Institute of Environmental Science and Research Ltd (ESR), Porirua 5240, New Zealand.
Institute of Environmental Science and Research Ltd (ESR), Christchurch 8041, New Zealand.
Sci Total Environ. 2021 Aug 20;783:146848. doi: 10.1016/j.scitotenv.2021.146848. Epub 2021 Apr 1.
Shellfish growing waters contaminated with inadequately treated human wastewater is a major source of norovirus in shellfish and poses a significant human health risk to consumers. Microbial source tracking (MST) markers have been widely used to identify the source (s) of faecal contamination in water but data are limited on their use for shellfish safety. This study evaluated the source specificity, sensitivity, occurrence and concentration of three viral MST markers i.e. cross-assembly phage (crAssphage), F-specific RNA bacteriophage genogroup II (F-RNA phage GII) and pepper mild mottle virus (PMMoV) using animal faeces (n = 119; 16 animal groups), influent wastewater (n = 12), effluent wastewater (n = 16) and shellfish (n = 33). CrAssphage, F-RNA phage GII and PMMoV had source specific values of 0.97, 0.99 and 0.91, respectively. The sensitivity of MST markers was confirmed by their 100% detection frequency in influent wastewaters. The frequency of detection in effluent wastewater ranged from 81.3% (F-RNA phage GII) to 100% (PMMoV). Concentration of F-RNA phage GII was one log (influent wastewater) and 2-3 log (effluent wastewater) lower than crAssphage and PMMoV, respectively. Despite lower prevalence of F-RNA phage GII in oysters and mussels compared to crAssphage and PMMoV, concentrations of the three MST markers were similar in mussels. As an indicator of norovirus contamination in shellfish, crAssphage and PMMoV had greater predictive sensitivity (100%; [95% CI; 81.5%-100%)]) and F-RNA phage GII had greater predictive specificity (93.3%; [95% CI; 68.1%-99.8%]). In contrast, crAssphage and F-RNA phage GII have similar accuracy for predicting norovirus in shellfish, however, PMMoV significantly overestimated its presence. Therefore, a combination of crAssphage and F-RNA phage GII analysis of shellfish could provide a robust estimation of the presence of human faecal and norovirus contamination.
贝类养殖水域受到未经充分处理的人类废水污染，是贝类中诺如病毒的主要来源，对消费者构成重大健康风险。微生物来源追踪 (MST) 标志物已广泛用于识别水中粪便污染的来源，但关于它们在贝类安全方面的应用数据有限。本研究使用动物粪便（n=119；16 个动物组）、进水废水（n=12）、出水废水（n=16）和贝类（n=33）评估了三种病毒 MST 标志物即组合噬菌体 (crAssphage)、F 型 RNA 噬菌体基因群 II (F-RNA 噬菌体 GII) 和胡椒轻斑驳病毒 (PMMoV) 的来源特异性、灵敏度、出现和浓度。crAssphage、F-RNA 噬菌体 GII 和 PMMoV 的来源特异性值分别为 0.97、0.99 和 0.91。通过 MST 标志物在进水废水中 100%的检测频率证实了其灵敏度。在出水废水中的检测频率范围为 81.3%（F-RNA 噬菌体 GII）至 100%（PMMoV）。F-RNA 噬菌体 GII 的浓度比 crAssphage 和 PMMoV 低一个对数（进水废水）和 2-3 个对数（出水废水）。尽管与 crAssphage 和 PMMoV 相比，F-RNA 噬菌体 GII 在牡蛎和贻贝中的检出率较低，但三种 MST 标志物在贻贝中的浓度相似。作为贝类中诺如病毒污染的指示物，crAssphage 和 PMMoV 具有更高的预测灵敏度（100%；[95%置信区间；81.5%-100%]），而 F-RNA 噬菌体 GII 具有更高的预测特异性（93.3%；[95%置信区间；68.1%-99.8%]）。相比之下，crAssphage 和 F-RNA 噬菌体 GII 对贝类中诺如病毒的预测具有相似的准确性，但 PMMoV 显著高估了其存在。因此，贝类中 crAssphage 和 F-RNA 噬菌体 GII 的组合分析可以对人类粪便和诺如病毒污染的存在进行稳健估计。
