Li Dong, Yang Min, Hu Jianying, Zhang Jing, Liu Ruyin, Gu Xin, Zhang Yu, Wang Zhenyu
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Beijing 100085, China.
Environ Microbiol. 2009 Jun;11(6):1506-17. doi: 10.1111/j.1462-2920.2009.01878.x. Epub 2009 Feb 18.
The antibiotic-resistance characteristics of bacterial strains in antibiotic production wastewater treatment plants (WWTP) that contain high concentrations of antibiotics are unknown, as are the environmental effects of the discharge of wastewater from such facilities. In this study, 417 strains were individually isolated from the effluent of a WWTP that treated penicillin G production wastewater, as well as from downstream and upstream areas of the receiving river. The minimum inhibition concentrations (MICs) of 18 antibiotics representing seven classes were then determined for each of these strains. Relatively high similarity in the bacterial composition existed between the wastewater and downstream river samples when compared with the upstream sample. High resistance ratios and MIC values were observed for almost all antibiotics in wastewater isolates, followed by strains from downstream river, of which the resistance ratios and levels were still significantly higher than those of upstream strains. The resistance ratios and levels also significantly differed among strains belonged to different species in the penicillin production wastewater effluent and downstream river. In both samples, the resistances to beta-lactam antibiotics were more frequent, with much higher levels, than the other class antibiotics. Then five clinically important resistant genes mainly coding for extended-spectrum beta-lactamases (ESBLs) were determined for all strains, only bla(TEM-1) which did not belong to ESBL was detected in 17.3% and 11.0% of strains isolated from wastewater and downstream river respectively. Class I integrons were detected in 14% of wastewater isolates and 9.1% of downstream isolates, and primarily contained gene cassettes conferring resistance to aminoglycoside antibiotics. The unexpectedly high levels of multiple antibiotic resistance in strains from wastewater and downstream river were speculated to be mainly due to multidrug efflux systems.
抗生素生产污水处理厂（WWTP）中含有高浓度抗生素，其中细菌菌株的抗生素抗性特征尚不清楚，此类设施排放的废水对环境的影响也未知。在本研究中，从处理青霉素G生产废水的污水处理厂的出水以及受纳河流的下游和上游区域分别单独分离出417株菌株。然后测定了代表七类的18种抗生素对这些菌株中每一株的最低抑菌浓度（MIC）。与上游样本相比，废水和下游河流样本中的细菌组成存在较高的相似性。在废水分离株中，几乎所有抗生素都观察到高抗性率和MIC值，其次是来自下游河流的菌株，其抗性率和水平仍显著高于上游菌株。青霉素生产废水出水和下游河流中不同物种的菌株之间的抗性率和水平也存在显著差异。在两个样本中，对β-内酰胺类抗生素的抗性更为常见，且水平远高于其他类抗生素。然后对所有菌株测定了五个主要编码超广谱β-内酰胺酶（ESBLs）的临床重要抗性基因，从废水和下游河流中分离出的菌株中分别有17.3%和11.0%检测到不属于ESBL的bla(TEM-1)。在14%的废水分离株和9.1%的下游分离株中检测到I类整合子，且主要包含赋予对氨基糖苷类抗生素抗性的基因盒。推测废水和下游河流中菌株意外高的多重抗生素抗性水平主要归因于多药外排系统。
