Arturo Casadevall, MD, PhD, MS

Arturo Casadevall, MD, PhD, MS
Chair, Department of Molecular Microbiology and Immunology,
Johns Hopkins Bloomberg School of Public Health
Baltimore, MD, USA
International Academy of Endodontics Annual Meeting
Long Essay Program
Friday, March 3, 2023
Ditch the term pathogen
Virulence is a microbial property that is expressed only in a susceptible host. This raises interesting evolutionary questions. For example: why are some microbes pathogenic while the majority are harmless? Are pathogenic and non-pathogenic microbes different? How does virulence emerge in environmental microbes pathogenic despite that have no need for their hosts? The talk will discuss the problem of mixed infections which characterize many oral infectious diseases. In addition, there will be a focus on the fungal kingdom, with its tremendous diversity, which provides insight into potential answers. Of the more than 1.5 million fungal species only about 150-300 are pathogenic for humans, and of these, only 10-15 are relatively common pathogens. In contrast to the paucity of fungal pathogens of mammals, fungi are major pathogens for plants and insects. Analysis of thermal tolerance in fungi suggests that vertebrate endothermy and homeothermy create a restricted environment for most fungal species. Hence, the combination of vertebrate adaptive immunity with endothermy probably accounts for the remarkable resistance of mammals to fungi. Dr. Casadevall will present the hypothesis that fungal diseases contributed to both the extinctions at the end of the cretaceous that resulted in the demise of the dinosaurs and to the great mammalian radiation that followed in the tertiary era. Finally, the seminar will consider possible consequences of climate change, which include the emergence of new fungal diseases as fungal species adapt to a warmer world.
Major topics to be addressed:
The ‘damage-response’ framework of microbial pathogens and the origin of microbial virulence.
Learning Objectives:
  1. New concepts on microbial pathogenesis
  2. Origin of virulence of pathogenic microbes
  3. The theory that fungal diseases led to the dominance of mammals after the dinosaur extinction event.
Johns Hopkins School of Public Health
Arturo Casadevall, M.D., Ph.D., is a Bloomberg Distinguished Professor and Alfred and Jill Summer Chair of the Molecular Microbiology and Immunology at Johns Hopkins School of Public Health. He received his M.D. and Ph.D. degrees from New York University. He completed his internship/residency in internal medicine at Bellevue Hospital and specialized in Infectious Diseases at the Albert Einstein College of Medicine. The author of over 900 papers, books, and chapters, his major research interests are in fungal pathogenesis and the mechanisms of antibody action. He is editor-in-chief of mBio, was Deputy Editor of the Journal of Clinical Investigation, and serves on several editorial boards. He has served on the National Science Board for Biosecurity and the National Commission on Forensic Science. He is currently chair of the Board of Governors of the American Academy of Microbiology, the honorific arm of the American Society for Microbiology. He has received numerous honors including election to the American Society for Clinical Investigation, American Academy of Physicians, American Academy of Microbiology, Fellow of the American Academy for the Advancement of Science, American Academy of Arts and Sciences, the National Academy of Medicine, and the National Academy of Sciences.