Lois Marta, Polo David, Pérez Del Molino María Luisa, Coira Amparo, Aguilera Antonio, Romalde Jesús L
CRETUS, Departament de Microbiología y Parasitología, CIBUS-Faculty de Biología, University de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Servicio de Microbiología, Hospital Clínico University de Santiago, 15706 Santiago de Compostela, Spain.
Viruses. 2025 Mar 28;17(4):489. doi: 10.3390/v17040489.
Wastewater surveillance has become a valuable tool to monitor the emergence of SARS-CoV-2 variants of concern (VOCs) at the community level. In this study, we aimed to evaluate the presence of Alpha (B.1.1.7), Beta (B.1.351), Delta (B.1617.2), and Omicron (B.1.1.529) VOCs in samples from the inlet of a wastewater treatment plant (WWTP) as well as from two different sewer interceptors (SI-1 and SI-2) from the urban sewage system in Santiago de Compostela (Galicia, NW of Spain) throughout 2021 and January 2022. For this purpose, detection and quantification of the four VOCs was performed using four duplex SARS-CoV-2 allelic discrimination RT-qPCR assays, targeting the S-gene. An N1 RT-qPCR gene assay was used as a reference for the presence of SARS-CoV-2 RNA in wastewater samples. All VOCs were detected in wastewater samples. Alpha, Beta, Delta, and Omicron VOCs were detected in 45.7%, 7.5%, 66.7%, and 72.7% of all samples, respectively. Alpha VOC was dominant during the first part of the study, whereas Delta and Omicron detection peaks were observed in May-June and December 2021, respectively. Some differences were observed among the results obtained for the two city sectors studied, which could be explained by the differences in the characteristics of the population between them. Wastewater-based epidemiology allowed us to track the early circulation and emergence of SARS-CoV-2 variants at a local level, and our results are temporally concordant with clinical data and epidemiological findings reported by the health authorities.
废水监测已成为在社区层面监测严重急性呼吸综合征冠状病毒2（SARS-CoV-2）变异株（VOCs）出现情况的一项重要工具。在本研究中，我们旨在评估西班牙西北部加利西亚自治区圣地亚哥-德孔波斯特拉市城市污水系统中一座污水处理厂（WWTP）进水口以及两个不同的下水道截流器（SI-1和SI-2）的样本中，阿尔法（B.1.1.7）、贝塔（B.1.351）、德尔塔（B.1617.2）和奥密克戎（B.1.1.529）变异株在2021年全年及2022年1月的存在情况。为此，使用四种针对刺突蛋白基因的双重SARS-CoV-2等位基因鉴别逆转录定量聚合酶链反应（RT-qPCR）检测法对这四种变异株进行检测和定量。使用N1 RT-qPCR基因检测法作为废水样本中SARS-CoV-2 RNA存在情况的参考。在废水样本中检测到了所有变异株。阿尔法、贝塔、德尔塔和奥密克戎变异株分别在所有样本的45.7%、7.5%、66.7%和72.7%中被检测到。在研究的第一阶段，阿尔法变异株占主导地位，而德尔塔和奥密克戎变异株的检测峰值分别出现在2021年5月至6月和12月。在所研究的两个城市区域获得的结果之间观察到了一些差异，这可能是由它们之间人口特征的差异所解释的。基于废水的流行病学使我们能够在地方层面追踪SARS-CoV-2变异株的早期传播和出现情况，我们的结果在时间上与卫生当局报告的临床数据和流行病学调查结果一致。
