Texas Tech University

Devendra Shah, BVSc (DVM), MVSc, PhD

Professor of Veterinary Microbiology & Infectious Disease

  • Email: devendra.shah@ttu.edu
  • Area of Expertise: Infectious disease and food safety with a focus on molecular mechanisms of pathogenesis, antimicrobial resistance, and patho-genomics of foodborne bacterial pathogens.
  • Publications:

About Me

Devendra grew up in a rural community in Western India. He was trained as a veterinarian at Bombay Veterinary College. He practiced in mixed animal, and poultry medicine in clinical and industrial setting before pursuing academic career path in veterinary clinical microbiology and infectious disease research. As a graduate student, Devendra worked on the epidemiology of poultry salmonellosis and bovine tuberculosis. Later, he pursued post-doctoral trainings at Chonbuk National University College of Veterinary Medicine, South Korea, and at Washington State University College of Veterinary Medicine. Devendra served as an Associate Professor of veterinary microbiology, Caroline Engle distinguished professor of infectious disease research, and an Associate Chair of DVM education at Washington State University.


Veterinary Clinical Microbiology and Infectious Diseases; Critical Thinking and Research Design in Food Safety & Molecular Mechanisms Underlying Bacterial Infectious Diseases


Research in my laboratory is focused on molecular mechanisms underlying pathogenesis and antimicrobial resistance of bacterial pathogens in food animal systems. Over the past two decades, my laboratory has employed comparative pathogenomics and epidemiologic approaches to study contemporary and archived clinical collections of bacterial pathogens such as Salmonella, E. coli, Listeria, Campylobacter, Enterobacter, Staphylococcus, that are significant to the food safety, animal and human health.

The primary aim of this research is to better understand the epidemiological & evolutionary dynamics of established & emerging pathogens to inform translational outcomes such as the discovery of novel genetic and phenotypic traits that are promising targets for the development of novel diagnostic assays, therapeutics, and prophylactic alternatives to antibiotics with direct and tangible impact on the animal industry, food safety, and public health. Current research in my laboratory is focused on the following areas:

  1. Population dynamics of Salmonella: Using contemporary & archived strains of epidemiologically diverse host-adapted and non-host adapted Salmonella populations, our research seeks to establish phenotype-to-genotype associations as a prelude to providing mechanistic insights into genetic traits (eg., bacterial genes, proteins, and pathways) implicated in phenotypic traits such as host-association, pathogenicity, antimicrobial resistance, adaptation to stress, emergence, persistence, and dissemination among food-animals and via food-chain to humans. Genetic traits identified through this process become the subject of hypothesis-driven research to determine their role in a given phenotypic trait. Following are a few examples of ongoing research on novel genetic traits of Salmonella originally identified in my laboratory.
    1. Metabolic fitness and nutritional virulence of Salmonella at animal-human interface: For a versatile pathogen such as Salmonella which efficiently jumps between different hosts, access to host nutrients in infected tissues is fundamental for its growth, virulence, disease progression, and infection control. However, our understanding of this crucial process for this important foodborne pathogen is still rather limited because of experimental and conceptual challenges. My laboratory employs genomics, proteomics, computational, and animal infection models to unravel the mechanisms underlying nutrient acquisition by Salmonella nutrition for growth and persistence in food animals and infection in humans. For example, my laboratory was the first to discover Salmonella pathogenicity island 13 (SPI-13, a ~21 kb island with 21 genes encoding proteins of unknown functions) and its role in the pathogenicity of Salmonella. Our work has revealed that SPI-13 plays a critical role in the acquisition of energy for Salmonella growth from two specific micronutrients (tyramine and glucuronic acid) that are found in the gastrointestinal tract of mammalian hosts including humans. Recently, we have discovered that a globally disseminating, multi-drug resistant lineage of Salmonella Kentucky ST198 which is associated with increased human infections has evolved to acquire energy for growth from specific micronutrients (propanediol and inositol) that likely makes this emergent Salmonella more virulent in humans. Current research in my laboratory is focused on understanding the roles of these micronutrients in the virulence of Salmonella and understanding the mechanisms underlying nutrient switching of Salmonella as this organism jumps between animal and human hosts.
    2. Role of KsgA as a novel bacterial cell-wall builder: The cell wall is an important driver of Salmonella's success on all fronts because it plays a central role in sensing, responding, and adapting to pH, osmotic, oxidative, nutrient, and temperature stress, and to other external chemicals (eg., biocides, antibiotics) and biological processes (eg., host-pathogen interactions and immune clearance). Thus, genetic traits that strengthen the structural and functional integrity of the bacterial cell wall are generally considered attractive therapeutic or immunoprophylactic targets. My laboratory was the first to discover the role of universally conserved KsgA (dimethyladenosine transferase) as a novel cell-wall builder in Salmonella. Our research has revealed that KsgA plays an important role in strengthening the structural and functional integrity of the Salmonella cell wall. Lack of KsgA weakens cell-wall fitness and as a result, Salmonella strains show reduced ability to colonize chickens, impaired Salmonella-host cell interactions, and reduced ability to withstand acidic stress, oxidative stress, and altered susceptibility to clinically relevant antibiotics. The ongoing research is focused on understanding the molecular mechanisms underlying how KsgA mediates the building of a bacterial cell wall and discovering novel small molecule KsgA-inhibitors as potential anti-Salmonella drugs.
  2. Persistence, dissemination and evolutionary fate of antimicrobial resistance: My laboratory is interested in understanding the mechanisms underlying how the selective pressures exerted by different antibiotics and the absence of such selective pressures influence the evolutionary trajectories of antimicrobial resistance in multi-drug resistant bacterial pathogens (eg., Salmonella, E. coli) and in complex microbial communities within food-animal production systems.
  3. Food safety: My laboratory is also interested in understanding the bacterial and environmental factors that influence the survival and persistence of Salmonella, Campylobacter, and other bacterial pathogens in food animals and a high and low moisture foods.


Devendra has served on numerous regional, national, and international committees and working groups. Devendra is a member of the USDA-NIFA NC1202 multi-state committee on enteric diseases of food animals: enhanced prevention, control, and food safety, the Conference for Research Workers in Animal Diseases, the American Society of Microbiology, and the Poultry Science Association. Devendra has served as a member of the research oversight committee of a multi-institutional research project on a Syst-OMICS approach to ensuring food safety and reducing the economic burden of salmonellosis. He is also an associate editor of Zoonoses and Public Health and Veterinary Sciences.