research – College of Veterinary Medicine UNIVERSITY of FLORIDA Tue, 25 Oct 2016 18:51:43 +0000 en-US hourly 1 Liang Zhou Mon, 11 Jan 2016 19:40:01 +0000 Associate Professorphotograph of Dr. Liang Zhou

Department of Infectious Diseases and Pathology
PO Box 110880
2015 SW 16th Ave
Gainesville, FL  32611-0880
352-294-8293 (office)
352-294-8289, 294-8290 or 294-8291 (labs)
FAX 352-392-9704


  • MD, Nanjing Medical University, China; Department of Clinical Medicine, 1996
  • PhD, University of California, Los Angeles; Department of Microbiology, Immunology, and Molecular Genetics, 2004

Honors and Awards

  • 2013: Burroughs Wellcome Fund Investigators in the Pathogenesis of Infectious Disease Award
  • 2011: Pew Scholar in Biomedical Sciences
  • 2011:  Cancer Research Institute Investigator Award
  • 2010:  ICS Young Investigator Award – International Cytokine Society
  • 2005:  Ariad Research Fellow – Cancer Research Institute-Irvington Institute Fellowship

Research Interests

The goal of my laboratory is to determine the transcriptional regulation of intestinal immune responses. We have characterized the interactions between various transcription factors (e.g., RORγt and Foxp3) involved in specifying development of Th17 cells and the related iTreg lineage and how they eventually determine whether the T cell adopts the Th17 or Treg cell fate. Recently, we have been focusing on the molecular regulation of RORγt+ innate lymphoid cells by the aryl hydrocarbon receptor (Ahr), a ligand-dependent transcription factor under steady-state physiological conditions, during inflammation or autoimmunity. This work has implications for understanding how to modulate intestinal immune responses in different disease settings, may ultimately lead to identification of new therapeutic targets for human IBD or colon cancer.

Selected Publications

  • Li, S., Heller, J. J, Bostick, J. W., Lee, A., Schjerven, H., Kastner, P., Chan, S., Chen, Z. E., Zhou, L.  Ikaros inhibits Group 3 innate lymphoid cell development and function by suppressing the aryl hydrocarbon receptor pathway. Immunity, 45 (1) 185-197 (2016).
  • Zhou, L. Ahr function in lymphocytes: emerging concepts.  Trends Immunol. 37(1):17-31 (2016).
  • Bostick, J., Zhou, L. Innate lymphoid cells in intestinal immunity and inflammation. Cellular and Molecular Life Sciences. 73(2):237-52 (2016).
  • Heller, J. J., Schjerven, H., Li, S., Lee, A., Qiu, J., Chen Z. E., Smale, S. T., Zhou, L. Restriction of IL-22-producing T Cell Responses and Differential Regulation of Treg compartments by Zinc finger transcription factor Ikaros.  J. Immunol. 193(8): 3934-46 (2014).
  • Guo, X., Qiu, J., Tu, T., Deng, L., Anders, R. A., Zhou, L. *, Fu, Y-X *. Induction of innate lymphoid cell-derived interleukin-22 by the transcription factor STAT3 mediates protection against intestinal infection. Immunity. 40(1): 25-39 (2014). * Co-corresponding authors
  • Qiu, J., Zhou, L. Aryl Hydrocarbon Receptor Promotes RORγt+ ILCs and Controls Intestinal Immunity and Inflammation. SeminImmunopathology 35(6):657-70 (2013).
  • Qiu, J., Guo, X., Chen Z. E., He, L., Sonnenberg, G. F., Artis D., Fu, Y-X., Zhou, L. Group 3 innate lymphoid cells inhibit T cell-mediated intestinal inflammation through aryl hydrocarbon receptor signaling and regulation of microflora. Immunity. 39(2): 386-99 (2013).
  • Qiu, J., Heller J. J., Guo, X, Chen Z. E., Fish, K., Fu Y-X, and Zhou, L. The Aryl hydrocarbon receptor regulates gut immunity through modulation of innate lymphoid cells. Immunity 36, 92-104 (2012).
  • Zhou, L., Lopes, J., Chong, M. M. W., Ivanov, I. I., Min, R., Victora, G. D., Shen, Y., Du, J., Rubtsov, Y. P., Rudensky, A. Y., Ziegler, S. F., Littman, D. R. TGF-β-induced Foxp3 inhibits Th17 cell differentiation by antagonizing RORγt function. Nature  453 (7192), 236-40 (2008).
  • Zhou, L., Ivanov, I. I., Spolski, R., Min, R., Shenderov, K., Egawa, T., Levy, D. E., Leonard, W. J., Littman, D. R. IL-6 programs Th17 cell differentiation by promoting sequential engagement of the IL-21 and IL-23 pathways. Nature  Immunol.  8 (9), 967-74 (2007).
  • Ivanov, I. I.*, McKenzie, B. S.*, Zhou, L *, Tadokoro, C. E., Lepelley, A., Lafaille, J. J., Cua, D. J., Littman, D. R. The orphan nuclear receptor RORγt directs the differentiation program of proinflammatory IL-17+ T helper cells.  Cell.  126 (6) 1121-33 (2006). *equal contributions
Christopher D. Vulpe Wed, 06 Jan 2016 20:24:03 +0000 Chris_VulpeProfessor

Department of Physiological Sciences
Box 100144
Gainesville, FL 32610-0103
Office: 352-294-4010
Fax: 352-392-2938
Vulpe Lab website


  • M.D., Medicine, University of California, San Francisco, 1996
  • Ph.D., Biochemistry, Genetics, University of California, San Francisco, 1994
  • S.B., Biology, Massachusetts Institute of Technology, 1986

Research Interests

Copper and Iron Metabolism
Copper and iron are vital nutrients with a highly conserved and interwoven metabolism that is required for the growth and development of all organisms. An overall research goal of the laboratory is to further understand copper and iron metabolism in mammals with a focus on 1) characterizing the role of the multi-copper ferroxidases (Fe (II)-> Fe(III) in iron homeostasis and 2) identifying the genetic factors that influence iron status in mammals using “in silico” QTL analysis of inbred mouse strains and collaborations to study genetic determinants of iron deficiency in zebrafish and humans.

Toxicogenomics and Green Chemistry
We are utilizing systematic functional analysis through the use of “barcoding” analysis in the budding yeast Saccharomyces cerevisiae to identify conserved toxicity pathways that may provide insight on toxicant susceptibility in people. We are currently focused on breast cancer carcinogens, mitochondrial toxicants, pesticides and emerging contaminants. Most recently we have started using whole genome CRISPR approaches in a similar approach in mammalian cell lines.

We are developing a novel approach for identifying and understanding the toxicity of xenobiotics in aquatic ecosystems by monitoring changes in global gene expression patterns in aquatic indicator species representative of different trophic levels, including Daphnia magna (a crustacean), and Pimephales promelas (fathead minnow). We are assessing the sensitivity, specificity and utility of an ecotoxicogenomics approach for ecological toxicity assessment in real world environmental settings. Tools we are using include traditional microarray technologies as well as high-throughput sequencing methods.

Selected Publications

  • DE Vidal-Dorsch, SM Bay, S Moore, B Layton, AC Mehinto, CD Vulpe. M Brown-Augustine, A Loguinov, H Poynton, N Garcia-Reyero, EJ Perkins, L Escalon, ND Denslow, CR Cristina, T Doan, S Shukradas, J Bruno, L Brown, GV Agglen, P Jackman, M Bauer Ecotoxicogenomics: Microarray interlaboratory comparability. Chemosphere 2016 144, 193-200.
  • Pan S, Yuan C, Tagmount A, Rudel RA, Ackerman, JM, Yaswen, P, Vulpe CD, Leitman, DC. Parabens and Huan Epidermal Growth Factor Receptor Ligands Cross-Talk in Breast Cancer Cells. Environ Health Perspet. 2015 Oct 17.
  • Vidal-Dorsch DE, Bay SM, Moore S, Layton B, Mehinto AC, Vulpe CD, Brown-Augustine, M, Loguinov A, Poynton, H, Gracia-Reyero, N, Perkins, EJ, Escalon, L, Denslow, ND, Cristina CR, Doan, T, Shukradas, S, Bruno, J, Brown, L, Van Agglen, G, Jackman, P, Bauer, M. Ecotoxicogenomics: Microarray Interlaboratory Comparability. Chemosphere 2015 Sep 9;144:293-300. doi: 10.1016/j.chemosphere.2015.08.019.
  • Scanlan LD, Loguinov AV, Teng Q, Antczak P, Dailey KP, Nowinski DT, Kornbluh J, Lin XX, Lachenauer E, Arai A, Douglas NK, Falciani F, Stapleton HM, Vulpe CD. Gene Transcription, Metabolite and Lipid Profiling in Eco-Indicator Daphnia magna Indicate Diverse Mechanisms of Toxicity by Legacy and Emerging Flame-Retardants. Environ Sci Technol. 2015 Jun 16;49(12):7400-10. doi: 10.1021/acs.est.5b00977.
  • Lee SM, Lee SB, Prywes R, Vulpe CD. Iron Deficiency Upregulates Egr1 Expression. Genes Nutr. 2015 Jul; 10(4):468. doi: 10.1007/s.12263-015-0468-0.
  • Jiang R, Hua C, Wan Y, Jiang B, Hu H, Zheng J, Fuqua BK, Dunaief JL, Anderson GJ, David S, Vulpe CD, Chen H. Hephaestin and ceruloplasmin play distinct but interrelated roles in iron homeostasis in mouse brain. J Nutr. 2015 May;145(5):1003-9. doi: 10.3945/jn.114.207316.
  • Gaytán BD, Vulpe CD. Functional toxicology: tools to advance the future of toxicity testing. Front Genet 2014 5:110; doi:10.3389/fgene.2014.00110.
  • Fuqua BK, Lu Y, Darshan D, Frazer DM, Wilkins SJ, Wolkow N, Bell AG, Hsu J, Yu CC, Chen H, Dunaief JL, Anderson GJ, Vulpe CD. The multicopper ferroxidase hephaestin enhances intestinal iron absorption in mice. PLoS One. 2014 Jun 4;9(6):e98792. doi: 10.1371/journal.pone.0098792.

Additional Publications here

New species of parasite discovered as disease agent in domestic cats Wed, 17 Jul 2013 13:18:15 +0000 Research distinguishes the parasite that causes the disease in cats from the agent that causes it in cows
Owen Rae, Ph.D., a professor of large animal clinical sciences, and. Heather Walden, Ph.D., a research assistant professor in the University of Florida College of Veterinary Medicine, are shown with cows from a UF herd. Walden has identified a new species of parasite in domestic cats. Another species previously thought to be the same affects cattle, and Walden’'s research has looked closely at the different parasites in both species.

Dr. Owen Rae, a professor of large animal clinical sciences, and. Dr. Heather Walden, a research assistant professor in the UF College of Veterinary Medicine, are shown with cows from a UF herd. Walden has identified a new species of parasite in domestic cats. Another species previously thought to be the same affects cattle, and Walden’’s research has looked closely at the different parasites in both species.

University of Florida researchers have identified a new species of Tritrichomonas in domestic cats, distinguishing the parasite that causes the disease in felines from the agent long thought to affect both cats and cattle.

Although the disease is just beginning to be understood and tested for in cats, it costs cattle producers millions of dollars each year in lost revenue, researchers say.

“Up to now, there has only been one species, Tritrichomonas foetus, described in the reproductive tract of cattle and the intestine of cats,” said Dr. Heather Walden, a research assistant professor in the UF College of Veterinary Medicine, a part of UF Health. “We conducted experimental studies putting the feline isolate in cows and the bovine isolate in cats, and saw differences in the disease-causing capacity in each of these animal hosts.”

These studies, combined with molecular analysis of a small group of genes with similar sequencing patterns in cats and in cattle, noted key differences between the species. The study and findings appeared online in a recent issue of Parasitology Research. Walden named the newly discovered species Tritrichomonas blagburni in honor of Dr. Byron Blagburn, the Auburn University professor who was her mentor and led her doctoral studies there. “Although we were not the first to note that there were differences genetically between the pathogens that cause trichomoniasis in both cats and cows, in previous studies, many people focused on the genetics of the organism in order to determine species,” Walden said. “Our thought was, you have to look further at hosts and disease states in addition to some of the genetics.”

Feline trichomoniasis is an intestinal disease that results in chronic diarrhea, flatulence and fecal incontinence. Bovine trichomoniasis is a sexually transmitted disease of cattle that infects the reproductive tract of cows, causing uterine infections and possible mid- to late-term abortions.

“In cats, people are becoming more aware of the disease and testing for it more frequently now,” Walden said. “Treatment of cats with this disease is problematic — it sometimes works and sometimes doesn’t.”

In cattle, however, there is no treatment that prevents infection and the disease is very difficult to test for, particularly in big herds, Walden said.

“It’s one of those things where often the cattle owner will just cull the bulls or the cows that show symptoms of the disease,” she said. “Some cattle owners may try to control the disease through the use of artificial insemination, but that’s expensive and most owners won’t take that approach.”

Dr. Raoul Boughton heads the Disease Ecology Program at the Archbold Biological Station in Venus, Fla. He said Tritrichmonas foetus of cattle was a disease of “high economic concern” that can lead to the loss of 20 to 40 percent of calves from an infected herd.

He called Walden’s work on understanding the genetic relationship and ecology of infection of the Tritrichomonas species “an important step if we are to further our understanding and develop a solution to controlling this parasite that costs the cattle industry hundreds of millions of dollars a year in lost revenue.” Walden’s research group is now analyzing additional genes from a conserved genetic area obtained from parasites found in domestic cats and parasites obtained from cattle in order to characterize more genetic differences and help solidify the previous findings.

“The research by Dr. Walden and the description of Tritrichomonas blagburni and its association with different pathogenicities in the cat and cattle performs the great service of distinguishing these very similar agents, their hosts, and the diseases they cause in their respective hosts,” said Dr. Dwight Bowman, a professor of parasitology at Cornell University’s College of Veterinary Medicine.

“This is good for cats because it removes them as the reservoir source for infections of cattle on farms,” he added.

Other investigators involved in the study include a team of scientists from Auburn University and Virginia Tech. Walden completed her doctoral program at Auburn in 2008, focusing her dissertation on protozoan parasites, specifically Tritrichomonas foetus.

UF veterinarians develop technique to test for manatee heart problems Thu, 27 Jun 2013 13:37:36 +0000  

An adult manatee receives an echocardiogram by Dr. Amara Estrada, a UF veterinary cardiologist, in the field at a Crystal River health assessment in the fall of 2011.

An adult manatee receives an echocardiogram by Dr. Amara Estrada, a UF veterinary cardiologist at Tampa’s Lowry Park Zoo. (Photo by Dave Parkinson, Lowry Park Zoo)

Leisurely swims in warm, tropical waters fueled by the gaze of admiring fans and a healthy vegetarian diet.

The life of a manatee hardly seems likely to prompt concerns about heart disease. But researchers at the University of Florida say the lumbering, loveable sea cow’s ticker deserves a closer look because of the animal’s endangered status.

That’s why they’ve developed a technique to test for cardiac problems in endangered manatees, both in the wild and in captivity. The new technique will enhance knowledge of how the manatee heart functions.

The UF researchers are using the technique to gather data they hope to share with wildlife and zoo veterinarians to ultimately save more manatee lives. Collaborating with scientists from Tampa’s Lowry Park Zoo and the Florida Fish and Wildlife Conservation Commission’s marine mammal pathology laboratory in St. Petersburg, they are using echocardiography on the large creatures, making use of a specially designed table built to hold animals weighing up to 2,000 pounds.

“There are a lot of gaps in our knowledge base on basic anatomy and physiology of manatees due to the obvious limitations of working with a 1,000- to 1,500-pound animal that spends its entire life in the water,” said Dr. Trevor Gerlach, an intern in UF’s aquatic animal health program and lead author on a paper that documents the first phase of the researchers’ study in the June issue of the Journal of Zoo and Wildlife Medicine. “Due to their current endangered status, it is important that we understand the animal in its entirety so that we can better tailor conservation efforts for the species.”

The researchers’ long-term goal is to provide practitioners at rehabilitation facilities and those working in the field with data from clinically healthy animals. Such animals could be compared to animals of concern to determine if cardiac disease is present.

To allow for effective testing, the researchers first developed a table built to hold the weight of 2,000-pound animals that were part of a large-scale manatee health assessment conducted by the U.S. Geological Survey in Crystal River. Fourteen healthy, wild and captive Florida manatees underwent echocardiography, administered using the table technique, between fall 2011 and winter 2012. The group included eight females and six males of various ages.

Manatee sonogram

A manatee receives an echocardiogram administered by Dr. Ivan Sosa, center, a UF veterinary cardiology resident. Also shown assisting are veterinary technician Melanie Powell, second from right, and Dr. Trevor Gerlach, an aquatic animal health intern, far right. (Photo courtesy of Lowry Park Zoo.)

“We were able to clearly visualize all valves and chambers,” Gerlach said, adding that other key indicators of heart function also were successfully obtained. Some abnormalities in the study animals also were documented.

“Our results indicate that echocardiography in the Florida manatee is possible, which has both clinical and research implications in larger epidemiologic studies evaluating diseases of the cardiopulmonary and cardiovascular systems,” Gerlach said.

Although extensive research has been conducted on comparative anatomy, physiology and ecology of sea cows, very few studies have evaluated the manatee heart. Basic cardiac morphology and a test called an electrocardiogram have been examined, but the diagnostic value is limited to electrical imbalances in the heart, the researchers said.

“Echocardiography is the gold standard for diagnosing valve diseases and structural abnormalities, and provides other information as well,” Gerlach said.

Researchers are finishing up the second phase of the study, which entails collecting more data from echocardiographs to establish normal testing parameters for manatees of various ages.

“Once we establish the parameters, we can begin larger epidemiological studies on the prevalence of heart disease in the wild population, which is one of our long-term goals,” Gerlach said.

Dr. Bob Bonde, a manatee researcher with the USGS, praised the new technique.

“Out-of-water, real-time assessment of these large aquatic mammals will benefit our evaluation of manatee health-related indices in the wild population,” “Knowledge of manatee reproductive fitness and nutritional condition is paramount to our fully understanding their recovery.”

Dr. Amara Estrada, a veterinary cardiology specialist who mentored Gerlach while he was a UF veterinary student and assisted with his research, said the collaborative aspects of the project were especially valuable to her both professionally and personally.

“The opportunity to work with such a diverse group of people toward a common goal is especially meaningful to me as a clinician/researcher and can only be accomplished by being a part of the University of Florida,” Estrada said.

Thomas B. Waltzek Mon, 24 Jun 2013 20:21:43 +0000 Waltzek2Assistant Professor
Research Coordinator, Aquatic Animal Health Program

Department of Infectious Diseases and Pathology
PO Box 110880
Bldg. #1379, Mowry Road
Gainesville, FL 32611-0880
FAX 352-392-9704


  • PhD, Comparative Pathology, University of California at Davis, 2010
  • DVM, University of California at Davis, 2009
  • MS, Ecology, University of California at Davis, 2002
  • BS, Biological Sciences, Florida State University, 1998

Honors and Awards

  • 2010 – John L. Pitts Veterinary Student/Recent Graduate Scholarship
  • 2009 – Merck Achievement Award, UC Davis
  • 2009 – Wilds Scholastic Award, UC Davis
  • 2009 – AVMA Achievement Award, UC Davis
  • 2007 – Best Student Presentation, 33rd Eastern Fish Health Workshop

Research Interests

  • Characterization of Emerging Aquatic Animal Viruses (EAAVs) using Metagenomics;
  • Phylogenomics to study the Biology, Epidemiology, and Evolution of EAAVs;
  • Development of Broadly Applicable Diagnostic Methodologies to Track EAAVs;
  • Determining the Role that International Commerce of Aquatic Animals Plays in the Emergence of AAVs as it Relates to Global Aquaculture and Ecosystem Health.
  • Aquatic Animal Zoonoses, Public Health, One Health

Recent Publications

New UF center focuses on inflammation and disease Thu, 30 May 2013 16:29:15 +0000

Dr. Mansour Mohamadzadeh directs new center for inflammation and mucosal immunology

By Lindy McCollum-Brounley

Mansour Mohamadzadeh _MBF_IMG_0423Recognizing growing evidence that inflammation influences many diseases — including diabetes, certain cancers and even Alzheimer’s — University of Florida Health has established the Center for Inflammation and Mucosal Immunology to foster collaboration among members of the UF biomedical research community with shared interest in inflammation and disease.

“Though the center is very new, our members already number more than 40 UF scientists whose interdisciplinary research efforts explore the whole gamut of complex biological responses of inflammation and immunology,” said center director Mansour Mohamadzadeh, Ph.D., a professor in the UF College of Veterinary Medicine department of infectious diseases and pathology, and a faculty member in the UF College of Medicine division of gastroenterology, hepatology and nutrition in the department of medicine. “The center’s primary goal is to foster research collaborations among these multidisciplinary scientists, leading to new discoveries that alleviate human sickness and death caused by immune-mediated auto-inflammatory diseases.”

Inflammation has been found to influence many medical maladies. These include colon and other cancers, irritable bowel syndrome, eosinophilic esophagitis, chronic infectious diseases, systemic pulmonary fibrosis, type 1 diabetes, arthritis and Alzheimer’s. Facilitating interdisciplinary research of the inflammatory processes behind these conditions should accelerate scientific discoveries leading to improved prevention and treatment.

To open doors for networking and collaboration among UF researchers, the center hosts a monthly seminar series wherein members share their research and learn about the research of others. In addition, a research retreat, anticipated to become an annual event, is planned for October and will feature a nationally prominent keynote speaker on inflammation and mucosal immunology. One of the greatest benefits of center membership may be access to core equipment and animal research platforms.

“In addition to providing access to advanced technologies that are perhaps too expensive for individual labs to purchase, such as flow cytometry, confocal microscopy and cell analysis, one of the very important membership benefits is access to the center’s germ-free mouse and zebrafish models,” Mohamadzadeh said. “These germ-free animal platforms are free of contaminating microorganisms or disease, and can be deliberately modified with specific bacteria, making it possible to directly investigate the impact of colonization in a living organism. We believe these core resources will prove to be invaluable assets to UF scientists, giving them a competitive edge in the national research community.”

For more information about the UF Center for Inflammation and Mucosal Immunology or to submit a membership application, visit


UF veterinarians help aquatic mammals tangled in fishing line Mon, 07 Jan 2013 20:46:05 +0000 UF researchers: Rare human parasite found in U.S. horse for first time Thu, 15 Nov 2012 19:53:39 +0000


By Sarah Carey

Dr. Sarah Reuss and Dr. Jim Wellehan inspect the ear of a healthy horse.

Dr. Sarah Reuss and Dr. Jim Wellehan inspect the ear of a healthy horse. (Photo by Maria Farias)

A rare, potentially fatal species of parasite never before found in North America has been identified in a Florida horse.

University of Florida veterinarians identified the parasite, called Leishmania siamensis, in the summer of 2011. This particular species of parasite previously had been found only in Thailand and parts of Europe while other species of Leishmania have been found all over the world. No Leishmania infections of any species had been previously reported in a horse native to the United States.

The UF discovery raises awareness of how widespread the parasite is and suggests a need for watchfulness regarding potential transmission to humans, the researchers said.

“We now know the parasites that cause this disease also exist here in the U.S. and that we have some insect, presumably the sandfly, that is capable of transmitting the disease,” said Sarah Reuss, V.M.D., a clinical assistant professor of large animal medicine at the UF College of Veterinary Medicine, who along with UF colleagues and a private practice clinical pathologist described the findings in the September issue of Emerging Infectious Diseases, a journal of the Centers for Disease Control and Prevention. “Our findings raise several potential avenues of further investigation, including the prevalence of this disease in horses in the U.S., a better understanding of the sandfly life cycle and the potential of this leishmaniasis species to be transmitted from animals to humans.”

Leishmaniasis is a parasitic infection spread through the bites of infected sandflies. The disease shows up most commonly in two forms: cutaneous, which causes sores on the skin, is self-healing; and visceral, the most severe form, which affects the entire body and is almost always fatal if left untreated. After malaria, leishmaniasis is the leading parasitic cause of death in humans. The disease has been found in four continents and is considered to be endemic in 88 countries, including 16 developed nations, according to the World Health Organization. The WHO estimates the worldwide prevalence at 12 million cases, with about 350 million people at risk of infection and about 60,000 people dying from the disease each year. Leishmaniasis is rare in people in the U.S.

“It really hasn’t been a disease that has affected Americans, but there are really good data with climate change models that predict sandfly ranges will expand, making this disease much more of a threat because of global warming,” said co-author James Wellehan Jr., D.V.M., Ph.D., a veterinarian from the UF research team, who confirmed the presence of the disease in the Florida horse by analyzing the genes of the parasite.

The visceral form of leishmaniasis is endemic in foxhounds in the U.S, associated with a different species of Leishmania. But aside from some regional transmission in the Southwest, most of the cases of skin infection due to leishmaniasis in the U.S. are believed to have occurred in animals brought in from countries where the disease is common, or in people who had recently spent time in those countries.

“Thousands of people serving in the U.S. military have returned from Iraq and Afghanistan with cutaneous or visceral leishmaniasis,” said Christine Petersen, D.V.M., Ph.D., an associate professor of veterinary pathology at Iowa State University’s College of Veterinary Medicine and an expert on Leishmania transmission, immune responses and veterinary disease, who was not involved in the study. “In a few cases, these individuals have brought dogs back with them that also have leishmaniasis.”

The horse diagnosed at UF had no history of travel outside of the eastern U.S. The pregnant 10-year-old Morgan mare was treated as an outpatient at the University of Florida Large Animal Hospital for sores inside her left ear. A biopsy done in the field had suggested that the rare parasite was present when organisms that looked like the protozoa were seen within the inflammatory cells in that tissue. Further tissue samples and genetic analysis were used to identify the species of the disease-causing organism at UF.

Often, leishmaniasis of the skin will resolve without medical treatment. But the mare’s sores worsened over time — a development the veterinarians attributed to the pregnancy.

“Many of the horses in other countries that have been diagnosed with leishmaniasis were pregnant, so we think perhaps these horses have pregnancy-altered immune systems and are therefore more vulnerable to the disease,” Reuss said.

The drug used to treat horses with the disease in other parts of the world isn’t readily available in the U.S., and surgery wasn’t an option because the sores were inside the horse’s ear. After treatment with anti-fungal drugs, the sores eventually regressed. Horses housed at home with the affected horse did not show any signs of illness. Though the disease needs the sandfly as a carrier and does not pass directly among horses or between horses and humans, veterinary experts say the discovery of the new parasitic species in the U.S. is cause for increased vigilance.

“As a disease of animals capable of being transmitted to humans, leishmaniasis requires more attention to ensure we do not have vector-borne transmission within larger areas of the country,” Petersen said.


Analysis of bacterial genes may help ID cause of dog brain disease, say UF researchers Thu, 27 Sep 2012 20:39:00 +0000 Analysis of bacterial genes may help ID cause of dog brain disease, say UF researchers
Dr. Dan Brown and bioscientist Dina Michaels

Dr. Dan Brown and bioscientist Dina Michaels use a fluorescence microscope to analyze cells of the canine immune system during infection with Mycoplasma canis. (Photo by Maria Farias)

By analyzing the genes of bacteria, University of Florida researchers have moved a step closer to pinpointing how two brain disorders common in small-breed dogs occur.

The researchers found that the bacteria, known as Mycoplasma canis, invade dog’s cells and suppress their immune system responses.

“This could explain how the bacteria are able to enter the brain in certain circumstances,” said lead investigator Daniel Brown, an associate professor of infectious diseases at the UF College of Veterinary Medicine. “If our theory is correct, it is possible that antibiotic therapy aimed at the mycoplasma could be beneficial if the condition is diagnosed early enough.”

The findings, which appear in the August issue of the Journal of Bacteriology, were also presented at the annual meeting of the International Organization for Mycoplasmology in France.

The researchers studied two common brain syndromes called granulomatous meningoencephalomyelitis, or GME, and necrotizing meningoencephalitis, or NME, which occur primarily in small toy-breed dogs such as pugs, Malteses, Yorkshire terriers, Chihuahuas and Pomeranians. The diseases affect the central nervous system, causing brain damage and symptoms such as seizures, decreased alertness and difficulty maintaining balance. There is no cure, but drugs can control the brain inflammation by suppressing the immune system.

No clear data exist on how widespread the disorders are.

“Although reliable information on new and existing cases is pretty scarce or nonexistent, inflammatory central nervous system disease is certainly one of the most common problems we deal with as veterinary neurologists,” said Christopher Mariani, D.V.M., Ph.D., an assistant professor of neurology at North Carolina State University’s College of Veterinary Medicine. Mariana was not involved in the UF study.

The syndromes previously were thought to be caused by a virus or by an attack of the body’s own immune system. But University of Georgia researchers Renee Barber, and Scott Schatzberg, and colleagues, including Brown, reported earlier this year that whereas viruses were absent from the brain tissues of dogs with the diseases, the bacterium Mycoplasma canis was unexpectedly common. Interestingly, the researchers also found traces of the bacteria in some dogs that did not have the disease.

The bacteria would not have been detected by the methods used previously to search for a presumed viral agent.

In the new study, Brown and colleagues examined five strains of Mycoplasma canis isolated from three different parts of the body — the brain, the genital tract and the throat.

They found no difference between the genetic makeup of the bacteria from brain tissue and that of the bacteria from other sites.

What they did find was evidence that the bacteria don’t just sit on the surfaces of cells, but actually penetrate inside cells. That may be what enables entry into the bloodstream and eventually, to the brain, the researchers said.

“This finding is tantalizing, because it may offer an explanation as to why scientists have never been able to specify a viral, autoimmune or other cause of GME and NME,” Brown said.

In addition, different strains of bacteria were not equally efficient at suppressing the dogs’ immune responses.

The researchers are continuing to analyze the effects of bacterial infection on immune system cells known as macrophages to determine how the bacteria could breach the blood-brain barrier. Later, they will extend their studies to examining how the bacteria interact with different types of brain cells.

“The study is intriguing, but more work needs to be completed to determine the significance of these bacteria as a possible cause of GME and NME,” said Karen Vernau, an associate clinical professor and chief of neurology/neurosurgery at the University of California, Davis’ College of Veterinary Medicine, who was not involved in the study.

Immunology researcher named associate dean for research Tue, 18 Sep 2012 18:06:02 +0000 Dr. Ammon Peck

Dr. Ammon Peck

Dr. Ammon B. Peck, an immunology researcher and professor at the University of Florida, has been named associate dean of research and graduate studies at the UF College of Veterinary Medicine, effective Sept. 1.

Peck was most recently a professor in the College of Medicine’s department of pathology, immunology and laboratory medicine, with a joint appointment in the College of Dentistry’s department of oral biology. He helped build the graduate student program in immunology and molecular pathology within the College of Medicine during the 1980s and early 1990s.

Since then, Peck has continued to be engaged in classroom lectures, seminars and journal clubs in addition to directing independent research projects and mentoring undergraduate and graduate students in addition to postdoctoral fellows pursuing research careers.

He succeeds Dr. Charles Courtney following Courtney’s retirement from the position after 30 years of service on the college faculty.

“We are very fortunate to have attracted such an accomplished researcher and mentor to lead our Office of Research and Graduate Studies,” said Glen Hoffsis, D.V.M., the college’s dean.

While at UF, Peck has served as president of the College of Medicine faculty and as a member and vice chair of the Academic Health Center’s Institutional Review Board. He also established and co-directed the Type II Center for Research on Women’s Health, an intercollegiate center encompassing all six AHC colleges.

An active entrepreneur and consultant, Peck cofounded Ixion Biotechnology Inc. to commercialize research discoveries in diabetes and hyperoxaluria, a hereditary disorder that causes a type of stone to form in the kidneys and urine, beginning in childhood. The company received the Tibbetts Award from the Small Business Association in Washington, D.C., in 2000 and is currently conducting clinical trials of a product developed as a treatment for hyperoxaluria.

Peck’s research focuses on three main areas: the molecular mechanisms underlying the causes of autoimmune diseases, the pathogenesis of human and animal diseases involving hyperoxaluria, and stem cell biology.

Among the many honors Peck has received in his academic career are the 2012 International Association of Dental Research’s Distinguished Scientist Award for Salivary Research, the College of Medicine’s Exemplary Teacher Award in 2008, the Council of Biotechnology Award from Japan’s Tsurumi University in 2002, UF’s Step Professorship in 2001, and the UF Research Foundation’s distinguished professor designation in 1999.

Peck received his doctorate in medical microbiology from the University of Wisconsin-Madison in 1972. From 1974 to 1982, he worked at Uppsala University in Sweden, which overlapped with his appointment at UF in 1979.