Division for Marine and Environmental Research , Rudjer Boskovic Institute , Bijenicka c. 54 , 10000 Zagreb , Croatia.
Environ Sci Technol. 2019 Jul 2;53(13):7463-7472. doi: 10.1021/acs.est.9b01420. Epub 2019 Jun 20.
A one-year study on the occurrence and fate of macrolide antibiotics and their metabolites, synthesis byproducts, and transformation products (TPs) was performed in the wastewater treatment plant of the city of Zagreb (Croatia). The target compounds were found in all analyzed influent and effluent samples with the total concentrations of azithromycin-, clarithromycin-, and erythromycin-related compounds reaching up to 25, 12, and 0.25 μg/L, respectively. The most prominent individual constituents were the parent macrolides azithromycin and clarithromycin. However, a substantial contribution of their derivatives, formed by deglycolysation and microbial phosphorylation, was also detected. In addition, widespread presence of several linearized nontarget TPs was confirmed for the first time in real wastewater samples by suspect screening analysis. Complex characterization of macrolide-derived compounds enabled decoupling of industrial and therapeutic sources from the in situ transformations. Due to the high inputs and incomplete removal and/or formation of several TPs during the conventional wastewater treatment, the average mass load of azithromycin-related compounds in secondary effluents exceeded 3.0 g/day/1000 inhabitants. This is the first study to reveal the importance of metabolites, byproducts, and TPs for the overall mass balance of macrolide antibiotics in urban wastewater systems.
一项为期一年的研究在萨格勒布市（克罗地亚）的污水处理厂进行，旨在研究大环内酯类抗生素及其代谢物、合成副产物和转化产物（TPs）的产生和归宿。目标化合物在所有分析的进水和出水样品中均被检出，总浓度高达 25、12 和 0.25μg/L，分别对应阿奇霉素、克拉霉素和红霉素相关化合物。最突出的个别成分是大环内酯类抗生素阿奇霉素和克拉霉素。然而，通过可疑筛选分析，首次在实际废水样品中证实了其去糖基化和微生物磷酸化形成的衍生物也大量存在。对大环内酯类衍生化合物的复杂特征分析，使得能够将工业和治疗来源与原位转化区分开来。由于在传统污水处理过程中输入量高，且部分 TPs 去除不彻底或形成，二级出水中阿奇霉素相关化合物的平均质量负荷超过 3.0 克/天/1000 居民。这是首次揭示代谢物、副产物和 TPs 对城市废水处理系统中大环内酯类抗生素总体质量平衡的重要性的研究。
