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Casey M. Theriot, PhD

Associate Professor

Office: 919.513.0711
Lab: Theriot Microbe Lab

My past research experiences have spanned the fields of molecular microbiology, protein biochemistry, microbial ecology, and bacterial pathogenesis. This multi-disciplinary training has fostered an ability to think outside the box in developing new approaches to understand mechanisms of bacterial pathogenesis. As an undergraduate researcher at the University of Georgia I studied the presence and absence of Desulfovibrio in the intestinal tracts of primates exposed to elemental mercury. After graduating from UGA, I went to work at the Centers for Disease Control and Prevention in Atlanta, Georgia. At CDC I was able to work with NARMS, the National Antimicrobial Resistance Monitoring System, and work on a collection of clinical enteric pathogen isolates from around the United States. My graduate work was a departure from working with intestinal pathogens and was focused on characterizing metalloproteases in Archaeal organisms. During my graduate career at North Carolina State University, I worked closely with the Army Research Office to engineer proteins from Pyrococcus species for stable and long term detoxification of nerve agents. The training in biochemistry and protein structure has been valuable in my current research, analyzing the structure and function of the gastrointestinal tract and its role in Clostridium difficile pathogenesis.

To build upon my prior research training and to contribute to public health research, I went to the University of Michigan to complete my postdoctoral training with Dr. Vincent Young, a leader in the field of microbial ecology and bacterial pathogenesis. My research is multidisciplinary and collaborative, bridging basic research with translational research. My postdoctoral research training has focused on exploring the interplay between the gastrointestinal tract microbiota and the pathogen C. difficile, a significant and re-emerging public health problem. C. difficile infection (CDI) is the leading cause of antibiotic-associated colitis, and is responsible for significant morbidity, mortality, and increased healthcare costs. My research has shown that antibiotics disrupt the indigenous gut microbiota reducing resistance to C. difficile colonization. My broad research career goal is to understand the complex interactions among the gastrointestinal microbiota, pathogens, and the host. I am currently focused on characterizing these mechanisms with respect to antibiotic usage. To accomplish my research goals I integrate data obtained from high-throughput methods that analyze the gastrointestinal microbiome, metabolome and host immune responses in animal models and human biological specimens to model these interactions.
The American Society for Microbiology
North Carolina Branch, The American Society for Microbiology
Anaerobe Society of the Americas
B.S. Environmental Health Science, The University of Georgia, Athens, GA
Ph.D. Microbiology, North Carolina State University, Raleigh, NC
Computational Biology and Bioinformatics, Gastroenterology, Global Health, Infectious Diseases
• Identifying the role of the gastrointestinal tract microbiome and metabolome in shaping colonization resistance against Clostridium difficile
• Clostridium difficile physiology and pathogenesis
• Metabolism of bile acids by the indigenous gastrointestinal microbiota
  • (2016) Metabolic model-based integration of microbiome taxonomic and metabolomic profiles elucidates mechanistic links between ecological and metabolic variation.Noecker, C., A. Eng, S. Srinivasan, C.M. Theriot, V.B. Young, J.K. Jansson, D.N. Fredricks, E. Borenstein. | mSystems 1(1):e00013-15. doi:10.1128/mSystems.00013-15
  • (2016) Antibiotic induced alterations of the gut microbiota alter secondary bile acids and allow forTheriot, C.M.#, A.A. Bowman, V.B. Young. | mSphere (1):e00045-15. doi: 10.1128/mSphere.00045-15. #Corresponding author.
  • (2015) Interactions between the Gastrointestinal Microbiome and Clostridium difficile.Theriot, C.M. and V.B. Young. | Annu Rev Microbiol. 2015 Oct 15;69:445-61. doi: 10.1146/annurev-micro-091014-104115
  • (2015) Fecal microbiota transplant eliminates Clostridium difficile in a murine model of relapsing disease.Seekatz, A.M., C.M. Theriot, C. Molloy, K. Wozniak, I. Bergin, V. Young. | Infect Immun. 2015 Oct;83(10):3838-46. doi: 10.1128/IAI.00459-15. Epub 2015 Jul 13
  • (2015) Dynamics and Establishment of Clostridium difficile Infection in the Murine Gastrointestinal Tract.Koenigsknecht, M.J., C.M. Theriot, I.L. Bergin, C.A. Schumacher, P.D. Schloss and V.B. Young. | Infection and Immunity 2015 Mar; 83(3):934-41. doi: 10.1128/IAI.02768-14
  • (2015) The Effects of Tigecycline and Vancomycin Administration on Established Clostridium difficile Infection.Theriot, C.M.#, C.M. Bassis, C.A. Schumacher, A.M. Seekatz, V.B. Young. | Antimicrobial Agents and Chemotherapy. 2015 Mar; 59(3):1596-604. doi: 10.1128/AAC.04296- #Corresponding author.
  • (2015) IL22 and CD160 Play Additive Roles in the Mucosal Host Response to Clostridium difficile Infection in Mice.Sadighi Akha, A.A., A.J. McDermott, C.M. Theriot, P.E. Carlson Jr., R.A. McDonald, N.R. Falkowski, I.L. Bergin, V.B. Young, G.B. Huffnagle. | Immunology. 2015 Apr; 144(4):587-97. doi: 10.1111/imm.12414.
  • (2014) difficile–Induced Colitis in Mice is Independent of Leukotrienes.Trindade. B.C., C.M. Theriot, J.L. Leslie, P.E. Carlson, I.L. Bergin, M. Peters-Golden, V.B Young, D.M. Aronoff. C. | Anaerobe. 2014 Dec; 30:90-8. doi: 10.1016/j.anaerobe.2014.09.006
  • (2014) Alteration of the Murine Gastrointestinal Microbiota by Tigecycline Leads to Increased Susceptibility to Clostridium difficile Infection.Theriot, C.M.*,#, C.M. Bassis*, V.B. Young | Antimicrobial Agents and Chemotherapy. 2014 May;58(5):2767-74. doi: 10.1128/AAC.02262-13 *Co-first authors. #Corresponding author.
  • (2014) Antibiotic-induced Shifts in the Mouse Gut Microbiome and Metabolome Increase Susceptibility to Clostridium difficile Infection.Theriot, C.M., M.J. Koenigsknecht, P.E. Carlson, G.E. Hatton, A.M. Nelson, B. Li, G. Huffnagle, J. Li, V.B. Young. | Nat. Commun. 5:3114 doi: 10.1038/ncomms4114
  • (2014) Microbial and Metabolic Interactions Between the Gastrointestinal Tract and Clostridium difficile Infection.Theriot, C.M.#, V.B. Young. | Gut Microbes 2014 Jan 1;5(1):86-95
  • (2013) The Complete Campylobacter jejuni Transcriptome During Colonization of a Natural Host Determined by RNAseq.Taveirne, M.E., C.M. Theriot, J. Livney, V.J. DiRita. | PLoS One 2013 Aug 21;8(8):e73586. doi: 10.1371/journal.pone.0073586. eCollection 2013.
  • (2013) Antibiotic-associated Diarrhea. In: Nelson K. (Ed.) Encyclopedia of Metagenomics: Springer ReferenceTheriot C.M., Young V. | Springer-Verlag Berlin Heidelberg, 0. DOI: 10.1007/SpringerReference_303379 2013-01-02 03:33:57 UTC.
  • (2013) Huffnagle. Acute Infection of Mice with Clostridium difficile Leads to an Innate Immune Response, eIF2α Phosphorylation and Pro-survival Signaling.Sadigh Akha, A.A., C.M. Theriot, J.R. Erb-Downward, A.J. McDermott, N.R. Falkowski, H.M. Tyra, R.A. McDonald, D.T. Rutkowski, V.B. Young, G.B. | Immunology 2013 Sep; 140(1):111-122. doi: 10.1111/imm.12122
  • (2011) Cefoperazone-treated Mice as an Experimental Platform to Assess Differential Virulence of Clostridium difficile StrainsTheriot, C.M., C.K. Koumpouras, P.E. Carlson, I.L. Bergin, D.M. Aronoff, V.B. Young | Gut Microbes 2(6):326-334. doi: 10.4161/gmic.19142
  • (2011) Improving the Catalytic Activity of Hyperthermophilic Pyrococcus horikoshii Prolidase for Detoxification of Organophosphorus Nerve Agents over a Broad Range of TemperaturesTheriot, C.M., B. Semcer, S. Shah, A.M. Grunden | Archaea 2011:Article ID 565127:1-9. doi: 10.1155/2011/565127
  • (2011) The Interplay Between Microbiome Dynamics and Pathogen Dynamics in a Murine Model of Clostridium difficile InfectionReeves, A.E., C.M. Theriot, I.L. Bergin, G.B. Huffnagle, P.D. Schloss, V.B. Young | Gut Microbes 2(3):145-58
  • (2011) Hydrolysis of Organophosphorus Compounds by Microbial Enzymes.Theriot, C.M., A.M. Grunden | Applied Microbiology and Biotechnology. 89(1):35-43. doi: 10.1007/s00253-010-2807-9
  • (2010) Improving the Catalytic Activity of Hyperthermophilic Pyrococcus Prolidases for Detoxification of OP Nerve Agents over a Broad Range of TemperaturesTheriot, C.M., X. Du, S.R. Tove, A.M. Grunden. | Applied Microbiology and Biotechnology. 87(5):1715-26. doi: 10.1007/s00253-010-2614-3
  • (2010) Characterization of Two Proline Dipeptidases (Prolidases) from the Hyperthermophilic ArchaeonTheriot, C.M., S.R. Tove, A.M. Grunden. | Pyrococcus horikoshii. Applied Microbiology and Biotechnology 86(1):177-88. doi: 10.1007/s00253-009-2235-x.