By Sarah Carey

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.

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.

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.

Department of Physiological Sciences
Box 100144
1600 SW Archer RD
Gainesville, FL  32610-0144
stevosian@ufl.edu
352-294-4364
FAX 352-294-8012

 Education

• PhD, Tufts University, 1997

Research Interests

Genetics

Recent Publications

• DMRT1 Owner's Manual: Synchronized Installation Required to Operate.

Additional publications here

Education

• Doctorate, Biomedical Sciences/Parasitology – 2008. Auburn University
• Master of Science, Biology – 2004. Appalachian State University
• Bachelor of Science, Biology – 1999. University of Kentucky

Honors and Awards

• 2008 – Intervet/AAVP Outstanding Graduate Student
• 2008 – Byrd Dunn Award for Best Student Presentation
• 2007 – Phi Zeta Best Graduate Student Presentation
• 2007 – Bayer/AAVP Best Graduate Student Presentation

Research Interests

Research in our laboratory is centered on parasites of importance to veterinary medicine. Protozoan parasites are of particular interest, including the relationships between parasite and host and resulting pathogenesis of disease. Our laboratory also diagnosis parasitic infections or infestations and routinely identifies parasitic helminths, protozoa and arthropods.

Recent Publications

Book Chapters

Stockdale HD, Spencer JA, Blagburn BL. 2007. Prophylaxis and Chemotherapy. In: Fayer R and Xiao L, Eds. Cryptosporidium and Cryptosporidiosis. 2nd Ed. CRC Press, Boca Raton, FL, p. 544.

Peer Reviewed Publications

Rosypal AC, Ripley A, Stockdale-Walden HD, Blagburn BL, Grant DC and Lindsay DS. 2011. Survival of a feline isolate of Tritrichomonas foetus in the environment. Vet Par: Submitted.

Stockdale HD, Givens MD, Dykstra CC and Blagburn BL. 2009. Tritrichomonas foetus in surveyed pet cats. Vet Par. 160: 13-17.

Stockdale HD and Blagburn BL. 2008. Consultant on Call: Feline Trichomoniasis. NAVC Clinician’s Brief: 6(4): 9-11.

Stockdale HD and Blagburn BL. 2008. Diagnostic Tree: Feline Chronic Large Bowel Diarrhea. NAVC Clinician’s Brief. 6(4): 14-15.

Stockdale HD, Dillon AR, Newton JC, Bird RC, BonDurant RH, Deinnocentes P, Barney S, Butler J, Land T, Spencer JA, Lindsay DS, Blagburn BL. 2008. Experimental infection of cats (Felis catus) with Tritrichomonas foetus isolated from cattle. Vet Par. 145: 156-161.

Rodning SP, Wolfe DF, Carson RL, Wright JC, Stockdale HD, Pacoli ME, Busby HC, Rowe SE. 2008. Prevalence of Tritrichomonas foetus in several subpopulations of Alabama beef bulls. Theriogenology 69: 212-217.

Stockdale HD, Rodning SP, Givens MD, Carpenter DM, Lenz SD, Spencer JA, Dykstra CC, Lindsay DS, Blagburn BL. 2007. Experimental infection of cattle with a feline isolate of Tritrichomonas foetus. J. Parasitol. 93(6): 1429-1434.

Stockdale HD, West GS, Hankes TH, McMillan KL, Whitley M, Spencer JA, Dykstra CC, Blagburn BL. 2006. Feline Trichomoniasis: An Emerging Disease? Compend Contin Educ Pract Vet. 28(6): 463-471.

Additional publications here

Department of Physiological Sciences
vickroy@ufl.edu
PO Box 100144
1600 SW Archer Rd
Room B2-10, BSB
Gainesville, FL 32610-0144
352-294-4036
FAX:  352-294-9874

Education

• B.S., Biophysics & Biochemistry, Penn State University, State College, 1977.
• Ph.D., Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, 1982.

Honors and Awards

• Clinical Sciences Teacher of the Year Award, UF College of Veterinary Medicine, 2006.
• Teacher of the Year Award (Class of 1996), UF College of Veterinary Medicine, 1998.
• Teaching Improvement Program Award, UF College of Veterinary Medicine, 1994.
• C.E. Cornelius Outstanding Young Investigator Award, UF College of Veterinary Medicine, 1991.

Research Interests

My principal research interests are neuropharmacology, pharmacokinetics and regulation of drugs that are used in major and minor food animal species. At present, I serve as one of the national directors for the Food Animal Residue Avoidance and Detection (FARAD) program, which is designed to prevent or mitigate chemical residues in animal-derived foods (meat, milk, eggs, etc.) by therapeutic treatments (e.g., extra-label drug use) or accidental exposures to pesticides, toxins or other environmental contaminants. Detailed information on the FARAD program can be found at www.farad.org. In addition, I serve as Southern Region Drug Coordinator for the Minor-Use Animal Drug program (MUADP). This program works with industrial partners and stakeholder groups to identify drug needs for minor food-animal species (sheep, goats, gamebirds, aquaculture, etc.) or minor use drugs in major species. MUADP coordinators conduct or oversee suitable trials to generate and disseminate data that demonstrate safety and efficacy in target animal species as well as human food safety and work with groups within the Food and Drug Administration Center for Veterinary Medicine (FDA/CVM) to gain regulatory approvals for drugs. More information about MUADP can be obtained at www.nrsp7.org.

Recent Publications

• Improved nonaqueous capillary electrophoresis for tetracyclines at subparts per billion level.

Additional publications here

Education

• MS, Quantitative Genetics, Louisiana State University, 1980
• PhD, Genetics, University of Arizona, 1987

Honors and Awards

• Who’s Who in Veterinary Medicine Higher Education, 2008
• Phi Zeta National Honor Society of Veterinary Medicine, 2007
• International Organization for Mycoplasmology Derrick Edward Award for Outstanding Research in Mycoplasmology, 2004
• University of Florida College of Veterinary Medicine C.E. Cornelius Young Investigator Award, 1994

Research Interests

Cellular microbiology focuses on the host cell responses elicited by interactions with microorganisms. Recent and ongoing research in my laboratory includes culture- and non-culture-based discovery of new bacterial pathogens and commensals from clinical specimens; experimental infection studies and epidemiology; bacterial genome sequencing and annotation; molecular analysis of bacterial virulence mechanisms; comparative immunology; CD44, CD95, and TLR signaling in pro-apoptotic and inflammatory responses to bacterial infection; and genome-based predictive modeling of pathogen evolution.

Recent Publications

• Genome annotation of five Mycoplasma canis strains.
  

Additional publications here

Department of Physiological Sciences
wronskit@ufl.edu
PO Box 100144
1600 SW Archer Rd.
Gainesville, FL 32610-0144
(352) 294-4044
FAX: (352) 392-5145

Education

• B.S., Biology, St. Joseph’s College, Philadelphia, 1972
• Ph.D., Anatomy, University of Utah, Salt Lake City, 1979

Honors & Awards

• Graduated Cum Laude, St. Joseph’s College, 1972
• NASA Cosmos Achievement Award, for participation in U.S. experiments on the Soviet Cosmos 1129 biological satellite, 1981
• C.E. Cornelius Young Investigator Award, College of Veterinary Medicine, University of Florida, 1988
• Member, Editorial Board for the journal Bone, 1989-present
• Graduate Student Service Award, College of Veterinary Medicine, University of Florida, 1994
• SmithKline Beecham Award for Research Excellence, College of Veterinary Medicine, University of Florida, 1994
• NIH MERIT Award for sustained contributions to aging research, National Institute on Aging, 1997
• Member, External Advisory Council for the National Space Biomedical Research Institute, 1997-2003
• Research Professorship Award for a distinguished record of research and scholarship, University of Florida, 1999
• Member, Board of Directors for the International Society of Bone Morphometry, 1999-present
• Member, Board of Scientific Counselors for the National Space Biomedical Research Institute, 2003-present
• Teacher of Year Award, Class of 2007, College of Veterinary Medicine, University of Florida, 2004
• Member, Editorial Board for the Journal of Bone and Mineral Research, 2006-2010
• President, International Society of Bone Morphometry, 2009- present
• Teacher of the Year Award, UF College of Veterinary Medicine, 2013

Research Interests

My research involves preclinical testing of new drugs and hormones for the prevention and treatment of postmenopausal osteoporosis, a bone disorder that afflicts millions of elderly women. These studies are performed in the ovariectomized rat, a widely accepted animal model for postmenopausal bone loss. Bone samples are subjected to histomorphometric analysis with a computer-assisted, image analysis system to determine the effects of the various treatments on bone mass and levels of bone resorption and formation. In addition, molecular biology techniques are used to determine the effects of novel osteoporosis therapies on gene expression for selected growth factors, cytokines, and bone matrix proteins. The same histomorphometric and molecular biology techniques are used to investigate the skeletal effects of actual and simulated space flight.

Recent Publications

• A rehabilitation exercise program induces severe bone mineral deficits in estrogen-deficient rats after extended disuse.

Additional publications here

Research Professor

Department of Infectious Diseases and Pathology
romeroc@ufl.edu
PO Box 110880
2015 SW 16th Ave
Gainesville, FL 32608-0880
352-294-4171
FAX: 352-392-9704