Summerbell has published over 150 peer-reviewed papers in mycology, botany and bacteriology, including research papers in Nature and Philosophical Transactions of the Royal Society. Much of the research explores opportunistic fungal pathogens—those that grow on (and at the expense of) humans and animals—and the unique ways in which these organisms exploit their environments. These environments are diverse. They include biofilms in hospital plumbing that harbour fungal pathogens which attack patients hospitalized for leukemia or major organ transplants. They also include waterfront vacation properties on streams, lakes or rivers that infect otherwise healthy visitors with the often deadly disease blastomycosis.