Raphael H. Valdivia

Professor of Molecular Genetics and Microbiology
Amgen Faculty Mentor
CMB – Molecular Genetics and Microbiology
Third Year Mentor – Molecular Medicine Study Program (MolMed)
Duke University School of Medicine, Durham, U.S.A.

Raphael Valdivia, PhD, received his B.S. in Microbiology from Cornell University in 1991. He moved to California to begin graduate studies with Stanley Falkow in the Department of Microbiology and Immunology at Stanford University. In Dr. Falkow’s laboratory Dr. Valdivia devised a fluorescence-based screen to identify virulence factors that are induced when pathogens enter a host cell and which are involved in remodeling the host cell’s endosomal compartments.  In the process, he developed new generations of green fluorescent proteins that are widely used today.  In 1998, Dr. Valdivia moved to the University of California, Berkeley to study endosome dynamics and biogenesis in the laboratory of Randy Schekman. Dr. Valdivia used the formidable tools of genetics and biochemistry of the yeast Saccharomyces cerevisiae to uncover novel transport pathways between endosomal compartments.

Dr. Valdivia also serves as an editor in multiple journals (PLoS Pathogens, Pathogens and Disease, the Journal of Bacteriology, and Infection and Immunity), is a standing member of NIH review panels, and was elected Fellow of the American Association for the Advancement of Science (AAAS) in 2012. Dr. Valdivia is the founding Director of the Duke Center for the Genomics of Microbial System (GeMS) and Vice Dean for Basic Sciences at the School of Medicine.

Dr. Valdivia’s laboratory focuses on identifying and characterizing the bacterial factors that are secreted into the host cell cytoplasm to manipulate cellular functions. They use a combination of cell biology techniques, biochemistry, genetics, genomics, proteomics and molecular biology to determining the function of virulence factors that reveal novel facets of the cell biology of host-pathogen interactions. The ultimate goal is to understand how these obligate intracellular bacterial pathogens manipulate host cellular functions to replicate, disseminate and cause disease.

A second area of focus in Dr. Valdivia’s research group is the development of new methods to perform genetic analysis in many of the microbes that reside in our gut. Understanding how the collection of genetic information of microbes associated with our bodies (microbiomes) impact our health is one of the new frontiers in microbiology.  The group is currently studying how bacteria that proliferate in the mucus layers of our gut contribute to nutrient homeostasis and immunological health.

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