December 30 , 2002

DNA Sequencing Helps Researchers Become First to Prove Same Protozoan Affects Both Humans and Swans

History making find also discovers that swans show a spontaneous remission upon removal of cysts caused by the protozoan.

ORLANDO, Florida -- Six Florida researchers working with a Michigan State University associate professor and a medical mycologist from the Centers for Disease Control and Prevention in Atlanta, Georgia have become the first to prove that rhinosporidiosis in swans is the same protozoan affecting both humans and other animals.

Dr. Geoffrey R. Gardner, a Lakeland veterinarian and researcher with the The Regal SwanTM team, removed eye cysts caused by the protozoan, Rhinosporodium seeberi, from 41 infected swans at Lake Morton in Lakeland, Florida. Dr. Leonel Mendoza, an associate professor with the Medical Technology Program, in the Department of Microbiology and Molecular Genetics from Michigan State University and Dr. Libero Ajello, a medical mycologist in the Mycotic Diseases Branch of the Centers for Disease Control, utilized DNA sequencing analysis to determine the genetic makeup of the protozoan. DNA taken from the eye cysts of the swans was subsequently examined and tested with
DNA from cysts with rhinosporidiosis taken from humans. The DNA analysis revealed the R. seeberi in both species is the same species.

This find is historically important. Rhinosporidiosis, once thought to be caused by a fungus is now proven to be a protozoan. This organism is found in moist, warm environments and is most prevalent in India, Sri Lanka and southeast Asia, although cases have occurred in Africa, Central and South America, Europe and
the United States. This protozoan has never been cultured and its natural habitat remained unknown. Rhinosporidium seeberi is a natural occurring microorganism that infects the mucus surfaces of humans and animals who come into contact with it. Rhinosporidiosis is a byproduct of the microorganism. It’s a non-contagious chronic infection that usually manifests itself in the form of slow-growing-tumor-like masses that affect the nasal passages or the eyes. Currently, surgical removal is the only available treatment.

However, this study showed that by surgically removing the cysts, the swans showed a spontaneous remission (no noted reoccurrence of the parasite). More testing is expected to be conducted by the doctors and The Regal SwanTM researchers to find more information on this elusive parasite.

The DNA testing was conducted in conjunction with a three-year study by The Regal SwanTM for a vaccine for botulism in swans. The group recently found that Pfizer’s Ultrabac® CD is highly successful in combatting the deadly Clostridia bacterial toxin.

Researchers for The Regal SwanTM include: Geoffrey R. Gardner, D.V.M., Lakeland Veterinary Hospital, Lakeland, Florida; W. Brown, D.V.M., Central Florida relief veterinarian, Orlando, Florida; Fanchon F. Funk, Ed.D., associate professor, Florida State University, Tallahassee, Florida; Sheila A. Bolin, M.S., swan keeper, Orange Lake Resort & Country Club, Orlando, Florida; Rebecca Webb Wilson, J.D., professional photographer and lifetime trustee of the Memphis Zoological Society, Memphis, Tennessee; and Shirley A. Bolin, A.G.S., head photographer and staff writer, Orange Lake Resort & Country Club, Orlando, Florida.

In addition to working with Drs. Mendoza and Ajello, The Regal SwanTM researchers have also been working closely with Her Majesty’s Royal Swan Warden, Dr. Christopher Perrins, director of the Earl Grey Institute of Ornithology, Oxford University, London, England; and Her Majesty’s Swan Marker, David Barber, London, England, during the three-year study conducted at Lake Morton, in Lakeland, Florida and Orange Lake Resort & Country Club, in Orlando, Florida.

For more information on The Regal SwanTM, please go to:

Sponsors Include:

Pfizer Animal Health, Orange Lake Resort & Country Club, City of Lakeland, Florida, Lakeland Veterinarian Hospital, Antech Diagnostic Labs, Inc., American Camper, Blitz® USA, Bushnell Sports Optics Worldwide, Cobra Electronics, Hunt Manufacturing Company, Kaz Incorporated, Lab Essentials, Inc., The National High Magnetic Laboratory, Florida State University; The Memphis Zoo, Orlando Science Center, ( Thamesweb, Windsor, England; Sharn Veterinary, Inc., The Sports Authority, Times®, VetCare, Vicks Company, IQ Scientific Instruments and Western Pest Services.



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Photos by: Shirley A. Bolin and Rebecca Webb Wilson