Raphael Valdivia, PhD


Headshot of Raphael Valdivia, PhD4112 MSRBIII
Box 3580 DUMC
Durham, N.C. 27710
Phone: (919) 668-3831
Fax: (919) 681-9193


research • biographylab members • publications • lab website


Chlamydia infections are responsible for the bulk of sexually transmitted bacterial diseases and are the leading cause of infectious blindness (trachoma) in the world. My laboratory’s main interest is to understand how these obligate intracellular bacterial pathogens manipulate host cellular functions to replicate, disseminate and ultimately cause disease.

Chlamydia trachomatis resides within a membrane bound compartment (“inclusion”). From this location, the pathogen manipulates the actin cytoskeleton, microtubule-based motors, inhibits lysosomal recognition of the inclusion, activates signaling pathways, re-routes lipid transport, and prevents the onset of programmed cell death. Remarkably, all of these functions are achieved with a genome that encodes < 900 proteins, indicating that the Chlamydia genome is streamlined for intracellular survival.

Our laboratory focuses on identifying and characterizing the bacterial factors that are secreted across the inclusion to manipulate eukaryotic cellular functions. We use a combination of cell biological techniques, biochemistry, genetics, genomics, proteomics and molecular biology to determining the function of chlamydial virulence factors that reveal novel facets of the cell biology of host-pathogen interactions and how these factors are translocated into the host. We also have developed new methods to perform genetic analysis in these formerly genetically intractable bacteria which we have now extended to other microbes of importance in human health.