Zhang Chong-Miao, Du Cong, Xu Huan, Miao Yan-Hui, Cheng Yan-Yan, Tang Hao, Zhou Jin-Hong, Wang Xiao-Chang
a Key Lab of Northwest Water Resource , Environment and Ecology, MOE, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology , Xi'an , China.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2015;50(7):744-9. doi: 10.1080/10934529.2015.1011995.
Antibiotic resistance of fecal coliforms in an urban river poses great threats to both human health and the environment. To investigate the occurrence and distribution of antibiotic resistant bacteria in an urban river, water samples were collected from the Chanhe River in Xi'an, China. After membrane filtration of water samples, the tetracycline resistance rate of fecal coliforms and their resistance genes were detected by plating and polymerase chain reaction (PCR), respectively. We found that fecal coliforms were generally resistant to tetracycline and saw average resistance rates of 44.7%. The genes tetA and tetB were widely detected, and their positive rate was 60%-100% and 40%-90%, respectively. We found few strains containing tetC, tetK, tetQ and tetX, and we did not identify any strains containing tetG, tetM or tetO. The prevalence of tetA and tetB over other genes indicated that the main mechanism for resistance to tetracycline is by changes to the efflux pump. Our analysis of the types and proportion of tetracycline resistance genes in the Chanhe River at locations upstream and downstream of the urban center suggests that the increased number of tetracycline-resistant fecal coliforms and spatial variation of tetracycline resistance genes diversity were related to municipal wastewater treatment plant discharge.
城市河流中粪大肠菌群的抗生素抗性对人类健康和环境都构成了巨大威胁。为了调查城市河流中抗生素抗性细菌的发生和分布情况，从中国西安的浐河采集了水样。对水样进行膜过滤后，分别通过平板接种和聚合酶链反应（PCR）检测粪大肠菌群的四环素抗性率及其抗性基因。我们发现粪大肠菌群普遍对四环素具有抗性，平均抗性率为44.7%。广泛检测到tetA和tetB基因，其阳性率分别为60%-100%和40%-90%。我们发现含有tetC、tetK、tetQ和tetX的菌株很少，并且未鉴定出任何含有tetG、tetM或tetO的菌株。tetA和tetB相对于其他基因的流行表明，对四环素抗性的主要机制是通过外排泵的变化。我们对城市中心上游和下游位置的浐河四环素抗性基因类型和比例的分析表明，四环素抗性粪大肠菌群数量的增加和四环素抗性基因多样性的空间变化与城市污水处理厂排放有关。
