Makowska Nicoletta, Koczura Ryszard, Mokracka Joanna
Department of Microbiology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, 61-614 Poznań, Poland.
Department of Microbiology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, 61-614 Poznań, Poland.
Chemosphere. 2016 Feb;144:1665-73. doi: 10.1016/j.chemosphere.2015.10.044. Epub 2015 Oct 28.
Wastewater treatment plants are considered hot spots for multiplication and dissemination of antibiotic-resistant bacteria and resistance genes. In this study, we determined the presence of class 1 integron integrase and genes conferring resistance to tetracyclines and sulfonamides in the genomes of culturable bacteria isolated from a wastewater treatment plant and the river that receives the treated wastewater. Moreover, using PCR-based metagenomic approach, we quantified intI1, tet and sul genes. Wastewater treatment caused the decrease in the total number of culturable heterotrophs and bacteria resistant to tetracycline and sulfonamides, along with the decrease in the number of intI1, sul and tet gene copies per ml, with significant reduction of tet(B). On the other hand, the treatment process increased both the frequency of tetracycline- and sulfonamide-resistant bacteria and intI1-positive strains, and the relative abundance of all quantified antibiotic resistance genes (ARGs) and intI1 gene; in the case of tet(A) and sul2 significantly. The discharge of treated wastewater increased the number of intI1, tet and sul genes in the receiving river water both in terms of copy number per ml and relative abundance. Hence, despite the reduction of the number of ARGs and ARBs, wastewater treatment selects for bacteria with ARGs in effluent.
污水处理厂被认为是抗生素抗性细菌和抗性基因增殖与传播的热点。在本研究中，我们测定了从一家污水处理厂以及接纳处理后废水的河流中分离出的可培养细菌基因组中1类整合子整合酶以及赋予对四环素和磺胺类药物抗性的基因的存在情况。此外，我们采用基于PCR的宏基因组学方法对intI1、tet和sul基因进行了定量分析。污水处理导致可培养异养菌总数以及对四环素和磺胺类药物具有抗性的细菌数量减少，同时每毫升中intI1、sul和tet基因拷贝数也减少，tet(B)显著降低。另一方面，处理过程增加了四环素和磺胺类抗性细菌以及intI1阳性菌株的频率，以及所有定量抗生素抗性基因（ARGs）和intI1基因的相对丰度；tet(A)和sul2的情况尤为显著。处理后废水的排放增加了接纳河流水中intI1、tet和sul基因的数量，无论是每毫升的拷贝数还是相对丰度。因此，尽管抗生素抗性基因和抗生素抗性细菌的数量有所减少，但污水处理仍会选择出在流出物中带有抗生素抗性基因的细菌。
