废水处理厂(WWTP)旨在减少废水中的污染;然而,研究表明,抗菌素抗性基因(ARGs)在治疗后持续存在,有可能导致它们从人口稠密的地区传播到环境中。这项研究评估了在保加利亚的Iskar河上为125,000人提供服务的大型污水处理厂的影响,通过表征地表水细菌群落动态和抗性曲线的空间和短期时间动态。每四个日期从两个不同的地点每两周收集一对样本,一个在污水处理厂废水后约800米,另一个在下游10公里处。分类学分类揭示了假单胞菌和碘细菌的优势,特别是黄杆菌属,Aquirufa,Acidovorax,多核杆菌,和Limnohabitans.分类学结构与litic和lotic淡水栖息地相对应,黄杆菌在研究期间表现出显着下降。主坐标分析显示,在不同日期收集的样品之间,细菌群落组成存在统计学上的显着差异。差异丰度分析确定了多核杆菌属和陆生动物的显着富集。在早期和晚期采样日期之间,富集或耗尽的细菌类群发生了变化。基因erm(B)的相对丰度较高,erm(F),mph(E),msr(E)(大环内酯类);tet(C),tet(O),tet(W),检测到tet(Q)和tet(X)(四环素);sul1和sul2(磺酰胺);和cfxA3,cfxA6(β-内酰胺),在最新的采样日期和更靠近污水处理厂的位置,存在增加的趋势。值得注意的是,鉴定了赋予碳青霉烯类blaOXA-58和blaIMP-33样抗性的基因。ARGs和可移动遗传元件在推定质粒上的共现分析表明,根据MetaCompare2.0估计的人类健康风险评分(0.19)较低。总的来说,回收了29个宏基因组组装的基因组,只有几只藏有ARG。这项研究增强了我们对淡水微生物群落动态和抗生素抗性概况的理解,强调需要继续监测ARGs。
Waste Water Treatment Plants (
WWTP) aim to reduce contamination in effluent water; however, studies indicate antimicrobial resistance genes (ARGs) persist post-treatment, potentially leading to their spread from human populated areas into the environment. This study evaluated the impact of a large
WWTP serving 125,000 people on the Iskar River in Bulgaria, by characterizing the spatial and short-term temporal dynamics in bacterial community dynamics and resistance profiles of the surface water. Pairs of samples were collected biweekly on four dates from two different locations, one about 800 m after the
WWTP effluents and the other 10 km downstream. Taxonomic classification revealed the dominance of Pseudomonodota and Bacteriodota, notably the genera Flavobacterium, Aquirufa, Acidovorax, Polynucleobacter, and Limnohabitans. The taxonomic structure corresponded with both lentic and lotic freshwater habitats, with Flavobacterium exhibiting a significant decrease over the study period. Principal Coordinate Analysis revealed statistically significant differences in bacterial community composition between samples collected on different dates. Differential abundance analysis identified notable enrichment of Polynucleobacter and Limnohabitans. There were shifts within the enriched or depleted bacterial taxa between early and late sampling dates. High relative abundance of the genes erm(B), erm(F), mph(E), msr(E) (macrolides); tet(C), tet(O), tet(W), tet(Q) and tet(X) (tetracyclines); sul1 and sul2 (sulphonamides); and cfxA3, cfxA6 (beta-lactams) were detected, with trends of increased presence in the latest sampling dates and in the location closer to the
WWTP. Of note, genes conferring resistance to carbapenems blaOXA-58 and blaIMP-33-like were identified. Co-occurrence analysis of ARGs and mobile genetic elements on putative plasmids showed few instances, and the estimated human health risk score (0.19) according to MetaCompare2.0 was low. In total, 29 metagenome-assembled genomes were recovered, with only a few harbouring ARGs. This study enhances our understanding of freshwater microbial community dynamics and antibiotic resistance profiles, highlighting the need for continued ARGs monitoring.