John M. Leong,
M.D., Ph.D.

Contact: John.Leong@Tufts.edu
Tufts Pages: Faculty Profile | Leong Lab

My lab’s work focuses on the interaction of pathogenic Escherichia coli, Borrelia burgdorferi (the Lyme disease spirochete) and Streptococcus pneumoniae with host immune and epithelial cells in order to understand the infectious process and develop novel therapies to prevent or treat these infections.

Research

In causing disease, bacterial pathogens establish an infectious niche and generate damage within the mammalian host. We investigate three bacterial pathogens to understand the host-microbe interactions that promote colonization and disease, and then, during resolution of infection, mediate microbial clearance. For each pathogen, our studies encompass bacterial genetic, biochemical, cell biological, and animal modeling approaches. Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a food-borne intestinal pathogen that colonizes the intestinal epithelium and produces Shiga toxin, which causes systemic disease, including renal failure. We developed a murine model of EHEC infection to understand mechanisms of colonization and disease, as well as to develop therapeutic or preventative interventions. Streptococcus pneumoniae, an important cause of lung infection particularly among the aged, causes damage largely by inducing a vigorous host inflammatory response, and we are investigating how the pathogen is recognized by the host with a goal of modulating the acute immune response to mitigate disease. Finally, the Lyme disease spirochete, Borrelia burgdorferi, can establish a localized infection but are also capable of spreading throughout the host. We investigate spirochete-host interactions that promote bloodstream survival and tissue invasion. 

You can learn more about our work on our Research page.

Appointments and Background

Primary Appointment: Edith Rieva and Hyman S. Trilling Professor; Chair of Molecular Biology & Microbiology, Tufts University School of Medicine

Programs: I teach in the graduate programs for Biomedical Sciences, Immunology, and Molecular Microbiology at the Tufts Graduate School of Biomedical Sciences.

Academic Background:  

  • BA, Biology, Brown University 
  • MD, PhD, Molecular Biology, Brown University 
  • Postdoctoral Training, Tufts University School of Medicine

Stuart B. Levy Center for Integrated Management of Antimicrobial Resistance (Levy CIMAR)

I serve as a member of the Senior Leadership Team for the Levy CIMAR along with Dr. David Snydman (MD, FACP, FIDSA, FAST). Our Directors are Drs. Ralph Isberg (PhD), Helen Boucher (MD, FACP, FIDSA).

Antimicrobial resistance (AMR) is ranked among the World Health Organization’s top 10 threats to global health. With AMR outpacing the development of new antimicrobial drugs, we risk returning to an era when life-threatening infectious diseases such as tuberculosis were a death sentence. AMR is a complex problem requiring close monitoring and coordination with human and veterinary healthcare, sanitation, education, and government policymakers to prevent its spread. No single sector has the capacity to stop AMR alone. The Levy CIMAR was launched in 2018 with a “One Health” focus to connect and integrate the key players needed to solve this multifaceted problem. Partnering Tufts Medical Center and Tufts University’s schools of Medicine, Veterinary Medicine, and Arts & Sciences (as well as members from Engineering, Nutrition, and Drug Development) under a single umbrella, our Center is uniquely poised to lead AMR research, drug discovery, patient care, and education.

You can learn more about our work at CIMAR at www.LevyCIMAR.org.