宏基因组方法比较分析深海和珠江口沉积物中抗生素耐药基因的特征

Metagemomic analysis on characteristics of antibiotic resistance genes in the deep ocean and Pearl River Estuary sediments

细菌对抗生素的耐药性是全球关注的环境健康问题之一。该研究旨在使用宏基因组方法比较分析西太平洋深海和珠江口沉积物中抗生素耐药基因,认识抗生素使用与环境细菌耐药性间的关系。研究发现,深海沉积物多重耐药基因的含量高达77.8%;珠江口沉积物多重耐药基因只有27.2%,常用抗生素的耐药基因(磺胺类、大环内酯类、氨基糖苷类等)含量明显提高(约70%)。沉积物中共发现45种耐药基因亚型,其中7种基因亚型(acrB、amrB、bacA、ceoB、macB、mexB和smeE)能在所有沉积物中发现。深海沉积物中质粒仅携带0.3%的耐药基因,而珠江口沉积物则超过40%。研究表面,由于珠江口周边区域常用抗生素的广泛使用,其沉积物中细菌抗生素耐药性明显提高、耐药机制趋于多样化。

Antibiotic resistance is one of the most important environmental issues in the world. The relationship between antibiotic use and antibiotic resistance of environmental bacteria were investigated using metagenomic analysis of antibiotic resistance genes（ ARGs） in the sediments collected from the Western Pacific（ WP） and the Pearl River Estuary（ PRE） in this work. The result indicated that multidrug resistance genes（ MRGs） were accounted as 77. 8% of the total ARGs in the WP sediments,and the PRE sediments as 27. 2%. ARGs in the PRE sediments were characterized by increasing abundance of ARGs specific to common antibiotics（ e. g.,sulfonamides,macrolides,aminoglycoside,etc.） and decreasing relative percentage of MRGs. A total of 45 ARG subtypes were identified in the sediments,and thereof 7subtypes,including acr B,amr B,bac A,ceo B,mac B,mex B and sme E,concurrently existed in all sediments. Approximately 0. 3% of ARGs in the WP sediments were potentially carried by the plasmids. Different from the WP,relative percentage of plasmid-carrying ARGs in the PRE sediments was higher than40%. It was suggested that the abundance and diversity of ARGs in the PRE environment were substantially increased probably due to wide use of antibiotics in the nearby regions.