Effect of ultraviolet irradiation and chlorination on ampicillin-resistant Escherichia coli and its ampicillin resistance gene  

作　　者：Yuchen PANG Jingjing HUANG Jinying XI Hongying HU Yun ZHU 

机构地区：[1]Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing 100084, China [2]State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China [3]China Power Engineering Consulting Group Corporation, Beijing 100120, China [4]Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China [5]School of Life Sciences, Tsinghua University, Beijing 100084, China

出　　处：《Frontiers of Environmental Science & Engineering》2016年第3期522-530,共9页环境科学与工程前沿（英文）

基　　金：The author thanks the National Natural Science Foundation of China （Key Project, Grant No. 51138006） and State Key Joint Laboratory of Environment Simulation and Pollution Control （Project, No. 13L01ESPC） for financial support. The research is also supported by the Collaborative Innovation Center for Regional Environmental Quality.

摘　　要：Antibiotic resistance is a serious public health risk that may spread via potable and reclaimed water. Effective disinfection is important for inactivation of antibiotic-resistant bacteria and disruption of antibiotic resistance genes. Ampicillin is a widely prescribed antibiotic but its effectiveness is increasingly undermined by resistance. In this study, changes in ampicillin resistance for Escherichia coli （E. coli） CGMCC 1.1595 were analyzed after exposure to different doses of ultraviolet （UV） or chlorine, and damage incurred by the plasmid encoding ampicillin resistance gene blaTEM-1 was assessed. We reported a greater stability in ampicillinresistant E. coli CGMCC 1.1595 after UV irradiation or chlorination when compared with previously published data for other E. coli strains. UV irradiation and chlorination led to a shift in the mortality frequency distributions of ampicillin-resistant E. coli when subse-quently exposed to ampicillin. The ampicillin hemiinhibitory concentration （IC5o） without disinfection was 3800mg·L^-1, and an increment was observed after UV irradiation or chlorination. The IC50 of ampicillin-resistant E. coli was 1.5-fold higher at a UV dose of 40 mJ·cm^-2, and was 1.4-fold higher when exposed to 2.0 mg·L^-1 chlorine. These results indicate that UV irradiation and chlorination can potentially increase the risk of selection for E. coli strains with high ampicillin resistance. There was no evident damage to blaTEM-1 after 1-10 mg Cl2· L^-1 chlorination, while a UV dose of 80 mJ·cm^-2 yielded a damage ratio for blaTEM-1 of approximately 1.2-log.Therefore, high UV doses are required for effective disruption of antibiotic resistance genes in bacteria.Antibiotic resistance is a serious public health risk that may spread via potable and reclaimed water. Effective disinfection is important for inactivation of antibiotic-resistant bacteria and disruption of antibiotic resistance genes. Ampicillin is a widely prescribed antibiotic but its effectiveness is increasingly undermined by resistance. In this study, changes in ampicillin resistance for Escherichia coli （E. coli） CGMCC 1.1595 were analyzed after exposure to different doses of ultraviolet （UV） or chlorine, and damage incurred by the plasmid encoding ampicillin resistance gene blaTEM-1 was assessed. We reported a greater stability in ampicillinresistant E. coli CGMCC 1.1595 after UV irradiation or chlorination when compared with previously published data for other E. coli strains. UV irradiation and chlorination led to a shift in the mortality frequency distributions of ampicillin-resistant E. coli when subse-quently exposed to ampicillin. The ampicillin hemiinhibitory concentration （IC5o） without disinfection was 3800mg·L^-1, and an increment was observed after UV irradiation or chlorination. The IC50 of ampicillin-resistant E. coli was 1.5-fold higher at a UV dose of 40 mJ·cm^-2, and was 1.4-fold higher when exposed to 2.0 mg·L^-1 chlorine. These results indicate that UV irradiation and chlorination can potentially increase the risk of selection for E. coli strains with high ampicillin resistance. There was no evident damage to blaTEM-1 after 1-10 mg Cl2· L^-1 chlorination, while a UV dose of 80 mJ·cm^-2 yielded a damage ratio for blaTEM-1 of approximately 1.2-log.Therefore, high UV doses are required for effective disruption of antibiotic resistance genes in bacteria.

关 键 词：antibiotic resistance Escherichia coli ampicillin resistance gene ultraviolet irradiation CHLORINATION 

分 类 号：S852.63[农业科学—基础兽医学] TS103.823[农业科学—兽医学]