摘要
      人为排放的营养物质、金属和抗生素对水生生态系统和人类的健康构成了多重威胁，例如，导致富营养化，并将抗性基因引入人类病原体。微生物群落、抗性基因和城市湖泊富营养化水平之间的潜在联系是复杂的，目前尚不清楚，这对生态和人类健康风险评估至关重要。在这里，研究了五个不同营养条件的城市湖泊，以量化其微生物多样性，并建立了抗生素抗性基因（ARGs）和金属抗性基因（MRGs）的高分辨率图谱。元基因组和多变量分析表明，不同湖泊的微生物结构、抗性基因和移动遗传元件（MGE）的分布以及毒力因子基因（VFG）存在显著差异。超富营养湖泊南湖的微生物多样性最低，但抗性基因水平最高。微生物群落和MGE被确定为形成ARGs和MRGs图谱的主要驱动因素，而外部环境因素在抗性基因的变化中起着间接作用。变形杆菌的两个成员Aestuariivirga和Limnohabitans被鉴定为大多数样本中ARGs的主要细菌宿主。此外，城市湖泊中的耐药性风险评分与水质因素呈正相关，与微生物多样性呈负相关。我们的研究为微生物多样性、MGE和ARGs在城市湖泊中的潜在传播风险之间的联系提供了新的见解。
Abstract
Anthropogenic discharge of nutrients, metals, and antibiotics poses multiple threats to the health of aquatic ecosystems and humans, e.g., causing eutrophication, and introduction of resistance genes into human pathogens. The potential link between microbial communities, resistance genes, and eutrophication levels in urban lakes is complex and remains unclear, which is crucial for ecological and human health risk assessment. Here, five urban lakes of different trophic conditions were investigated to quantify their microbial diversity, and high-resolution profiles of antibiotic resistance genes (ARGs) and metal resistance genes (MRGs) were established. Metagenome and multivariance analyses indicated that the microbial structures, distribution of resistance genes and mobile genetic elements (MGEs), and virulence factor genes (VFGs) significantly differed between the lakes. The hypereutrophic lake Nanhu harbored the lowest microbial diversity but the highest level of resistance genes. Microbial communities and MGEs were identified as the main drivers in shaping the profiles of ARGs and MRGs, while external environmental factors played an indirect role in the changing resistance genes. Two members of Proteobacteria, Aestuariivirga and Limnohabitans were identified as predominant bacterial hosts of ARGs in most samples. In addition, the resistome risk scores were found positively correlated with water quality factors and negatively correlated with microbial diversity in the urban lakes. Our study provides novel insights into the link between microbial diversity, MGEs, and the potential dissemination risk of ARGs in urban lakes.

https://www.sciencedirect.com/science/article/pii/S2772416623000049