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Stephen Atkinson standing outside of an industrial building.

Stephen Atkinson

Associate Professor (Senior Research)
Department of Microbiology

Stephen Atkinson

Associate Professor (Senior Research)
Department of Microbiology


My research focuses on fish parasites, specifically myxozoans. These are microscopic animals related to corals and jellyfish, but which are parasites that require two hosts to complete their life cycles. I investigate the structure, function, development and genetics of problematic myxozoans of salmon and trout, and discover and describe new parasite species.

Current research projects

  • Klamath River fish health studies (Bureau of Reclamation grant to Dr. Bartholomew and Dr. Hallett)
    • Parasite detection and quantification in river water samples
    • Genomics and transcriptomics of Ceratonova shasta
    • Hunting for cryptic sources of parasites
    • Characterization and detection of the invertebrate host
  • USDA Capacity Building Grant to Robert Durburow (KSU) and Stephen Atkinson (OSU)
    • We are developing computer learning games to promote awareness and education of fish diseases: Fish Detective and SimFish; with Dr. Sascha Hallett, u/g Paris Myers, Professor Yue Zhang and MS student Kevin Hung (OSU College of Electrical and Computer Engineering). We are also expanding, a database of fish diseases and pathogens, and a portal for connecting public inquiries with fish health experts; in collaboration with ODFW, undergraduate students and Dr. Sascha Hallett.
  • “A novel approach for preventing Myxozoan infection in fish: Control of polar capsule activation”
    • Together with Jerri Bartholomew and Tamar Lotan (U. Haifa, Israel), and grad student Ben Americus, we are working to understand the fundamental structural and functional workings of myxozoan parasite spores: how they are built, if they can envenomate their hosts, and what types of chemical compounds can block their activation.

Other ongoing research collaborations include

  • Microscopy and genetics of myxozoan mitochondria with Dorothee Huchon (Tel Aviv University, Israel). Dual stained developing parasite cells. Blue=DNA stained with DAPI. Red=mitochondria stained with MitoTracker. The blue nuclei are about 5 µm across.
  • Phylogenetics of Ceratonova shasta across the Pacific Northwest, with Rachel Breyta (OSU / USGS).
  • Discovering cryptic life cycles of marine myxozoan parasites, with Isaure DeBuron, College of Charleston, SC.
  • Novel and introduced myxozoan parasites, with Tiago Milanin, U. Sao Paulo, Brazil.

Science and art

I use my scientific research to inspire artistic interpretations and representations for my own enjoyment, and to promote outreach and engagement with the wider community. I use paint, paper collage, digital illustration and 3D printing. I am one of 3 faculty advisors (with Jerri Bartholomew and Andrew Myers), of the interdisciplinary student club Seminarium. The club engages students with cross-disciplinary approaches to create exhibitions on campus and for the general public.


I teach 2 courses in the OSU Honors College: (1) HC407: Life: The Biosphere through Space and Time. (2) HC407: Have Rocket Will Travel. And I co-teach the biannual summer salmon disease workshop.


  • Americus, B., Hams, N., Klompen, A.M.L., Alama-Bermejo, G., Lotan, T., Bartholomew, J.L., and Atkinson, S.D. Accepted September 2021. The cnidarian parasite Ceratonova shasta utilizes inherited and recruited venom-like compounds during infection. PeerJ.
  • Alama-Bermejo, G., Hernandez-Orts, J.S., Huchon, D., and Atkinson, S.D. 2021. Two novel myxosporean parasite species of Ceratomyxa Thélohan, 1892 from the banded cusk-eel Raneya brasiliensis (Kaup) (Ophidiiformes: Ophidiidae) off Patagonia, Argentina. Parasitol. Intl. 85:102433.
  • Pekmezi, G.Z., Atkinson, S.D., Yardimci, B., Bolukbas, C.S., Ozppicak, M., and Yilmaz, S. 2021. Novel and known myxobolids (Cnidaria: Myxozoa) infecting Chondrostoma angorense (Cypriniformes: Leuciscidae) in Turkey. Parsitol. Intl. 83:102339.
  • Brekhman, V., Ofek-Lalzar, M., Atkinson, S.D., Alama-Bermejo, G., Maor-Landaw, K., Malik, A., Bartholomew, J.L., and Lotan, T. 2021. Proteomic analysis of the parasitic Cnidarian Ceratonova shasta (Cnidaria: Myxozoa) reveals diverse roles of actin in motility and spore formation. Front. in Mar. Sci. 8:632700.
  • Americus, B., Schisler, G.J., Bartholomew, J.L., and Atkinson, S.D. 2021. Myxobolus cerebralis Causes Presporogonic Mortality in Juvenile Mountain Whitefish J. of Aquatic Animal Hlth. 33(2):116-122.
  • Bartošová-Sojková, P., Kyslík, J., Alama-Bermejo, G., Hartigan, A., Atkinson, S.D., Bartholomew, J.L., Picard-Sánchez, A., Palenzuela, O., Faber, M.N., Holland, J.W., and Holzer, A.S. 2021. Evolutionary Analysis of Cystatins of Early-Emerging Metazoans Reveals a Novel Subtype in Parasitic Cnidarians Biology 10(2):110.
  • Americus, B., Bartholomew, J.L., Lotan, T., Atkinson, S.D. 2020. A comparison of the structure and function of nematocysts in free-living and parasitic cnidarians (Myxozoa). Inter. J. for Parasitol., 50: 763-769. DOI:10.1016/j.ijpara.2020.04.012.
  • Americus, B., Austin, B., Lotan, T., Bartholomew, J., and Atkinson, S. 2020. In vitro and in vivo assays reveal that cations affect nematocyst discharge in Myxobolus cerebralis (Cnidaria: Myxozoa). Parasitol., 147(12):1352-1358. DOI:10.1017/S0031182020001158.
  • Kyger, R., Luzuriaga, A., Peri, S., Layman, T., Sandberg, T.O.M., Singh, D., Atkinson, S.D., Bartholomew, J.L., Huchon, D., Soojin, V., and Alvarez-Ponce, D. 2020. Myxosporea (Myxozoa, Cnidaria) lack DNA cytosine methylation. Molec. Biol. and Evol.. msaa214. DOI:10.1093/molbev/msaa214.
  • Tilic, E., Atkinson, S.D., and Rouse, G. 2020. Mitochondrial genome of the freshwater annelid Manayunkia occidentalis Mitochondrial DNA Part B: Resources, 5(3): 3313-3315. DOI:10.1080/23802359.2020.1815604.
  • Alama-Bermejo, G., Meyer, E., Atkinson, S.D., Holzer, A.S., Wiśniewska, M.W., Kolísko, M., and Bartholomew, J.L. 2020. Transcriptome-wide comparisons and virulence gene polymorphisms of host-associated genotypes of the cnidarian parasite Ceratonova shasta in salmonids. Genome Biol. and Evol., 12(8), 1258-1276. DOI:10.1093/gbe/evaa109.
  • Borkhanuddin, M.H., Goswami, U., Cech, G., Molnár, K., Atkinson, S.D., and Székely, C. 2020. Description of myxosporeans (Cnidaria: Myxozoa) infecting the popular food fish Notopterus notopterus (Pisces: Notopteridae) in Malaysia and India. Food and Waterborne Parasitol. DOI:10.1016/j.fawpar.2020.e00092.
  • Yahalomi, D., Atkinson, S.D., Neuhof, M., Chang, E.S., Philippe, H., Cartwright, P., Bartholomew, J.L., and Huchon, D. 2020. A cnidarian parasite of salmon (Myxozoa: Henneguya) lacks a mitochondrial genome. PNAS, 117(10):5358-5363.
  • Atkinson, S.D., Bartholomew, J.L., and Rouse, G.W. 2020. The invertebrate host of salmonid fish parasites Ceratonova shasta and Parvicapsula minibicornis (Cnidaria) is a novel fabriciid annelid. Manayunkia occidentalis sp. nov. (Sabellida: Fabriciidae). Zootaxa, 4751(2):310-320.
  • Milanin, T., Bartholomew, J.L., and Atkinson, S.D. 2020. An introduced host with novel and introduced parasites: Myxobolus spp. (Cnidaria:Myxozoa) in yellow perch Perca flavescens. Parasitol. Res. DOI:10.007/S00436-019-06585-3.
  • Breyta, R., Atkinson, S.D., and Bartholomew, J.L. 2019. Evolutionary dynamics of Ceratonova species in the Klamath River basin reveals different host adaptation strategies. Infection, Genetics and Evolution, 78:104081.
  • Richey, C.A., Kenelty, K.V., Van Stone Hopkins, K., Stevens, B.N., Martínez-López, B., Barnum, S.M., Stevens, B.N., Hallett, S.L., Atkinson, S.D., Bartholomew, J.L., and Soto, E. 2020. Validation of environmental DNA sampling for determination of Ceratonova shasta (Cnidaria: Myxozoa) distribution in Plumas National Forest, CA. Parasitol. Res.
  • Alama-Bermejo, G., Viozzi, G.P., Waicheim, M.A., Flores, V.R., and Atkinson, S.D. 2019. Host-parasite relationship of Ortholinea lauquen n. sp. (Cnidaria:Myxozoa) and the fish Galaxias maculatus (Jenyns, 1842) in Northwest Patagonia, Argentina. Dis. Aquat. Organisms 136(2):163-174.
  • Borkhanuddin, M.H., Cech, G., Molnár, K., Shaharom-Harrison, F., Duy Khoa, T.N., Samshuri, M.A. Mazeland, S., Atkinson, S.D., and Székely, C. 2019. Henneguya (Cnidaria:Myxosporea:myxobolidae) infections of cultured barramundi, Lates calcarifer (Perciformes:Latidae) in an estuarine wetlands system of Malaysia: Description of Henneguya setiuensis n. sp., Henneguya voronini n. sp. and Henneguya calcarifer n. sp. Parasitol. Res. 119(1):85-96.
  • Atkinson, S.D., Hallett, S.L., Díaz Morales D., Bartholomew, J.L., and de Buron, I. 2019. First myxozoan infection (Cnidaria: Myxosporea) in a marine polychaete from North America, and erection of actinospore collective group Saccimyxon. J. Parasitol. 105(2):252-262. DOI:10.1645/18-183.
  • Fromm, A., Atkinson, S.D., Alama-Bermejo, G., Cartwright, P., Bartholomew, J., and Huchon, D. 2019. A new mitochondrial gene order in the banded cusk-eel Raneya brasiliensis (Actinopterygii, Ophidiiformes). Mitochondrial DNA Part B, 4:1, 1-4.
  • Howell, C.K., Atkinson, S.D., Bartholomew, J.L., and Hallett, S.L. 2019. Development and application of a qPCR assay targeting Ichthyophthirius multifiliis in environmental water samples. Dis. Aquatic Org. 134; 43-55.