基于高通量定量PCR研究城市化小流域微生物污染特征

水体微生物污染(包括致病菌、病毒、寄生虫)会引起多种传染病和寄生虫病,对生产生活用水安全和人体健康造成重要威胁。本研究应用基于Taq Man探针的高通量荧光定量PCR技术对厦门市后溪流域冬季微生物污染进行检测,包含了5种粪便污染源(人源、反刍动物源、猪源、家禽源、狗源)微生物源示踪分子标记物与12种病原微生物。结果表明,该流域在上游及水库5个位点没有粪便污染,仅在其中一个水库位点检测出棘阿米巴,微生物污染极小;中下游检测出人类、反刍动物、猪、家禽、狗粪便污染,并且检测出产气荚膜梭菌、肠聚集性大肠杆菌、肠毒素型大肠杆菌、幽门螺杆菌、霍乱弧菌、副溶血弧菌、棘阿米巴、克雷伯氏肺炎杆菌等病原菌,其中流经旧城区居民生活生产区水样微生物污染严重,下游新城区微生物污染较小。这些结果暗示着城市人类活动是流域微生物污染主要来源,应从污染源头加强微生物污染控制。

Characterization of Microbial Contaminants Using High-throughput Quantitative PCR in a Small Urbanizing Catchment

Microbial contaminants of waterbodies, including pathogenic bacteria, viruses and parasites, pose significant threat to human health. In this study, we used TaqMan probe-based high-throughput quantitative PCR for detection and quantification of a series of specific markers to characterize microbial contamination in an urbanizing catchment, Houxi River of Xiamen in winter. These assays included Microbial Source Tracking (MST) markers targeting 5 common fecal sources, and pathogenic microbial markers targeting 12 pathogens. Fecal contamination or pathogens was not detected in the upstream and reservoir sites, except that Acanthamoeba spp. was detected in one of reservoir sites, indicating that microbial contamination was low. Whereas we detected human, ruminant, pig, poultry and dog fecal pollution in the middle and lower reaches, as well as pathogens including Clostridium perfringens, enteroaggregative E. coli, enterotoxigenic E. coli, Helicobacter pylori, Vibrio cholera, Vibrio parahaemolyticus, Acanthamoeba spp., and Klebsiella pneumoniae. The abundance of fecal indicators and pathogens were the highest in the downtown sites. The level of microbial contaminants decreased in downstream from the new-built district. These results suggest that human activities are the major sources of microbial contamination in Houxi River of Xiamen. Detection of multiple microbial contaminants in urban stream arise the urgent need for routine surveillance of potential microbial pollution.