University of California at Santa Cruz
Helicobacter pylori: Proteins and Processes that Contribute to Persistent Infection.
Bacterial pathogens that chronically infect humans cause a variety of illnesses such as
tuberculosis, stomach ulcers, and leprosy. For example, one such bacterium, Helicobacter
pylori, sustains infections for many years, an ability that can result in gastritis, gastric and
duodenal ulcers, and/or stomach cancer. Little is known of the H. pylori factors that allow
this bacterium to survive in the human stomach for such long periods. Studies of
persistence have been hindered by a lack of ways to follow H. pylori infection in animal
models without sacrificing the individual being studied. Because of this, long term studies
are population-based and require many animals.
We are interested in the processes and proteins that promote persistent infection. Towards
the identification of these, we propose to develop techniques to non-invasively monitor H.
pylori infection in a mouse. We will then utilize these detection systems to ascertain the
dynamics of wild-type H. pylori infection and compare this to mutants that are lacking a
factor that may be needed for persistence, motility. Finally, we propose experiments to
identify H. pylori genes that are induced only after the bacteria have initiated infection.
These genes are likely to be needed for the chronic infection exhibited by H. pylori.
Together, these three components will provide us the tools to study long-term infection,
information about how motility aids persistent infection, and the identity of gene products
that contribute to stable infection by this world-wide pathogen. Because chronic infections
are the therapeutic target for H. pylori, it is crucial that we identify bacterial processes
used to sustain infection to facilitate development of novel antimicrobial therapies.
Contact Dr. Ottemann