摘要

       生活在城市河流系统中的动物在微生物群落和抗生素耐药性的传播中发挥着关键作用，这对公共健康构成了严重威胁。这项研究提供了来自巴河沿岸五个地点的尖头鱼（Hemiculter leucisculus）和周围水体的微生物群和抗生素抗性基因（ARG）的综合概况。结果表明，变形杆菌、厚壁菌门和梭杆菌是H. leucisculus肠道中的优势菌群。随着水体污染的加剧，鱼肠道的细菌生物量显着下降，变形菌门的比例增加，最终成为最主要的门。为了用结构方程模型（SEM）量化影响因素对肠道微生物组模式的贡献，证实水细菌是扰乱鱼类肠道微生物组的最大压力源。 SourceTracker 模型表明，不断恶化的生活环境促进了水病原体对鱼肠道生态环境的入侵。此外，H. leucisculus 肠道是巴河 ARGs 的重要库，相对丰度高达 9.86 × 10−1/份。在 ARG 中，检测到显性丰度的四环素和喹诺酮抗性基因。外部环境的恶化导致鱼肠道中 ARGs 的积累。肠道 I 类整合子、环境重金属残留和肠道细菌被确定为 H. leucisculus 肠道 ARGs 谱的关键驱动因素。对 ARGs 和细菌宿主之间的 SEM 和共现模式的分析表明，I 类整合子和细菌群落在 ARGs 通过水-鱼途径传播中起着至关重要的作用。总的来说，这项研究强调了水污染对水生动物微生物群和 ARGs 的危害，并为更好地了解细菌和 ARGs 在城市河流生态系统中的传播提供了新的视角。

       Animals living in urban river systems play critical roles in the dissemination of microbiome and antibiotic resistance that poses a strong threat to public health. This study provides a comprehensive profile of microbiota and antibiotic resistance genes (ARGs) of sharpbelly (Hemiculter leucisculus) and the surrounding water from five sites along the Ba River. Results showed Proteobacteria, Firmicutes and Fusobacteria were the dominant bacteria in gut of H. leucisculus. With the aggravation of water pollution, bacterial biomass of fish gut significantly decreased and the proportion of Proteobacteria increased to become the most dominant phylum eventually. To quantify the contributions of influential factors on patterns of gut microbiome with structural equation model (SEM), water bacteria were confirmed to be the most stressors to perturb fish gut microbiome. SourceTracker model indicated that deteriorating living surroundings facilitated the invasion of water pathogens to fish gut eco-environments. Additionally, H. leucisculus gut is an important reservoir of ARGs in Ba River with relative abundance up to 9.86 × 10−1/copies. Among the ARGs, tetracycline and quinolone resistance genes were detected in dominant abundance. Deterioration of external environments elicited the accumulation of ARGs in fish gut. Intestinal class I integron, environmental heavy metal residues and gut bacteria were identified as key drivers of intestinal ARGs profiles in H. leucisculus. Analysis of SEM and co-occurrence patterns between ARGs and bacterial hosts indicated that class I integron and bacterial community played vital roles in ARGs transmission through water-fish pathway. In general, this study highlighted hazards of water contamination to microbiome and ARGs in aquatic animals and provided a new perspective to better understand the bacteria and ARGs dissemination in urban river ecosystems.

https://www.sciencedirect.com/science/article/pii/S026974912036485X