Despite increased public health concerns on the occurrences of potentially pathogenic/mycotoxigenic fungi in public drinking water system, dissemination of hygienically relevant fungi and their associated mycotoxins via distribution system under the dual burden of ageing infrastructure and ancillary distribution network lacking infrastructure for high-pressure water delivery systems is unknown. In this study, the diversity of fungi and occurrence of mycotoxins at 30 different points along treated piped water supply and ancillary distribution networks in Johannesburg, South Africa, were monitored for 12 months. Mycological analysis using cultural and molecular methods yielded 282 fungi belonging to phylum Ascomycota, having Aspergillus (91%), Penicillium (65%) and Trichoderma (31%) as dominant genera, with Aspergillus fumigatus, Penicillium citrinum, Purpureocillium lilacinum and Aspergillus flavus as the most prevalent species. Communal standpipe and reservoir outlets had significantly higher prevalence than other water samples. There was no strong correlation between total coliforms (r = 0.4266) and residual chlorine (r = − 0.1937), and fungal prevalence at p < 0.05. LC-MS/MS analysis detected aflatoxins B1, M1, G1 and G2 in 50, 9, 9 and 46% of water samples analysed, respectively, ranging between 0 and 3.18 ng/l. Deoxynivalenol (DON), 3-acetyl DON and 15-acetyl DON levels were between 8.4–96.1, 18.7–145.7 and 15.2–71.6 ng/l, respectively. However, the estimated average daily dose (ADD) for detected mycotoxins was below the tolerable daily intake (TDI), suggesting no toxicological risk. Presence of potentially mycotoxigenic fungi, despite the low toxicological risk, demonstrates a need for appropriate monitoring for fungi and mycotoxins in treated drinking water distribution systems for improved water quality and long-term public health assurance.

中文翻译：

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南非经过处理的饮用水分配系统中水生真菌和相关真菌毒素的发生和多样性：对水质和公共卫生的影响。

尽管公众对公共饮用水系统中潜在的致病/致真菌性真菌的危害日益增加，但在老龄化基础设施和缺乏高压水基础设施的辅助分配网络的双重负担下，通过分配系统传播了与卫生相关的真菌及其相关霉菌毒素的传播传送系统未知。在这项研究中，监测了南非约翰内斯堡沿处理过的自来水和辅助供水网络的30个不同点处真菌的多样性和霉菌毒素的发生，监测了12个月。使用文化和分子方法进行的真菌学分析产生了282种真菌，属于子囊菌门，具有曲霉菌（91％），青霉菌（65％）和木霉属（31％），为优势属，与烟曲霉，柑桔青霉，Purpureocillium lilacinum和黄曲霉如最常见的物种。公用立管和水库出口的患病率明显高于其他水样。总大肠菌群（r  = 0.4266）和残留氯（r  = − 0.1937）与p处的真菌患病率之间无显着相关性。 <0.05。LC-MS / MS分析分别在50％，9％，9％和46％的水样本中检测到黄曲霉毒素B1，M1，G1和G2，范围为0至3.18 ng / l。脱氧雪腐酚（DON），3-乙酰基DON和15-乙酰基DON的水平分别在8.4–96.1、18.7–145.7和15.2–71.6 ng / l之间。但是，检测到的霉菌毒素的估计平均日剂量（ADD）低于可耐受的每日摄入量（TDI），表明没有毒理学风险。尽管具有低毒理学风险，但仍存在潜在的致毒毒素真菌，这表明需要对经过处理的饮用水分配系统中的真菌和霉菌毒素进行适当监测，以改善水质和长期公共卫生。