School of Public Health, Department of Environmental Health, University of São Paulo, São Paulo, Brazil.
School of Veterinary Medicine and Animal Science, Department of Pathology, University of São Paulo, São Paulo, Brazil.
Trop Med Int Health. 2024 May;29(5):424-433. doi: 10.1111/tmi.13986. Epub 2024 Mar 28.
The spread of antimicrobial resistance (AMR) through multiple reservoirs is a global concern. Wastewater is a critical AMR dissemination source, so this study aimed to assess the persistence of resistance genetic markers in wastewater using a culture-independent approach. Raw and treated wastewater samples (n = 121) from a wastewater treatment plant (WWTP), a human hospital, a veterinary hospital, and a pig farm were monthly collected and concentrated by filtration. DNA was extracted directly from filter membranes, and PCR was used in the qualitative search of 32 antimicrobial resistance genes (ARGs). Selected genes (bla, bla, qnrB, and mcr-1) were enumerated by quantitative real-time PCR (qPCR). Twenty-six ARGs were detected in the qualitative ARGs search, while quantitative data showed a low variation of the ARG's relative abundance (RA) throughout the months, especially at the human hospital and the WWTP. At the WWTP, despite significantly reducing the absolute number of gene copies/L after each treatment stage (p < 0.05), slight increases (p > 0.05) in the RAs of genes bla, qnrB, and mcr-1 were observed in reused water (tertiary treatment) when compared with secondary effluent. Although the increase is not statistically significant, it is worth noting that there was some level of ARGs concentration after the disinfection process. No significant absolute or relative after-treatment quantification reductions were observed for any ARGs at the veterinary hospital or the pig farm. The spread of ARGs through sewage needs to be continuously addressed, because their release into natural environments may pose potential risks of exposure to resistant bacteria and impact local ecosystems.
抗生素耐药性（AMR）在多个储层中的传播是一个全球性的关注点。废水是 AMR 传播的重要来源，因此本研究旨在采用非培养方法评估废水中耐药基因标记的持久性。每月从一家污水处理厂（WWTP）、一家医院、一家兽医医院和一家养猪场收集原始和处理后的废水样本（n=121）并通过过滤进行浓缩。直接从滤膜中提取 DNA，并使用聚合酶链反应（PCR）对 32 种抗生素耐药基因（ARGs）进行定性搜索。通过定量实时 PCR（qPCR）对选定基因（bla、bla、qnrB 和 mcr-1）进行计数。在定性 ARGs 搜索中检测到 26 种 ARGs，而定量数据显示，ARG 相对丰度（RA）在整个月份变化不大，尤其是在医院和 WWTP。在 WWTP，尽管在每个处理阶段后（p<0.05）绝对基因拷贝数/L 显著减少，但在再用水（三级处理）中观察到 bla、qnrB 和 mcr-1 基因的 RA 略有增加（p>0.05）与二级出水相比。尽管这种增加在统计学上并不显著，但值得注意的是，在消毒过程后存在一定程度的 ARGs 浓缩。在兽医医院或养猪场，任何 ARGs 的后处理定量减少均无明显的绝对或相对减少。需要持续解决 ARGs 通过污水传播的问题，因为它们释放到自然环境中可能会对接触耐药细菌和对当地生态系统产生潜在风险。
