重金属介导的抗生素抗性基因接合转移研究进展

Recent Advances in Heavy Metals-mediated Conjugation of Antibiotic Resistance Genes

抗生素抗性基因(ARGs)在人类-动物-环境之间的跨界面传播和聚集已成为公共卫生和环境生态系统的主要问题,ARGs和携带这些基因的可移动遗传元件(MGEs)已被视为新出现的环境污染物。环境重金属介导的ARGs水平转移增加了ARGs在本土微生物中富集的潜在风险。目前,研究重金属及其它新污染物诱导的ARGs水平转移已成为环境及其相关学科领域的研究热点。该文综述了重金属作为共选择剂对环境中ARGs接合转移的影响,重点从分子生物学角度分析了重金属引起ARGs接合转移增加的相关机制。重金属介导的ARGs接合转移是ARGs丰度增加的主要原因,重金属引起的接合频率的变化主要与其浓度相关,与毒物兴奋效应一致。相关调控机制包括调节活性氧(ROS)的产生、启动SOS反应、增强细胞膜通透性以及影响接合转移相关基因的表达和ATP合成。阐明在污染环境中(复合)重金属以及重金属与抗生素协同,在不同环境条件下增强ARGs水平转移的机制是今后研究的关键方向,可为重金属介导的ARGs环境行为研究提供一定的参考。

Cross-interface spread and aggregation of antibiotic resistance genes(ARGs)at human-animal-environment has become a major problem in public health and environmental ecosystems,ARGs and mobile genetic elements(MGEs)carrying ARGs have been recognized as emerging environmental contaminants.Heavy metal-mediated horizontal transfer of ARGs increases the potential risk of ARG enrichment in indigenous microorganisms.Currently,the study of horizontal transfer of ARGs mediated by heavy metals and other emerging contaminants has become a hot research topic in the field of environment and its related disciplines.The review outlines the effects of heavy metals as co-selectants on the conjugation of ARGs in the environment,focusing on the mechanisms associated with the increased conjugation of ARGs induced by heavy metals from a molecular biological perspective.The heavy metal-mediated conjugation of ARGs was the main reason for the increased abundance of ARGs,and the heavy metal-induced changes in conjugation frequency were mainly related to their concentra⁃tions,which is consistent with the hormesis.Related regulatory mechanisms include regulation of reactive oxygen species(ROS)production and initiation of SOS responses,enhancement of cell membrane permeability,and effects on conjugation transfer-related gene expression and ATP synthesis.Elucidation of the mechanisms that enhance the horizontal transfer of ARGs in contaminated environments with heavy metals(or compound heavy metals)and antibiotics under different environ⁃mental conditions is a key direction for future research.It can provide some reference for the study of heavy metal-mediated environmental behavior of ARGs.