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Sarah L. Poynton, PhD


Associate ProfessorSarah Poynton

Molecular and Comparative Pathobiology
joint appointment in Art As Applied to Medicine

733 N. Broadway
Edward D. Miller Research Building
Suite 851
Baltimore, MD 21205

Office: 410-502-5065
Department: 443-287-2953
Fax: 443-287-2954

Education and Training

  • 1980  B.Sc. (Hons) Biology  University of Southampton, England
  • 1985  Ph.D. (Parasitology)  University of Southampton, England
  • 1985 – 1986 Academic Visitor, Department of Zoology, University of Oxford, England
  • 1986 – 1988 Visiting Fellow, Federal Department of Fisheries and Oceans, Halifax, Canada
  • 1989 – 2000 Calander Binford Fellow, Armed Forces Institute of Pathology, Washington, DC

Professional Appointments

Dr. Poynton joined the Faculty of Johns Hopkins University School of Medicine in 1989 as a Lecturer. She  was promoted to Assistant Professor in 2000, and to Associate Professor in 2005. Dr. Poynton’s academic experience has also included one year as visiting faculty at the University of Maryland at College Park, and extended periods as a guest scientist at the Institute for Marine Sciences in Kiel, Germany, and at the Leibniz Institute for Freshwater Ecology and Inland Fisheries, in Berlin, Germany.  

Honors and Awards

  • Dr. Poynton was awarded a Visiting Professorship from the National Science Foundation (1992 – 1993).
  • She was awarded a Mercator Guest Professorship from the German Research Foundation (2003 – 2005), during which time she undertook research and teaching at the Leibniz Institute for Freshwater Ecology and Inland Fisheries, and at Humboldt University, Berlin.
  • In 2010, Dr. Poynton received the Ranice W. Crosby Distinguished Achievement Award from the Department of Art as Applied to Medicine, at Johns Hopkins University School of Medicine, in recognition of her mentoring achievements. 

Current Roles

Within the Department of Molecular and Comparative Pathobiology, Dr. Poynton is active in parasitology research with a focus on protozoans (especially diplomonad flagellates), and education, particularly the recognition of parasites in tissue sections. Via her joint appointments in Art as Applied to Medicine, and Molecular Microbiology and Immunology, she teaches courses in Scientific Writing and Biomedical Writing.  Dr. Poynton’s principal scholarly activity in 2014 is completing the writing and assembly of her book entitled “Aquaculture Parasitology: Global Impacts and Management in Finfish”, to be published by Wiley-Blackwell, for which she is coordinating editor.


Dr. Poynton has expertise in host-parasite interactions and parasite ultrastructure, especially of pathogenic protozoa in aquatic and exotic animals held for research, exhibit and aquaculture. The focus of Dr. Poynton’s research are pathogenic diplomonad flagellates of the genus Spironucleus, among which the piscine species Spironucleus salmonis, is of particular interest. Diplomonads, long considered as amitochondriate, are not only significant enteric pathogens of many different vertebrates, but are also of fundamental interest to cell biologists. Along with colleagues in Norway and Germany, she is investigating multiple aspects of Spironucleus species including: (i) developing improved diagnostic tools using ultrastructural and molecular approaches, (ii) characterizing encystment, (iii) identifying new treatment targets with emphasis on the encystment stage of the life cycle, and (iv) investigating innate immunity as a basis for a novel plasma incubation test to predict host susceptibility to infection.
Dr. Poynton collaborates intensively with veterinary staff at the National Aquarium in Baltimore. These productive interactions have yielded publications on a diversity of parasites, ranging from description of a new genus of flagellate in the respiratory tract of a cetacean, to a comprehensive study of the parasite fauna of endangered poison dart frogs.

Teaching and Graduate Program Affiliations

Dr. Poynton teaching in the following courses

Department of Molecular and Comparative Pathobiology

  • ME 680.701 Comparative Pathobiology & Genetically Engineered Mice
  • ME 680.707 - Experimental Design and Scientific Writing
  • ME 680.711 Comparative Pathology Conference (Slide Conference)
  • She also provides the specialized instruction “Identification of Parasites in Tissue Sections”, and supports students, residents and fellows with sign-outs of pathology cases.

Department of Art as Applied to Medicine

  • ME 120.757 Scientific Communication (Course Director)
  • ME 120.754 Research and Thesis

Graduate Training Program in Clinical Investigation (GTPCI)

  • PH 390.710 Biomedical Writing (Part I) (Course Director)
  • PH 390.711 Biomedical Writing (Part II) (Course Director)
  • Dr. Poynton also provides the following instruction for courses and workshops

Office of Faculty Development (OFD)

  • Scientific and Biomedical Writing for Junior Faculty (new course in fall 2014)
  • Writing Letters of Recommendation (Emerging Women’s Leadership Program)

Professional Development Office (PDO)

  • Networking and Visibility
  • Planning a Successful International Research Career

Dr. Poynton has served as a member of the thesis committee for numerous Bachelors, Masters and Ph.D. students in the USA and in Germany.

University Committees

Since 2010, Dr. Poynton has served as departmental representative for the Faculty Senate (formerly Medical School Council). After serving her initial term from 2010 – 2013, she was reelected to a second term, from 2013 – 2016.  Dr. Poynton has also served on the Joint Oversight Committee on Faculty Development and Gender, and played a key role in revising the format of the most recent Faculty Satisfaction Survey.

Professional Societies

  • Dr. Poynton has held leadership roles in the Society of Protozoology (nominations committee), and the International Association for Aquatic Animal Medicine (book review editor, Secretary-Treasurer and Board Member, and student liaison committee). She is currently a member of the American Fisheries Society (Fish Health Section), and the European Association of Fish Pathologists.
  • On behalf of the American Fisheries Society (Fish Health Section), and with her colleague, Dr. Andrew Kane, Dr. Poynton was co-chair of the organizing committee of two International Symposia on Aquatic Animal Health; ISAAH-3 in Baltimore, MD, in 1998, and ISAAH-6 in Tampa, FL, in 2010. 

Advisory committees, review groups and study sections, journal reviewer

Dr. Poynton has been a reviewer for numerous agencies including: California Sea Grant, Maryland Sea Grant (Marine Biotechnology), National Oceanic and Atmospheric Administration, Science and Engineering Research Council of Canada, and the United States Department of Agriculture. She has reviewed manuscripts for 19 national and international journals, and has served on the Editorial Board of Acta Protozoologica.

Internation Experience

  • Dr. Poynton has served as a consultant for the Food and Agriculture Organization of the United Nations (FAO (UN)). Her responsibilities included: (i) co-chairing Regional Workshops on Aquaculture Development for North Africa in Cairo, Egypt, and for the Near East in Muscat, Oman, (ii) authoring the FAO (UN) publication “Regional Review on Aquaculture Development 2. Near East and North Africa, and (iii) participating in an Expert Workshop, in China, on Prospective Analysis of Global Aquaculture Development.
  • Dr. Poynton has worked at the Leibniz-Institute for Freshwater Ecology and Inland Fisheries, in Berlin, Germany, for many blocks of time over a 10 year period, as a Guest Scientist and as a Mercator Guest Professor. While in Berlin, she undertook research on pathogenic flagellates, supervised Bachelors, Masters and Ph.D. students, taught classes in parasitology at Humboldt University, and founded a comprehensive program of classes in Scientific Communications for students, scientists and staff at the Leibniz-Institute.
  • Dr. Poynton has also taught classes in scientific writing at the Chinese Academy of Sciences in Wuhan, and at the University of San Carlos in Cebu City in the Philippines. 


Dr. Poynton has received research funding from the National Science Foundation, Food and Drug Administration, National Aquarium in Baltimore, University of Florida, and the German Research Foundation.

Additional achievements

  • Dr. Poynton is the coauthor, along with Dr. Chris Gardiner, of the book “An Atlas of Metazoan Parasites in Animal Tissues”, which is used as a standard teaching and reference text in veterinary parasitology.
  • She has given invited talks at scientific meetings nationally and internationally, and at the German Center for Research and Innovation in New York. 
  • Dr. Poynton coordinated the production of a poster entitled “Advancing Knowledge for Humankind: Species in Space 1947 - 2007”, which commemorated the diversity of animal species which have flown in space. The poster was flown aboard the NASA Space Shuttle, by Dr. Richard Linehan, who had completed some of his veterinary training at Johns Hopkins.









Cairo cochairs
Co-chairing FAO (UN) Regional Workshop on Aquaculture Development for North Africa Region, Cairo, Egypt












FAO (UN) staff and consultants (Dr. Poynton at right), FAO (UN) Regional Office for the Near East










Muscat Group


Muscat Press






















The pathogenic flagellate Ichthyobodo sp. Infecting the gills of an octopus. Transmission electron micrograph showing extension of the cytostome feeding tube into the host cell.

Selected publications: