Dr. Jerri Bartholomew
Associate Professor, Department
of Microbiology
PhD 1989, Oregon State University.
e-mail: bartholj at science.oregonstate.edu
My research interest is pathogens of fishes, and particularly parasites of the phylum Myxozoa. This group is distinguished by having a complex life cycle, requiring not only a fish host, but an aquatic annelid. Although there are greater than 1200 known myxozoan species, the life cycles of less than 30 have been described, and we are trying to add to this number. However, three species that cause disease in salmonids are the main focus of our research.
Ceratomyxa shasta. This parasite is found only in the Pacific Northwest of the U.S. and Canada, and in some river systems it can be a serious disease problem for salmon and trout. We described the life cycle of this parasite, finding that its alternate host is an unusual freshwater polychaete worm. This finding opened the door to investigations on the ecology of the relationship between the parasite and its hosts to answer why it is present in certain areas and not found in others. Recent studies on C. shasta in the Klamath River have resulted in mapping the distribution and habitat requirements of the polychaete host, in documenting the effects of temperature and water flow, and in development of molecular detection methods that can measure parasite numbers in water samples. Together, these advances are providing important keys to understanding the effects of this pathogen in that system and developing a model for predicting parasite. Our goal is to provide resource managers with tools for mitigating those effects.
Another area of investigation is the genetic and immunological basis of resistance against this parasite. Strains of fish from endemic areas are not generally susceptible to infection and disease unless exposed to large numbers of parasites. However, we lack even basic knowledge about how infection occurs. Studies on the infectious process in resistant and susceptible strains aims to answer these questions.
Parvicapsula minibicornis. This parasite was recently detected in Chinook salmon in the Klamath River and little is known about its potential effects. However, as it can cause severe kidney pathology, there is concern that it may affect survival of these fish as they enter the ocean. During the past year we have been able to solve the life cycle of this myxozoan, finding that it requires the same invertebrate host as C. shasta. As a result, we already know a great deal about its life cycle and this will allow for a more effective management approach in rivers where these parasites are present.
Myxobolus cerebralis. This myxozoan is the cause of whirling disease in trout. Interest in whirling disease has resurfaced in the past decade because of its impacts on wild trout populations in the Rocky Mountain states. This has caused a reexamination of what we know about the parasite and its impact in other regions. Of particular interest in my lab is the effect that it may have on anadromous salmon populations, and the potential of these migratory fish for disseminating the parasite to new areas. Another topic of interest is the role that the genetics of the invertebrate host, Tubifex tubifex, plays in influencing infection. We are addressing these questions in laboratory studies and in field studies in northeastern Oregon, where the parasite is endemic and lower Columbia River tributaries where it is most likely to become established. This work has recently expanded to Alaska in response to questions about the risk of introduction and establishment of this parasite in waters in that state.
These research interests led me to join the Whirling Disease Foundation as their science coordinator. This foundation was established in 1995 with a mission to raise funds needed for solutions to the damage caused by whirling disease. The Foundation has sponsored annual symposia that have focused attention on the problem and funded research projects of regional interest.
Current students and their research:
Stephen Atkinson – Myxozoan life cycles
Sarah Bjork – Ceratomyxa shasta pathogenesis and host resistance
Adam Ray – Modeling the Ceratomyxa shasta life cycle
Christopher Zielinski – Assessing the risk of Myxobolus cerebralis introduction in the
Deschutes River, Oregon
Recent publications
Bjork, S. J. and J. L. Bartholomew. The effects of water velocity on the Ceratomyxa shasta infectious cycle. Journal of Fish Disease. Accepted May 2009
Arsan, E. L. and J. L. Bartholomew. Potential for the dissemination of the non-native salmonid parasite Myxobolus cerebralis in Alaska. Journal of Aquatic Animal Health. In Press
Arsan, E. L. and J. L. Bartholomew. Potential dispersal of the non-native parasite Myxobolus cerebralis in the Willamette River Basin, Oregon: A qualitative analysis of risk. Reviews inFisheries Science. In Press (2009 publication)
Bartholomew, J. L., S. D. Atkinson, S. L. Hallett, L. J. Lowenstine, M. M. Garner, C. H. Gardiner, B. A. Rideout, M. K. Keel and J. D. Brown. 2008. Myxozoan parasitism in waterfowl. International Journal for Parasitology
Hallett, S. L. and J. L. Bartholomew. 2008. Effects of water flow on the infection dynamics of Myxobolus cerebralis. Parasitology 135:371-384.
Garner, M. M., S. D. Atkinson, S. L. Hallett, J. L. Bartholomew, R. W. Nordhausen, H. Reed, L.
Adams and B. Whitaker. 2008. Renal myxozoanosis in weedy sea dragons (Phyllopteryx taeniolatus) due to Sinuolinea phyllopteryxa n.sp. Journal of Fish Diseases 31:27-35.
Bartholomew, J. L., S. D. Atkinson, S. L. Hallett, C. M. Zielinski and J. S. Foott. 2007. Distribution and abundance of the salmonid parasite Parvicapsula minibicornis (Myxozoa) in the Klamath River Basin (Oregon-California, USA). Diseases of Aquatic Organisms. 78:137-146.
Arsan, E. L., S. D. Atkinson, S. L. Hallett, T. Meyers, and J. L. Bartholomew. 2007. Expanded geographical distribution of Myxobolus cerebralis: first detections from Alaska. Journal of Fish Diseases 30:483-491.
Arsan, L., S. Hallett, and J. Bartholomew. 2007. Tubifex tubifex from Alaska:
distribution and susceptibility to Myxobolus cerebralis. Journal of Parasitology 93:1332-1342
Atkinson, S. D., S. L. Hallett and J. L. Bartholomew. 2007. The life cycle of Chloromyxum auratum (Myxozoa) from goldfish (Crassius auratus) involves and antonactinomyxon actinospores. Journal of Fish Diseases 30:149-156.
Bartholomew, J. L., H. V. Lorz, S. D. Atkinson, S. L. Hallett, D. G. Stevens, R. A. Holt, K. Lujan and A. Amandi. 2007. Evaluation of a management strategy to control the spread of Myxobolus cerebralis in a lower Columbia River tributary. North American Journal of Fisheries Management 27:542-550
Stocking, R. W., H. L. Lorz, R. A. Holt and J. L. Bartholomew. 2007. Surveillance for Ceratomyxa shasta in the Puget Sound watershed, WA, USA. Journal of Aquatic Animal Health 19:116-120.
Stocking, R. W. and J. L. Bartholomew. 2007. Distribution and habitat characteristics of Manayunkia speciosa and infection prevalence with the parasite, Ceratomyxa shasta, in the Klamath River, OR-CA, USA. Journal of Parasitology 93:78-88
Bartholomew, J. L., S. D. Atkinson and S. L. Hallett. 2006. Involvement of Manayunkia speciosa (Annelida: Polychaeta: Sabellidae) in the life cycle of Parvicapsula minibicornis, a myxozoan parasite of Pacific salmon. Journal of Parasitology 92:742-748
Hallett, S. L. and J. L. Bartholomew. 2006. Application of a real-time PCR assay to detect and quantify the myxozoan parasite Ceratomyxa shasta in water samples. Diseases of Aquatic Organisms 71:109-118.
Hallett, S.L., Atkinson, S.D., Holt, R.A., Banner, C.R. & Bartholomew, J.L. 2006 A new myxozoan from feral goldfish (Carassius auratus). Journal of Parasitology 92:357-363.
Stocking, R. W., R. A. Holt, J. S. Foott and J. L. Bartholomew. 2006. Spatial and Temporal Occurrence of the Salmonid Parasite Ceratomyxa shasta (Myxozoa) in the Oregon-CaliforniaKlamath River Basin. Journal of Aquatic Animal Health. 18: 194-202.
Bartholomew, J. L., B. L. Kerans, R. P. Hedrick, S. C. MacDiarmid and J. R. Winton. 2005. A risk assessment based approach for the management of whirling disease. Reviews In Fisheries Science 13:205-230.
Garner M. M, Bartholomew L. J, Whipps C. M, Nordhausen R. W, Raiti P. 2005. Renal myxozoanosis in Crowned River Turtles Hardella thurjii: description of the putative agent Myxidium hardella n. sp., by Histopathology, Electron Microscopy, and DNA Sequencing. Veterinary Pathology 42: 589-595.
Hallett, S. L., S. D. Atkinson and J. L. Bartholomew. 2005. Countering morphological ambiguities: development of a PCR assay to assist the identification of Tubifex tubifex oligochaetes. Hydrobiologia. 543:305-309