Department of Environmental Microbiology, Faculty of Environmental Sciences, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1, 10-720 Olsztyn, Poland.
Department of Environmental Microbiology, Faculty of Environmental Sciences, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1, 10-720 Olsztyn, Poland.
Sci Total Environ. 2018 Jun 1;626:377-383. doi: 10.1016/j.scitotenv.2018.01.100. Epub 2018 Feb 19.
The objective of this study was to identify the determinants of antibiotic resistance and virulence of Aeromonas spp. isolated from treated wastewater (WW) and from samples of river water collected upstream (URW) and downstream (DRW) from the effluent discharge point. The resistance of Aeromonas spp. to antibiotics that are widely used in human and veterinary medicine, including beta-lactams, tetracyclines, glycylcyclines, fluoroquinolones, aminoglycosides and sulfamethoxazole-trimethoprim, was analyzed by disk diffusion method. The prevalence of hemolysins, aerolysins (virulence factors) and integrase genes was determined. A total of 83 Aeromonas spp. strains were selected from the isolates obtained from river water and wastewater samples. The highest percentage (81.8%) of multidrug-resistant isolates was noted in DRW samples. The analyzed isolates were most frequently resistant to beta-lactams, tetracyclines and aminoglycosides, whereas resistance to glycylcyclines was least common. Isolates resistant to beta-lactams most frequently harbored bla and bla genes. The group of genes encoding resistance to tetracyclines was most frequently represented by tet(E) and tet(O). Genes encoding virulence ahh1 (heat-labile hemolysin) or integrase intI1 occurred more frequently in the strains isolated from DRW than URW. An analysis of genetic relatedness revealed two main clusters - one with closely related WW and DRW isolates and one with less related isolates from all analyzed samples. The results of this study indicate that regardless of the applied treatment, municipal sewage may be a reservoir of antibiotic-resistant bacteria, antibiotic resistance and virulence genes and that treated water can contaminate other environmental domains.
本研究旨在确定从处理后的废水（WW）和从污水排放点上游（URW）和下游（DRW）采集的河水样本中分离出的气单胞菌属对抗生素的耐药性和毒力的决定因素。采用圆盘扩散法分析气单胞菌属对广泛应用于人和兽医医学的抗生素（包括β-内酰胺类、四环素类、甘氨酰环素类、氟喹诺酮类、氨基糖苷类和磺胺甲恶唑-甲氧嘧啶）的耐药性。确定了溶血素、aerolysins（毒力因子）和整合酶基因的流行情况。从河水和废水样本中获得的分离物中选择了总共 83 株气单胞菌属菌株。在 DRW 样本中，多药耐药分离株的比例最高（81.8%）。分析的分离株对β-内酰胺类、四环素类和氨基糖苷类最常耐药，而对甘氨酰环素类的耐药性最不常见。对β-内酰胺类耐药的分离株最常携带 bla 和 bla 基因。编码对四环素类耐药的基因最常由 tet(E)和 tet(O)组成。编码毒力 ahh1（热不稳定溶血素）或整合酶 intI1 的基因在从 DRW 分离的菌株中比在 URW 中更频繁出现。遗传相关性分析显示了两个主要的聚类 - 一个与 WW 和 DRW 密切相关的分离株聚类，另一个与所有分析样本中较少相关的分离株聚类。本研究的结果表明，无论采用何种处理方法，城市污水都可能是抗生素耐药菌、抗生素耐药性和毒力基因的储存库，处理过的水可能会污染其他环境领域。
