NUS Environmental Research Institute, National University of Singapore, 1 Create way, Create Tower, #15-02, Singapore 138602, Singapore.
National Centre for Food Science, Singapore Food Agency, 7 International Business Park, Singapore 609919, Singapore.
Water Res. 2024 Nov 15;266:122353. doi: 10.1016/j.watres.2024.122353. Epub 2024 Aug 28.
Antimicrobial resistance (AMR) is a global challenge that has impacted aquaculture and surrounding marine environments. In this study, a year-long monitoring program was implemented to evaluate AMR in two different aquaculture settings (i.e., open cage farming, recirculating aquaculture system (RAS)) and surrounding marine environment within a tropical coastal region. The objectives of this study are to (i) investigate the prevalence and co-occurrence of antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARGs), antibiotics (AB) and various associated chemical compounds at these study sites; (ii) explore the contributing factors to development and propagation of AMR in the coastal environment; and (iii) assess the AMR risks from different perspectives based on the three AMR determinants (i.e., ARB, ARGs and AB). Key findings revealed a distinct pattern of AMR across the different aquaculture settings, notably a higher prevalence of antibiotic-resistant Vibrio at RAS outfalls, suggesting a potential accumulation of microorganisms within the treatment system. Despite the relative uniform distribution of ARGs across marine sites, specific genes such as qepA, bla and bacA, were found to be abundant in fish samples, especially from the RAS. Variations in chemical contaminant prevalence across sites highlighted possible anthropogenic impacts. Moreover, environmental and seasonal variations were found to significantly influence the distribution of ARGs and chemical compounds in the coastal waters. Hierarchical cluster analysis that was based on ARGs, chemical compounds and environmental data, categorized the sites into three distinct clusters which reflected strong association with location, seasonality and aquaculture activities. The observed weak correlations between ARGs and chemical compounds imply that low environmental concentrations may be insufficient for resistance selection. A comprehensive risk assessment using methodologies such as the multiple antibiotic resistance (MAR) index, comparative AMR risk index (CAMRI) and Risk quotient (RQ) underscored the complexity of AMR risks. This research significantly contributes to the understanding of AMR dynamics in natural aquatic systems and provides valuable insights for managing and mitigating AMR risks in coastal environments.
抗微生物药物耐药性（AMR）是一个全球性挑战，已经对水产养殖和周围的海洋环境产生了影响。在本研究中，实施了为期一年的监测计划，以评估热带沿海地区两个不同水产养殖环境（即开放式笼养和循环水养殖系统（RAS））和周围海洋环境中的 AMR。本研究的目的是：（i）调查这些研究地点的抗生素耐药细菌（ARB）、抗生素耐药基因（ARGs）、抗生素（AB）和各种相关化学化合物的流行率和共存情况；（ii）探讨沿海环境中 AMR 发展和传播的促成因素；（iii）基于 AMR 的三个决定因素（即 ARB、ARGs 和 AB），从不同角度评估 AMR 风险。主要发现揭示了不同水产养殖环境中 AMR 的明显模式，特别是 RAS 出水口处的抗生素耐药性弧菌的流行率较高，表明处理系统内微生物的潜在积累。尽管海洋地点的 ARGs 分布相对均匀，但在鱼类样本中发现了一些特定基因，如 qepA、bla 和 bacA，尤其是在 RAS 中。化学污染物流行率在各地点的差异突出了人为影响的可能性。此外，环境和季节性变化被发现显著影响沿海水域中 ARGs 和化学化合物的分布。基于 ARGs、化学化合物和环境数据的层次聚类分析将这些地点分为三个不同的聚类，这些聚类与位置、季节性和水产养殖活动密切相关。观察到 ARGs 和化学化合物之间的弱相关性表明，环境浓度低可能不足以进行耐药性选择。使用多重抗生素耐药性（MAR）指数、比较 AMR 风险指数（CAMRI）和风险商（RQ）等方法进行的综合风险评估强调了 AMR 风险的复杂性。这项研究极大地促进了对自然水生系统中 AMR 动态的理解，并为管理和减轻沿海环境中的 AMR 风险提供了有价值的见解。
