摘要

    起泡是许多废水处理厂（WWTP）的活性污泥（AS）中发生的常见操作问题，但泡沫中通常缺乏抗生素抗性基因（ARG）和人类病原菌（HPB）的特征。在这里，我们采用了宏基因组学的方法来表征来自农药废水的大规模污水处理厂的泡沫和AS中ARG和HPB的特征。 AS和泡沫样品之间的微生物群落没有显着差异。泡沫中ARG的多样性和丰度与相关AS样品中的相似。 Procrustes分析表明，细菌群落是ARGs的主要驱动力。元基因组装配还表明，大多数ARG（例如，多药，利福霉素，肽，大环内酯-林可酰胺-链霉菌素，四环素，氟喹诺酮和β-内酰胺抗性基因）均由染色体携带，而不是由移动遗传元件携带。此外，泡沫样品中还富集了HPB，恶臭假单胞菌和耻垢分枝杆菌的相对丰度。鉴定出9种HPB为21种ARG亚型的携带者，其中铜绿假单胞菌可携带12种ARG亚型。总体而言，这项研究表明泡沫中普遍存在ARGs，HPB和携带ARG的HPB，这突出了泡沫将ARGs和HPB散布到周围环境中的潜在风险。

    Foaming is a common operational problem that occurs in activated sludge (AS) from many wastewater treatment plants (WWTPs), but the characteristic of antibiotic resistance genes (ARGs) and human pathogenic bacteria (HPB) in foams is generally lacking. Here, we used a metagenomic approach to characterize the profile of ARGs and HPB in foams and AS from full-scale WWTPs receiving pesticide wastewater. No significant difference in the microbial communities was noted between the AS and foam samples. The diversity and abundance of ARGs in the foams were similar to those in the pertinent AS samples. Procrustes analysis suggested that the bacterial community is the major driver of ARGs. Metagenomic assembly also indicated that most ARGs (e.g., multidrug, rifamycin, peptides, macrolide-lincosamide-streptogramin, tetracycline, fluoroquinolone, and beta-lactam resistance genes) were carried by chromosomes rather than mobile genetic elements. Moreover, the relative abundances of HPB, Pseudomonas putida and Mycobacterium smegmatis, were enriched in the foam samples. Nine HPB were identified as carriers of 21 ARG subtypes, of which Pseudomonas aeruginosa could carry 12 ARG subtypes. Overall, this study indicates the prevalence of ARGs, HPB, and ARG-carrying HPB in foams, which highlights the potential risk of foams in spreading ARGs and HPB into the surrounding environments.

    https://www.sciencedirect.com/science/article/abs/pii/S0304389420328466