COLLEGE PARK, Md. -- The molecular keys to the serious poultry disease, known as Gumboro disease, have been discovered for the first time by scientists of the University of Maryland Biotechnology Institute and the Virginia-Maryland Regional College of Veterinary Medicine. At UMBI's Center for Agricultural Research (CAB), virologist Vikram N. Vakharia and colleagues report finding specific amino acid residues in the Gumboro-causing viruses that are responsible for its infection, virulence and disease development in poultry.
In the late 1980's, concern was heightened in the poultry industry of the Delmarva (Delaware/Maryland/Virginia) Peninsula when researchers found new strains of infectious bursal disease virus (IBDV) that causes serious disease. The region produces over 600 million broiler chickens annually. The IBDV strains found there caused wasting away of the bursa, which is the major immunological organ of chickens, but did not cause the hemorrhaging condition and high death rates of earlier, so-called classic, strains found in the United States in the 1960's. However in the 1990's, strains of IBDV emerged in Europe and Asia that killed up to 70 percent of some chicken flocks.
UMBI's Vakharia has recently created new, cost-effective recombinant vaccines to fight IBDV. However, the unpredictable nature of the Gumboro outbreaks, from mild to severe, is due to the ability of the virus to mutate and adapt in chicken tissues and continue to threaten the industry.
The discovery of the virus amino acids responsible for severe outbreaks will now help Vakaria to more rapidly respond to new strains of the virus with even more effective genetically engineered vaccines that can be administered to the chicken but will not cause the disease, while producing a strong protective immune response.
In the December 2001 issue of the Journal of Virology, the scientists report that three amino acid residues in the major coat protein of IBDV are responsible for its virulence and infection to the precursors of antibody-producing B cells of the bursa. The malady leads to severe immuno-suppression and death of young chickens. The experiments were carried out using the reverse-genetics systems that have only recently become available, says Vakharia.
The poultry industry in the United States is valued at about 12.2 billion dollars, according to U.S. Department of Agriculture.
The University of Maryland Biotechnology Institute was mandated by the state of Maryland legislature in 1985 as "a new paradigm of state economic development in biotech-related sciences." Five UMBI research and education centers are dedicated to leading and partnering to advance biotechnology. The centers are Center for Advanced Research in Biotechnology in Rockville; Center for Agricultural Biotechnology in College Park; and Center of Marine Biotechnology, Medical Biotechnology Center, and the Institute of Human Virology, all in Baltimore.
The above story is based on materials provided by University Of Maryland Biotechnology Institute. Note: Materials may be edited for content and length.
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