| Live poultry area of wetmarket is one of the few remaining area of cross-infection to humans and animals. Bodies and faeces of live poultry usually carry a lot of pathogens and antibiotic resistance genes which may enter the human respiratory system through the air to cause infection of surrounding residents. There is a big health risk. At present, researches on aerosols community characteristics and antibiotic resistance genes(Antibiotic Resistance Genes, ARGs) pollution of wetmarket is relatively few. Assessment of pathogens and antibiotic resistance genes pollution extent of wetmarket is the premise to control the risk of contamination of the the wetmarket.In this study, the typical urban wetmarket at the community level was taken as the research subjects. The culture-dependent method was used to quickly detect and evaluate wetmarket microbial aerosol concentration and size distribution of bacteria. A suitable microbial aerosol sampling methods for community characteristics and ARGs was established based on the concentration of bacteria. Microbial community structure, pathogen sources and antibiotic resistance genes pollution characteristics of the wetmarket and the surrounding aerosol were also studied.The results showed that the live poultry area of wet market was very seriously polluted. Bacterial concentration in the market is two orders of magnitude higher than the outdoor. The farther the distance between sampling point and live poultry area, the lower the bacterial aerosol concentrations. The general area of wet market is serious polluted with PM2.5 accounted for around 44.2% while 10 m to market entrance is slightly polluted and 100 m and 400 m from the market is clean.Based on the environmental concentration of bacteria, smart large flow TSP samplers(1.05 m3/min)was used to established a aerosol sampling methods which can meet the requirements of air microbial diversity and antibiotic resistance genes in microbial analysis. After the collection of aerosol by glass fiber membranes, pretreatment and kit extraction method were used to efficiently recycled air microbial DNA information to meet the needs of the subsequent analysis.Major bacterial groups of wetmarket microbial aerosols were Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Cyanobacteria and Deinococcus-Thermus. Flora structure of aerosol samples is similar to the live poultry area faeces. Dominant pathogen of live poultry area aerosol are Corynebacterium, Escherichia coli, Staphylococcus epidermidis and Enterococcus faecalis. Pathogens mainly came from live birds faeces. With increasing distance from and live poultry area, number of pathogens is showing a significant reduction phenomenon.Different media of wetmarket has a serious pollution of antibiotic resistance genes Four kinds of antibiotic resistance genes were highly detected in, feces, dust of ground and soles, rinse water and aquaculture water of wetmarket, which were more than 90%. The content order of samples of different wetmarket media in the four resistance gene is tet G> sul2> erm C> tet C. The distribution of aerosol antibiotic resistance gene content of wet market within the general area and the surrounding environment were hightly affected by aerosols of live poutry district.The most polluted area is live poultry. With the distance being farther, descending trend is observed.Live poultry district of wetmarket is a repository of potential pathogenic bacteria and antibiotic resistance genes. Pathogen pollution control is more efficient started from feces and rinse water. At the same time, disinfection can effectively control the pathogen content. The main sources of pollution have been controlled by way of wastewater and solid waste treatment. The air transmission and the potential risk of infection have long been neglected. So the impact on the surrounding residents is more direct and lasting. It is thus recommended to gradually control and reduce the size of live poultry trade in urban area. |
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