城市社区农贸市场空气微生物及抗生素抗性基因研究

社区农贸市场活禽交易区是城市重要的人畜交叉感染区域,区内高存量的微生物和抗生素抗性基因(antibiotic resistance genes,ARGs)可通过粪便、冲洗水、空气等介质传播扩散。而空气介质中通过微生物气溶胶形式的传播途径,因其隐秘性、持久性的特点而对社区居民健康构成严重威胁。本文研究了深圳市某典型社区农贸市场内空气微生物及抗生素抗性基因。结果表明,活禽交易区可培养细菌浓度高达105CFU·m-3,远高于一般室内区域(103CFU·m-3),其中PM2.5精细颗粒物(0.65~3.3μm)中所含菌量占总菌量42%以上;活禽交易区空气介质中,抗生素抗性基因tet G、tet W、sul1和sul2检出率达70%以上,其绝对浓度在10~4~10~9copies·m-3之间;周边环境空气样品中,随着与活禽交易区距离的增加,空气微生物及抗生素抗性基因含量呈显著下降趋势。结果表明,农贸市场活禽交易区是微生物和抗生素抗性基因的一个重要储存库,活禽交易区空气会严重影响农贸市场及其外周边空气质量。

Investigation on Airborne Bacteria and Antibiotic Resistance Genes in Urban Community Farmers Market

The live poultry trading zones in urban community farmers markets are important across-infection areas between human and animals, where large amounts of bacteria and antibiotics resistance genes (ARGs) can be spread by manure, rinse water and air. The dissemination through the microbial aerosol in air, due to the characteristics of concealment and persistence, poses a serious threat to public health. This paper studies the bacteria and ARGs in the ambient air of a typical urban community farmers market in Shenzhen. The results show that the concentration of culturable bacteria is up to 10⁵ CFU·m^-3 in the live poultry trading zone, which is much higher than that found in general indoor area (10³ CFU·m^-3). The bacteria content in PM_2.5 account for above 42% of the total bacteria content. The positive detection rates of ARGs including tetG, tetW, sul1 and sul2 in the air of the live poultry trading zone are above 70% and the absolute ARGs concentrations range from 10⁴ to 10⁹ copies·m^-3. The concentrations of airborne bacteria and ARGs in ambient air decrease significantly with the increase in distance from the live poultry trading zone, suggesting that the live poultry trading zone in urban community farmers market is an important reservoir for the bacteria and ARGs, which affects the air quality of the market and its surroundings seriously.