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Sarah L. Poynton, PhD

Sarah L. Poynton, Ph.D.
Associate Professor, Molecular and Comparative Pathobiology
and joint appointment Art As Applied to Medicine

Office: 410-502-5065

Background & Training:
Dr. Poynton is a parasitologist who received her Ph.D. from the University of Southampton, England, and completed research and fellowships at the Department of Zoology, University of Oxford, the Department of Fisheries and Oceans, Halifax, Canada, and the Armed Forces Institute of Pathology in Washington, D.C. Through these experiences, Dr. Poynton has developed expertise in host-parasite interactions and parasite ultrastructure, especially of pathogenic protozoa in aquatic and exotic animals held for research, exhibit and aquaculture. She has received Visiting Professorships from the National Science Foundation, and the German Research Foundation.

Current Roles:
Within the Department, Dr. Poynton is active in parasitology research, education and diagnostic work. She teaches the parasitology component of “Rodent Biology and Diseases”, “Topics in Lab Animal Medicine”, and “Principles of Animal Pathology and Genetically Engineered Mice”. She also supports students, residents and fellows with sign-outs of pathology cases. She serves on the Curriculum Committee, and is chair of the Faculty Retreat Committee.     

Her expertise and counsel on parasitology and aquaculture is frequently sought by other institutions, both nationally and internationally. She has recently served as a Regional Reviewer for Aquaculture, for the Food and Agriculture Organization of the United Nations, with special responsibility for the Near East and North Africa. Dr. Poynton is a frequent Guest Scientist at the Leibniz-Institute for Freshwater Ecology and Inland Fisheries, in Berlin, Germany.  

Dr. Poynton is passionate about the art of scientific communication and the craft of professional development. She teaches classes in scientific writing, oral presentations, and networking skills in the Department of Molecular and Comparative Pathobiology, Department of Art as Applied to Medicine, and the Office of Faculty Development. 

The focus of Dr. Poyntons research are pathogenic diplomonad flagellates of the genus Spironucleus, among which the piscine species S. 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 developing improved diagnostic tools using ultrastructural and molecular approaches, identifying new treatment targets with emphasis on the encystment stage of the life cycle, and investigating innate immunity as a basis for a novel plasma incubation test to predict host susceptibility to infection.

Selected publications:
Gardiner CH, Poynton SL. An Atlas of Metazoan Parasites in Animal Tissues. American Registry of Pathology, Washington, D.C. 1999.

Poynton SL, Sterud E. Guidelines for species descriptions of diplomonad flagellates from fish. Journal of Fish Diseases 25: 15-31, 2002.

Reimschuessel R, Gieseker CM, Driscoll C, Baya A, Kane AS, Blazer VS, Evans JJ, Kent MK, Moran JDW, Poynton SL. Myxosporean plasmodial infection, associated with ulcerative lesions in young-of-the year Atlantic menhaden Brevoortia tyrannus (Latrobe) (Clupeidae) in a tributary of the Chesapeake Bay, and possible links to Kudoa clupeidae. Diseases of Aquatic Organisms 53:143-166, 2003.

Poynton SL, Saghari Fard MR, Jenkins J, Ferguson HW. Ultrastructure of Spironucleus salmonis n.comb. (formerly Octomitus salmonis sensu Moore 1922, Davis 1926 and Hexamita salmonis sensu Ferguson 1979), with a guide to Spironucleus species. Diseases of Aquatic Organisms 60: 49 – 64. 2004.

Helke KL, Poynton SL. Myxidium mackiei (Myxosporea) in Indo-Gangetic flap-shelled turtles Lissemys punctata andersonii: parasite –host interaction and ultrastructure. Diseases of Aquatic Organisms 63: 215-230. 2005.

Poynton SL. Regional review on aquaculture development. 2. Near East and North Africa. FAO Fisheries Circular No. 1017/2. Food and Agriculture Organization of the United Nations, Rome. 2006.

Bonar CJ, Poynton SL, Schulman FY, Rietcheck RL, Garner MM. Hepatic Calyptospora sp. (Apicomplexa) infection in a wild-born, aquarium-held clutch of juvenile arapaima Arapaima gigas (Osterglossidae). Diseases of Aquatic Organisms 70: 81-92. 2006.

Helke KL, Cooper TK, Mankowski JL, Poynton SL. Disseminated visceral coccidiosis in Indo-Gangetic flap-shelled turtles, Lissemys punctata andersonii. Journal of Wildlife Diseases 42: 788 – 796, 2006.

Saghari Fard MR, Jørgensen A, Sterud E, Bleiss W, Poynton SL. Ultrastructure and molecular diagnosis of Spironucleus salmonis (Diplomonadida) from rainbow trout Oncorhynchus mykiss in Germany. Diseases of Aquatic Organisms, 75: 37 – 50, 2007.

Gieseker CM, Serfling SG, Poynton SL, Reimschuessel R. Laboratory transmission of the monogenean Acolpenteron ureteroecetes (Dactylogyridae: Dactylogyrinae) infecing the posterior kidneys of largemouth bass, Micropterus salmoides (Perciformes: Centrachidae): time course and pathology. Journal of Aquatic Animal Health, in press, 2007.

Saghari Fard MR, Weisheit C, Poynton SL. Intestinal pH profile in rainbow trout Oncorhynchus mykiss and microhabitat preference of the flagellate Spironucleus salmonis (Diplomonadida). Diseases of Aquatic Organisms, in press, 2007.


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