College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China.
Sci Total Environ. 2012 Apr 1;421-422:173-83. doi: 10.1016/j.scitotenv.2012.01.061. Epub 2012 Feb 25.
Antibiotics and corresponding resistance genes and resistant bacteria have been considered as emerging pollutants worldwide. Wastewater treatment plants (WWTPs) are potential reservoirs contributing to the evolution and spread of antibiotic resistance. In this study, total concentrations of tetracycline and sulfonamide antibiotics in final effluent were detected at 652.6 and 261.1ng/L, respectively, and in treated sludge, concentrations were at 1150.0 and 76.0μg/kg dry weight (dw), respectively. The quantities of antibiotic resistance genes and antibiotic resistant bacteria in final effluent were quantified in the range of 9.12×10(5)-1.05×10(6) gene abundances /100mL (genomic copies/100mL) and 1.05×10(1)-3.09×10(3)CFU/mL, respectively. In treated sludge, they were quantified at concentrations of 1.00×10(8)-1.78×10(9) gene abandances/100mL and 7.08×10(6)-1.91×10(8)CFU/100mL, respectively. Significant reductions (2-3 logs, p<0.05) of antibiotic resistance genes and antibiotic resistant bacteria were observed between raw influent and final effluent. The gene abundances of tetO and tetW normalized to that of 16S rRNA genes indicated an apparent decrease as compared to sulI genes, which remained stable along each treatment stage. Significant correlations (R(2)=0.75-0.83, p<0.05) between numbers of resistant bacteria and antibiotic concentrations were observed in raw influent and final effluent. No significance (R(2)=0.15, p>0.05) was found between tet genes (tetO and tetW) with concentration of tetracyclines identified in wastewater, while a significant correlation (R(2)=0.97, p<0.05) was observed for sulI gene and total concentration of sulfonamides. Correlations of the quantities of antibiotic resistance genes and antibiotic resistant bacteria with corresponding concentrations of antibiotics in sludge samples were found to be considerably weak (R(2)=0.003-0.07).
抗生素及其相应的耐药基因和耐药菌已被认为是全球范围内的新兴污染物。污水处理厂（WWTP）是促进抗生素耐药性进化和传播的潜在储集库。本研究检测到最终出水的四环素和磺胺类抗生素的总浓度分别为 652.6 和 261.1ng/L，而处理污泥中的浓度分别为 1150.0 和 76.0μg/kg 干重（dw）。最终出水的抗生素耐药基因和抗生素耐药菌数量分别在 9.12×10(5)-1.05×10(6)基因丰度/100mL（基因组拷贝/100mL）和 1.05×10(1)-3.09×10(3)CFU/mL 范围内进行定量。在处理污泥中，其浓度分别为 1.00×10(8)-1.78×10(9)基因丰度/100mL 和 7.08×10(6)-1.91×10(8)CFU/100mL。在原水和最终出水之间观察到抗生素耐药基因和抗生素耐药菌显著减少（2-3 个对数，p<0.05）。与 sulI 基因相比，归一化为 16S rRNA 基因的 tetO 和 tetW 基因丰度明显下降，而 sulI 基因在各个处理阶段保持稳定。在原水和最终出水中，均观察到耐药菌数量与抗生素浓度之间存在显著相关性（R(2)=0.75-0.83，p<0.05）。在废水中鉴定的四环素浓度与 tet 基因（tetO 和 tetW）之间没有显著相关性（R(2)=0.15，p>0.05），而 sulI 基因与磺胺类抗生素的总浓度之间存在显著相关性（R(2)=0.97，p<0.05）。在污泥样品中，抗生素耐药基因和抗生素耐药菌的数量与相应抗生素浓度之间的相关性较弱（R(2)=0.003-0.07）。
