College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 550025, China.
College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang 550025, China.
Sci Total Environ. 2024 May 20;926:171806. doi: 10.1016/j.scitotenv.2024.171806. Epub 2024 Mar 19.
Hospital wastewater treatment systems (HWTSs) are a significant source and reservoir of antibiotic resistance genes (ARGs) and a crucial hub for transmitting ARGs from clinical to natural environments. However, there is a lack of research on the antibiotic resistome of clinical wastewater in HWTSs. In this study, we used metagenomics to analyze the prevalence and abundance of ARGs in five typical HWTSs. A total of 17 antibiotics from six categories were detected in the five HWTSs; β-lactam antibiotics were found at the highest concentrations, with up to 4074.08 ng·L. We further found a total of 21 ARG types and 1106 subtypes of ARGs with the highest percentage of multi-drug resistance genes (evgS, msbA, arlS, and baeS). The most abundant last-resort ARGs were mcr, which were detected in 100 % of the samples. HWTSs effluent is a major pathway for the transmission of last-resort ARGs into urban wastewater networks. The removal of antibiotics, antibiotic-resistant bacteria, and ARGs from HWTSs was mainly achieved by tertiary treatment, i.e., chlorine disinfection, but antibiotics and ARGs were still present in the HWTSs effluent or even increased after treatment. Moreover, antibiotics and heavy metals (especially mercury) in hospital effluents can exert selective pressure for antibiotic resistance, even at low concentrations. Qualitative analyses based on metagenome-assembled genome analysis revealed that the putative hosts of the identified ARGs are widely distributed among Pseudomonas, Acidovorax, Flavobacterium, Polaromonas, and Arcobacter. Moreover, we further assessed the clinical availability of ARGs and found that multidrug ARGs had the highest clinical relevance values. This study provides new impulses for monitoring and removing antibiotics and ARGs in the hospital sewage treatment process.
医院废水处理系统（HWTSs）是抗生素耐药基因（ARGs）的重要来源和储存库，也是将 ARGs 从临床环境传播到自然环境的关键枢纽。然而，HWTSs 中临床废水的抗生素抗性组研究还很缺乏。在这项研究中，我们使用宏基因组学分析了五个典型 HWTSs 中 ARGs 的流行程度和丰度。在五个 HWTSs 中共检测到来自六个类别的 17 种抗生素；β-内酰胺类抗生素的浓度最高，最高可达 4074.08ng·L-1。我们进一步发现了总共 21 种 ARG 类型和 1106 种 ARG 亚型，其中多药耐药基因（evgS、msbA、arlS 和 baeS）的比例最高。最丰富的最后手段的 ARGs 是 mcr，在 100%的样本中都有检测到。HWTSs 出水是将最后手段的 ARGs 传播到城市废水网络的主要途径。HWTSs 中抗生素、耐药菌和 ARGs 的去除主要通过三级处理，即氯消毒来实现，但抗生素和 ARGs 仍存在于 HWTSs 出水中，甚至在处理后增加。此外，医院废水中的抗生素和重金属（尤其是汞）会对抗生素耐药性产生选择压力，即使浓度很低。基于宏基因组组装基因组分析的定性分析表明，所鉴定的 ARGs 的潜在宿主广泛分布于假单胞菌、食酸菌、黄杆菌、极地单胞菌和弧菌属中。此外，我们进一步评估了 ARGs 的临床可用性，发现多药耐药 ARGs 具有最高的临床相关性值。本研究为监测和去除医院污水处理过程中的抗生素和 ARGs 提供了新的动力。
