摘要
      城市附近的自然水道受到包括微生物群落在内的人为活动的严重影响。河流中日益引起公众健康关注的污染物是抗生素抗性基因（ARGs），它可以在相邻细菌之间传播，并增加AR细菌传播给动物和人类的可能性。为了确定AR最受关注的基质，我们比较了2017年至2018年美国俄亥俄州Scioto河流域样本类型之间的ARG负荷和微生物群落结构。从26个河流地点收集了五种环境基质（水、沉积物、周边生物、碎屑和鱼肠）。由于我们专注于临床相关的ARGs，通过DropletDigital对三种碳青霉烯类耐药基因（blaKPC、blaNDM和blaOXA-48）进行了定量™ 聚合酶链式反应。在9个城市化地点的一个子集，我们进行了16S rRNA基因测序和功能基因预测。对所有基质中的碳青霉烯抗性基因进行了定量，其中检测最多的是blaKPC（88%的样本），其次是blaNDM（64%）和blaOXA-48（23%）。鱼类肠道样本显示，blaKPC和blaNDM的浓度高于任何其他基质，这表明ARG具有潜在的生物累积性，并有通过水生和近岸食物网更广泛传播的风险。Periphyton的blaNDM浓度高于水、沉积物或碎屑。微生物群落分析根据样本类型确定了群落多样性和结构的差异。沉积物样品的微生物群落最为多样，而碎屑则最少。Spearman相关性并未揭示监测到的ARGs浓度与微生物群落多样性之间的显著关系。然而，根据样本类型确定了几个差异丰富的分类群和微生物功能，这确定了这些基质在河流生态系统和栖息地类型中的作用。总之，鱼类肠道和外周生物是AR的宿主，因为它们具有相对高浓度的碳青霉烯类抗性基因、多样的微生物群落和促进AR的自然功能。
Abstract
Natural waterways near urban areas are heavily impacted by anthropogenic activities, including their microbial communities. A contaminant of growing public health concern in rivers is antibiotic resistant genes (ARGs), which can spread between neighboring bacteria and increase the potential for transmission of AR bacteria to animals and humans. To identify the matrices of most concern for AR, we compared ARG burdens and microbial community structures between sample types from the Scioto River Watershed, Ohio, the United States, from 2017 to 2018. Five environmental matrices (water, sediment, periphyton, detritus, and fish gut) were collected from 26 river sites. Due to our focus on clinically relevant ARGs, three carbapenem resistance genes (blaKPC, blaNDM, and blaOXA-48) were quantified via DropletDigital™ PCR. At a subset of nine urbanized sites, we conducted16S rRNA gene sequencing and functional gene predictions. Carbapenem resistance genes were quantified from all matrices, with blaKPC being the most detected (88 % of samples), followed by blaNDM (64 %) and blaOXA-48 (23 %). Fish gut samples showed higher concentrations of blaKPC and blaNDM than any other matrix, indicating potential ARG bioaccumulation, and risk of broader dissemination through aquatic and nearshore food webs. Periphyton had higher concentrations of blaNDM than water, sediment, or detritus. Microbial community analysis identified differences by sample type in community diversity and structure. Sediment samples had the most diverse microbial communities, and detritus, the least. Spearman correlations did not reveal significant relationships between the concentrations of the monitored ARGs and microbial community diversity. However, several differentially abundant taxa and microbial functions were identified by sample type that is definitive of these matrices' roles in the river ecosystem and habitat type. In summary, the fish gut and periphyton are a concern as AR reservoirs due to their relatively high concentration of carbapenem resistance genes, diverse microbial communities, and natural functions that promote AR.

https://www.sciencedirect.com/science/article/abs/pii/S0048969722051415