紫外线辐照对四环素耐药细菌及基因的消毒特性

采用紫外线辐射处理市政污水,考察紫外消毒对市政污水厂中耐四环素的总异养菌、粪大肠菌群和单一大肠杆菌以及tetA和tetO两种耐药基因的消毒特性。结果表明:随紫外线剂量的提高,对耐四环素总异养菌的杀灭效果显著增强,当消毒剂量为10 m J/cm^2时,灭活率高于99%;紫外线对耐四环素粪大肠菌群和大肠杆菌K12的杀灭趋势和总异养菌类似;耐药基因tetA随消毒剂量的增加而不断降低,在消毒剂量为5 m J/cm^2时已基本被完全灭活;低消毒剂量下(<5m J/cm^2)耐四环素细菌尤其是某些革兰氏阴性耐药细菌,一定程度上对紫外消毒具有耐受性,它们对水体的生态风险需要引起重视。

Disinfection Characteristics of Tetracycline Resistant Bacteria and Genes in Wastewater by UV Radiation

Disinfection characteristics of tetracycline resista nt bacteria including heterotrophic bacteria , fecal coliform, Escherichia coli K12 , and genes including tetA and tetO were investigated . The results showed that the disinfection effect of tetracycline resistant heterotrophic bacteria increased significantly with the increase of UV dose, and the removal rate exceeded 99% when the disinfection dose was 10 mJ/cm^2. The disinfection characteristics of fecal coliform and Escherichia coli K12 were similar to that of the heterotrophic bacteria. tetA decreased with the increase of UV radiation dose, which was completely inactivated at 5 mJ/cm^2. Tetracycline resistant bacteria, especially the gramegative bacteria, were partially resistant to UV when the disinfection dose was below 5 mJ/cm^2, which demonstrated an urgent need to focus on the ecological risks of drug-resistant bacteria in municipal wastewater treatment plant.