Wang Mingyu, Shen Weitao, Yan Lei, Wang Xin-Hua, Xu Hai
State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan 250100, China.
Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China.
Environ Pollut. 2017 Dec;231(Pt 2):1578-1585. doi: 10.1016/j.envpol.2017.09.055. Epub 2017 Sep 28.
Bacteria, antibiotics, and antibiotic resistance determinants are key biological pollutants in aquatic systems, which may lead to bacterial infections or prevent the cure of bacterial infections. In this study, we investigated how the wastewater treatment processes in wastewater treatment plants (WWTPs) affect these pollutants. We found that the addition of oxygen, polyaluminum chloride (PAC), and polyacrylamide (PAM), as well as ultraviolet (UV) disinfection could significantly alter the bacterial communities in the water samples. An overall shift from Gram-negative bacteria to Gram-positive bacteria was observed throughout the wastewater treatment steps, but the overall bacterial biomass was not reduced in the WWTP samples. The antibiotic contents were reduced by the WWTP, but the size of the reduction and the step when antibiotic degradation occurred differed among antibiotics. Ciprofloxacin, sulfamethoxazole and erythromycin could be removed completely by the WWTP, whereas cephalexin could not. The removal of ciprofloxacin, cephalexin, and erythromycin occurred in the anaerobic digester, whereas the removal of sulfamethoxazole occurred after the addition of PAC and PAM, and UV disinfection. Antimicrobial resistance determinants were highly prevalent in all of the samples analyzed, except for those targeting vancomycin and colistin. However, wastewater treatment was ineffective at removing antimicrobial resistance determinants from wastewater. There were strong correlations between intI1, floR, sul1, and ermB, thereby suggesting the importance of integrons for the spread of these antimicrobial resistance genes. In general, this study comprised a stepwise analysis of the impact of WWTPs on three biological pollutants: bacteria, antibiotics, and antimicrobial resistance determinants, where our results suggest that the design of WWTPs needs to be improved to address the threats due to these pollutants.
细菌、抗生素及抗生素抗性决定因素是水生系统中的关键生物污染物，可能导致细菌感染或阻碍细菌感染的治愈。在本研究中，我们调查了污水处理厂（WWTPs）的废水处理过程如何影响这些污染物。我们发现，添加氧气、聚合氯化铝（PAC）和聚丙烯酰胺（PAM）以及紫外线（UV）消毒可显著改变水样中的细菌群落。在整个废水处理步骤中，观察到从革兰氏阴性菌到革兰氏阳性菌的总体转变，但污水处理厂样本中的总细菌生物量并未减少。污水处理厂降低了抗生素含量，但不同抗生素的降低幅度以及抗生素降解发生的步骤有所不同。环丙沙星、磺胺甲恶唑和红霉素可被污水处理厂完全去除，而头孢氨苄则不能。环丙沙星、头孢氨苄和红霉素的去除发生在厌氧消化池中，而磺胺甲恶唑的去除发生在添加PAC和PAM以及紫外线消毒之后。除了针对万古霉素和黏菌素的那些之外，抗微生物抗性决定因素在所有分析样本中都高度普遍。然而，废水处理在去除废水中的抗微生物抗性决定因素方面效果不佳。intI1、floR、sul1和ermB之间存在很强的相关性，从而表明整合子对于这些抗微生物抗性基因传播的重要性。总体而言，本研究对污水处理厂对三种生物污染物（细菌、抗生素和抗微生物抗性决定因素）的影响进行了逐步分析，我们的结果表明需要改进污水处理厂的设计以应对这些污染物带来的威胁。
