CAREER: Degradation and Deactivation of Extracellular and Intracellular Antibiotic Resistance Genes during Disinfection Processes

职业：消毒过程中细胞外和细胞内抗生素抗性基因的降解和失活

• 批准号: 1254929
• 负责人: Michael Dodd
• 金额: $ 40.85万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-01 至 2019-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1254929&HistoricalAwards=false
• 关键词: CAREER; Degradation; Deactivation; Extracellular; Intracellular

CBET-1254929Michael DoddUniversity of Washington ? SeattleThe prevalence of antibiotic resistance traits has increased dramatically amongst bacterial populations within health-care settings during the last several decades. Concurrently, it has also become clear that antibiotic resistant bacteria (ARB) and their associated antibiotic resistance genes (ARGs) are widely distributed within aquatic environmental systems (e.g., municipal wastewaters, agricultural waste streams, and even treated drinking waters). Within this context, the use of disinfectants (i.e., chemical or physical agents applied to aqueous matrixes or inanimate surfaces) and antiseptics (i.e., chemical or physical agents applied to living tissues) to inactivate ARB present in water supplies, in municipal wastewater, or on contaminated surfaces can provide a critical means for mitigating dissemination of antibiotic resistance. However, even if ARB are fully inactivated during disinfection processes, intact segments of their ARG-containing DNA may remain within the resulting cell debris and confer antibiotic resistance traits to temporally- or spatially-separated bacterial populations by means of horizontal gene transfer processes not requiring live DNA donor cells, such as natural transformation. This research project is being undertaken to: (a) quantify the likelihood of intact, biologically-active ARGs ?surviving? disinfection processes even after ARB inactivation, and (b) to provide the data necessary to evaluate and mitigate risks posed by such ARGs in promoting dissemination of antibiotic resistance amongst environmental and clinically-relevant bacterial communities. A suite of conventional and molecular microbiological analytical tools will be utilized to examine the fate of free (extracellular) and cell-associated (intracellular) chromosomal and plasmid-borne ARGs from a variety of bacterial species during exposure to the disinfectant and antiseptic agents most commonly applied in water treatment and health-care settings. The results obtained from these investigations will enable quantitative modeling of extracellular and intracellular ARG deactivation during disinfection processes currently applied in water treatment and health-care practice, in turn making it possible to design disinfectant and antiseptic applications specifically for deactivation of ARGs.This work will provide the first systematic investigation into the use of disinfectant and antiseptic agents expressly for the degradation and deactivation of ARGs. The resulting data will not only facilitate optimization of disinfection processes for minimizing the transfer of intact ARGs amongst natural and engineered aquatic environments and health-care settings, but will also greatly improve fundamental understanding of DNA reactivity toward various disinfectants and antiseptics and the mechanisms by which bacterial cells are inactivated during disinfection processes. Because of high public awareness as to the societal importance of antibiotic resistance, this topic also represents an exceptional opportunity to engage K-12 teachers and students in strengthening STEM curricula. The project will therefore be utilized as a platform from which to partner with groups of STEM teachers and underrepresented students from regional high schools, in order to develop suites of instructional laboratory modules focusing on concepts relevant to the project scope. These laboratory modules will subsequently be implemented within regional high school curricula, as well as utilized by the PI to aid in the training of new undergraduate and graduate research assistants. The project will also support the career development of a graduate student and several underrepresented undergraduate students.

CBET-1254929迈克尔·多德华盛顿大学？西雅图 在过去的几十年里，医疗保健机构内的细菌群体中抗生素耐药性特征的流行率急剧增加。同时，我们也清楚抗生素抗性细菌（ARB）及其相关的抗生素抗性基因（ARG）广泛分布在水生环境系统（例如城市废水、农业废水，甚至经过处理的饮用水）中。在此背景下，使用消毒剂（即应用于水性基质或无生命表面的化学或物理制剂）和防腐剂（即应用于活体组织的化学或物理制剂）来灭活供水、城市废水中存在的ARB，或在受污染的表面上进行消毒可以为减轻抗生素耐药性的传播提供重要手段。然而，即使ARB在消毒过程中完全失活，其含有ARG的DNA的完整片段也可能保留在产生的细胞碎片中，并通过水平基因转移过程赋予时间或空间分离的细菌群体抗生素抗性特征，而不需要活体DNA供体细胞，例如自然转化。该研究项目的目的是：(a) 量化完整的、具有生物活性的 ARGs“存活”的可能性。即使在 ARB 灭活后也能进行消毒过程，以及 (b) 提供必要的数据来评估和减轻此类 ARG 在促进环境和临床相关细菌群落中抗生素耐药性传播方面所带来的风险。将利用一套常规和分子微生物分析工具来检查最常见的接触消毒剂和防腐剂期间来自各种细菌物种的游离（细胞外）和细胞相关（细胞内）染色体和质粒携带的 ARG 的命运应用于水处理和医疗保健环境。从这些研究中获得的结果将能够对目前应用于水处理和医疗保健实践的消毒过程中细胞外和细胞内 ARG 失活进行定量建模，从而使设计专门用于 ARG 失活的消毒剂和防腐剂应用成为可能。这项工作将首次对专门用于 ARG 降解和失活的消毒剂和防腐剂的使用进行系统研究。由此产生的数据不仅有助于优化消毒过程，最大限度地减少完整 ARG 在自然和工程水生环境和医疗保健环境中的转移，而且还将极大地提高对各种消毒剂和防腐剂的 DNA 反应性及其机制的基本了解。细菌细胞在消毒过程中被灭活。由于公众对抗生素耐药性的社会重要性的高度认识，该主题也提供了一个让 K-12 教师和学生参与加强 STEM 课程的绝佳机会。因此，该项目将被用作一个平台，与来自地区高中的 STEM 教师和代表性不足的学生合作，开发一套侧重于与项目范围相关的概念的教学实验室模块。这些实验室模块随后将在地区高中课程中实施，并由 PI 用来帮助培训新的本科生和研究生研究助理。该项目还将支持一名研究生和几名代表性不足的本科生的职业发展。

项目成果

Degradation Kinetics of Antibiotic Resistance Gene mecA of Methicillin-Resistant Staphylococcus aureus (MRSA) during Water Disinfection with Chlorine, Ozone, and Ultraviolet Light

• DOI: 10.1021/acs.est.0c05274
• 发表时间: 2021-02-16
• 期刊: ENVIRONMENTAL SCIENCE & TECHNOLOGY
• 影响因子: 11.4
• 作者: Choi, Yegyun;He, Huan;Lee, Yunho
• 通讯作者: Lee, Yunho

Degradation and Deactivation of Bacterial Antibiotic Resistance Genes during Exposure to Free Chlorine, Monochloramine, Chlorine Dioxide, Ozone, Ultraviolet Light, and Hydroxyl Radical

• DOI: 10.1021/acs.est.8b04393
• 发表时间: 2019-02-19
• 期刊: ENVIRONMENTAL SCIENCE & TECHNOLOGY
• 影响因子: 11.4
• 作者: He, Huan;Zhou, Peiran;Dodd, Michael C.
• 通讯作者: Dodd, Michael C.

Degradation and deactivation of plasmid-encoded antibiotic resistance genes during exposure to ozone and chlorine

暴露于臭氧和氯期间质粒编码的抗生素抗性基因的降解和失活

• DOI: 10.1016/j.watres.2021.117408
• 发表时间: 2021
• 期刊: Water Research
• 影响因子: 12.8
• 作者: Yoon, Younggun;He, Huan;Dodd, Michael C.;Lee, Yunho
• 通讯作者: Lee, Yunho