Pollution Characteristics Of Antibiotics And Antibiotic Resistance Genes In Urban Water Environment

In recent years,the widespread use of antibiotics has promoted the production of resistant bacteria and resistance genes.Antibiotics,resistant bacteria and resistance genes enter the water environment through various channels,and migrate and spread between different media and different species,posing a threat to the ecological environment and human health.Therefore,the environmental behavior of antibiotics,resistant bacteria and resistance genes is receiving more and more attention.The high performance liquid chromatography,plate counting method and real-time PCR method were used to quantitatively analyze 10 antibiotics,4 resistant bacteria and resistance genes to analyze the pollution characteristics of the Fuyang River and the Qin River in different seasons.The main results are as follows:In the aqueous phase,there were 6 target antibiotics detected in the Fuyang River in August,including sulfonamides and quinolones.The average concentration of the two categories of antibiotics were 218.5 ng/L and 149.17 ng/L.There were 6 target antibiotics detected in Qin River and the detected categories were the same as that of Fuyang River.The average content of sulfonamides and quinolones was 174.99ng/L and 142.21ng/L,respectively.In December,there were 8 target antibiotics detected in Fuyang River,including sulfonamides,quinolones and?-lactam antibiotics.The average concentration of the three antibiotics were 353.66 ng/L,248.58 ng/L and 33.21 ng/L,respectively.There were 7 target antibiotics detected in Qin River and the detection categories were the same as that of Fuyang River.The average contents of sulfonamides,quinolones and?-lactam antibiotics were 288.82 ng/L,210.41 ng/L and 30.23 ng/L,respectively..In the sediments,there were 6 target antibiotics detected in the Fuyang River in August,including sulfonamides and quinolones.The average concentration of the two antibiotics were34.39 ng/g and 55.31 ng/g.Five antibiotics were detected in Qin River,and the average levels of sulfonamides and quinolones were 25.34 ng/g and 36.3 ng/g,respectively.In December,there were 8 target antibiotics detected in Fuyang River,including sulfonamides and quinolones.The average concentration of the two types of antibiotics were 43.66 ng/g and 75.05 ng/g,respectively.There were 7 target antibiotics detected in Qin River,and the average concentration of sulfonamides and quinolones were 33.69 ng/g and 42.63 ng/g,respectively.Four resistant bacterias were detected in different periods of the two rivers.In the aqueous phase,the number of colonies of four categories of resistant bacteria in Fuyang River in August ranged from 5.6×10~2 CFU/mL to 4.77×10~3 CFU/mL,and the number of colonies of Qin River 4 resistant bacteria ranged from 1.11×10~2 CFU/mL.~3.58×10~3CFU/mL,the number of colonies of four categories of resistant bacteria in Fuyang River in December ranged from 1.10×10~2 CFU/mL to 1.44×10~3 CFU/mL.The number of colonies of the four types of resistance bacteria in Qin River ranged from 1.11×10~2CFU/mL to 3.58×10~3 CFU/mL.In sediments,the number of colonies of four categories of resistant bacteria in Fuyang River in August ranged from 2.2×10~4 CFU/g~9.50×10~4CFU/g,the number of colonies of four categories of resistance bacteria in Qin River ranged from 3.0×10~4 CFU/g to 1.0×10~5 CFU/g.In December,the number of colonies of four types of resistant bacteria in Fuyang River was 1.70×10~4 CFU/g~6×10~4 CFU/g.The number of colonies of the four categories of resistance bacteria of Qin River ranged from2.10×10~4 CFU/g to 8.0×10~4 CFU/g.The total number of colonies of four resistant bacteria in August was higher than that in December,and the distribution of colony of four resistant bacteria in the two rivers in different periods was generally the highest in the number of colonies of SDZ resistant bacteria and the number of colonies of NOR resistant bacteria lowest.The 15 resistance genes selected in the aqueous phase were detected in different degrees.In August,the dominant genes of the Fuyang River were int I,sul1 and sul2.The average absolute abundance of the three resistance genes was 3.72×10~2 copies/mL~6.56×10~4 copies/mL.The dominant gene of Qin River is the same as that of Fuyang River.The average absolute abundance of the three genes is 2.85×10~2 copies/mL~2.26×10~4copies/mL.In December,the dominant genes of Fuyang River and Qin River are the same as in August.The average absolute abundance of the three genes in Fuyang River ranged from 6.71×10~1 copies/mL to 6.75×10~3 copies/mL,and that of Qin River was 1.07×10~2copies/mL~7.47×10~3 copies/mL.In the sediment,the dominant gene is the same as the water phase.In August,the average absolute abundance of the three genes in the Fuyang River ranged from 1.93×107 copies/g to 2.31×108 copies/g,and the Qin River was1.62×10~6 copies/g~5.19×10~7 copies/g.The average absolute abundance of the three resistance genes in Fuyang River in December was 8.27×10~5 copies/g~2.26×10~7 copies/g,and that of Weihe was 1.19×10~5 copies/g~1.75×10~6 copies/g.The distribution of antibiotics in the aqueous phase and sediments of the Fuyang River at different monitoring points in different periods,the distribution of culturable bacteria number is the same,and the distribution of resistance genes is different.The distribution of antibiotics,the distribution of culturable bacteria and the distribution of resistance genes are different of the monitoring points of different periods of the water phase and sediment in the Qin River.It is indicated that antibiotics can greatly affect the distribution of microorganisms and the expression of resistance genes,but it is not the only influencing factor.