典型异噻唑啉酮类药物对抗生素抗性基因自然转化的影响  

Effect of typical Isothiazolinones on the natural transformation of antibiotic resistance genes

作　　者：张利兰 董国梁[1] 黄嘉平 于鹏飞 ZHANG Lilan;DONG Guoliang;HUANG Jiaping;YU Pengfei(Key Laboratory of Three Gorges Reservoir Region’s Eco-environment,Ministry of Education,Chongqing University,Chongqing 400044;State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044)

机构地区：[1]重庆大学三峡库区生态环境教育部重点实验室,重庆400044 [2]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044

出　　处：《环境科学学报》2025年第3期485-492,共8页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.42177363,42377387)。

摘　　要：人类广泛使用抗生素所带来的选择压力导致环境中抗生素抗性基因(ARGs)不断积累,并通过水平基因转移进一步在环境中扩散,对全球公共卫生安全具有巨大威胁.转化作为水平基因转移的一种重要方式,受到环境中不同污染物胁迫的调控.异噻唑啉酮类药物与抗生素的作用对象和作用机制相似,本研究旨在探讨该类药物是否会促进ARGs的自然转化以及可能的机制.结果表明,0.25、1、2 mg·L^(-1)的甲基异噻唑啉酮(MIT)和辛基异噻唑啉酮(OIT)的暴露均促进了pRK415质粒介导的ARGs自然转化速率,且同浓度的OIT对转化的促进效果大于MIT.OIT浓度与转化频率呈线性相关关系(R2=0.933),其中2 mg·L^(-1)的OIT暴露对转化频率的促进最高可达13.5倍(padj<0.01).进一步,通过分析异噻唑啉酮类药物暴露对细菌氧化应激水平、细胞膜通透性和能量代谢的影响,发现药物诱导活性氧中羟基自由基的过量产生,进而造成的氧化胁迫可能是MIT和OIT促进细菌转化吸收ARGs的主要机制.相较于MIT,OIT促进了细菌的质子动力,提高了细菌代谢和ROS中·OH生成量,推测其可能是同等浓度下OIT对细菌转化的促进效果大于MIT的原因之一.该研究首次明确了异噻唑啉酮类药物具备促进ARGs在环境中水平转移的潜在风险.The widespread use of antibiotics in humans has led to a significant increase in antibiotic resistance in the environment,with antibiotic resistance genes(ARGs)accumulating in bacteria and further spreading through horizontal gene transfer,posing a great threat to global public health security.Transformation,as an important pathway of horizontal gene transfer,is influenced by different levels of pollutant stress.Since Isothiazolinones have similar targets and mechanisms of action with antibiotics,this study aimed to investigate whether Isothiazolinones could promote the natural transformation of ARGs and explore the potential mechanisms involved.The results showed that the exposure of 0.25,1,and 2 mg·L^(-1)methylisothiazolinone(MIT)and octylisothiazolinone(OIT)promoted the natural transformation of ARGs mediated by pRK415 plasmid,and the same concentration of OIT promoted transformation more than that of MIT.The concentration of OIT showed a linear correlation with transformation frequency(R 2=0.933),with the exposure of 2 mg·L^(-1)OIT promoting the transformation frequency up to 13.5-fold(p adj<0.01).Furthermore,by analyzing the effects of Isothiazolinones exposure on bacterial oxidative stress level,membrane permeability and energy metabolism,it was found that the excessive production of hydroxyl radicals in reactive oxygen species induced by drugs may be the main mechanism of MIT and OIT promoting bacterial transformation and absorption of ARGs.Compared to MIT,OIT is suspected to enhance bacterial exogenous plasmid uptake by promoting bacterial proton dynamics,which in turn influences bacterial metabolism and the production of·OH in ROS.This is suggested to be a reason why OIT promote bacterial transformation than MIT at equivalent concentrations.This study has,for the first time,identified the potential risk of Isothiazolinones in promoting the horizontal transfer of ARGs in the environment.

关 键 词：异噻唑啉酮类药物 抗生素抗性基因 水平传播 自然转化 

分 类 号：X171.5[环境科学与工程—环境科学]