Dr. Jerri Bartholomew, Professor, Department Head,
Emile F. Pernot Distinguished Professorship
Director J.L. Fryer Aquatic Animal Health Laboratory
Research Interests: Salmon diseases, Myxozoan parasites, Host resistance mechanisms, Parasite evolution
Courses Taught: MB 491/591 Fish Disease, Salmonid Disease Workshop; MB 507 Seminar
Our research focuses on the pathogens that affect the health of wild Pacific salmon populations, particularly myxozoan parasites, which have a complex life cycle, requiring both a fish and annelid host.
Disease Effects on Wild Populations: The myxozoan Ceratomyxa shasta is endemic across the Pacific NW and causes high mortality in juvenile salmon in some river systems. A long-term project in the Klamath River integrates monitoring and research to develop recommendations for fishery management by providing real time data on parasite densities and their predicted effects on juvenile salmon, and by linking areas of high disease risk with physical parameters such as water flows and temperature. We are applyinig similar approaches to the Deschutes River. Research in the Willamette River further investigates C. shasta dynamics in this system as well as conducting surveys for parasites of native and introduced fishes.
Interactions Between Hatchery and Wild Fish: Research being conducted in the Willamette River basin investigates pathogen transmission between hatchery populations and naturally reproducing populations. We are also looking at the effects of multiple infections on salmon survival.
Climate Change Effects on Disease: Climate change is expected to have profound effects on host-pathogen interactions. We are examining how this might affect myxozoan disease by developing predictions for how the phenology of parasite life cycles will change under future climates, how changing flow dynamics will alter disease, and to identify river habitats that should be protected as refugia.
Parasite Evolution and Diversity: Myxozoans not only have complex life histories, but enigmatic relationships as revealed by molecular sequence analysis. Continued investigations into the genetics of C. shasta have revaled that it is actually a parasite complex, with different strains specifically evolving with different salmonid hosts. This finding has caused us to rethink assumptions about host-parasite interactions. We are currently involved in genome sequencing and transcriptomic studies that will aid us in developing better diagnostic tools as well as to answer questions about basic parasite biology and phylogenetic relationships.
Parasite Invasion: The first step in Myxozoan infection is activation of their polar capsules. These specialized cells resemble the nematocysts of their cnidarian relatives and could offer possibilities for development of therapeutants. We are working with Israeli scientists to understand the physical process and the genes that control it, as well as to test candidate treatments that affect the process.
Evolution of the Immune System and Role of Mucosal Immunity: This salmonid-C. shasta relationship has proved an ideal model for investigating mucosal immunity in a primitive host and is the basis for a collaboration with Oriol Sunyer, University of Pennsylvania, funded by the National Science Foundation and National Institutes of Health.
Richey, C.A., Kenelty, K.V., Hopkins, K.V.S., Stevens, B.N., Martinez-López, B., 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. PMID: 31897785.
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. of Aquatic Org. 134:43-55.
Kosakyan, A., Alama-Bermejo, G., Bartošová-Sojková, P., Born-Torrijos, A., Šima, R., Nenarokova, A. Eszterbauer, E., Bartholomew, J., and Holzer, A.S. 2019. Author Correction: Selection of suitable reference genes for gene expression studies in myxosporean (Myxozoa, Cnidaria) parasites. Sci. Rep. 9(1):18589.
Breyta, R., Atkinson, S.D., and Bartholomew, J.L. 2019. Evolutionary dynamics of Ceratonova species (Cnidaria: Myxozoa) reveal different host adaptation strategies. Infect. Genet. Evol. 78:104081.
Kosakyan, A., Alama-Bermejo, G., Bartošová-Sojková. P., Born-Torrijos, A., Šíma, R., Nenarokova, A., Eszterbauer, E., Bartholomew, J., and Holzer, A.S. 2019. Selection of suitable reference genes for gene expression studies in myxosporean (Myxozoa, Cnidaria) parasites. Sci Rep. 2019 Oct 21;9(1):15073. doi: 10.1038/s41598-019-51479-0. PMID: 31636316.
Alama-Bermejo, G., Holzer, A.S., and Bartholomew, J.L. 2019. Myxozoan adhesion and virulence: Ceratonova shasta on the move. Microorgn. 7(10):doi:10.3390/microorganisms7100397.
Atkinson, S.D., Hallett, S.L., Diaz-Morales, D., Bartholomew, and J.L., deBuron, 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.
Javaheri, A., Babbar-SEbens, M., Miller, R.N., Hallett, S.L., and Bartholomew, J.L. 2019. An adaptive ensemble Kalman filter for assimilartion of mult-sensor, multi-modal water temperature observations into hydrodynamic model of shallow rivers. J. of Hydrology 572:682-691.
Zatti, S.A., Atkinson, S.D., Maia, A.A.M., Corrêa, L.L., Bartholomew, J.L., and Adriano, E.A. 2018. Novel freshwater Ellipsomyxa and Myxobolus species (Cnidaria: Myxozoa) parasiting Brachyplatystoma rousseauxii in the Amazon basin. Parasitol. Intl. 67(5):612-621.
Javaheri, A., Babbar-Sebens, M., Alexander, J., Bartholomew, J., and Hallett, S. 2018. Global sensitivity analysis of water age and temperature for informing salmonid disease management. J. of Hydrology, 561:89-97.
Atkinson, S.D., Bartholomew, J.L., and Lotan, T. 2018. Myxozoans: Ancient metazoan parasites find a home in phylum Cnidaria. Zool. 129:66-68.
Stinson, M.E.T., Atkinson, S.D, and Bartholomew, J.L. 2018. Widespread distribution of Ceratonova shasta (Cnidaria:Myxosporea) genotypes indicates evolutionary adaptation to its salmonid fish hosts. J. Parasitol. 10:1645/18-79.
Zatti, S.A., Atkinson, S.D., Maia, A.A.M., Corrêa, L.L., Bartholomew, J.L. and Adriano, E.A. 2018. Novel Myxobolus and Ellipsomyxa species (Cnidaria: Myxozoa) parasiting Brachyplatystoma rousseauxii (Siluriformes: Pimelodidae) in the Amazon basin, Brazil. Parasitol. Int. 67(5):612621.
Richey, C.A., Kenelty, K.V., Van Stone Hopkins, K., Stevens, B.N., Martinez-López, B., Barnum, S.M., Hallett, S.L., Atkinson, S.D., Bartholomew, J.L., and Soto, E. 2018. Distribution and prevalence of Myxobolus cerebralis in postfire areas of Plumas National Forest: Utility of environmental DNA sampling. J. Aquat. Animal Hlth. 30(2):130-143.
Atkinson, S.D., Hallett, S.L., and Bartholomew, J.L. 2018. Genotyping of individual Ceratonova shasta (Cnidaria: Myxosporea) myxospores reveals intra-spore ITS-1 variation and invalidates the distinction of genotypes II and III. Parasitology March 27:1-6 PMID 29580305.
Zatti, S.A., Atkinson, S.D., Maia, A.A.M., Bartholomew, J.L. and Adriano, E.A. 2018. Novel Henneguya spp. (Cnidaria: Myxozoa) from cichilid fish in the Amazon basin cluster by geographic origin. Parasitol. Res. 117(3):849-859.
Zatti, S.A., Atkinson, S.D., Maia, A.A.M., Bartholomew, J.L., and Adriano, E.A. 2018. Ceratomyxa gracillima n. sp. (Cnidaria: Myxosporea) provides evidence of panmixia and ceratomyxid radiation in the Amazon basin. Parasitology Jan 17:1-10. PMID: 29338808.
Vieira, D.H.M.D., Alama-Bermejo, G., Bartholomew, J.L., Abdallah, V.D., de Azebedo, R.K. 2017. Morphological and molecular description of Myxobolus batalhensis n. sp. (Myxozoa, Myxosporea), a liver and ovary parasite of Salminus hilarii in Brazil. Parasitol. Res. 116(12):3303-3313.
Piriatinskiy, G., Atkinson, S.D., Park, S., Morgenstern, D., Brekhman, V., Yossifon, G., Bartholomew, J.L., and Lotan, T. 2017. Functional and proteomic analysis of Ceratonova shasta (Cnidaria: Myxozoa) polar capsules reveals adaptations to parasitism. Sci. Rep. 7(1):9010.
Zatti, S.A., Atkinson, S.D., Bartholomew, J.L., Maia, A.A. and Adriano, E.A. 2017. Amazonian waters harbor an ancient freshwater Ceratomyxa lineage (Cnidaria: Myxosporea). Acta Trop. 169:100-106.
Alexander, J.D., Bartholomew, J.L., Wright, K.A., Som, A., and Hetrick, N.J. 20XX. Integrating models to predict distribution of the invertebrate host of myxosporean parasites. Freshwater Sci. Accepted.
Ben-David, J., Atkinson, S.D., Pollak, Y., Yossifon, G., Shavit, U., Bartholomew, J.L., and Lotan, T. 2016. Myxozoan polar tubules display structural and functional variation. Parasit. Vectors 9(1):549.
Foott, J.S., Stone, R., Fogerty, R., Bolick, A., True, J.L., Bartholomew, J.L., Hallett, S.L., Buckles, G.R., and Alexander, J.D. 2016. Ceratonova shasta myxospore production from salmon carcasses; Carcass removal is not a viable management option. J. of Aquatic Animal Hlth. 28:75-84.
Chiaramonte, L.V., Ray, R.A., Corum, R.A., Soto, T., Hallett, S.L. and Bartholomew, J.L. 2016. Klamath River thermal refuge provides juvenile salmon reduced exposure to the parasite Ceratonova shasta. Trans. of the Am. Fisheries Soc. 145:810-820.
Roon, S.R., Alexander, J.D., Jacobson, K.C., and Bartholomew, J.L. 2015. Effect of Nanophyetus salmincola and bacterial co-infection on mortality of juvenile chinook salmon. J. Aquat. Animal Hlth. 4:209-16.
Alexander, J.D., Hallett, S.L., Stocking, R.W., Xue, L. and Bartholomew, J.L. 2014. Host and parasite populations after a ten year flood: Manayunkia speciosa and Ceratonova shasta in the Klamath River. Northwest Sci. 88:219-233.
Hurst, C.N., Wong, P., Hallett, S.L., Ray, R.A., and Bartholomew. 2014. Transmission and persistence of Ceratomyxa shasta genotypes in chinook salmon. J. Parasitol. PMID: 24945751.
Ray, R.A., R.W. Perry, N.A. Som and J.L. Bartholomew. 2014. Using cure models for analyzing the influence of pathogens on salmon survival. Transactions of the American Fisheries Society. 143(2):
Atkinson, S.D., Foott, J.S., and Bartholomew, J.L. 2014. Erection of Ceratonova n. Gen. (Myxosporea: Ceratomyxidae) to encompass freshwater species C. gasterostea n. sp. from threespine stickleback (Gasterosteus aculeatus) and C. shasta n. comb. from salmonid fishes. J. Parasitol. PMID 24754344.
Adriano, E.A., Silva, M.R., Atkinson, S.D., Bartholomew, J.L., and Maia, A.A. 2014. Myxidium ceccarellii n. sp. (Myxosporea) from the gallbladder of Leporinus elongatus (Anastomidae) from the São Francisco River, Brazil. Parasitol. Res. PMID 24752369.
Bjork, S.J., Zhang, Y.A., Hurst, C.N., Alonso-Naveiro, M.E., Alexander, J.D., Sunyer, J.O., and Bartholomew, J.L. 2014. Defenses of susceptible and resistant Chinook salmon (Onchorhynchus tshawytscha) against the myxozoan parasite Ceratomyxa shasta. Fish Shellfish Immunol. 1:87-95.
Gómez, D., Bartholomew, J., and Sunyer, J.O. 2014. Biology and mucosal immunity to myxozoans. Dev. Comp. Immunol. 43(2): 243-56.
Polley, T.M., Atkinson, S.D., Jones, G.R., and Bartholomew, J.L. 2013. Supplemental description of Myxobolus squamalis (Myxozoa). J. Parasitol. 99:725-728.
Ray, A.R. and J.L. Bartholomew. 2013. Estimation of transmission dynamics of the Ceratomyxa shasta actinospore to the salmonid host. Parasitology. 140:907-916.
Bartošová, P., I. Fiala, M. Jirku, M. Cinkova, M. Caffara, M.L. Fioravante, S.D. Atkinson, J.L. Bartholomew and A.S. Holzer. 2013. Sphaerospora sensu stricto: Taxonomy, diversity and evolution of a unique lineage of myxosporeans (Myxozoa). Molec. Phylogentics and Evolution. 68:93-105.
Ray, A.R., R.A. Holt and J.L. Bartholomew. 2012. Relationship between temperature and C. shasta-induced mortality in Klamath River salmonids. Journal of Parasitology. 98:520-526.
Holzer, A.S., P. Bartošová, H. Pecková, T. Tyml, S. Atkinson, J. Bartholomew, D. Sipos, E. Eszterbauer and I. Dyková. 2013. Who's who in renal sphaerosporids (Bivalvulida: Myxozoa) from common carp, Prussian carp and goldfish -- Molecular identification of cryptic species, blood stages and new members of Sphaerospora sensu stricto. Parasitology. 140:40-60.
Ordás, M.C., R. Castro, B. Dixon, J.O. Sunyer, S. Bjork, J. Bartholomew, T. Korytar, B. Kollner, A. Cuesta and C. Tafalla. 2012. Identification of a novel CCR7 gene in rainbow trout with differential expression in the context of mucosal or systemic infection. Developmental and Comparative Immunology. 38:302-311.
Stinson, M.E.T. and J.L. Bartholomew. 2012. Predicted redistribution of Ceratomyxa shasta genotypes with salmonid passage in the Deschutes River, Oregon. J. of Aquatic Animal Hlth. 24:274-280.
Hallett, S.L., R.A. Ray, C.N. Hurst, R.A. Holt, G.R. Buckles, S.D. Atkinson and J.L. Bartholomew. 2012. Density of the waterborne parasite, Ceratomyxa shasta, and its biological effects on salmon. Applied and Environmental Microbiology 78:3724-3731.
Hurst, C.N., R.A. Holt and J.L. Bartholomew. 2012. Ceratomyxa shasta in the Williamson River, Oregon: Implications for reintroduced salmon. North American Journal of Fisheries Management. 32:14-23.
Atkinson, S.D., S.R.M. Jones, R.D. Adlard and J.L. Bartholomew. 2011. Geographic and host distribution patterns of Parvicapsula minibicornis (Myxozoa) small subunit ribosomal RNA genetic types. Parasitology 138:969-977.
Fujiwara, M., M.S. Mohr, A. Greenberg, J.S. Foott and J.L. Bartholomew. 2011. Effects of myxozoan disease on population dynamics of Pacific salmon. Transactions of the American Fisheries Society 140:1380-1391.
Zielinski, C.M., H.V. Lorz, S.L. Hallett, L. Xue and J.L. Bartholomew. 2011. Comparative susceptibility of Deschutes River (Oregon, USA) Tubifex tubifex populations to Myxobolus cerebralis. Journal of Aquatic Animal Health 23:1-8.
Zhang, Y-A., I. Salinas, J. Li, D. Parra, S. Bjork, S. LePatra, J. Bartholomew and J.O. Sunyer. 2010. IgT, a primitive immunoglobulin class specialized in mucosal immunity. Nature Immunology 11:827-835.
Bjork, S.J. and J.L. Bartholomew. 2010. Invasion of Ceratomyxa shasta (Myzozoa) and comparison of migration to the intestine between susceptible and resistant fish hosts. International Journal for Parasitology, 40:1087-1095.
Okamura, B., Gruhl, A. and Bartholomew, J.L. (Eds.) 2015. Myxozoan Evolution, Ecology and Development. Springer.
Okamura B., A. Gruhl and J. L. Bartholomew. 2015. An introduction to myxozoan evolution, ecology and development. In Myxozoan Evolution, Ecology and Development. Springer pp 1-23.
Atkinson, S. D., P. Bartosová-Sojková, C. M. Whipps and J. L. Bartholomew. 2015. Appropaches for characterising myxozoan species. In Myxozoan Evolution, Ecology and Development. Springer pp 111-124.
Hallett, S. L., S. D. Atkinson, J. L. Bartholomew and C. Széékely. 2015. Myxozoans exploiting homeotherms. In Myxozoan Evolution, Ecology and Development. Springer pp 125-138.
Ray R. A., J. D.Alexander, P. De Leenheer P and J. L. Bartholomew. 2015. Modeling the effects of climate change on disease severity: a case study of Ceratonova (syn Ceratomyxa) shasta in the Klamath River. In Myxozoan Evolution, Ecology and Development. Springer pp 363-378.
Bartholomew, J. L. and B. Kerans. 2015. Risk assessments and approaches for evaluating myxozoan disease impacts. In Myxozoan Evolution, Ecology and Development. Springer pp 379-396.
Jones, S. R. M., J. L. Bartholomew and J. Y. Zhang. 2015. Mitigating myxozoan disease impacts on wild fish populations. In Myxozoan Evolution, Ecology and Development. Springer pp 397-414.
Bartholomew, J.L. and S.L. Hallett. Myxobolus cerebralis and Ceratomyxa shasta. IN: Fish Parasites: Pathobiology and Protection. P.T.K. Woo and K. Buckmann Eds., CAB International, Wallingford, 2012.
Bartholomew, J.L. Myxobolus cerebralis. IN: Handbook of Global Freshwater Invasive Species. R. Francis, Ed., Earthscan, London. 2012.