This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
Vibrio species are part of the normal microflora of coastal waters throughout the world and are especially abundant in warmer waters. These organisms can survive and proliferate in fluctuating environmental conditions such as salinity, temperature and pH. However, the underlying mechanism of how these bacteria cope with rapid changes in growth conditions is poorly understood. Vibrio parahaemolyticus is a moderate halophile capable of growth at 0.1M to 1M NaCl. The dramatic increased incidences of V. parahaemolyticus in geographic climes such as in the Pacific Northwest have resulted in intense interest in the ecology of this organism. In this project, the principle investigator will determine the physiological responses of V. parahaemolyticus to changes in salinity. Work undertaken as part of this project will ascertain the underlying molecular mechanisms of osmotic tolerance and its role in microbial communities as a compatible solute producer using molecular genetics, genomics and phylogenetic analyses. Intellectual merits. V. parahaemolyticus is a key component of the aquatic ecosystem, and likely play an important role in the health of this ecosystem, therefore understanding how it adapts to a changing environment is essential, especially given the unknown effects global warming will have on this ecosystem.
Broader impacts and significance. In 1996, a novel pathogenic strain of V. parahaemolyticus emerged in Asia causing severe outbreaks and has now disseminated globally marking the emergence of a pandemic clone. How or why novel strains emerge remains unknown, in the case of V. parahaemolyticus global warming as well as the acquisition of novel traits may be key factors. The primary strategy for adaptation to high salinity in most living organisms is the accumulation of compatible solutes. An aim of the project is to determine the functional role and hierarchy of the solute synthesis and transporter systems in V. parahaemolyticus and reconstruct the phylogeny of these systems among bacteria. This work may provide insights into why novel strains of this bacterium emerge. Integration of research and teaching will occur during the project through the mentoring of high school, undergraduate and graduate students by the Principle Investigator. The research objectives proposed will give students a broad appreciation of the diversity and complexity of microbial communities in the aquatic ecosystem.
