Cummings School of Veterinary Medicine at Tufts University
Xingmin Sun

Research Assistant Professor
Assistant Professor (Second appointment)
Clinical and Translational Science Institute, Tufts University

Campus Phone:



  • PhD - University of Kiel, Germany - 2002
  • MSc - Nanjing Agricultural University, China - 1994
  • BSc - Nanjing Agricultural University, China - 1991
  1. Ali Y, S. Koberg, S. Heβner, X. Sun, B. Rabe, A. Back, H. Neve, K.J. Heller (2014). Temperate Streptococcus thermophilus phages expressing superinfection exclusion proteins of the Ltp type. Front Microbiol. 5: 98
  2. Chen X., M. Dong and X. Sun* (2013). Mechanisms of action and applications of probiotics for the treatment of Clostridium difficile infection. (a chapter in “Microbial pathogens and strategies for combating them: science, technology and education”,ISBN-13 Vol. 2: 978-84-942134-03 Formatex Research Center, Zurbaran, Spain). * Corresponding author
  3. Zhang H., W. Li, X. Rui, X. Sun, M. Dong (2013). Lactobacillus plantarum 70810 from Chinese paocai as a potential source of β-galactosidase for prebiotic galactooligosaccharides synthesis. Eur Food Res Technol 236:817-826.
  4. Steele J., K. Chen, X. Sun, Y. Zhang, H. Wang, S. Tzipori & H. Feng (2012).  Systemic dissemination of Clostridium difficile toxins A and B is associated with severe, fatal disease in animal models. J Infect Dis.205(3):384-91.  
  5. Wang H., X. Sun, Y. Zhang, S. Li, K. Chen, L. Shi, W. Nie, R. Kumar, S. Tzipori, J. Fang, T. Savidge & H. Feng (2012). Development of vaccines against Clostridium difficile infection. (Accepted by Infection Immun.).
  6. Wu, J.,  Z. Lu, M. Nie, H. Zhou, X. Sun, X. Xue, J. Bi, G. Fang (2012). Optimization of Cryopreservation Procedures for Porcine Endothelial Progenitor Cells.  J Biosci Bioeng.  113(1):117-23.
  7. Sun X., H. Wang, Y. Zhang, K. Chen, B. Davis & H. Feng (2011). A mouse relapse model of Clostridium difficile infection. Infection Immun.79(7):2856-64.
  8. Sun X., T. Savidge & H. Feng (2010). The enterotoxicity of Clostridium difficile toxins. Toxins. 2(7), 1848-1880. (Invited review).
  9. Sun X., X. He, S. Tzipori, R. Gerhard & H. Feng (2009). Essential role of the glucosyltransferase activity in Clostridium difficile toxin-induced secretion of TNF-α by macrophages. Microb Pathog. 46(6):298-305.
  10. He X., X. Sun*, S. Tzipori, H. Feng (2009). Antibody-enhanced, Fc{gamma}R-mediated endocytosis of Clostridium difficile toxin A.Infection Immun. 77(6):2294-303. *Co-first author.
  11. He X., J. Steele, X. Sun, S. Tzipori & H. Feng (2009). An ultrasensitive and rapid immunocytotoxicity method for detecting Clostridium difficiletoxins. J Microbiol Methods. 78(1):97-100.
  12. Yang, G., B. Zhou, J. Wang, X. He, X. Sun, W. Nie, S. Tzipori & H. Feng (2008). Expression of recombinant Clostridium difficile toxin A and B inBacillus megateriumBMC Microbiol. 8:192.
  13. Sun X., A. Göhler, K. J. Heller & H. Neve (2006). The ltp gene of temperate Streptococcus thermophilus phage TP-J34 confers superinfection exclusion to Streptococcus thermophilus and Lactococcus lactisVirology350 (1): 146-157.
  14. Sun X., D. F. Mierke, T. Biswas, S. Y. Lee, A. Landy & M. Radman-Livaja (2006). Architecture of the 99 bp DNA – Six Protein Regulatory Complex of the λ att Site. Mol Cell. 24(4):569-80. (This paper was highlighted on the cover of the journal.)

General Research Interests

My general research interest is microbial pathogenesis, host-pathogen interactions, inflammatory and immune response against pathogen infections, and development of immunotherapies.

My current research focus is on the pathogenesis of Clostridium difficile.  C. difficile infection (CDI) has become a significant public health threat in the past decade. Toxins TcdA and TcdB are two major virulent factors of C. difficile. We are investigating C. difficile toxin-mediated signal transduction, leading to the production of proinflammatory mediators, such as TNF-α. We are also developing preventive and therapeutic approaches targeting C. diffcile toxins and proinflammatory mediators in CDI. We have established several animal models of CDI.

Selected Research Projects

  1. Evaluation of novel therapeutics in animal models of CDI including mice and hamsters.
  2. The innate immune responses to CDI.
  3. The relative roles of C. difficile toxins in animal models.
  4. Signaling pathway of TNF-α production and Clostridium difficile infection (CDI). The major goal is to elucidate the signaling pathway of toxin-mediated TNF-α production and develop a novel therapy against CDI by targeted blocking of TNF-α production.
  5. Development of novel therapeutic agents against C. difficile infection.
  6. Regulation of C. difficile toxin production.

Lab Members

  • Dr. Keshan Zhang
  • Dr. Song Zhao