Gireesh Rajashekara, DVM, PhD

Gireesh Rajashekara, DVM, PhD
FTE: 90% Research, 10% Extension
Food Animal Health Building, CFAES Wooster
330-263-3745 - office, (330)263-3986 - lab
Degree Information: 
PhD Microbiology, University of Minnesota (1999)
MVSc Microbiology, University of Agricultural Sciences, India (1993).
BVSc (DVM) Veterinary Medicine, University of Agricultural Sciences, India (1990)
Molecular microbiology, host-pathogen interactions, virulence mechanisms, vaccine development
Additional Information: 

Areas of Expertise

  • Food Safety – Salmonella and Campylobacter
  • Food Security
  • Gut Microbiome
  • Ecology and Epidemiology of Foodborne Pathogens
  • Antimicrobial Resistance

Research focus: Research in Dr. Rajashekara’s lab is focused on pre-harvest control of bacterial zoonoses, specifically, Salmonella and Campylobacter and antimicrobial resistance (AMR) mitigation. Research is focused on defining the epidemiology and ecology of these pathogens in food animals; understanding the emergence of AMR in preharvest environment; understanding molecular mechanisms of how these zoonotic pathogens interact with food animals as well as fresh produce; and developing novel diagnostics, vaccines, therapeutics, and antibiotic alternative approaches for preharvest control of these zoonotic pathogens and mitigation of AMR. Research is focused on discovery of novel narrow spectrum antimicrobials (virulence and growth inhibitors) as well as probiotic bacteria to control foodborne and animal pathogens. Further studies are focused on elucidating molecular mechanisms of how malnutrition and associated changes in microbiota contributes to gut integrity and intestinal homeostasis and its impact on pathogenesis of enteric pathogens such as rotavirus and Campylobacter using omics approaches. We are looking at how Campylobacter infection combined with malnutrition affects gut integrity leading to environmental enteric dysfunction and stunting in children in low and middle income (LMIC) countries.  

In addition, Dr. Rajashekara’s lab uses in vivo imaging system to visualize in real-time the dynamics of bacterial pathogens colonization in a given host. We have applied bioluminescent imaging combined with transposon mutagenesis to gain greater insight into plant-phytopathogens as well as plant-foodborne pathogens interactions to (i) monitor infection over time, (ii) identify sites of bacterial colonization, and (iii) study the dynamics of infection including patterns of growth and clearance of bacteria in specific tissues. Further, we are combining this sensitive, real-time assay with high throughput chemical screening to identify effective antimicrobial strategies to control foodborne human-, animal- as well as phyto- pathogens.