PLPA 250 Seminar- Dr. Yujie Men

Yujie Men PLPA 250
Genomics Auditorium 1102A, UC Riverside

The Department of Microbiology and Plant Pathology's weekly Plant Pathology 250 seminar series is presented this week by Dr. Yujie Men, from the Department of Chemical and Environmental Engineering  at UC Riverside.

Seminar Title: "Effects of pesticides on antibiotic resistence emergence, propagation, and transmission"

Abstract: Identifying stressors that can influence antibiotic resistance evolution is pivotal to understand and control the development and widespread of resistant bacteria in many environments. Antibiotics at low concentrations are found to select for resistant mutations and shape evolutionary pathways. However, how co-occurring environmental stressors such as the non-antibiotic organic contaminants influence the emergence and transmission of antibiotic resistance remains unknown. To explore the evolution trajectory toward antibiotic resistance, susceptible Escherichia coli populations were exposed to sub-inhibitory antibiotics together with environmental-level pesticides as the co-stressor and evolved for 500 generations. Phenotypic resistance levels of the evolved populations were determined after every 100-generation passages, and population genetic mutations responsible for the phenotypic resistance change were identified by whole-genome sequencing. To explore the effect of pesticide-exposure on antibiotic resistance transmission among the same and different species, conjugation experiments were carried out.  Results show that the co-exposure of pesticides drove the evolutionary paths to higher resistance under sub-inhibitory antibiotic selection pressure and accelerate the transmission of antibiotic resistance. Dynamics of genetic mutations responsible for the resistance change in the co-exposed populations were distinct from those in the populations exposed to sub-inhibitory antibiotics only. Together, it unravels the evolutionary and genetic basis on which higher antibiotic resistance may be developed under the co-exposure of pesticides and antibiotics at environmentally relevant concentrations. The findings can guide the design of new antibiotic targets, as well as novel biomarkers/biosensors for antibiotic resistance monitoring.     

Bio: Dr. Yujie Men is an Assistant Professor in the Department of Chemical and Environmental Engineering at University of California, Riverside. Before she joined UCR July this year, she was an Assistant Professor in Civil and Environmental Engineering at University of Illinois, Urbana-Champaign. She earned her B.S. and M.S. from Tsinghua University, and Ph.D. from University of California, Berkeley. She worked as a postdoc scientist in Environmental Chemistry at Eawag, Switzerland. Her research focuses on engineering applications of environmental microbiology and microbial ecology principles, such as bioremediation of environmental organic contaminants, sustainable wastewater treatment and resource recovery.

Email:; Research website:

Seminar Host: Dr. Jason Stajich;

Contact Information
Margarita Flores
Plant Pathology 250
Target Audience
Students, Faculty