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Mary Sievers takes 1st Place in the Undergraduate Research Exhibition, Health and Life Science Category

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"The Importance of the Cpx Stress Response Pathway in Antibiotic Resistance"

Mary Sievers

Sievers is one of Penn State’s most recent graduates and is working at the National Institutes of Health (NIH) in Bethesda, Maryland as a Postbacc IRTA fellow. After a year or two in that program, she plans to apply to graduate school and pursue her PhD.  Sievers has always had an interest in fine details and smaller mechanisms coming together to create a system much larger than the sum of its parts.  In high school her favorite class was AP Biology. When she started looking into what sort of major might be right for her, molecular biology seemed like a really good fit, so she chose BMB. Arriving at Penn State and beginning her studies confirmed her decision. She loved learning about biochemical mechanisms and the workings of cells.  She also found that she had the fine motor skills and attention to detail necessary for success in lab.

Sievers started working in Ades lab during her sophomore year as part of the BMB 488 course, after she took Microbiology 203, a course she enjoyed very much.  The material covered within Microbiology 203 was very similar to the work done in Ades lab.  She found BMB 488 to be a great way to start her lab experience.  Sievers found that the Ades lab had many undergrads that she could work and learn with, and that the BMB 488’s weekly seminar allowed students to discuss scientific papers related to antibiotic resistance, the research interest of the Ades Lab.

The focus of her project was the way that a specific type of bacteria cell, known as Gram-negative bacteria, communicates with its external environment through the use of regulatory systems known as stress response pathways. These pathways help the cell to sense and respond to environmental stressors, which include antibiotics in the cell's surroundings, and thus they may play a role in helping the cell respond to and survive in the presence of antibiotics. Antibiotic resistance is a worldwide problem that is causing many of the common drugs that we use to treat bacterial infections to become ineffective. Thus, it is incredibly important for research to be conducted to investigate the mechanisms within the cell that may cause resistance so society can be better prepared to combat this threat. Sievers specifically studied the importance of a stress response pathway known as the Cpx stress response pathway in resistance to mecillinam, a beta-lactam antibiotic.  She studied this by "knocking out" or removing an essential gene for the pathway in mecillinam resistant mutants.  She analyzed the effect of this “knock out” on the resistance of the mutants.  Her results indicated that the Cpx pathway appears to play a role in the resistance of E. coli bacteria to mecillinam, though different strains of bacteria exhibit different levels of dependence on this pathway for their resistance.  Notably, several mutants reverted from several hundred times the resistance level of the normal, wild-type strain back to wild-type resistance upon the knockout of the use of this pathway.

Congratulations Mia on a well-deserved finish at the Undergraduate Research Exhibition!