| As a new environmental pollutant,antibiotic resistance genes poses a potential threat to public health.In particular,multiple resistant pathogens induced by excessive use of antiobiotics,which seriously affect the clinical treatment.At present,a large number of antibiotic resistance genes have been detected in water and soil environment,but the occurrence and spread of antibiotic resistance genes in atmospheric environment have not aroused widespread attention.antibiotic resistance genes can be assigned to the high mobility of antibiotic resistance bacteria to cross regional transmission through the atmospheric environment.As an important part of atmospheric,the physical and chemical properties of PM2.5 have been studied,but its ability to carry antibiotic resistance genes remain unclear.In this paper,investigates the source,spread and fate of antibiotic resistance genes and antibiotic resistance bacteria loaded by PM2.5 in the atmospheric environment of Handan.Firstly,the PM2.5 from four different areas in Handan city were collected in winter of 2017 to quantify the level of antibiotic resistance genes in the atmospheric environment.The results showed that distribution of resistance genes has obvious characteristics of urban functional areas.Among them,the resistance pollution of sewage treatment plant is the most serious,and the abundance of resistance genes in different places in the school is obvious,and the overall level of resistance pollution in parks is low.In addition,the potential health risks caused by resistance genes in different functional areas were evaluated,and the overall exposure dose of resistance genes in sewage treatment plant was higher and the quinolone in various environments was the highest.Furthermore,the study investigated the variation of antibiotic resistance genes abundance during the haze from 2013 to 2016 and two seasons of 2017 and analyzed the air mass backward trajectory in two seasons of 2017 by HYSPLIT software,the results were statistically analyzed by the Potential Source Contribution Function（PSCF）and the Concentration Weighted Trajectory（CWT）.The results showed that there was a strong correlation between the distribution characteristics of antibiotic resistance genes in the air and the degree of air pollution,when the pollution is serious,the microbial community have significant changes,and the concentration of antibiotic resistance genes will generally increase,and the characteristics of high concentration in winter and low level in summer in different seasons.In the winter,the high concentration of PM2.5from North China provides the nutrients needed for microbial growth.Clean marine air mass dominated the atmosphere of sampling sites in summer.Potential pollution sources contributed less to the sampling sites.The abundance of antibiotic resistance genes maintained a low level in summer.In the analysis of antibiotic resistance bacteria,138 strains of bacteria were isolated.According to the 16S r DNA sequencing results,all the isolated bacteria belonged to 10 genera.Among them,Bacillus accounted for the highest proportion and was the dominant genus.Through the analysis of multiple resistance of drug-resistant pathogens,it was found that the isolated pathogens were resistant to at least five antibiotics.In this paper,the distribution characteristics and spread mechanism of PM2.5resistance genes and resistant bacteria in different functional areas of Handan city from2013 to 2017.The potential exposure amount and source of resistance genes in the air of different functional areas were explored.The results of this paper have certain application value and reference significance for the comprehensive understanding of the long-distance cross regional transmission characteristics and fate of antibiotic resistance genes in atmospheric environment. |
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