课题组周宇同学（共同第一作者）于《Journal of Hazardous Materials》期刊上发表了题为《Highly sensitive detection of the tetracycline resistance gene tetA in water supply systems with an autocatalytic deoxyribonucleic acid-based cascade circuit》的论文。

抗生素抗性基因（ARGs）在水系统中的污染会加速抗菌素耐药性传播并威胁公共健康，亟需有效、低成本且稳定的现场检测方法。本研究将杂交链式反应（HCR）与脱氧核酶（DNAzyme）相结合，构建了等温、无酶、引发链可再生（IR）的HCR级联信号放大系统，用于供水系统中四环素抗性基因tetA的高灵敏检测。该系统由识别模块和信号放大模块组成：辅助发夹识别tetA后触发HCR，DNAzyme切割底物-阻断复合物并释放新的引发链，形成自催化反馈回路，实现荧光信号的指数放大。结果表明，该方法对tetA的检测限低至4.6 pM，在0.01–1 nM范围内呈良好线性关系（R²=0.997），并能有效区分16S rDNA、blaTEM-1和aac3-II等干扰序列。实际水样检测结果与ddPCR高度相关（R²=0.997），预测样本落在95%置信区间内，表明该方法无需PCR和复杂温控设备即可实现ARGs的灵敏、准确现场检测；通过更换识别序列还可拓展至其他ARGs。该研究可为供水系统中抗生素抗性基因的现场监测和风险预警提供技术参考。

Abstract

Antibiotic resistance genes (ARGs) contamination in water systems is a global concern, accelerating antimicrobial resistance and threatening public health, which demands an effective, low-cost and stable method for their on-site detection. Herein, we developed an innovative approach by combining the hybridization chain reaction (HCR) with deoxyribozymes to design an isothermal enzyme-free cascade initiator regenerating (IR) HCR-based amplification system. Minute quantities of targets can trigger exponentially amplified fluorescence signals through the self-catalytic feedback loop of the HCR mechanism. Tetracycline resistance genes (tetA) were specifically and sensitively detected with a remarkably low detection limit as low of 4.6 pM by introducing auxiliary hairpins. Furthermore, the adaptable nature of auxiliary hairpins enabled easy customization for detecting other ARGs by simply altering the recognition site, resulting in a high degree of specificity and versatility. The IR-HCR-based amplifier was used to analyze real water samples, and it was found that the detection results showed a good correlation with the detection results of ddPCR (R²=0.997), demonstrating its practical utility. The designed sensor operated in the absence of the polymerase chain reaction and accurately quantified the targets. It was sensitive and dependable for the on-site detection of ARGs within the environment and is expected to be broadly applied in environmental monitoring and detection.

Keywords

Hybridization chain reaction (HCR); DNAzyme; Tetracycline resistance genes

【文章链接】https://doi.org/10.1016/j.jhazmat.2025.138226