Gayatri Vedantam

(520) 626-6839
ACBS, Rm. 303

1117 E. Lowell St.

The goal of research in the Vedantam lab is to investigate the mechanism(s) of gut colonization by the diarrheic disease pathogen Clostridium difficile. Research is focused on the molecular characterization of non-toxin virulence factors of C. difficile and is aimed at designing interventions to combat as well as prevent C. difficile infection (CDI).

B.S.                                          University of Bangalore,  India
Ph.D.                                       University of Illinois, Chicago
Post-Doctoral Fellowship:       Loyola Univ. Medical Center,
Associate Professor
School of Animal and Comparative Biomedical Sciences
University of Arizona
1117 E. Lowell Street Rm 303
Tucson, Arizona 85721

Research Interests

The goal of our research is to investigate the mechanism(s) of gut colonization by the diarrheic disease pathogen Clostridium difficileC. difficileis the etiologic agent of C. difficile infection (CDI), a leading cause of nosocomial disease world-wide. CDI causes a spectrum of disease manifestations that range from mild diarrhea to lethal pseudomembranous colitis. Over 400,000 cases of CDI occur annually in the USA, imposing a $3.2 billion excess burden on the healthcare system. Research in our laboratory is focused on the molecular characterization of non-toxin virulence factors of C. difficile, and is aimed at designing interventions to combat as well as prevent CDI. We are also involved in multiple surveillance studies in Tucson-area hospitals that quantitate the incidence of both nosocomial and community-acquired CDI, via direct bacterial culture of patient samples as well as recovery of spores from abiotic environments such as hospital surfaces. 

Courses Taught
MIC/VSC 421B           Microbial Techniques Laboratory (Fall Semester)
MIC/VSC 595A           Colloquium – Topics in Bacterial Pathogenesis (Spring Semester)
Laboratory Members:
Dr. Michael Mallozzi             Post-Doctoral Fellow
Bryan Roxas                        Senior Research Specialist
Michelle Cho                        Graduate Student
Andrew Clark                       Graduate Student
Rebecca McQuade                Graduate Student
Farhan Anwar                      Undergraduate Researcher
Kevin Lewis                          Undergraduate Researcher
Keith Lammers                    Undergraduate Researcher
Chelsea Adamson                 Undergraduate Researcher
Selected Publications
 Merrigan MM, Venugopal A, Roxas JL, Anwar F, Mallozzi MJ, Roxas BA, Gerding DN, Viswanathan VK, Vedantam G. Surface-layer protein A (SlpA) is a major contributor to host-cell adherence of Clostridium difficile. PLoS One. 2013 Nov 12;8(11):e78404. doi: 10.1371/journal.pone.0078404. eCollection 2013. PubMed PMID: 24265687; PubMed Central PMCID: PMC3827033.
Monteiro MA, Ma Z, Bertolo L, Jiao Y, Arroyo L, Hodgins D, Mallozzi M, Vedantam G, Sagermann M, Sundsmo J, Chow H. Carbohydrate-based Clostridium difficile vaccines. Expert Rev Vaccines. 2013 Apr;12(4):421-31. doi: 10.1586/erv.13.9. Review. PubMed PMID: 23560922.
McQuade R, Roxas B, Viswanathan VK, Vedantam G. Clostridium difficile clinical isolates exhibit variable susceptibility and proteome alterations upon exposure to mammalian cationic antimicrobial peptides. Anaerobe. 2012 Dec;18(6):614-20. doi: 10.1016/j.anaerobe.2012.09.004. Epub 2012 Sep 24. PubMed PMID: 23017940.
Vedantam G, Viswanathan VK. Spirochaetes and their twisted ways. Gut Microbes. 2012 Sep-Oct;3(5):399-400. Epub 2012 Sep 1. Review. PubMed PMID: 22976336.
Roxas JL, Wilbur JS, Zhang X, Martinez G, Vedantam G, Viswanathan VK. The enteropathogenic Escherichia coli-secreted protein EspZ inhibits host cell apoptosis. Infect Immun. 2012 Nov;80(11):3850-7. doi: 10.1128/IAI.00335-12. Epub  2012 Aug 20. PubMed PMID: 22907816; PubMed Central PMCID: PMC3486051.
Vedantam G, Viswanathan VK. Naming names: eponyms and biological history. Gut  Microbes. 2012 May-Jun;3(3):173-5. doi: 10.4161/gmic.20454. Epub 2012 May 1. PubMed PMID: 22572826; PubMed Central PMCID: PMC3427210.
 Vedantam G, Clark A, Chu M, McQuade R, Mallozzi M, Viswanathan VK. Clostridium difficile infection: toxins and non-toxin virulence factors, and their contributions to disease establishment and host response. Gut Microbes. 2012 Mar-Apr;3(2):121-34. doi: 10.4161/gmic.19399. Epub 2012 Mar 1. Review. PubMed PMID: 22555464; PubMed Central PMCID: PMC3370945.
Bertolo L, Boncheff AG, Ma Z, Chen YH, Wakeford T, Friendship RM, Rosseau J, Weese JS, Chu M, Mallozzi M, Vedantam G, Monteiro MA. Clostridium difficile carbohydrates: glucan in spores, PSII common antigen in cells, immunogenicity of  PSII in swine and synthesis of a dual C. difficile-ETEC conjugate vaccine. Carbohydr Res. 2012 Jun 1;354:79-86. doi: 10.1016/j.carres.2012.03.032. Epub 2012 Apr 2. PubMed PMID: 22533919.
Nguyen M, Vedantam G. Mobile genetic elements in the genus Bacteroides, and their mechanism(s) of dissemination. Mob Genet Elements. 2011 Sep;1(3):187-196. Epub 2011 Sep 1. PubMed PMID: 22479685; PubMed Central PMCID: PMC3312300.
Vedantam G, Viswanathan VK. Leptin signaling protects the gut from Entamoeba  histolytica infection. Gut Microbes. 2012 Jan-Feb;3(1):2-3. doi: 10.4161/gmic.19424. Epub 2012 Jan 1. Review. PubMed PMID: 22356851.
Siddiqui F, O'Connor JR, Nagaro K, Cheknis A, Sambol SP, Vedantam G, Gerding  DN, Johnson S. Vaccination with parenteral toxoid B protects hamsters against lethal challenge with toxin A-negative, toxin B-positive clostridium difficile but does not prevent colonization. J Infect Dis. 2012 Jan 1;205(1):128-33. doi: 10.1093/infdis/jir688. Epub 2011 Nov 28. PubMed PMID: 22124129.
Vedantam G, Viswanathan VK. Unlocking the gates to inflammatory bowel disease: the role of Enterococcus faecalis gelatinase. Gastroenterology. 2011 Sep;141(3):795-8. doi: 10.1053/j.gastro.2011.07.022. Epub 2011 Jul 23. PubMed PMID: 21791208.
Vedantam G, Viswanathan VK. A more perfect union. Gut Microbes. 2011 May-Jun;2(3):125-6. Epub 2011 May 1. PubMed PMID: 21637032.
Merrigan, M., Venugopal, A., Mallozzi, M., Roxas, B., Viswanathan, V.K., Johnson, S., Gerding, D.N., Vedantam, G.. 2010. Human hypervirulent Clostridium difficile strains exhibit increased sporulation as well as robust toxin production. J Bacteriol. 2010, 192(19):4904-11.  PMCID: PMC2944552.
Viswanathan, V.K., Mallozzi, M.M., and Vedantam, G. 2010. Clostridium difficile Infection – An Overview of the Disease and its Pathogenesis, Epidemiology and Interventions. Gut Microbes. 2010. 1(4)234-242. PMID: 21327030.
Mallozzi, M.M., Viswanathan, V.K. and Vedantam, G. 2010. Spore-Forming Bacilli and Clostridia in Human Disease. Future Microbiology 5(7):1109-23. PMID: 20632809.
Lepp, D., Roxas, B., Parreira, V.R., Marri, P.R., Rosey, E.L., Gong, J., Songer, J.G., Vedantam, G., and Prescott, J.F. Identification of Novel Pathogenicity Loci in Clostridium perfringens Strains That Cause Avian Necrotic Enteritis. 2010. PLoS ONE 5(5): e-PUB 05/24/2010., e10795.  PMCID: PMC2879425.
Coursodon, C.F., Trinh, H.T., Mallozzi, M, Vedantam, G., Glock R.D., Songer J.G. 2010. Clostridium perfringens alpha toxin is produced in the intestines of broiler chicks inoculated with an alpha toxin mutant. Anaerobe, 2010 Dec;16(6):614-7. PMID: 20934524
Lyras D, Howarth PM, Sambol SP, Carter GP, Phumoonna T, Poon R, Adams V, Vedantam G, Johnson S, Gerding DN & Rood JI. 2009. Toxin B is essential for virulence of Clostridium difficile. Nature. 458(7242):1176-9. PMCID: PMC2679968.
Vedantam, G. 2009. Antibiotic resistance in Bacteroides sp: mechanisms of action and dissemination. Future Microbiology, 4(4):413-23. PMID: 19416011.
O'Connor JR, Galang MA, Sambol SP, Hecht DW, Vedantam G, Gerding DN, Johnson S. Rifampin and Rifaximin Resistance in Clinical Isolates of Clostridium difficile. Antimicrob. Agents Chemother. Antimicrob Agents Chemother. 2008 52 (8):2813-7. PMCID: PMC2493101
Nishiguchi, M.K., Hirsch, A.M., Devinney, R., Vedantam, G., Riley, A.M., and Mansky, L.M. Deciphering evolutionary mechanisms between mutualistic and pathogenic symbioses. Viet et Milieu – Life and Environment. 2008, 58 (2): 87-106. PMCID: PMC2719982
Hecht, D.W., Kos, I.M., Knopf, S., and Vedantam, G. 2007. Characterization of BctA, a mating apparatus protein required for transfer of the Bacteroides fragilis conjugal element BTF-37. Research in Microbiology, 158(7):600-7.
Vedantam G, Hecht DW. Antibiotics and anaerobes of gut origin. Curr Opin Microbiol. 2003 Oct;6(5):457-61. Review.
Courses Taught: