Education

• 2014-2016 Research Assistant in Microbiology at the Forsyth Institute / Harvard School of Dental Medicine, Cambridge, MA.
• 2011-2013 Research Assistant in Microbiology at Massachusetts Eye and Ear Infirmary / Harvard Medical School, Boston, MA.
• Ph.D. (2011) Microbiology. The University of Texas at Austin. Austin, TX.
• M.S. (2003) Microbiology. The University of Oklahoma, Norman, OK.
• B.S. (2000) Biology. Louisiana Tech University, Ruston, LA.

Teaching

• CMB201 Medical Microbiology
• CMB211 Introductory Microbiology

Research Areas

My laboratory is interested in polymicrobial interactions in the human oral microbiome. Many oral bacteria are dependent on these multispecies interactions for survival. Our work includes finding bacterial interactions of interest in both health and disease and identifying the mechanisms underlying these interactions so we can exploit them as future targets for anti- or probiotic therapy to either treat or prevent oral infections.

Our current investigations focus on interactions between healthy oral microbiota constituents in supragingival plaque which is an attached polymicrobial community on the tooth surface above the gumline. This community, despite being one of the more accessible human microbiome sites, still holds many mysteries. For example, why species diversity within this microbiome exists and varies from person to person is not fully understood. Also, how polymicrobial interactions occur at a mechanistic level through signal or metabolite-mediated processes, is under investigation in our lab.

We are also interested in the relationship between systemic disease and the human oral microbiome. For example, individuals with type-II diabetes are much more likely to develop severe oral infections and the overall oral microbiota of these individuals seems to be substantially different from non-diabetics. Our research investigates how interactions between oral microbes might change from non-diabetic to diabetic patients and also how this might lead to other health complications such as heart disease where oral microbe involvement has been implicated.

Selected Publications

• Ramsey MM, Freire MO, Gabrilska RA, Rumbaugh KP, Lemon KP. Staphylococcus aureus
  Shifts toward Commensalism in Response to Corynebacterium Species. Frontiers in
  microbiology. 2016; 7:1230.
• Gilmore MS, Rauch M, Ramsey MM, Himes PR, Varahan S, Manson JM, Lebreton F, Hancock LE. Pheromone killing of multidrug-resistant Enterococcus faecalis V583 by native commensal strains. Proceedings of the National Academy of Sciences of the United States of America. 2015; 112(23):7273-8.
• Sassoubre LM, Ramsey MM, Gilmore MS, Boehm AB. Transcriptional response of Enterococcus faecalis to sunlight. Journal of photochemistry and photobiology. B, Biology. 2014; 130:349-56.
• Ramsey M, Hartke A, Huycke M. The Physiology and Metabolism of Enterococci Gilmore MS, Clewell DB, Ike Y, Shankar N, editors. Boston: Massachusetts Eye and Ear Infirmary; 2014. Chapter physiology
• Miller DJ, Araújo PA, Correia PB, Ramsey MM, Kruithof JC, van Loosdrecht MC, Freeman BD, Paul DR, Whiteley M, Vrouwenvelder JS. Short-term adhesion and long-term biofouling testing of polydopamine and poly(ethylene glycol) surface modifications of membranes and feed spacers for biofouling control. Water research. 2012; 46(12):3737-53.
• Koley D, Ramsey MM, Bard AJ, Whiteley M. Discovery of a biofilm electrocline using real-time 3D metabolite analysis. Proceedings of the National Academy of Sciences of the United States of America. 2011; 108(50):19996-20001.
• Ramsey MM, Rumbaugh KP, Whiteley M. Metabolite cross-feeding enhances virulence in a model polymicrobial infection. PLoS pathogens. 2011; 7(3):e1002012.
• Liu X, Ramsey MM, Chen X, Koley D, Whiteley M, Bard AJ. Real-time mapping of a hydrogen peroxide concentration profile across a polymicrobial bacterial biofilm using scanning electrochemical microscopy. Proceedings of the National Academy of Sciences of the United States of America. 2011; 108(7):2668-73.
• Ramsey MM, Whiteley M. Polymicrobial interactions stimulate resistance to host innate immunity through metabolite perception. Proceedings of the National Academy of Sciences of the United States of America. 2009; 106(5):1578-83.
• Chen J, Wu M, Sezate SA, Matsumoto H, Ramsey M, McGinnis JF. Interaction of glyceraldehyde-3-phosphate dehydrogenase in the light-induced rod alpha-transducin translocation. Journal of neurochemistry. 2008; 104(5):1280-92.
• Ramsey MM, Whiteley M. Pseudomonas aeruginosa attachment and biofilm development in dynamic environments. Molecular microbiology. 2004; 53(4):1075-87.
• Chang IS, Groh JL, Ramsey MM, Ballard JD, Krumholz LR. Differential expression of Desulfovibrio vulgaris genes in response to Cu(II) and Hg(II) toxicity. Applied and environmental microbiology. 2004; 70(3):1847-51.
• Bausch C, Ramsey M, Conway T. Transcriptional organization and regulation of the L-idonic acid pathway (GntII system) in Escherichia coli. Journal of bacteriology. 2004; 186(5):1388-97.
• Qa’Dan M, Ramsey M, Daniel J, Spyres LM, Safiejko-Mroczka B, Ortiz-Leduc W, Ballard JD. Clostridium difficile toxin B activates dual caspase-dependent and caspase-independent apoptosis in intoxicated cells. Cellular microbiology. 2002;  4(7):425-34.