Study On The Effects Of Disinfection On The Antibiotic Resistance Genes In Water And Its Related Factors

Chlorine disinfection technology is widely used in drinking water and sewage treatment system,studies have found that it may be to a certain extent promoted the spread of ARGs as a new model of environmental pollutants.And it is quite necessary to find the effect of the actual application process of water disinfection on the spread and pollution of antibiotic resistance genes.However,the current research mainly focuses on the level of iARGs,the eARGs pollution is rarely studied and reported.Based on this,using a sewage treatment plant in Tianjin city as a pilot,study was done on iARGs and eARGs in effluent before and after the disinfection of ClO₂.It was designed to clarify the contribution of ClO₂ disinfection on ARGs and ARB diffusion and pollution in water,also clarify the key water quality influencing factors of ARGs in water pollution.The main source of ARGs pollution related microbes was revealed.In addition,the pollution of iARGs and eARGs in drinking water pipe network waterwe was also studied.The main researches were as follows:CN-CA membrane and self-made nucleic acid adsorption column were used to enrich antibiotic resistance bacteria and eARGs separately in effluent before and after disinfection.And the type and concentration of ARGs were detected by qPCR.In the financial effluent,22 kinds of iARGs and eARGs were detected?tetA,tetB,tetC,tet M,tetQ,tetX;ermA?1?,ermB;ampC,blaTEM;sul1,sul2,sul3;qnrA,gyrA;aph?2'?-Id,aadA;catA1;rpoB1,kat G;dfrA1?1?;vanA?.iARGs ranged from 10¹ to 10⁸ GC/L,eARGs 0¹0⁶ GC/L.After disinfection,the relative abundance of 16 kinds of iARGs?tetA,sul1,et al?increased,and 6 kinds eARGs?sul3,aph?2'?-Id,vanA,et al?concentration increased.After disinfection,different water quality indexes had different correlation with different resistance genes.The total concentration of eARGs showed significant differences in the number of total coliform group,conductivity and turbidity significantly.The total concentration of iARGs showed significant differences in the total phosphorus and total bacteria significantly.Using high-throughput sequencing analyze the effect of chlorine dioxide disinfection on bacteria community,it was found that Proteobacteria was the advantage bacterium group before and after disinfection.There was a significant difference of Planctomycetes between effluent and disinfected effluent.Distribution of ARGs combined to bacteria community,Spearman and CCA were applied to gain bacteria community related to ARGs.Results showed that there was a significant positive correlation between the relative abundance of 6 species related to antibiotic resistance genes and the specific bacteria in water samples before disinfection.katG,dfrA1?1?,vanA,aadA and Candidatus-Competibacte had a significant positive correlation.Sul1,ermB and Nitrosomonadaceae had a significant positive correlation.qPCR detection of drinking water pipe network water pollution ARGs found that iARGs and eARGs pollution existed widely.In 22 kinds of resistance genes?tetA,sul1,qnrA,et al?,iARGs was all detected,with the concentration in the range of 0¹0⁶GC/L;and 14 kinds eARGs were detected,with the concentration in the range of0¹0⁵ GC/L,involving tetA,sul1,qnrA,blaTEM,and ampC,et al.This article provided a basis for studying the ARGs horizontal transfer mechanism and scientific evaluation of ecological risk from antibiotic resistance genes during the process of disinfection.