Adaptation of S. pneumoniae

The dissertation research of Microbiology & Immunology doctoral student Ellyn Schinke focuses on Streptococcus pneumoniae, a bacterium that colonizes the human nasopharynx, causing a diversity of infections including meningitis, pneumonia, septicemia, and otitis media. Despite the fact that there is a vaccine available, S. pneumoniae continues to cause problems due to its ability to adapt to its environment through genetic exchange and bacterial competition. These abilities are controlled by the competence (com) and bacteriocin-like peptide (blp) quorum-sensing systems, respectively.

Ellyn’s research focuses on the interaction between the com and blp systems and how these systems work together and independently to promote the adaptation of S. pneumoniae. Her dissertation seeks to better characterize the crosstalk of these two systems within a more biologically-relevant biofilm context to better understand how these systems participate in genetic exchange.

Ellyn’s dissertation has three components:

  • Population sciences: As opposed to human population sciences, Ellyn is looking at these quorum-sensing systems in a bacterial population, allowing for evaluation of how these systems function within these biofilm communities.
  • Laboratory sciences: In the laboratory, Ellyn is designing fluorescent reporters and using immunological techniques to be able to visualize the activation of these com and blp quorum-sensing systems within the biofilm.
  • Mathematical modeling: Using mathematical modeling approaches, Ellyn will be analyzing detailed aspects of these quorum-sensing systems that we currently can’t assess in a lab situation. These include things such as diffusion dynamics and how mutants within the bacteria populations effect com and blp activation within a biofilm context.


ITiMS Co-Mentors: Suzanne Dawid, MD, PhD and Denise Kirschner, PhD