Shantanu Bhatt, Ph.D.
Discipline Taught: Biology
Office: Science Center 124
B.S. in Biology - Denison University, Granville, OH (2001-2004)
PhD in Microbiology & Molecular Genetics - Emory University, Atlanta, GA (2005-2011)
Postdoctoral Researcher - National Institutes of Health (NIH), Bethesda, MD (2012-2013)
VanOrsdel CE*, Bhatt S*, Allen RJ, Brenner EP, Hobson JJ, Jamil A, Haynes BM, Genson AM, Hemm MR. J Bacteriol. 2013 Aug;195(16):3640-50. doi: 10.1128/JB.00324-13. Epub 2013 Jun 7. [*- both authors contributed equally and are co-first authors]
Bommarius B, Anyanful A, Izrayelit Y, Bhatt S, Cartwright E, Wang W, Swimm AI, Benian GM, Schroeder FC, Kalman D. PLoS One. 2013;8(1):e54456. doi: 10.1371/journal.pone.0054456. Epub 2013 Jan 23.
Bhatt S, Anyanful A, Kalman D. J Bacteriol. 2011 Sep;193(17):4516-22. doi: 10.1128/JB.05197-11. Epub 2011 Jun 24.
Bhatt S, Romeo T, Kalman D. Trends Microbiol. 2011 May;19(5):217-24. doi: 10.1016/j.tim.2011.01.004. Epub 2011 Feb 18.
Bhatt S, Edwards AN, Nguyen HT, Merlin D, Romeo T, Kalman D. Infect Immun. 2009 Sep;77(9):3552-68. doi: 10.1128/IAI.00418-09. Epub 2009 Jul 6.
Nguyen HT, Dalmasso G, Powell KR, Yan Y, Bhatt S, Kalman D, Sitaraman SV, Merlin D.
Gastroenterology. 2009 Oct;137(4):1435-47.e1-2. doi: 10.1053/j.gastro.2009.06.043. Epub 2009 Jun 21.
Bhatt S, Weingart CL. Curr Microbiol. 2008 May;56(5):418-22. doi: 10.1007/s00284-008-9114-z. Epub 2008 Feb 21.
Stevenson LG, Strisovsky K, Clemmer KM, Bhatt S, Freeman M, Rather PN. Proc Natl Acad Sci U S A. 2007 Jan 16;104(3):1003-8. Epub 2007 Jan 10.
Enteropathogenic E. coli (EPEC) is a major public health concern in developing countries where it causes significant morbidity and mortality in infants. EPEC, along with a few other related pathogens namely enterohemorrhagic E. coli (EHEC), Citrobacter rodentium, rabbit enteropathogenic E. coli (REPEC), and Escherichia albertii constitute a group collectively referred to as attaching and effacing (A/E) pathogens. They are so called because upon infection these pathogens attach intimately to intestinal cells and destroy cellular microvilli. Destruction of the microvilli reduces the ability of the cells to absorb water and nutrients, which ultimately leads to diarrhea. Upon destruction, the infected bacterium recruits the structural proteins from the microvilli and remodels them to form filament-like protrusions that extend out of the infected cell and are crowned on top by the infecting bacterium (Fig. 1). This histopathological structure is commonly referred to as attaching and effacing (A/E) pedestal. The ability of EPEC to form A/E lesions and cause disease depends on the presence of a pathogenicity island called locus of enterocyte effacement (LEE). The LEE encodes a type 3-secretion system that connects the cytoplasm of the bacteria to that of the host and enables EPEC to traffic a constellation of factors directly into the host, which aid bacterial colonization and cause disease. My lab is interested in identifying bacterial factors that regulate the LEE and modulate the resulting pathogenicity of EPEC. Identification of such virulence factors and their mechanism of action is essential for the development of effective therapeutic measures to combat EPEC infections, especially in light of the emergence of highly drug-resistant strains of EPEC. We use a highly interdisciplinary approach by incorporating tools and techniques from bioinformatics, genetics, and biochemistry to interrogate and characterize such virulence factors.
Figure 1A – Cartoon depicting the formation of pedestals by EPEC and EHEC - Under inducible conditions EPEC upregulates the expression of its Type III Secretion System (T3SS) that links the bacterial cytoplasm to that of the host cell (a). After the maturation of the translocon, effectors are trafficked into the host’s cytoplasm (a). One of these effectors, Tir, is inserted into the host plasma membrane where it interacts with its ligand, intimin, located on the outer bacterial membrane. Tir-intimin interactions promote the clustering of Tir and initiate a signal transduction cascade that culminates with recruitment and remodeling of actin to form fibrillar protrusions, termed “attaching and effacing (A/E) pedestals”, underneath adherent bacteria (b).
1B - Scanning electron micrographic (SEM) image of EPEC forming pedestals on infected mammalian cells. Inset – Pseudocolored image of two EPEC bacteria (green) infecting HeLa cells (purple). EM Image courtesy of Jorge Giron (University of Florida).