Research Interests
Epidemiological and sequence data are used to evaluate the evolution and population structure of pathogenic bacteria, including Helicobacter pylori , Salmonella enterica , Escherichia coli and Yersinia pestis . Sequences of housekeeping genes from global collections have been used to define multi-locus sequence types for epidemiological purposes. Sequence relationships have also been used to determine population genetic structures. We are currently developing fine typing for species such as Y. pestis whose housekeeping genes are highly uniform. Novel mathemical approaches are being developed to extract information content from extensive sequence-based datasets. Bayesian approaches have been applied to the population structure of H. pylori and are being extended to other organisms in order to provide algorithms that can be used in general. A major goal is to deduce the phylogenetic structure and ancestry of bacterial species that experience frequent recombination. Molecular epidemiology has been performed on a variety of organisms in an attempt to reveal the microevolution of these bacteria over periods of decades to centuries. Formerly, epidemic Neisseria meningitides were investigated extensively but a large proportion of current efforts are addressed to the global population structure of H. pylori.