Govindsamy Vediyappan, Assistant Professor
339 Ackert Hall
Ph.D., 1994, University of Madras, India.
Area(s) of Specialization
Medical mycology, Pathogenic Microbiology and Bacterial multidrug resistance (MDR) efflux pumps.
We are interested in understanding the pathogenic mechanisms of Candida albicans, the major fungal pathogen of humans. C. albicans and other Candida species cause mucosal, disseminated and invasive infections, especially among patients who are immune suppressed or hospitalized with diseases such as cancer or HIV. Better understanding of C. albicans virulence, particularly its yeast-to-hypha conversion and hyphal growth, will allow us to design novel intervention strategies. In this regard, we have identified and characterized a medicinal plant derived compounds, gymnemic acids (GAs) that affected C. albicans hyphal growth without affecting cell viability (Vediyappan et. al., PLOS ONE, 2013). Using GAs as research tools, we want to answer the question how GAs specifically block ‘polarized’ hyphal but not the ‘isotropic’ yeast cell growths.
We are also interested in deciphering the molecular mechanisms of antimicrobial resistance in bacterial pathogens, particularly contribution of multiple drug resistance (MDR) by efflux pumps, which extrudes drugs from the bacteria. Active drug efflux is one of the major intrinsic mechanisms of MDR in bacteria. A single MDR efflux pump system (e.g. AcrAB-TolC) can effectively remove hundreds of structurally diverse antimicrobial drugs from bacterial cells leading to therapeutic failures in clinics. Understanding MDR efflux pumps in bacteria will allow us to develop effective therapeutics.
Vediyappan G. , V. Dumontet, F. Pelisser and C. d’Enfert. 2013. Gymnemic acids inhibit hyphal growth and virulence in Candida albicans. PLOS ONE 8: e74189, PMID: 24040201. http://www.k-state.edu/media/newsreleases/jun13/vediyappan91213.html
Barabote, R.D., J. Thekkiniath, R.E. Strauss, G. Vediyappan, J.A. Fralick and M.J. San Francisco. 2011. Xenobiotic efflux in bacteria and fungi: a genomics update. Adv. Enzymol. Relat. Areas Mol. Biol. 77:237-306, PMID: 21692371, Review (Editor Toone, E.J., Publisher: John Wiley & Sons, Inc.)
Vediyappan G, T. Rossignol, and C. d'Enfert. 2010. Interaction of Candida albicans biofilms with antifungals: transcriptional response and binding of antifungals to beta-glucans.Antimicrob Agents Chemother. 54(5):2096-111.
Govind, R., G. Vediyappan, R.D. Rolfe, B. Dupuy, and J.A. Fralick. 2009. Bacteriophage mediated toxin gene regulation in Clostridium difficile. J. Virology 83 (23):12037-45.
Enjalbert, B., A. Rachini, G. Vediyappan, D. Pietrella, R. Spaccapelo, A. Vecchiarelli, A.J. Brown, and C. d'Enfert. 2009. A multifunctional, synthetic Gaussia princeps luciferase reporter for live imaging of Candida albicans infections. Infect Immun. 77(11):4847-58.
Vediyappan, G., T. Borisova, and J.A. Fralick. 2006. Isolation and characterization of VceC gain-of-function mutants that can function with the AcrAB multiple-drug-resistant efflux pump of Escherichia coli. J Bacteriol. 188(11):3757-62.
Govind, R., G. Vediyappan, R.D. Rolfe, and J.A. Fralick. 2006. Evidence that Clostridium difficile TcdC is a membrane-associated protein. J Bacteriol. 188(10):3716-20.
View the complete publication list in NCBI