Garima Agrahari, MS

Graduate Student

Garima - Agrahari, MS

Contact Info

Phone: 574-631-2318
Email: garima.agrahari.1@nd.edu

Biography

2011–present Ph.D. candidate, Biochemistry, University of Notre Dame
2011 Senior Research fellow, Center of Food Technology, University of Allahabad, INDIA
2008–2010 Research Associate, W. M. Keck Center for Transgene Research, University of Notre Dame
2005–2006 Quality Control Officer, Choksi Laboratories Limited, INDIA
2003–2005 M.S., Food Technology, University of Allahabad, INDIA
2000–2003 B.S., Chemistry and Biology, Ewing Christian College, INDIA

Honors & Awards

2015-2016 American Heart Association (AHA) Predoctoral Fellowship (Midwest Affiliate)
2013 National Institutes of Health fellowship for attending XIVth International Workshop – Molecular and Cellular Biology of Plasminogen Activation  
2011–2012 Graduate Assistant teaching fellowship

Research Interests

Group A Streptococcus (GAS) is a spherical, gram-positive bacterium that is responsible for numerous diseases with diverse clinical manifestations specifically in humans. GAS likely plays a role in global health issues such as impetigo, pharyngitis, scarlet fever and life-threatening diseases such as necrotizing fasciitis, toxic shock, acute post-streptococcal glomerulonephritis, acute rheumatic fever and rheumatic heart disease. The pathogenesis of invasive GAS infections involves several stages e.g., adhesion to epithelial surfaces, colonization, transmigration of the bacteria through the epithelium and subepithelium, survival in blood, penetration through the endothelium, and invasion into deep tissue. To accomplish these steps, GAS possesses numerous genes encoding virulence factors, many of which need to be transcribed and/or repressed at specific stages of infection. The multiple gene activator (mga) system is one of the best-studied regulators that activate and inactivate genes rapidly in GAS under changing environmental conditions. The cluster of virulence (cov) intracellular responder (covR)/extracellular sensor (CovS) system (covRS) is a two-component sensor/responder gene regulatory system in GAS that regulates repression and depression of ~15% of the GAS genome. At several stages of dissemination of GAS, this microorganism must develop strategies to evade the host innate immune system, especially complement-mediated elimination of the microbe in order to survive. Our studies have implicated CovRS in regulating the opsonophagocytosis of GAS by the host complement system which is a part of innate immune system. Therefore, my primary focus of interest is to study the regulation of bacterial opsonophagocytosis by the CovRS regulatory system.

Recent Papers

Agrahari G, Liang Z, Glinton K, Lee SW, Ploplis VA, Castellino FJ. Streptococcus pyogenes Employs Strain-dependent Mechanisms of C3b Inactivation to Inhibit Phagocytosis and Killing of Bacteria. J Biol Chem. 2016 Apr 22;291(17):9181-9. doi: 10.1074/jbc.M115.704221. Epub 2016 Mar 4. PMID: 26945067

Mayfield JA, Liang Z, Agrahari G, Lee SW, Donahue DL, Ploplis VA, and Castellino FJ. Mutations in the Control of Virulence Sensor Gene from Streptococcus pyogenes after Infection in Mice Lead to Clonal Bacterial Variants with Altered Gene Regulatory Activity and Virulence. PLoS One. 2014 Jun 26;9(6):e100698. doi: 10.1371/journal.pone.0100698. eCollection 2014

Agrahari G, Liang Z, Mayfield JA, Balsara RD, Ploplis VA, and Castellino FJ. Complement-mediated opsonization of invasive group A Streptococcus pyogenes strain AP53 is regulated by the bacterial two-component cluster of virulence responder/sensor (CovRS) system. J Biol Chem. 2013 Sep 20;288(38):27494-504. doi: 10.1074/jbc.M113.494864. Epub 2013 Aug 8

Liang Z, Zhang Y, Agrahari G, Chandrahas V, Glinton K, Donahue DL, Balsara RD, Ploplis VA, and Castellino FJ. A natural inactivating mutation in the CovS component of the CovRS regulatory operon in a pattern D Streptococcal pyogenes strain influences virulence-associated genes. J Biol Chem. 2013 Mar 1;288(9):6561-73. doi: 10.1074/jbc.M112.442657. Epub 2013 Jan 13