Research Fellows Directory
Dr Jeanne Salje
University of Oxford
Orientia tsutsugamushi is a mite-borne bacterium that is the causative agent of the severe but neglected human disease scrub typhus. This is a leading cause of fever in many parts of Asia, and is thought to affect at least one million people per year. O. tsutsugamushi is a member of the Rickettsiaceae family of bacteria, an unusual and fascinating group of organisms that can only grow and replicate when physically located within the cytoplasm of another cell. This lifestyle makes them a powerful group of organisms to study, because they can reveal information about the intimate interface between pathogens and their hosts.
The focus of my Fellowship is to study the cell wall of O. tsutsugamushi. The cell wall is the structure that surrounds bacterial cells and that gives them shape and rigidity. The molecule that makes up this important component of bacterial cells is called peptidoglycan, and is a highly cross-linked mesh-like structure that typically encloses bacterial cells. It is only found in bacteria, and animals have evolved to recognise this structure as a marker of infection, and to mount a huge immune response against it. Because it is only present in bacterial cells, and also because it is absolutely required in order for the bacteria to survive, it is a major target of several classes of antibiotics.
Obligate intracellular bacteria, such as O. tsutsugamushi, other Rickettsias and also Chlamydia, are under strong evolutionary pressure to reduce the abundance of their peptidoglycan because it is such a strong stimulator of the immune response. However, they still need this molecule in order to grow and divide, and this makes the peptidoglycan of obligate intracellular pathogens particularly interesting to study. My research aims to uncover the structure of peptidoglycan in O. tsutsugamushi and to understand how this impacts the growth and division of this bacteria as well as its interaction with host cells.
Interests and expertise (Subject groups)