Organisms in the ocean depend ultimately on phytoplankton as it is the base of the marine food web. Through the use of satellite imaging, indicators of photosynthesis such as chlorophyll-A are used as an index of primary production in the ocean over large areas and variable time scales. Phytoplankton is dependent on large-scale ocean processes such as water temperature and water column mixing. Such estimates might provide insights in food availability for larger predators that eat plankton eating fish such as the Magellanic penguin. Located on the southeast coast of Argentina, Punta Tombo is among the largest breeding colonies for Magellanic penguins. The Boersma Lab at the University of Washington has studied the colony since 1982 and have determined reproductive success for 35 years. Although many factors influence the overall success of the colony, starvation of chicks is responsible for 40% of chick deaths. Through the use of spatial analysis tools, we have looked at chlorophyll-A patterns and seasonal water temperature variation around Punta Tombo and compared these two variables with reproductive success of Magellanic penguins. We expect a strong positive relationship between the two datasets: water temperature and chlorophyll-A. Further we expect that when values are higher closer to the colony, reproductive success of birds is higher, and parents forage closer to the colony.

In cystic fibrosis (CF), a genetic defect in the CFTR anion channel compromises host defenses and causes chronic lung infections with organisms like Staphylococcus aureus. Our lab has been studying the effects of combining ivacaftor, a CFTR modulator which increases CFTR channel activity, with a period of intensive antibiotic treatment. We found that S. aureus lung infections generally persisted despite this aggressive treatment. However, most subjects undergoing treatment were found to be infected by different S. aureus strains one year after treatment than were present before treatment was initiated. Understanding the dynamics of strain switching provide new knowledge about the natural history of chronic CF infections, help define the effects of CFTR modulators and antibiotics, and inform new approaches that might produce infection eradication. We hypothesize that (1) strain switching is most likely to occur during the period of combined ivacaftor and antibiotic treatment, as sputum bacterial burdens were lowest during combined treatment; and that (2) strain switching is rare in the absence of combined treatment. To test this, we used a new population-based multilocus sequence typing (PopMLST) method we developed to perform strain-level genotyping on S. aureus. PopMLST uses PCR amplification and next generation sequencing of housekeeping genes from bacterial isolate pools cultured from sputum. Sequencing determines the number and relative abundance of unique sequence types present, and the data can be used to infer the number of strains present. This analysis was performed on samples obtained before treatment, during treatment with ivacaftor alone, and during combined treatment. We also examined a cohort of subjects receiving usual care. These data improve understanding of strain dynamics during CF infections and suggest new strategies to eliminate infection.