91¶ÌÊÓƵ

Ph.D. in Biochemistry and Molecular Biology, The 91¶ÌÊÓƵ of Chicago, (2011)

Waste Management Facility Operator License, Class III

Sponsoring Organization: Commonwealth of Virginia

Date Obtained: 2021-01-01

Expertise

Research Interests

small molecule signaling contributing to virulence and persistence in Clostridium difficile

Articles

Purcell, E., Siegal-Gaskins, D., Rawling, D. C., Fiebig, A. and Crosson, S. (2007). A photosensory two-component system regulates bacterial cell attachment. Proceedings of the National Academy of Sciences of the United 91¶ÌÊÓƵs of America 104 (46) , pp. 18241-6.

Purcell, E., McDonald, C. A., Palfey, B. A. and Crosson, S. (2010). An analysis of the solution structure and signaling mechanism of LovK, a sensor histidine kinase integrating light and redox signals. Biochemistry 49 (31) , pp. 6761-70.

Purcell, E., McKee, R. W., McBride, S. M., Waters, C. M. and Tamayo, R. (2012). Cyclic diguanylate inversely regulates motility and aggregation in Clostridium difficile. Journal of Bacteriology 194 (13) , pp. 3307-16.

McKee, R. W., Mangalea, M. R., Purcell, E., Borchardt, E. K. and Tamayo, R. (2013). The second messenger cyclic Di-GMP regulates Clostridium difficile toxin production by controlling expression of sigD. Journal of Bacteriology 195 (22) , pp. 5174-85.

Bordeleau, E., Purcell, E., Lafontaine, D. A., Fortier, L. C., Tamayo, R. and Burrus, V. (2015). Cyclic di-GMP riboswitch-regulated type IV pili contribute to aggregation of Clostridium difficile. Journal of Bacteriology 197 (5) , pp. 819-32.

Purcell, E., McKee, R. W., Bordeleau, E., Burrus, V. and Tamayo, R. (2015). Regulation of type IV pili contributes to surface behaviors of historical and epidemic strains of Clostridium difficile. Journal of Bacteriology 198 (3) , pp. 565-77.

Purcell, E. and Crosson, S. (2008). Photoregulation in prokaryotes. Current Opinion in Microbiology 11 (2) , pp. 168-78.

Purcell, E. and Tamayo, R. (2016). Cyclic diguanylate signaling in Gram-positive bacteria. FEMS Microbiology Reviews 40 (5) , pp. 753-73.

Poudel, A., Pokhrel, A., Oludiran, A., Coronado, E. J., Alleyne, K., Gilfus, M. M., Gurung, R. K., Adhikari, S. B. and Purcell, E. (2022). Unique features of alarmone metabolism in Clostridioides difficile. Journal of Bacteriology 204 (4) , pp. e0057521.

Purcell, E. (2022). Second messenger signaling in Clostridioides difficile. Current Opinions in Microbiology 65 , pp. 138-144.

Poudel, A., Oludiran, A., Sozer, E. B., Casciola, Purcell, E. and Muratori, C. (2021). Growth in a biofilm sensitizes Cutibacterium acnes to nanosecond pulsed electric fields. Bioelectrics 140 , pp. 107797.

Pokhrel, Poudel, A., Kory, C. B., Celestine, M. J., Adenrele, O., Rinehold, A. J., Resek, A. M., Mhanna, M. A. and Purcell, E. (2020). The (p)ppGpp Synthetase RSH Mediates Stationary-Phase Onset and Antibiotic Stress Survival in Clostridioides difficile.. Journal of Bacteriology 202 (19) , pp. e00377-20.

Oludiran, A., Courson, D. S., Stuart, M. D., Radwan, A. R., Poutsma, J. C., Cotten, M. L. and Purcell, E. (2019). How Oxygen Availability Affects the Antimicrobial Efficacy of Host Defense Peptides: Lessons Learned from Studying the Copper-Binding Peptides Piscidins 1 and 3. International Journal of Molecular Sciences 20 (21) , pp. 5289.

Courson, D. S., Pokhrel, A., Scott, C., Madrill, M., Rinehold, A. J., Tamayo, R., Cheney, R. and Purcell, E. (2019). Single cell analysis of nutrient regulation of Clostridioides (Clostridium) difficile motility.. Anaerobe 59 , pp. 205-211.

Pokhrel, A., Poudel, A. and Purcell, E. (2018). A Purfication and in vitro Activity Assay for a (p)ppGpp Synthetase from Clostridium difficile. Journal of Visualized Experiments 141 , pp. e585547.

Purcell, E., McKee, R. W., Courson, D. S., Garrett, E. M., McBride, S. M., Cheney, R. E. and Tamayo, R. (2017). A nutrient-regulated cyclic diguanylate phosphodiesterase controls Clostridium difficile biofilm and toxin production during stationary phase. Infection and Immunity 1885 (9) , pp. 1-17.

Alexandre, M. T., Purcell, E., van Grondelle, R., Robert, B., Kennis, J. T. and Crosson, S. (2010). Electronic and protein structural dynamics of a photosensory histidine kinase. Biochemistry 49 (23) , pp. 4752-9.

Key, J., Hefti, M., Purcell, E. and Moffat, K. (2007). Structure of the redox sensor domain of Azotobacter vinelandii NifL at atomic resolution: signaling, dimerization, and mechanism. Biochemistry 46 (12) , pp. 3614-23.

Rajagopal, S., Key, J. M., Purcell, E., Boerema, D. J. and Moffat, K. (2004). Purification and initial characterization of a putative blue light-regulated phosphodiesterase from Escherichia coli. Journal of Photochemistry and Photobiology 80 (3) , pp. 542-7.

Book Chapters

Purcell, E., Boutte, C. C. and Crosson, S. (2008). Two-component signaling systems and cell cycle control in Caulobacter crescentus Advances in Experimental Medicine and Biology (pp. 122-30) New York, NY: Springer Publishing.

Purcell, E. and Tamayo, R. (2013). Identification and characterization of cyclic nucleotide phosphodiesterases Methods in Molecular Biology (pp. 235-43) Clifton, NJ: Humana Press.

Presentations

(November 4, 2020). Mechanisms of Stress Avoidance and Survivial in Vegetative Clostridioides difficile. Poster 7th International C. difficile Symposium Virtual.

(October , 2020). Hitting the (magic) spot: Defining the role of (p)ppGpp in Clostridioides difficile stress survival. Poster Cold Spring Harbor Laboratory Microbiome Meeting Virtual.

(June 18, 2020). The Atypical (p)ppGpp Synthetase CdRSH Mediates Clostridioides difficile Antibiotic Survival Poster ASM Microbe Virtual.

Pokhrel, A., Castro, K. and Purcell, E. (February , 2019). The (p)ppGpp-Mediated Stringent Response Contributes to Antibiotic Tolerance in Vegetative Clostridium difficile. Oral Presentation the Mid-Atlantic Microbial Pathogenesis Meeting Wintergreen, VA.

Purcell, E. (January 25, 2019). Finding the Signaling Pathways That Allow Antibiotic Resistance in Clostridium difficile. Lecture Molecular Biology and Chemistry Departmental Seminar Newport News, VA.

Purcell, E. (October 2, 2018). Probing the Molecular Basis of Clostridium difficile Antibiotic Resistance Lecture Frank Reidy Research Center for Bioelectrics Seminar Series Norfolk, VA.

Purcell, E. (March 23, 2018). Identifying the small signaling molecules that mediate antibiotic tolerance in Clostridium difficile Lecture Institute for Structural Biology, Drug Discovery and Development Spring Seminar Series Richmond, VA.

Purcell, E., McKee, R. W., Bordeleau, E., Burrus, V. and Tamayo, R. (January , 2015). Regulation of type IV pili contributes to surface behaviors of historical and epidemic strains of Clostridium difficile. Paper the Mid-Atlantic Microbial Pathogenesis Meeting Wintergreen, VA.

Purcell, E., McKee, R. W., Courson, D. S., Garrett, E. M., McBride, S. M., Cheney, R. E. and Tamayo, R. (May , 2013). A nutrient-regulated cyclic diguanylate phosphodiesterase controls Clostridium difficile biofilm and toxin production during stationary phase. Paper the American Society for Microbiology General Meeting Denver, CO.

• 2013: UNC Microbiology & Immunology Postdoctoral Research Symposium. Best talk award,
• 2012: UNC Center for Gastroenterology and Disease Poster Contest. First prize,
• 2010: 91¶ÌÊÓƵ of Chicago Biological Sciences Divisional Travel Award,
• 2003: Johns Hopkins 91¶ÌÊÓƵ Departmental Honors in Biophysics,
• 2002: Phi Beta Kappa, Phi Beta Kappa