Analysis Of Temporal And Spatial Evolution Laws Of River Resistance Genes And Flora Characteristics Propagation

The transmission problem of antibiotic resistance genes?ARGs?in aquatic ecosystems has drawn more and more attention worldwide.In recent years,both of the production of antibiotic and the demands towards antibiotic are huge especially in medical industry and breeding industry.Vestigial antibiotic in the environment would exert immense influences upon primary bacterial community.In this study,urban contaminated rivers and sewage treatment plants were selected as research objects.Moreover,real-time quantitative PCR and 16 S rRNA gene sequencing technology were adopted in this study to detect the antibiotic resistance genes of tetA,tetB,sul1 and sul2,and to study the rivers in cities.In addition,the Antibiotic Resistance Genes in urban rive and the seasonal changes of microbial community will be researched.The analysis of structural features of Antibiotic Resistance Genes and microbial community will be given and the internal relations of flora structures will be proved,thereby providing basic data basis for ARGs pollution control and water quality safety guarantee in the river.The research results are as follows:1)Four antibiotic resistance genes were detected in spring rivers,and the abundances of sulfonamide resistance genes sul1 and sul2 were generally higher than those of tetracycline resistance genes tetA and tetB,and the sul1 resistance gene was the most abundant.After treatment with water from sewage treatment plants,the abundance of four antibiotic resistance genes increased.The transmission of resistance genes is only related to a specific flora.Dechloromonas and Clostridium sensu stricto 1 are the main factors affecting the abundance of sul1,sul2 and tetB resistance genes,Methylotenera are affecting sul1,sul2 and tetA resistance.The main factor in the abundance of gene distribution.Moreover,the genetic relationship between tetA and tetB is far from the difference,and the genus of the affected species is quite different.2)Four resistance genes in the summer river were detected in each sampling point of the river.Sulfonamide resistance gene abundance is two orders of magnitude higher than tetracycline.The abundance of tetB and sul2 resistance genes tends to be stable in rivers.Macellibacteroides and Simplicispira are the main factors affecting the abundance of tetA resistance genes.Desulfatitalea,Syner-01,Halomonas and Candidatus_Methanofastidiosum are the main factors affecting the abundance of tetB resistance genes,Candidatus_Berkelbacteria_bacterium_Rifoxya2_Full₄3₁0,Youngiibacter,Luteolibacter and ML602J-51 genus is the main factor affecting the distribution abundance of sul1 resistance gene,and Methylotenera genus is the main factor affecting the distribution abundance of sul2 resistance gene.3)Four antibiotic resistance genes in the autumn river were detected in both the sewage treatment plant and the receiving river.The abundance of sulfonamide resistance genes is one order of magnitude higher than that of tetracyclines and the abundance of sul2 resistance genes is significantly higher than that of other resistance genes.After treatment with water from sewage treatment plants,the abundance of four antibiotic resistance genes increased.Christensenellaceae_R-7_group and JGI-0000079-D21 are the main factors affecting the abundance of sul1 and sul2 resistance genes.The f_<sub>TC1_Unclassified genus is the main factor affecting the abundance of tetA resistance gene.CI75 cm.2.12 genus is the main factor affecting the distribution abundance of tetB resistance gene.4)Four resistance genes were detected in winter rivers.The abundance of resistance genes in surface waters of winter rivers is two orders of magnitude higher than that in sediments.The abundance of sulfonamide resistance genes is one order of magnitude higher than that of tetracyclines.The abundance of sul2 resistance genes is significantly higher than that of other resistance genes.River surface water is slightly different from the dominant flora in sediments.The resistance gene has a greater impact on the sample and the correlation between the microbial community and the resistance gene is greater.tetB has the greatest impact on the sample and temperature has the least impact on the sample.It was found that the four resistance genes studied were positively correlated with the surface water samples of the river.Only sul1 was positively correlated with WS1 and QS1,and the others were negatively correlated.The spread of resistance genes is only related to a specific flora.Most of the genus are the main factors affecting the abundance of the four resistance genes,and there are more bacteria affecting the tetracycline resistance genes.Only a few species are associated with routine water quality indicators.5)The tetA,tetB,sul1 and sul2 resistance genes were detected in a one-year river surface water and sediment monitoring.Most of the four resistance genes were the most abundant in autumn.The abundance of resistance genes in surface waters of winter rivers was two orders of magnitude higher than that in sediments.The abundance of resistance genes in surface waters in other seasons and the abundance of resistance genes in sediments did not show obvious regularity.The abundance of sulfonamide resistance genes is two orders of magnitude higher than the abundance of tetracycline resistance genes.The type of bacteria in the winter river is the most abundant,while the dominant bacteria account for the smallest proportion.The abundance of Proteobacteria in river sediments is higher than that in river surface waters.The dominant flora in the river varies slightly with the seasons,but the Proteobacteria have always been the dominant bacteria in the river.