萄球菌感染发病率为每婴儿年1.17例。83.64%的表皮葡萄球菌对甲氧西林耐药（MRSE），84.5%属于序列类型2（ST2）或相关类型，携带III型或IVa型葡萄球菌盒式染色体mec（SCCmec）。单核苷酸多态性（SNP）分析表明，表皮葡萄球菌感染是由源自不同地方流行源（<50个SNP）的三条ST2传播链共存导致的。每条传播链都具有特定的抗生素耐药性、毒力特征以及葡萄球菌盒式染色体元件（SCCmec、SCC非mec和ACME）的含量。在传播过程中，其他可移动遗传元件被获得/丢失，参与黏附、信号转导、一般代谢、复制、重组和修复的基因出现突变。追踪NICU中表皮葡萄球菌的传播链需要深入的基因组分析，结合细菌遗传背景和辅助基因组。本研究强调了整合全基因组测序作为NICU感染控制关键监测工具的必要性。
