迪沟采煤沉陷区水体中人体肠道病原菌致病基因丰度变化及其影响因素

Human Intestinal Pathogenic Bacteria in Waterbody of Digou Coal Mining Subsidence Area Changes in Abundance of Pathogenic Genes and Their Influencing Elements

【目的】水体污染不仅会影响水质,且会对水体中人体肠道病原微生物的种类组成和数量造成影响。【方法】以安徽阜阳迪沟采煤沉陷区为对象,以合肥市饮用水源地董铺水库为参照系。基于qPCR(实时荧光定量PCR,Quantitative Real-time PCR)技术,探究上覆水和沉积物中5种人体肠道病原菌致病基因(0157:H7型大肠杆菌的eae基因、肠炎沙门氏菌的ttr基因、志贺氏菌的ipaH基因、粪肠球菌的divIVA基因和小肠结肠炎耶尔森菌的ail基因)相对丰度的差异,探讨迪沟采煤沉陷区水域作为饮用水源地的合适性。【结果】采煤沉陷区水体中5种致病基因的相对丰度具有显著的空间差异,且在上覆水和沉积物中的空间分布趋势不一致;上覆水中,3个研究区域受eae基因污染的程度依次是生活污水区>煤矸石污染区>养殖废水区,受ttr、ipaH、ail和divIVA基因污染的程度依次是养殖废水区>生活污水区>煤矸石污染区;沉积物中,3个研究区域受eae基因污染的程度依次生活污水区>养殖废水区>煤矸石污染区,受ipaH基因污染的程度依次是养殖废水区>生活污水区>煤矸石污染区,受ttr、divIVA和ail基因污染程度最大的均是养殖废水区,生活污水区和煤矸石污染区受到的影响较小,无明显差异;沉积物中5种人体肠道病原菌致病基因的相对丰度均比上覆水中高;水体中氮和磷的含量与5种致病基因的相对丰度呈正相关,Cu和Zn的含量与divIVA和ail基因的相对丰度呈正相关;与董铺水库相比,迪沟采煤沉陷区水域中致病基因的相对丰度显著高于前者。【结论】基于研究区和对照区水体中致病基因相对丰度及理化性质的比较,从公共卫生安全的角度考虑,迪沟采煤沉陷区水域不适合作为饮用水源地。研究结果可为皖北缺水地区的水资源保护和利用提供科学依据。

【Objective】Water pollution not only affected water quality,but also affected the composition and quantity of human intestinal pathogenic microorganisms in the water.【Method】In this study,the coal mining subsidence area in Digou,Fuyang,Anhui province was taken as the object,and the Dongpu reservoir,the source of drinking water in Hefei city,was used as the reference system.Based on qPCR(Quantitative Real-time PCR)technology,the difference in the relative abundance of the pathogenic genes of five human intestinal pathogens in the overlying water and sediments(eae gene of Escherichia coli O157:H7,ttr gene of Salmonella,ipaH gene of Shigella,divIVA gene of Enterococcus faecalis,and ail gene of Yersinia)were analyzed.【Result】The relative abundance of the five pathogenic genes in the water body of the coal mining subsidence area had significant spatial differences,and the spatial distribution trends in the overlying water and sediments were inconsistent.In the overlying water,the degree of contamination by eae gene in the three study areas was in the order of domestic sewage area>coal gangue pollution area>farming wastewater area,and the degree of pollution by ttr,ipaH,ail and divIVA genes was in order of farming wastewater area>domestic sewage area>coal gangue pollution area.In the sediment,the degree of eae gene pollution in the three study areas was in the order of domestic sewage area>farming wastewater area>coal gangue pollution area,the order of the degree of pollution by ipaH gene was farming waste water area>domestic sewage area>coal gangue pollution area,the most polluted by ttr,divIVA and ail genes was the farming wastewater area,the domestic sewage area and the coal gangue polluted area were less affected and there was no significant difference.The sediment in the study area was contaminated by pathogenic bacteria more serious than the overlying water.The content of total nitrogen and total phosphorus in the overlying water and sediments and the content of Zn in the sediments are positively correlated with the relative abundance of pathogenic genes of human intestinal pathogens.Compared with Dongpu reservoir,the relative abundance of pathogenic genes in the waters of Digou coal mining subsidence area is significantly higher than the former.【Conclusion】Based on the comparisons of the relative abundance and physical and chemical properties of pathogenic genes in the study area and the control area,from the perspective of public health and safety,the waters of the Digou coal mining subsidence area are not suitable for drinking water sources.The research results can provide a scientific basis for the protection and utilization of water resources in water-deficient areas in northern Anhui.