Amino acid residues lead to poultry disease
the serious poultry disease, Gumboro disease. Researchers at the
University of Maryland Biotechnology Institute and the
Virginia-Maryland Regional College of Veterinary Medicine report
finding specific amino acid residues in the Gumboro-causing viruses
that are responsible for its infection, virulence and disease
development in poultry.
Scientists in the US claim to have discovered the molecular keys to the serious poultry disease, Gumboro disease. Researchers at the University of Maryland Biotechnology Institute and the Virginia-Maryland Regional College of Veterinary Medicine 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 1980s concern was heightened in the US poultry industry when researchers found new strains of infectious bursal disease virus (IBDV) that can cause serious disease. The IBDV strains found caused wasting away of the bursa, which is the major immunological organ of chickens, but did not cause the haemorrhaging condition and high death rates of earlier, so-called classic, strains found in the United States in the 1960s.
In the 1990s, strains of IBDV emerged in Europe and Asia and reportedly killed up to 70 per cent of some chicken flocks.
At UMBI's Center for Agricultural Research (CAB), virologist Vikram N. Vakharia and colleagues 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 continues to threaten the industry.
The discovery of the virus amino acids responsible for severe outbreaks will help researchers respond more rapidly to new strains of the virus with 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, said leading researcher Vakharia.
According to the US Department of Agriculture the poultry industry in the United States is currently valued at about $12.2 billion (€13.8m).
