高通量定量PCR研究环境中的微生物污染特征

Tracking microbial contaminants in environments by high-throughput quantitative PCR

微生物污染(包括细菌、真菌、病毒、寄生虫)会引起多种传染病和寄生虫病,对环境安全和人体健康造成重要威胁.本研究利用可同时检测33种病原微生物以及10种不同粪便污染源的基于TaqMan探针的高通量qPCR检测技术,对污水处理厂进出水、长期施加有机肥(污泥或鸡粪)或化肥土壤中的微生物污染状况进行了研究.结果表明,污水处理厂中检测出的微生物污染种类和丰度较高,污染状况较严重,土壤环境微生物污染较小.在污水处理厂中,共检出13种人类病原微生物,进水中检测到的病原菌数目和丰度高于出水,其中,克雷伯氏肺炎杆菌和致病性大肠杆菌在污水处理厂进出水具有最高丰度,并发现污水处理厂中具有人类、猪、狗粪便污染;土壤中共检出3种病原菌,其中军团杆菌和棘阿米巴检测丰度最高,有机肥(污泥或鸡粪)施用显著增加土壤中病原菌丰度,同时发现这些土壤中存在家禽粪便污染.研究表明,污水处理设施虽可去除污水中部分微生物污染,但仍有相当数量的微生物污染可能排放到自然水体中,成为下游环境如土壤等中的微生物污染源,进而影响人类健康.

Microbial contamination,including pathogenic bacteria,fungi,viruses and parasites,can cause a variety of infectious and parasitic diseases,threatening environmental safety and human health.In this study,a TaqMan-based high-throughput qPCR approach,which could simultaneously quantify 33 human pathogens and 10 different sources of fecal pollution,was applied to investigate the microbial contamination in the influent and effluent of wastewater treatment plants(WWTPs)and the long-term fertilizer-applied soils(sludge,chicken manure,and chemical fertilizers).The results showed that the number and abundance of microbial contaminations in WWTP samples were higher,and the soil microbial pollution was less.A total of 13 human pathogens were detected in WWTPs,and influent harbored higher number of and more abundant pathogens than those in effluent.Klebsiella pneumoniae and enteropathogenic Escherichia coli were the dominant pathogens in WWTPs.The fecal pollutions from human,pig and dog were the main source of microbial contaminations in WWTPs.Soils were detected with three pathogens,of which Legionella spp.and Acanthamoeba spp.were predominant.The application of organic fertilizers(sewage sludge or chicken manure)significantly increased the abundance of pathogens.Livestock manure was the main pollution source of these fertilized soils.These data suggested that there is still a considerable amount of microbial contaminants in the effluent of WWTPs,despite sewage treatment facilities could remove a majority of microbial pollution in the sewage.These persistent microbial contaminants can serve as potential pollution source for the downstream environments,posing a potential health risk.