Christina Ahn Hickey, M.D., M.A

Gastroenterology, Hepatology and NutritionPathobiology

phone: 314-362-4249

Research Interests

Defining host-microbial interactions that lead to development of inflammatory bowel disease My main research interest is in the microbial-host interaction in inflammatory bowel disease (IBD). Because of this interest, I am working in Thaddeus Stappenbeck’s lab on the mechanism of the colitogenic potential of commensal bacteria in a genetically predisposed IBD mouse model. My core hypothesis is that the colitogenic potential of a given Bacteroides sp. is directly related to its ability to evade and penetrate host defenses such as mucus and the epithelial layer. I recently found that one such commensal, Bacteroides thetaiotaomicron (B. theta) antigen accesses host immune cells in a sulfatase dependent manner. B. theta does so via a novel mechanism, outer membrane vesicles, which contain enzymatic properties. My current work is focused on the specific mechanisms of B. theta OMVs to traverse through the mucus and epithelial layer. I am using a combination of primary cell culture techniques, genomic screens, and genetic mouse models to pursue this question. Currently, I am supported with funding from the Pediatric Scientist Development Program to pursue a basic science project in my area of interest.


  • B.S., Graduated with Distinction (top 15% of class), Stanford University2003
  • M.D., Elisabeth L. Demonchaux Prize in Pediatrics, Washington University School of Medicine2009
  • M.A., Washington University School of Medicine2009


  • Residency, Washington University2009 - 2012
  • Fellowship, Washington University2012 - 2015

Licensure and Board Certification

  • Pediatric Board Certified2013
  • MO, State of Missouri Medical License2015


  • National Merit Scholar1999
  • Stanford University Chemistry Summer Undergraduate Research Bing Fellowship2001 - 2001
  • Phi Beta Kappa2003
  • Olin Fellowship full tuition scholarship to Washington University School of Medicine2004 - 2009
  • First place in prose division of The Legible Script National Literary Competition for Medical Students2006
  • Essay selected for Princeton Review's "Medical School Essays that have Made a Difference"2007
  • Doris Duke Clinical Research Fellowship2007 - 2008
  • Distinguished Graduate in Medicine, highlighted in the Washington Record Graduation Issue2009
  • Elisabeth L. Demonchaux Prize in Pediatrics2009
  • Teaching and Tomorrow participant in NASPGHAN's October 2010 Conference2010
  • Pediatric Scientist Development Program grant recipient2012 - Pres

Selected Publications view all (6)

Publication Co-Authors

  1. Hickey CA, Kuhn KA, Donermeyer DL, Porter NT, Jin C, Cameron EA, Jung H, Kaiko GE, Wegorzewska M, Malvin NP, Glowacki RW, Hansson GC, Allen PM, Martens EC, Stappenbeck TS. Colitogenic Bacteroides thetaiotaomicron Antigens Access Host Immune Cells in a Sulfatase-Dependent Manner via Outer Membrane Vesicles. Cell Host Microbe. 2015;17(5):672-80. doi:10.1016/j.chom.2015.04.002  PMCID:PMC4432250  PMID:25974305  
  2. Hickey CA, Beattie TJ, Cowieson J, Miyashita Y, Strife CF, Frem JC, Peterson JM, Butani L, Jones DP, Havens PL, Patel HP, Wong CS, Andreoli SP, Rothbaum RJ, Beck AM, Tarr PI. Early volume expansion during diarrhea and relative nephroprotection during subsequent hemolytic uremic syndrome. Arch Pediatr Adolesc Med. 2011;165(10):884-9. doi:10.1001/archpediatrics.2011.152  PMCID:PMC4064458  PMID:21784993  
  3. Ahn CK, Russo AJ, Howell KR, Holt NJ, Sellenriek PL, Rothbaum RJ, Beck AM, Luebbering LJ, Tarr PI. Deer sausage: a newly identified vehicle of transmission of Escherichia coli O157:H7. J Pediatr. 2009;155(4):587-9. doi:10.1016/j.jpeds.2009.02.051  PMID:19773004  
  4. Pollock KG, Stewart A, Beattie TJ, Todd WT, Ahn CK, Tarr PI, Cowden JM. From diarrhoea to haemolytic uraemic syndrome - when to seek advice. J Med Microbiol. 2009;58(Pt 4):397-8. doi:10.1099/jmm.0.007179-0  PMID:19273631  
  5. Ahn CK, Holt NJ, Tarr PI. Shiga-toxin producing Escherichia coli and the hemolytic uremic syndrome: what have we learned in the past 25 years? Adv Exp Med Biol. 2009;634:1-17. PMID:19280844  
  6. Ahn CK, Klein E, Tarr PI. Isolation of patients acutely infected with Escherichia coli O157:H7: low-tech, highly effective prevention of hemolytic uremic syndrome. Clin Infect Dis. 2008;46(8):1197-9. doi:10.1086/587664  PMID:18444855