Malla Bikash, Shrestha Sadhana, Sthapit Niva, Hirai Soichiro, Raya Sunayana, Rahmani Aulia Fajar, Angga Made Sandhyana, Siri Yadpiroon, Ruti Annisa Andarini, Haramoto Eiji
Interdisciplinary Center for River Basin Environment, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan.
Department of Civil and Environmental Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan.
Sci Total Environ. 2025 Feb 15;965:178661. doi: 10.1016/j.scitotenv.2025.178661. Epub 2025 Feb 1.
Plasmid pBI143, abundant in the human gut, is a promising human-specific fecal marker. However, studies on its optimal concentration methods, seasonal variations, and potential as a normalization parameter for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), remain limited. Among the three concentration methods compared, polyethylene glycol (PEG) precipitation and centrifugation demonstrated comparable efficiencies (9.3 ± 0.6 and 9.2 ± 0.6 log copies/L, respectively; n = 8 each), outperforming membrane filtration (8.0 ± 0.6 log copies/L; n = 8). PEG precipitation was further applied to quantify pBI143, together with other human-specific fecal markers (crAssphage and pepper mild mottle virus (PMMoV)), in 52 wastewater samples collected weekly over a one year from a wastewater treatment plant in Yamanashi Prefecture, Japan, by quantitative polymerase chain reaction. The higher pBI143 concentrations (9.6 ± 0.5 log copies/L) compared to PMMoV (8.2 ± 0.2 log copies/L) and crAssphage (8.0 ± 0.2 log copies/L) highlighted its potential as a robust marker for human fecal contamination. Unlike PMMoV and crAssphage that remained stable across seasons, pBI143 showed seasonal fluctuations, especially during summer and autumn, suggesting its greater sensitivity to environmental conditions. The study evaluated the suitability of pBI143, crAssphage, and PMMoV for normalizing SARS-CoV-2 concentrations in wastewater; however, non-normalized SARS-CoV-2 concentrations showed the highest correlation with COVID-19 cases (ρ = 0.74), whereas normalization reduced this correlation (PMMoV-normalized, ρ = 0.72; crAssphage-normalized, ρ = 0.70; and pBI143-normalized, ρ = 0.50), likely due to differences in the persistence and structural properties of the markers, indicating that these markers are less effective for SARS-CoV-2 normalization. This study underscores the promising utility of pBI143 in wastewater surveillance but highlights the need for further research across diverse regions to validate its applicability.
质粒pBI143在人类肠道中大量存在，是一种很有前景的人类特异性粪便标志物。然而，关于其最佳浓缩方法、季节变化以及作为2019冠状病毒病（COVID-19）病原体严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的标准化参数的潜力的研究仍然有限。在比较的三种浓缩方法中，聚乙二醇（PEG）沉淀法和离心法显示出相当的效率（分别为9.3±0.6和9.2±0.6 log拷贝/L；每组n = 8），优于膜过滤法（8.0±0.6 log拷贝/L；n = 8）。通过定量聚合酶链反应，将PEG沉淀法进一步应用于对日本山梨县一家污水处理厂一年内每周收集的52份废水样本中的pBI143以及其他人类特异性粪便标志物（crAssphage和辣椒轻斑驳病毒（PMMoV））进行定量分析。与PMMoV（8.2±0.2 log拷贝/L）和crAssphage（8.0±0.2 log拷贝/L）相比，pBI143的浓度更高（9.6±0.5 log拷贝/L），突出了其作为人类粪便污染可靠标志物的潜力。与PMMoV和crAssphage在不同季节保持稳定不同，pBI143表现出季节波动，尤其是在夏季和秋季，这表明它对环境条件更加敏感。该研究评估了pBI143、crAssphage和PMMoV对废水中SARS-CoV-2浓度进行标准化的适用性；然而，未标准化的SARS-CoV-2浓度与COVID-19病例的相关性最高（ρ = 0.74），而标准化则降低了这种相关性（PMMoV标准化，ρ = 0.72；crAssphage标准化，ρ = 0.70；pBI143标准化，ρ = 0.50），这可能是由于标志物的持久性和结构特性不同，表明这些标志物对SARS-CoV-进行标准化的效果较差。这项研究强调了pBI143在废水监测中的潜在用途，但也突出了需要在不同地区进行进一步研究以验证其适用性。
