饮用水消毒工艺对抗生素耐药性风险的影响及其机理

Influence and mechanism of drinking water disinfection strategies on antibiotic resistance risk

为探究饮用水消毒工艺对耐药性风险的影响及其机制,本研究模拟了中试运行条件下不同消毒工艺的运行,采用基于高通量测序的宏基因组学方法分析不同消毒工艺对抗生素耐药基因(ARGs)丰度、潜在移动性和潜在致病性的影响,综合评估其对ARGs风险的控制效果并解析其机制。结果表明,臭氧-氯化消毒(O-C)显著降低了ARGs的总相对丰度,季铵盐树脂-氯化消毒(AR-C)和季铵盐树脂-紫外消毒(AR-UV)则显著增加了ARGs的总相对丰度。同时,AR-C和AR-UV增加了可移动遗传元件(MGEs)的总相对丰度,促进了ARGs与MGEs的共存在。此外,这2种消毒工艺提高了毒力因子(VFGs)的总相对丰度,其中进攻型和其他型VFGs的贡献最大。AR-UV还能促进ARGs与VFGs的共存在,多重耐药类ARGs与VFGs的基因组合是主要的共存模式。总的来说,AR-C和AR-UV提高了ARGs的潜在风险。消毒改变了ARGs潜在宿主的组成和丰度,宿主改变和水平基因转移是消毒过程中ARGs变化的关键因素。

To explore the impact and mechanism of drinking water disinfection on the risk of antibiotic resistance,the operation of different disinfection processes was simulated under pilot conditions in this study,and the metagenomic approach based on high-throughput sequencing was employed to analyze the effects of different disinfection processes on the abundance,potential mobility,and potential pathogenicity of antibiotic resistance genes(ARGs).Their control effectiveness on ARGs risk was comprehensively evaluated and the underlying mechanisms were deciphered.The results indicated that ozone-chlorine disinfection(O-C)significantly reduced the total relative abundance of ARGs,while antimicrobial resin-chlorine disinfection(ARC)and antimicrobial resin-ultraviolet disinfection(AR-UV)significantly increased the total relative abundance of ARGs.Simultaneously,AR-C and AR-UV increased the total relative abundance of mobile genetic elements(MGEs),promoting the co-occurrence of ARGs and MGEs.In addition,these two disinfection processes increased the total relative abundance of virulence factor genes(VFGs),of which the offensive and other VFGs made the most contribution.AR-UV also facilitated the co-occurrence of ARGs and VFGs,and the gene combination of multidrug resistance genes and VFGs was the main co-occurrence mode.Overall,AR-C and AR-UV increased the potential risk of ARGs.Disinfection altered the composition and abundance of ARGs potential hosts,and host changes and horizontal gene transfer were the key factors for the variation of ARGs during the disinfection process.