Devendra H. Shah
Associate Professor; Engle Distinguished Professor of Infectious Diseases
Office Phone: 509-335-6071 Lab Phone: 509-335-8529
Education and Training
- BVSc: Bombay Veterinary College, India. 1995
- MVSc: College of Veterinary Medicine, Anand Agricultural University, India. 1997
- PhD: Indian Veterinary Research Institute, India. 2002
- Postdoctoral Fellow: College of Veterinary Medicine, Chonbuk National University, South Korea. 2003-2005
- Postdoctoral Fellow: College of Veterinary Medicine, Washington State University. 2005-2008
Dr. Shah received his Bachelor in Veterinary Science (equivalent to DVM) in 1995 from Bombay Veterinary College in Mumbai, India. With a short stint in small animal veterinary practice in Mumbai, in 1996, Dr. Shah entered a graduate program in veterinary microbiology & pathology at the College of Veterinary Medicine at Anand, India. In 1997 Dr. Shah received a M.S. with research focus on pathobiology and epidemiology of multi-drug resistant Salmonella in commercial poultry production. Immediately after completing his M.S. degree, Dr. Shah joined Poultry Diagnostic and Research Center of Venkateshwara hatcheries in India to establish and direct the regional poultry diagnostic lab branch in Gujarat State of India and later, served as a state veterinarian for the government of Rajasthan State. In 1998, Dr. Shah entered a national competition and won the highly coveted Indian Council of Agricultural Research sponsored scholarship which supported his doctoral studies in veterinary bacteriology at a premier Indian Veterinary Research Institute, Izatnagar. In 2002, Dr. Shah completed his Ph.D. with a research focus on molecular epidemiology and diagnostic assay development for the differential detection of Mycobacterium bovis and Mycobacterium tuberculosis, causative agents of bovine and human tuberculosis, respectively. Immediately after completing Ph.D., Dr. Shah worked as an Assistant General Manager for poultry vaccine research, development and production at Ventri Biologicals in Pune, India.
Between 2003-2005, Dr. Shah moved to the biosafety research Institute, Chonbuk National University in South Korea to pursue postdoctoral training in the areas of molecular pathogenesis and diagnostics of Salmonella. Dr. Shah made landmark discoveries in the area of molecular pathogenesis and diagnostics of Salmonella. By employing a suite of technologies including high-throughput transposon mutagenesis, animal models of infection and other conventional molecular microbiological tools, Dr. Shah originally discovered Salmonella pathogenicity islands 13 and 14 and demonstrated their novel role in the pathogenicity of Salmonella. Dr. Shah also developed novel molecular diagnostic assays for rapid differential detection of avian adapted Salmonella serovars such as Gallinarum and Pullorum, causative agents of fowl typhoid and pullorum disease, respectively.
In 2005, Dr. Shah moved to Washington State University to pursue second post-doctoral training where his research was focused on developing innovative molecular approaches for production of recombinant proteins from a psychrophilic bacteria, Flavobacterium psychromphium (a causative agent of bacterial cold water disease in fish); studying type 3 secretion system gene regulation in a halophilic bacteria, Vibrio parahemolyticus, (an important food-borne pathogen); and in developing heterophil (avian counterpart of neutrophils) migration assay to study cytokine responses of avian cells against a microaerophilic bacteria Campylobacter jejuni (a significant food-borne pathogen).
- Course Director
- VM536, Veterinary Bacteriology, 4 credits, 2nd year Professional DVM curriculum
- VPa501, Diagnostic Challenge Case Development, 1 credit, 3rd and 4th year DVM Professional curriculum
- Case Facilitator
- Diagnostic challenge, 2nd year Professional DVM curriculum
Overall Course Philosophy (VM536, Veterinary Bacteriology): Traditionally, bacteriology has been taught in a taxonomy based manner in veterinary schools. With this approach, students are confronted with large number of facts about hundreds of infectious disease agents and the diseases they cause. Given the magnitude of the task, memorizing every bit of this taxonomic and allied information would be difficult and unproductive. It is practically impossible to retain this enormous amount of information for years to come in a way that can be applied logically in a clinical veterinary practice. Moreover, information changes with the emergence of new infectious agents, diseases, diagnostics, treatments and control measures. In every aspect of veterinary medicine, whether it be clinical or research, students and physicians will be faced with problems to be solved. In the real-world, adequate problem-solving requires a logical, step-by-step approach to integrate basic principles of establishment of infectious disease with basic principles of clinical diagnosis, treatment and prevention. Thus, my philosophy in teaching veterinary bacteriology is to stress on integrating fundamental principles of pathophysiology, diagnosis, treatment, and prevention of bacterial or mycotic disease and applying these principles to clinically relevant case-scenarios. To implement this philosophy in a meaningful way, my approach to instruction in this course is organ-system based wherein I utilize prototypic bacterial infectious diseases and infectious agents as examples that best illustrate a specific concept for a specific organ system. This philosophy is implemented using case-based instruction in both lectures and laboratory exercises and allows significantly reduced emphasis on taxonomic memorization and regurgitation of information. The laboratory component of the course utilizes clinical case scenarios to introduce common bacterial and fungal infectious diseases and the clinical microbiology techniques to identify these bacterial agents using a logical and case-based problem-oriented approach. The laboratory sessions are systematically integrated with the lecture sessions such that students get firsthand experience handling the infectious agents that cause infectious disease they just learned during lectures. The objective is to help students learn skills to systematically translate and apply basic principles learned during lectures and laboratory sessions from a prototypic bacterial disease to other bacterial diseases with similar pathogenesis and/or pathophysiological mechanisms. The overall goal of this approach is to help the student develop a solid base of conceptual framework that can be modified to incorporate novel infections, changes in management systems, and new prophylactic and therapeutic approaches that will develop during their veterinary medical careers. To develop this basic conceptual framework, majority of the course is divided in sections encompassing different organ systems and within each system, the instruction relies on two generalized themes based on the features that characterize all forms of parasitism:
Theme-1: There are common events that take place in the establishment of all infectious diseases:
Encounter: where infectious agent meets the host
Entry: the infectious agent enters the host
Multiplication: the infectious agent multiplies in the host
Spread: the infectious agent spreads in the host
Damage: the infectious agent, the host or both cause tissue damage
Outcome: the infectious agent or the host wins out, or they learn to co-exist
Theme-2: Each of these events may require some breach in the host defense/immunity and the manner in which an infectious agent combats host defense distinguishes it from other infectious agents.Learning objectives/outcomes: Learning objectives/outcomes for each organ system within the course are posted online.
Genomics; Food-safety; Antimicrobial Resistance; Bacterial Pathogenesis; Molecular Diagnostics
Research in my laboratory involves studying the mechanisms of pathogenesis and persistence exhibited by amazingly resilient and versatile food-borne pathogen Salmonella that shows extensive antigenic, phenotypic and genotypic diversity, uses wide spectrum of ecological niches including persistence in different animal hosts, environments or foods, and is transmitted from animals to people via variety of foods and other sources. The long-term goal of this research is to discover novel targets for the development of new/improved therapeutic (eg., anti-metabolites, passive immunotherapeutic) or prophylactic (eg., probiotics, vaccines) approaches, molecular diagnostic markers, and pre- and post-harvest strategies based on scientific evidence for the control of this public health pathogen. My laboratory is also interested in other food-borne bacterial pathogens including Campylobacter, E. coli and Listeria monocytogenes.
The current research is focused on following areas:
- Population dynamics of Salmonella: Using contemporary and archived strains of epidemiologically diverse Salmonella populations, our research seeks to establish phenotype-to-genotype associations as a prelude to provide 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 via food-chain. 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.
- Role of SPI-13 in metabolic fitness and nutritional virulence of Salmonella: Our laboratory was first to identify and establish role of SPI-13 (~21 kb island with 21 genes encoding proteins of unknown functions) in the pathogenicity of Salmonella. Our work has revealed that, in addition to its role in Salmonella pathogenicity, SPI-13 also plays an important role in efficient metabolism of two specific micronutrients (tyramine and glucuronic acid) that are found in the gastro-intestinal tract of mammalian hosts including human. Current research is focused on understanding the genetic mechanism underlying role of SPI-13 in the metabolism of these micronutrients and to determine if SPI-13 mediated tyramine and glucuronic acid metabolism is linked to the nutritional adaptation and virulence of Salmonella.
- Role of KsgA as a novel bacterial cell-wall builder: The cell-wall is an important driver of Salmonella’s success at 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 chemical (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 as attractive therapeutic or immunoprophylactic targets. Our laboratory was first to discover the role of universally conserved KsgA (dimethyl adenosine 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 Salmonella cell-wall. Lack of KsgA weakens cell-wall fitness and as a result, Salmonella strains show pleotropic phenotypes including 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 building of a bacterial cell-wall and to discover novel small molecule KsgA-inhibitors as potential anti-Salmonella drugs.
- 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 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.
- Food-safety: Determine the factors that influence survival and persistence of Salmonella and Campylobacter in poultry products and low-moisture foods.