Mills Molly, Lee Seungjun, Mollenkopf Dixie, Wittum Thomas, Sullivan S Mažeika Patricio, Lee Jiyoung
Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, OH, USA; Environmental Sciences Graduate Program, The Ohio State University, Columbus, OH, USA.
Department of Food Science and Nutrition, Pukyong National University, Busan, Republic of Korea.
Sci Total Environ. 2022 Dec 10;851(Pt 1):158042. doi: 10.1016/j.scitotenv.2022.158042. Epub 2022 Aug 13.
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 (bla, bla, and bla) 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 bla being the most detected (88 % of samples), followed by bla (64 %) and bla (23 %). Fish gut samples showed higher concentrations of bla and bla than any other matrix, indicating potential ARG bioaccumulation, and risk of broader dissemination through aquatic and nearshore food webs. Periphyton had higher concentrations of bla 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.
城市周边的天然水道受到包括微生物群落在内的人为活动的严重影响。河流中一种日益引起公众健康关注的污染物是抗生素抗性基因（ARGs），它可在邻近细菌之间传播，并增加AR细菌传播给动物和人类的可能性。为了确定最受关注的AR基质，我们比较了2017年至2018年美国俄亥俄州Scioto河流域不同样本类型之间的ARG负荷和微生物群落结构。从26个河流站点采集了五种环境基质（水、沉积物、周丛生物、碎屑和鱼肠道）。由于我们关注的是临床相关的ARGs，通过液滴数字™PCR对三种碳青霉烯抗性基因（bla、bla和bla）进行了定量。在九个城市化站点的子集中，我们进行了16S rRNA基因测序和功能基因预测。所有基质中均检测到碳青霉烯抗性基因，其中bla检出率最高（88%的样本），其次是bla（64%）和bla（23%）。鱼肠道样本中bla和bla的浓度高于其他任何基质，表明存在潜在的ARG生物累积，以及通过水生和近岸食物网更广泛传播的风险。周丛生物中bla的浓度高于水样本、沉积物样本或碎屑样本。微生物群落分析确定了不同样本类型在群落多样性和结构方面的差异。沉积物样本的微生物群落最多样化，而碎屑样本的微生物群落最少。Spearman相关性分析未揭示所监测的ARGs浓度与微生物群落多样性之间的显著关系。然而，通过样本类型确定了几种差异丰富的分类群和微生物功能，这些功能明确了这些基质在河流生态系统和栖息地类型中的作用。总之，鱼肠道和周丛生物因其相对较高的碳青霉烯抗性基因浓度、多样的微生物群落以及促进AR的自然功能，作为AR储存库令人担忧。
