Distribution Of Antibiotic Resistance Genes In Water Environment Of Typical Areas, Xinjiang

This study chose the surface water samples in typical water environments of Xinjiang (lake, river andwastewater treatment plant) as the research object to detect the pollution of antibiotic resistant bacteria andantibiotic resistance genes (ARGs), and to discuss the differences of distribution of ARGs in variousaquatic environments. The resuts showed the pollution status and distributed regularity of ARGs pollutionin study area, which could provide scientific basis for conducting the investigation of ARGs pollution inXinjiang and the control management of local water pollution.(1) Surface water samples were collected from representative lakes, rivers, and the wastewatertreatment plant of local city in northern and southern Xinjiang, of which three kinds of antibiotic resistantbacteria and seven corresponding ARGs were studied. We analyzed the drug-resistance of resistant bacteriascreened from the water samples by the heterotrophic plate count (HPC) method. Genomic DNA of watersamples was extracted successfully, and amplified the target genes by PCR method. Then we evaluated theconcentrations of ARGs in various water environments by fluorescence quantitative PCR.(2) The results showed that antibiotic resistant bacteria widely presented in study areas, and thedetection rates of three types of antibiotic resistant bacteria were100%. The concentrations of three classesantibiotic resistant bacteria in water environments were tetracycline resistant bacteria (101.94~1012.27CFU/mL), sulfonamide resistant bacteria (103.47~1012.30CFU/mL) and macrolide resistant bacteria(101.91~1010.9CFU/mL). There were great differences on the distribution of three antibiotic resistantbacteria in water samples, especially the wastewater treatment plant that has been seriously polluted.(3) The results of fluorescence quantitative PCR showed that antibiotic resistance genes have beenwidely spread in water environment. Except for the ermA gene, all other ARGs (sul1, sul2, tetM, tetW,tetO and ermB) were obtained in almost all samples. For natural water samples (lake and river), the ARGswere quantified and the overall trend of ARGs relative abundance was sulfonamide ARGs> macrolideARGs> tetracycline ARGs. There were significant differences on the distribution of ARGs in differentwater environments, especially in Bosten Lake, Manas River and Manas Lake, which had relatively highabundances of ARGs. Therefore, it was indicated that these water environments have been polluted byARGs contamination. Absolute quantification results showed that tetracycline ARGs (tetM) concentrationwas the highest as much as2.88×106copy/μL in raw wastewater samples. In addition, the studydiscovered that final effluents had high levels of ARGs, which were at least10-fold higher than that in rawwastewater samples. Once the final effluents discharged into the environment, there would produce adverseeffect to surrounding ecosystems.In conclusion, studies have shown that antibiotic resistant bacteria and resistance genes have existingin typical water environment in Xinjiang area. Therefore, it is very necessary to take measures to controlthe pollution of ARGs and prevent the abuse of antibiotics.