Sundermann Alexander J, Rangachar Srinivasa Vatsala, Mills Emma G, Griffith Marissa P, Evans Eric, Chen Jieshi, Waggle Kady D, Snyder Graham M, Pless Lora Lee, Harrison Lee H, Van Tyne Daria
Microbial Genomic Epidemiology Laboratory, Center for Genomic Epidemiology, University of Pittsburgh, Pittsburgh, PA, USA.
Department of Epidemiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
BMC Glob Public Health. 2025 Aug 13;3(1):69. doi: 10.1186/s44263-025-00186-2.
Vancomycin-resistant enterococcal (VRE) infections pose significant challenges in healthcare. Transmission dynamics of VRE are complex, often involving patient colonization and subsequent transmission through various healthcare-associated vectors. We utilized a whole genome sequencing (WGS) surveillance program at our institution to better understand the contribution of clinical and colonizing isolates to VRE transmission.
We performed whole genome sequencing on 352 VRE clinical isolates collected over 34 months and 891 rectal screening isolates collected over a 9-month nested period, and used single nucleotide polymorphisms to assess relatedness. We then performed a geo-temporal transmission analysis considering both clinical and rectal screening isolates compared with clinical isolates alone, and calculated 30-day clinical outcomes.
VRE rectal carriage constituted 87.3% of VRE acquisition, with an average monthly acquisition rate of 7.6 per 1000 patient days. We identified 185 genetically related clusters containing 2-42 isolates and encompassing 70% of all isolates in the dataset. The inclusion of rectal swab isolates increased the detection of clinical isolate clusters (from 53 to 67%, P < 0.01). Geo-temporal analysis identified hotspot locations of VRE transmission. Patients with clinical VRE isolates that were closely related to previously sampled rectal swab isolates experienced 30-day ICU admission (17.5%), hospital readmission (9.2%), and death (13.3%).
Our findings describe the high burden of VRE transmission at our hospital and shed light on the importance of using WGS surveillance of both clinical and rectal screening isolates to better understand the transmission of this pathogen. This study highlights the potential utility of incorporating WGS surveillance of VRE into routine hospital practice for improving infection prevention and patient safety.
耐万古霉素肠球菌（VRE）感染给医疗保健带来了重大挑战。VRE的传播动态复杂，通常涉及患者定植以及随后通过各种与医疗保健相关的载体进行传播。我们利用本机构的全基因组测序（WGS）监测计划，以更好地了解临床分离株和定植分离株对VRE传播的作用。
我们对在34个月内收集的352株VRE临床分离株以及在9个月嵌套期内收集的891株直肠筛查分离株进行了全基因组测序，并使用单核苷酸多态性评估亲缘关系。然后，我们进行了地理时间传播分析，将临床分离株和直肠筛查分离株与仅临床分离株进行比较，并计算了30天的临床结局。
VRE直肠携带占VRE获得的87.3%，平均每月获得率为每1000患者日7.6例。我们鉴定出185个遗传相关簇，包含2 - 42株分离株，占数据集中所有分离株的70%。纳入直肠拭子分离株增加了临床分离株簇的检测率（从53%提高到67%，P < 0.01）。地理时间分析确定了VRE传播的热点位置。临床VRE分离株与先前采样的直肠拭子分离株密切相关的患者经历了30天ICU入院（17.5%）、再次入院（9.2%）和死亡（13.3%）。
我们的研究结果描述了我院VRE传播的高负担，并阐明了对临床和直肠筛查分离株进行WGS监测以更好地了解该病原体传播的重要性。本研究强调了将VRE的WGS监测纳入医院常规实践以改善感染预防和患者安全的潜在效用。
