The Distribution Characteristics And Potential Risk Of Tetracyclines,Sulfonamides And Their Corresponding Genes Pollution In Sediment Of Hongze Lake

In recent years,antibiotics are widely used for the prevention and treatment of human diseases,animal husbandry and aquaculture industry is often used as animal growth promoters.But the antibiotics into the body after the body cannot be completely absorbed,most of the original drug or metabolite is still in the form of excreted into the environment.As antibiotic production and use increase,antibiotic-resistant strains and antibiotic resistance genes(ARGs)are introduced into the environment,and these substances are able to remain in the environment medium for a long time,threatening human health and ecological balance.Hongze Lake is the fourth largest freshwater lake in China.It is also the largest plain reservoir with comprehensive functions of flood control,irrigation,water transfer,aquatic products and water transportation.It is an important production base of fishery and livestock products.Has become an important vector of antibiotics and resistance gene contamination,the region's residents live,produce an impact.The distribution and content of typical tetracycline,sulfonamides and resistance genes in the sediments of Hongze Lake area are helpful to reveal the distribution and transmission of antibiotics and resistance genes in lake sediments environment.Ecological risk theory and data support.In this study,42 samples of typical sediments in Hongze Lake area were collected and the contents of tetracycline and oxytetracycline in the samples were determined by HPLC-MS and two kinds of sulfonamides(sulfadiazine,sulfamethazine)and two sulfonamides resistance genes(sul1,sul2)in the samples were analyzed by qPCR.The contents of the tetracycline resistance genes(fetA,tetC,tetM).Finally,the distribution of organic matter and other environmental factors were discussed,and its distribution and related influencing mechanisms were explored.The results could provide basis for further evaluation of ecological risk and pollution control of antibiotics and resistance genes in lake sediments.Research indicates as follow:First,the detection rate of two tetracycline antibiotics(tetracycline,oxytetracycline)and two sulfonamides(sulfadiazine,sulfadimidine)in the sediments of Hongze Lake were 100%.The content of tetracycline antibiotics ranged from 1.35 ?g·kg-1 to 25.43 ?g·kg-1,and the range of antibiotics was 0.18 ?g·kg-1 to 18.10 ?g·kg-1.The average tetracycline antibiotics were 5.57 ?g·kg-1 and 3.69 ?g·kg-1 for sulfonamides.Second,the detection rate of tetA,tetC,sull and sul2 genes in sediment samples was 100%,and the detection rate of tetM gene was 92.85%.The results showed that tetracycline resistance gene content was close to that of sulfonamides resistance gene at the level of 106copies g-1,but tetracycline resistance gene content showed tetC>tetA>tetM.Third,the content of tetracycline resistance gene in the sample was positively correlated with the product of tetracycline antibiotics and organic carbon(R2 = 0.6694,n =42).The content of tetracycline resistance in the samples was significantly higher than that in the control group(R2 = 0.7098,n = 42).The results showed that there was a significant positive correlation between the content of sulfonamide antibiotics and organic carbon.This indicates that the level of antibiotic resistance genes in Hongze Lake waters may be related not only to the level of exposure to antibiotics in the environment but also to the environmental factors such as organic matter content.In summary,the pollution of tetracycline,sulfonamides and their resistance genes in Hongze Lake sediments already existed,and the level of sediments was similar to other rivers and lakes in China.But also shows the content of antibiotics and organic carbon content and the content of resistance genes are related,can be further explored.