CBQF-Centro de Biotecnologia e Química Fina-Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua de Diogo Botelho 1327, 4169-005 Porto, Portugal.
Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, USA.
Int J Environ Res Public Health. 2019 Oct 30;16(21):4217. doi: 10.3390/ijerph16214217.
Standardized methods are needed to support monitoring of antibiotic resistance in environmental samples. Culture-based methods target species of human-health relevance, while the direct quantification of antibiotic resistance genes (ARGs) measures the antibiotic resistance potential in the microbial community. This study compared measurements of tetracycline-, sulphonamide-, and cefotaxime-resistant presumptive total and fecal coliforms and presumptive enterococci versus a suite of ARGs quantified by quantitative polymerase chain reaction (qPCR) across waste-, recycled-, tap-, and freshwater. Cross-laboratory comparison of results involved measurements on samples collected and analysed in the US and Portugal. The same DNA extracts analysed in the US and Portugal produced comparable qPCR results (variation <28%), except for gene (0%-57%). Presumptive total and fecal coliforms and cefotaxime-resistant total coliforms strongly correlated with and 1 (0.725 ≤ R ≤ 0.762; < 0.0001). Further, presumptive total and fecal coliforms correlated with the -specific biomarkers, and , suggesting that both methods captured fecal-sourced bacteria. The genes encoding resistance to sulphonamides ( and ) were the most abundant, followed by genes encoding resistance to tetracyclines ((A) and (O)) and β-lactams ( and), which was in agreement with the culture-based enumerations. The findings can help inform future application of methods being considered for international antibiotic resistance surveillance in the environment.
需要标准化的方法来支持环境样本中抗生素耐药性的监测。基于培养的方法针对与人类健康相关的物种，而抗生素耐药基因 (ARGs) 的直接定量测量则衡量了微生物群落中的抗生素耐药潜力。本研究比较了四环素、磺胺类和头孢噻肟耐药的总推定和粪便大肠菌群和推定肠球菌的测量值与通过定量聚合酶链反应 (qPCR) 定量的一系列 ARGs 在废水、再生水、自来水和淡水中的测量值。涉及在美国和葡萄牙收集和分析的样本的实验室间比较结果。在美国和葡萄牙分析的相同 DNA 提取物产生了可比的 qPCR 结果（差异<28%），除了 基因（0%-57%）。总推定和粪便大肠菌群和头孢噻肟耐药的总大肠菌群与 和 1 （0.725 ≤ R ≤ 0.762；<0.0001）高度相关。此外，总推定和粪便大肠菌群与 -特异性生物标志物 和 相关，表明这两种方法都捕获了粪便来源的细菌。编码对磺胺类药物（和）的耐药性的基因最为丰富，其次是编码对四环素（(A) 和 (O)) 和β-内酰胺类（和）的耐药性的基因，这与基于培养的计数结果一致。这些发现有助于为未来环境中国际抗生素耐药性监测中考虑使用的方法提供信息。
