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.

华盛顿的CBET-1254929 Michael Dodduniversity？在过去的几十年中，在医疗保健环境中细菌种群中，抗生素耐药性特征的患病率显着增加。同时，还清楚地表明，抗生素耐药菌（ARB）及其相关的抗生素耐药性基因（ARGS）广泛分布在水生环境系统中（例如，市政废物，农业废物流，农业废物流，甚至处理过的饮用水）。在这种情况下，使用消毒剂（即适用于水性基质或无生命表面的化学或物理剂）和防腐剂（即，适用于生物组织的化学或物理药物）以供水供应中的ARB灭活，在供水中提供了供应替代物或在污染物中提供污染物，以提供MITIG的关键分解。但是，即使在消毒过程中ARB完全灭活，其完整的含有ARG的DNA的段也可能保留在所得的细胞碎片范围内，并赋予抗生素耐药性特征，以通过无需实用DNA供体细胞（例如自然转化）的水平基因转移过程，以暂时或空间分离的细菌种群。该研究项目正在进行：（a）量化完整，生物活性args的可能性？消毒过程即使在ARB失活之后，以及（b）提供评估和减轻这种ARG在促进环境和临床上与临床上与临床相关的细菌群落之间促进抗生素耐药性时所带来的风险所必需的数据。一套常规和分子微生物学分析工具将用于检查自由（细胞外）和细胞相关（细胞内）染色体和质粒的命运，这些细菌在暴露于绝消毒和抗药性药物中的多种细菌物种中，在水上和医疗服务中应用。从这些研究中获得的结果将实现对当前用于水处理和保健实践应用的消毒过程中细胞外和细胞内ARD失活的定量建模，而这又有可能设计消毒剂和抗药性应用，以设计专门用于静止的工作。停用args。最终的数据不仅将促进对消毒过程的优化，以最大程度地减少自然和工程水生环境和保健环境之间完整的ARG转移，而且还将大大提高对DNA对各种消毒和抗菌物质的DNA反应性的基本理解，以及在哪些过程中灭活过程中的细菌细胞灭活的机制。由于公众对抗生素抗药性的社会重要性的认识很高，因此该主题也代表了吸引K-12教师和学生加强STEM课程的非凡机会。因此，该项目将被用作与STEM教师和来自区域高中的代表性不足的学生合作的平台，以开发针对与项目范围相关的概念的教学实验室模块套件。这些实验室模块随后将在区域高中课程中实施，并由PI使用，以帮助培训新的本科和研究生研究助理。该项目还将支持研究生的职业发展和几位代表性不足的本科生。

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