摘要

      在中国南方北江采集的 20 个水样中调查并量化了抗生素抗性基因 (ARG) 的出现情况。在收集的 20 个样本中，有 17 个和 14 个存在耐磺胺和四环素的细菌。对于磺胺类 ARG，在北江经常观察到 sulI 和 sulII。 sulI 的水平高于 sulII (p < 0.05)，平均值分别为 (1.41 ± 1.12) × 10−2 和 (1.58 ± 1.71) × 10−3 拷贝/16S rDNA。对于四环素 ARG，tetG 的频率最高，为 100%，其次是 tetA (85%)、tetO (85%)、tetC (70%)、tetX (60%)、tetM (40%) 和 tetQ (20%) , 而在北江的所有样品中均未检测到 tetE 和 tetS。另一方面，tetC 的浓度最高，范围从 8.30 × 10-2 到 13.20 个拷贝/16S rDNA。 ARGs 与抗生素浓度之间的相关性较差表明，即使没有抗生素选择压力，ARGs 的自我扩增和持久性是使 ARGs 存在于水环境中的原因。由于用于调查中国南方河流中 ARGs 水平的实地测量很少，本研究为更好地了解 ARGs 在此类生态系统中的发生和传播提供了重要见解。

      The occurrence of antibiotic resistance genes (ARGs) was investigated and quantified in 20 water samples collected in the Beijiang River, South China. Sulfonamide- and tetracycline-resistant bacteria were present in 17 and 14 of the collected 20 samples. For sulfonamide ARGs, sulI and sulII were frequently observed in the Beijiang River. The levels of sulI were higher than sulII (p < 0.05), with the mean values of (1.41 ± 1.12) × 10−2 and (1.58 ± 1.71) × 10−3 copies/16S rDNA, respectively. For tetracycline ARGs, tetG had the highest frequency, 100%, followed by tetA (85%), tetO (85%), tetC (70%), tetX (60%), tetM (40%) and tetQ (20%), while tetE and tetS were not detected in all the samples from the Beijiang River. On the other hand, tetC had the highest concentration, ranging from 8.30 × 10−2 to 13.20 copies/16S rDNA. The poor correlation between ARGs and antibiotic concentrations revealed that the self-amplification and persistence of ARGs were the reasons that made ARGs exist in the water environment even though the antibiotic selecting pressure was absent. Because so few field measurements have been conducted for investigating the levels of ARGs in rivers in South China, this study provides an important insight on better understanding the occurrence and spread of ARGs in such an ecosystem.

https://www.sciencedirect.com/science/article/abs/pii/S100107421260223X