城市污水处理厂四环素抗性菌的筛选及其抗性基因分析

Isolation of tetracycline resistant bacteria and the analysis of its antibiotic resistance genes from municipal wastewater treatment plant

城市污水处理厂中抗生素抗性菌的富集和扩散对受纳水体及公共卫生安全造成严重的威胁.本研究从上海某城市污水处理厂活性污泥中筛选得到一株四环素抗性菌株TC-1,基于形态特征、生理生化特性和16S r DNA结果鉴定,菌株TC-1属于节杆菌属(Arthrobacter sp.).对节杆菌属菌株的全基因组分析表明,菌株TC-1含有多种抗生素抗性基因,包括四环素、氯霉素、大环内酯类和青霉素抗性基因.对比节杆菌属抗生素抗性基因的基因簇分析表明,这些抗性基因在节杆菌属中具有普遍存在性,表明其来源于相关菌株的遗传而非单个菌株的偶然获得.鉴于节杆菌属是潜在的病原性微生物,该结论可为废水生物处理系统中含抗生素抗性基因的致病微生物环境行为和风险评估提供参考.

The accumulation and diffusion of antibiotic resistance bacteria in municipal wastewater treatment plants pose an ever serious threat to water safety and public health. In this work,a tetracycline resistant strain TC-1 was isolated from activated sludge of a municipal wastewater treatment plant. The strain TC-1 was identified as Arthrobacter sp. according to the physiological and biochemical characteristics,and the 16 S rDNA sequence analysis. It was found that multiple antibiotic resistance genes（ ARGs） were present in TC-1,including tetracycline,chloramphenicol,macrolide,and penicillin resistance genes,based on the whole genome annotation of Arthrobacter sp. According to the results of gene cluster analysis,these ARGs were ubiquitous in genus of Arthrobacter,thus suggesting the inherent source instead of accident. Since Arthrobacter sp. is a kind of potentially pathogenic microorganism,these results might be used as reference for assessing the environmental behavior and risk of antibiotic resistance pathogenic bacteria in biological treatment system of water treatment.