Dr. Michael Kent, Professor

                  Office 532 Nash Hall  kent 2 
Phone 541-737-8652
FAX 541-737-0496
Email Michael.Kent@oregonstate.edu
Ph.D. University of California

Research InterestsFish Diseases, Parasitology, Pathogens of Zebra Fish

Courses Taught:  MB 480/580 General Microbiology, VM 760 Veterinary Parastiology


Presently the Kent lab is focusing on two major research areas; diseases of zebrafish in research facilities and impacts of pathogens on wild fishes. In both areas, we are focusing on the study of chronic infectious diseases. In the past decade there has been a dramatic increase in the use of zebrafish as a model in biomedical research. Underlying chronic diseases are of concern as they relate to non-protocol induced variation in laboratory fish, as they would with any laboratory animal.  Microsporidosis (caused by Pseudoloma neurophilia); mycobacteriosis (caused by various species of Mycobacterium); and the nematode Pseudocapillaria tomentosa are under investigation at this time. This work is supported by NIH Office of Research Infrastructure Programs (NIH ORIP).  Dr. Kent is also a Co-PI at the Zebrafish International Resource Center, where he assists with health studies and their diagnostic service. We also have an on-line manual on zebrafish diseases.  We recently established the SPF (Specific Pathogen Free) zebrafish research colony here at OSU at the Sinnhuber Aquatic Resource Center in collaboration with Dr. Robert Tanguay. This was supported by the NIEHS Environmental Health Sciences Center and NIH ORIP.  

Working with colleagues at OSU and other institutions, the Kent lab is developing zebrafish as models for infectious diseases of humans.  For example, by adapting zebrafish to 37ºC, we recently demonstrated that zebrafish can become infected with Toxoplasma gondii.  This is the first report of this infection in a fish.  This pathogenic parasite infects about one-third of the world population, and is the second most important cause of lethal food-borne infections in the United States.

Regarding wild fishes in Oregon, we are now investigating the role of multiple pathogen infections with prespawning Chinook salmon from the Willamette River in collaboration with Dr. Carl Schreck and Dr. James Peterson (Dept. of Fisheries and Wildlife, OSU; and USGS) and through the support of the U.S. Army Corps of Engineers.  The Kent lab is also investigating the impacts of parasites on endangered sucker species in the Klamath Lake in collaboration with Dr. Doug Markle (Dept. of Fish and Wildlife, OSU).  This research is funded by the U.S. Bureau of Reclamation.

Dr. Kent also investigates other parasites, including those infecting terrestrial animals. For example, we described spirurid nematodes in cougars in Oregon and modified a new diagnostic test for Haemonchus contortus, an important trichostrongyle nematode of sheep, goats and camilids.  Working with colleagues from the Dept. of Integrative Biology (OSU), we recently described severe infections by an Alaria spp. (Trematoda) in garter snakes (see publications below).


See-through Casper zebrafish. Green - GFP labeled Mycobacterium marinum in various organs.  Red=heart (this is a "red heart mutant").

Casper (transparent) zebrafish infected with fluorescently-labeled Toxoplasma gondii (arrow) Pseudocapillaria tomentosa.
A nematode in the intestine
of a zebrafish.
Contracaecum larval worm in sucker heart (left).  Worm completely replaces ventricle.  Normal heart on right. Photo:  A. Janik, OSU.


Pub Med

Clemens, B.J., Spangler, J., Robertson, P., Gaolvich, G., Banner, G., Avery, D., Gunckel, S., Bowdem, K., Ketchum, L., Spagnoli, S., Kent, M., and Kirk, J.P.  In press.  Evidence suggesting that grass carp of Devils Lake, Oregon, are the oldest in North America.  N. Am. J. Fish. Mgmt.

Dolan, B.P., Fisher, K.M., Colvin, M.E., Benda, S.E., Peterson, J.T., Kent, M.L., and Schreck, C.B.  2015.  Innate and adaptive immune responses in mirgrating spring-run adult chinook salmon, Oncorhynchus tshawytscha.  Fish Shellfish Immunol.  S1050-4648(15)30234-5. 

Benda, S.E., Kent, M.L., Caudill, C.C., Schreck, C.B., and Naughton, G.  2015.  Cool, pathogen free refuge lowers pathogen associated prespawn mortality of Willamette River Chinook Salmon (Oncorhynchus tshawytscha).  Trans. Am. Fish Soc. 144(6):1159-1172.

Paquette, C.E., Kent, M.L., Peterson, T.S., Wang, R., Dashwood, R.H., and Löhr, C.V.  2015.  Immunohistochemical characterization of intestinal neoplasia in zebrafish Danio rerio indicates epithelial origin.  Dis. Aquat. Organ. 116(3):191-7.

Uhrig, E.J., Spagnoli, S.T., Tkach, V.V., Kent, M.L. and Mason, R.T.  2015.  Alaria mesocercariae in the tails of red-sided garter snakes:  evidence for parasite-mediated caudectomy.  Parasitol. Res. 114(12):4451-61.

Sanders, J.L., Jaramillo, A.G., Ashford, J.E., Feist, S.W., Lafferty, K.D. and Kent, M.L.  2015.  Two Myxozoans from the urinary tract of topsmelt, Atherinops affinis.  J. Parasitol. 101(5):577-86.

Spagnoli, S., Xue, L. and Kent, M.L.  2015.  The common neural parasite Pseudoloma neurophilia is associated with altered startle response habituation in adult zebrafish (Danio rerio):  Implications for the zebrafish as a model organism.  Behav. Brain Res.  doi:10.1016/j.bbr.2015.05.046.

Sanders, J.L., Zhou, Y., Moulton, H.M., Moulton, Z.X., McLeod, R.,  Dubey, J.P., Weiss, L.M., and Kent, M.L.  2015.  The zebrafish, Danio rerio, as a model for Toxoplasma gondii:  an initial description of infection in fish.  J. Fish. Dis.  38(7):675-9.

Spagnoli, S.T., Xue, L., Murray, K.N., Chow, F., and Kent, M.L.  2015.  Pseudoloma neurophilia:  a retrospective and descriptive study of nervous system and muscle infections, with new implications for pathogenesis and behavioral phenotypes.  Zebrafish.  12(2):189-201.

Feist, S.W., Stentiford, G.D., Kent, M.L., Ribeiro-Santos, A., and Lorance, P.  2015.  Histopathological assessment of liver and gonad pathology in continental slope fish from the northeast Atlantic Ocean.  2015.  Mar. Environ. Res. 106:42-50.

Colvin, M.E., Peterson, J.T., Kent, M.L., and Schreck, C.B.  2015.  Occupancy modeling for improved accuracy and understanding of pathogen prevalence and dynamics.  PLoS One. 10(3):e0116605.

Chow, F.W., Xue, L. and Kent, M.L.  2015.  Retrospective study of the prevalence of Pseudoloma neurophilia shows male sex bias in zebrafish Danio rerio (Hamilton-Buchanan).  J.Fish Dis. PMID:  25588311.

Whipps, C.M., Kent, M.L. and Murray, K.N.  2014.  Occurrence of a myxozoan parasite Myxidium streisingeri N. sp. in laboratory zebrafish Danio rerio.  2014.  J. Parasitol.  PMID:  25277837.

Hooper, K.J.  Bobe, G., Vorachek, W.R., Bishop-Stewart, J.K., Mosher, W.D., Pirelli, G.J., Kent, M.L., Hall, J.A.  Effect of selenium yeast supplementation on naturally acquired parasitic infection in ewes.  Biol. Trace Elem. Res. 161(3):308-17.

Lafferty, K.D., Harvell, C.D., Conrad, J.M., Friedman, C.S., Kent, M.L., Kuris, A.M., Powell, E.N., Rondeau, D., and Saksida, S.M.  2014.  Infectious diseases affect marine fisheries and aquaculture economics.  Ann. Rev. Mar. Sci. PMID 25251276.

Collymore, C., Watral, V., White, J.R., Colvin, M.E., Rasmussen, S., Tolwani, R.J. and Kent, M.L.  Tolerance and efficacy of emamectin benzoate and ivermectin for the treatment of Pseudocapillaria tomentosa in laboratory zebrafish (Danio rerio).  Zebrafish 11(5):490-7.

Wolf, J.C., Baumgartner, W.A., Blazer, V.S., Camus, A.C., Engelhardt, J.A., Fournie, J.W., Frasca, S., Jr., Groman, D.B., Kent, M.L., Khoo, L.H., Law, J.M., Lombardini, E.D., Ruehl-Fehlert, C., Segner, H.E., Smith, S.A., Spitsbergen, J.M>, Weber, K., Wolfe, M.J.  2014.  Toxicol. Pathol. PMID:  25112278.

Kent, M.L., and Dorstyn, D.S.  2014.  Psychological variables associated with employment following spinal cord injury:  a meta-analysis.  Spinal Cord.  PMID:  25091108.

Kent, M.L., Soderlund, K., Thomann, E., Schreck, C.B., and Sharpton, T.  2014.  Post-mortem sporulation of Ceratomyxa shasta (myxozoa) after death in adult chinook salmon.  J. Parasitol.  PMID 247250089.

West, K., Miles, R., Kent, M.L., and Frazer, J.K.  2014.  Unusual fluorescent granulomas and myonecrosis in Danio rerio infected by the microsporidian pathogen Pseudoloma neurophilia.  Zebrafish. PMID 24707848.

Kent, M.L., Buchner, C., Barton, C., and Tanguay, R.L.  2014.  Toxicity of chlorine to zebrafish embryos.  Dis. Aquat. Organ.  107(3):235-40. 

Sanders, J.L.  Peterson, T.S., and Kent, M.L.  2014.  Early development and tissue distribution of Pseudoloma neurophilia in the zebrafish, Danio rerio.  J. Eukaryot. Microbiol. 61(3):238-64.

Sanders, J.L., Kent, M.L.  2013.  Verification of intraovum transmission of a microsporidium of vertebrates:  Pseudoloma neurophilia infecting the zebrafish, Danio rerio.  PLOS one.  8(9):e76064.DOI:10.1371/journal.pone.0076064.

Peterson, T.S., Ferguson, J.A., Watral, V.G., Mutoji, K.N., Ennis, D.G., Kent, M.L.  2013.  Paramecium caudatum enhances transmission and infectivity of Mycobacterium marinum and Mycobacterium chelonae in zebrafish (Danio rerio).  Dis. Aquat. Org. 106:229-239.

Kent, M.L., Benda, S., St.-Hillaire, S., Schreck, C.B.  2013.  Sensitivity and specificity of histology for diagnoses of four common pathogens and detection of nontarget pathogens in adult Chinook salmon (Oncorhynchus tshawytscha) in freshwater.  J. Vet. Diag. Invest., 25:341-351.

Neal, J.T., Peterson, T.S, Kent, M.L., Guillemin, K.  2013.  H. pylori virulence factor CagA increases intestinal cell proliferation by Wnt pathway activation in a transgenic zebrafish model.  Dis. Model Mech. Mar. 1.

Kent, M.L., Harper, C., Wolf, J.C.  2012.  Documented and potential research impacts of subclinical diseases in zebrafish.  ILAR J.  53:  126-134.

Sanders, J.S., Kent, M.L.  2012.  Control of microsporidiosis in laboratory zebrafish colonies.  ILAR J.  53:  106-113.

Sanders, J., Myers, M.S., Tomanek, L., Cali, A M., Takvorian, P,M.  Kent, M.L. 2012.  Ichthyosporidium weissii n. sp. (Microsporidia) infecting the arrow goby (Clevelandia ios).  J. Eurk. Microbiol. (J59:  258-267).

Ferguson, J.A., Koketsu, W.,  Ninomiya, I.,  Rossignol,  P.A.,  Jacobson, K.C., Kent, M.L. 2011.  Mortality of coho salmon (Oncorhynchus kisutch) associated with burdens of multiple parasite species.  Intl. J. Parasitol. 41: 1197-11205.

Sanders J.L., Kent M.L.   2011. Development of a sensitive assay for the detection of Pseudoloma neurophilia in laboratory ­populations of the zebrafish Danio rerio. Dis Aquat Org. 96:145-156

Ferguson, J.A., Romer, J., Sifneos, J., Madsen, L, Glynn, M., Schreck, C.B., Kent, M.L.  2012. Impacts of multispecies parasitism on juvenile Oregon Coho Salmon (Oncorhynchus kisutch).  Aquaculture  (in press, available online).

Ferguson, J.A., St-Hilaire, S., Peterson, T.S., Rodnick, K., Kent, M.L. 2011. Survey of parasites in threatened stocks of coho salmon (Oncorhynchus kisutch) in Oregon by examination of wet tissues and histology.  J. Parasitol.  97: 1085-1098.

Peterson, T.S., Spitsbergen, J.M., Feist, S.W., Kent, M.L. 2011. The Luna stain, an improved selective stain for detection of microsporidian spores in histologic sections. Dis. Aquat. Org.  95: 175–180.

Kent, M.L., Buchner, C., Watral, V.G., Sanders, J.L. LaDu, J., Peterson, T.S., Tanguay, R.L. 2011. Development and maintenance of a specific pathogen free (SPF) zebrafish research facility for Pseudoloma neurophilia.  Dis. Aquat. Org. 95: 73–79.

Ferguson, J.A., Woodberry, K., Gillin, C.M., Jackson, D.H., Sanders, J., Madigan, W., J. Bildfell, R.J., Kent, M.L. 2011. Cylicospirura species (Nematoda: Spirocercidae) and stomach nodules in cougars (Puma concolor) and bobcats (Lynx rufus) in Oregon. J. Wildl. Dis. 47:140-153.

Brown, A. M. V., Kent, M.L., Adamson, M.L. 2010. Description of five new Loma (Microsporidia) species in Pacific Fishes with redesignation of the type species Loma morhua Morrison & Sprague, 1981, based on morphological and molecular species-boundaries tests. J. Eurk. Microbiol. 57: 529-553.

Jurasek, M.E. Bishop-Stewart, J.K., Storey, B.E., Kaplan, R.M., Kent, M.L.  2010. Modification and further evaluation of a fluorescein-labeled peanut agglutinin test for identification of Haemonchus contortus eggs. Vet. Parasitol.  69:209-213.

Sanders, J.L., Lawrence, C., Nichols, D.K., Bru , J.F., Peterson, T.S., Murray, K.N., Kent, M.L. 2010. Pleistophora hyphessobryconis (Microsporidia) infecting zebrafish 9911:47-56.

Brown, A.M.V., Kent, M.L., Adamson, M.L. 2010.  Low genetic variation in the salmon and trout parasite Loma salmonae (Microsporidia) supports marine transmission and clarifies species boundaries. Dis. Aquat. Org. 91:35-46.

Mansfield, K.G., Riley, L., Kent, M.L.  2010. Workshop summary: detection, impact, and control of specific pathogens in animal resource facilities. ILAR. 51:171-179.

Whipps, C.M., Boorom, K., Bermudez, L.E., Kent, M.L. 2010. Molecular characterization  of Blastocystis species in Oregon identifies multiple subtypes. Parasitol. Res. 106: 827-832.

Landers, D.H. , Simmonich, S.M., Jaffe, D., Geiser, L., Campbell, D.H., Schwindt, A.,  Schreck, C.B., Kent, M.L., Hafner, W., Kimberly, H., Usenko, S., Ackerman, L., Schrlau, J., Rose, N., Blett, T.,  Erway, M. M. 2010. The Western Airborne Contaminant Assessment Project (WACAP): An Interdisciplinary Evaluation of the Impacts of Airborne Contaminants in Western U. S. National Parks. Environ. Sci. Tech. Environ.44: 855–859.

Ramsay, J.M., Watral, V., Schreck, C.B., Kent, M.L. 2009. Husbandry stress exacerbates mycobacterial infections in adult  zebrafish, Danio rerio (Hamilton). J. Fish Dis. 32: 931-941.

Schwindt, A.R., Kent, M.L., Ackerman, L.K., Simonich, S.L., Landers, D.H., Blett, Schreck, C.B. 2009. Reproductive abnormalities in fish from Western U.S. National Parks. Trans. Am. Fish Soc. 138: 522-531.

Jacobs, J.M., Stine, C.S., Baya, A.M., Kent, M.L. 2009. A review of mycobacteriosis in marine fishes. J. Fish Dis. 32: 119-130.

Selected Book Chapters

Saksida, S.M., Gardner, I., and Kent, M.L.  2014.  Transmission of infectious agents between wild and farmed fish.  Chapter 9.  IN:  Woo, P.T.K. and Bruno, D.  Diseases of Finfish in Cage Culture.  CAB Intl. Publ.  Wallingford, Oxon, England, pp. 313-329.

Kent, M.L., Shaw, R.W., and Sanders, J.  2014.  Fish Microsporidia.  Chapter 20.  IN:  Microsporidia:  Pathogens of Opportunity.  IN:  Weiss, L.M. and Becnel, J.J.  (eds.).  Wiley Enterprise.  pp. 357-370.

Kent, M.L. and Fournie, J.  2007.  Parasites of Fishes.  IN:  D.G.  Baker (eds.).  Flynn's Parasites of Laboratory Animals.  Blackwell Publ.  pp. 69-117.