Department of Parasitology, Microbiology and Immunology, Institute of Biological Sciences, Federal University of Juiz de Fora - UFJF, José Lourenço Kelmer, Martelos, CEP 36036-900 Juiz de Fora, MG, Brazil.
Department of Parasitology, Microbiology and Immunology, Institute of Biological Sciences, Federal University of Juiz de Fora - UFJF, José Lourenço Kelmer, Martelos, CEP 36036-900 Juiz de Fora, MG, Brazil; Faculty of Biological and Agricultural Sciences, Mato Grosso State University - UNEMAT, Perimetral Rogério Silva - Norte 2, CEP 78580-000 Alta Floresta, MT, Brazil.
Sci Total Environ. 2021 Nov 1;793:148552. doi: 10.1016/j.scitotenv.2021.148552. Epub 2021 Jun 19.
Water is the main resource for maintaining life. Anthropic activities influence the microbial epidemiological chain in watersheds, which can act as ways of disseminating microorganisms resistant to antimicrobial drugs, with impacts on human, animal, and environmental health. Here, we characterized aquatic microbial communities and their resistomes in samples collected along Rio das Ostras watershed during two seasons. Surface water samples were collected at eleven sites from the Jundiá, Iriry, and Rio das Ostras rivers in two seasons (dry and wet season). Microbial DNA was extracted, high-throughput sequenced and screened for antimicrobial resistance genetic (ARG) markers. The physicochemical characteristics and the microbiota data confirmed that Rio das Ostras watershed can be divided into three well defined portions: rural, urban, and marine. Rural areas were enriched by bacteria typically found in limnic environments and Patescibacteria phyla. The urban portion was characterized by sites with low pH and groups associated with iron oxidation. Some genera of clinical relevance were also identified, though in relatively low abundance. The marine site was enriched mainly by Cyanobacteria and bacteria that showed strong correlation with conductivity, salinity, and chloride. Twenty-six ARG markers were identified on the resistome, being found most frequently in the urban area, despite being present in rural sites. Among them were some related to classes of great clinical concern, such as genes coding for extended-spectrum beta-lactamase (bla and bla), resistance to carbapenems (bla) and to methicillin by Staphylococcus aureus (mecA). These results broaden our understanding of the microbial community of a watershed impacted by anthropogenic actions. The large number of ARGs detected along the Rio das Ostras watershed contrasts with the small number of microorganisms of clinical relevance observed, suggesting that antimicrobial resistance has arisen from non-clinical environments and microbes. Our results corroborate that freshwater acts as a reservoir of antimicrobial resistance genes.
水是维持生命的主要资源。人为活动影响流域中的微生物流行病学链，这些链可以作为传播对抗微生物药物具有抗性的微生物的途径，从而对人类、动物和环境健康产生影响。在这里，我们对在两个季节沿里奥达斯奥斯特拉斯流域采集的水样中的水生微生物群落及其抗药性进行了特征描述。在两个季节（旱季和雨季），从 Jundiá、Iriry 和 Rio das Ostras 河流的 11 个地点采集了地表水样本。提取微生物 DNA，高通量测序并筛选抗微生物药物抗性遗传（ARG）标记物。理化特性和微生物组数据证实，里奥达斯奥斯特拉斯流域可以分为三个明确的部分：农村、城市和海洋。农村地区富含通常在湖泊环境中发现的细菌和 Patescibacteria 门。城市部分的特点是 pH 值低，与铁氧化有关的组。还确定了一些具有临床相关性的属，尽管数量相对较少。海洋地点主要富集蓝细菌和与电导率、盐度和氯化物强烈相关的细菌。在抗药性组中鉴定出 26 个 ARG 标记物，尽管在农村地区也存在，但在城市地区发现的频率最高。其中一些与临床高度关注的类别有关，例如编码扩展谱β-内酰胺酶（bla 和 bla）、耐碳青霉烯类（bla）和耐甲氧西林金黄色葡萄球菌（mecA）的基因。这些结果扩展了我们对受人为活动影响的流域中微生物群落的理解。沿里奥达斯奥斯特拉斯流域检测到的大量 ARGs 与观察到的临床相关微生物数量较少形成对比，这表明抗药性是从非临床环境和微生物中产生的。我们的结果证实了淡水是抗微生物药物抗性基因的储库。
