The Abundance Of Pathogenic Genes And Influencing Factors Of Pathogenic Bacteria In Water Of Digou Coal Mining Subsidence Area

Water body pollution not only influences water quality and accelerates eutrophication but also affects the variety and quantity of microorganism.Furthermore,discharge of pollutants also introduced human enteric pathogens into water body,which threatens human health.In this research,with the Digou coal mining subsidence of Fuyang,Anhui as an example and Hefei drinking water source Dongpu Reservoir as a reference system,the difference and influencing factors of spatial distribution concerning abundance of five pathogenic genes of human enteric pathogens（eae gene of O157:H7 Escherichia coli,ttr gene of Salmonella enteritidis,ipa H gene of Shigella,div IVA gene of Enterococcus faecalis and ail gene of Yersinia enterocolitica）in overlying water and sediment were researched through single factor variance analysis,RDA analysis,Arcgis and other analysis methods using q PCR（fluorescent quantitation PCR）technology based on analysis of water body quality for comprehensive discussion of suitability of waters in Digou coal mining subsidence to serve as drinking water source.The relevant research results are as follows:（1）The analysis result of physical and chemical property of water body in coal mining subsidence suggested:most of the water body was Class IV and V water.Where,the overlying water was alkalescent（p H 7.70～8.16）with high content of nitrogen and phosphorus:the content of ammonia nitrogen（NH₃-N）and nitrate nitrogen（NO₃-N）was 0.15～3.34 mg/L and 0.33～2.18 mg/L respectively;the total nitrogen（TN）content and total phosphorus（TP）content were 1.40～6.18 mg/L and0.11～1.57 mg/L respectively;the content of dissolved oxygen and COD_Mnwas5.25～11.23 mg/L and 3.61～14.13 mg/L respectively;the content of NO₃-N,NH₃-N,TN,TP and potassium permanganate index were 3.17,5.94,5.57,5.58 and 1.52 times respectively than those in the contrast area.The sediment was alkalescent（p H7.35～8.42）.The content of NH₃-N and NO₃-N was 16.14～120.05 mg/L and14.54～120.23 mg/L respectively;the TN content and TP content were150.49～2847.49 mg/L and 329.71～4557.42 mg/L respectively;the content of As,Zn and Cu（with maximum value of 35.23 mg/L,500.16 mg/L and 83.49 mg/L respectively）was significantly higher than those in Dongpu Reservoir.（2）The relative abundance of five pathogenic genes demonstrated significant spatial difference with consistency of spatial distribution in overlying water and sediment;in overlying water,the relative abundance of pathogenic genes was0.09×10^-4～9.83×10^-4and the genes with maximum and minimum relative abundance were ipa H gene and ail gene respectively.As to the three major polluted areas,their ranking was domestic sewage area>coal gangue polluted area>aquaculture waste water area in terms of the extent to which they were influenced by eae gene;and aquaculture waste water area>domestic sewage area>coal gangue polluted area in terms of the extent to which they were influenced by ttr,ipa H,ail and div IVA genes.With regard to sediment,the relative abundance of pathogenic genes was0.39×10^-4～80.09×10^-4and the genes with maximum and minimum relative abundance were eae and ipa H genes respectively.As to the three major polluted areas,their ranking was domestic sewage area>aquaculture waste water area>coal gangue polluted area in terms of the extent to which they were influenced by eae gene;and aquaculture waste water area>domestic sewage area>coal gangue polluted area in terms of the extent to which they were influenced by ipa H gene.The aquaculture waste water area was mostly influenced by ttr,div IVA and ail genes while the domestic sewage area and coal gangue polluted area were least influenced without significant difference.The relative abundance of five pathogenic genes of human enteric pathogens in sediment was higher than that in overlying water.However,the area polluted by enteric pathogens in sediment was smaller than that in overlying water.Compared with Dongpu Reservoir,the abundance of pathogenic genes in waters in Digou coal mining subsidence were significantly higher.（3）The TN and dissolved oxygen content in overlying water and the TP and Zn content in sediment had significant influence on relative abundance of eae gene and div IVA gene respectively in overlying water.The COD and dissolved oxygen content in overlying water had significant influence on relative abundance of eae gent in sediment.The TN content in sediment had significant influence on relative abundance of ipa H gene therein.The Zn content had significant influence on relative abundance of div IVA and ail genes in sediment.There was a negative correlation between the content of heavy metal element in sediment and the relative abundance of eae gene in water body.However,there was a positive correlation between the content of Cu and Zn and the relative abundance of div IVA and ail genes.To sum up,based on comparison of abundance of five pathogenic genes of human enteric pathogens in as well as physical and chemical property of water bodies in Digou coal mining subsidence and Dongpu Reservoir,the waters in Digou coal mining subsidence was not suitable to serve as drinking water source from the perspective of public health security.The research result may serve as a basis for protection and utilization of water resources in water-deficient areas in North Anhui province.