An innovative approach to tackle avian infectious bronchitis

Infectious bronchitis virus is a coronavirus that causes the respiratory disease infectious bronchitis and is a major problem for the global poultry industry. Photo: Canva

The Pirbright Institute researchers, in collaboration with US live sciences company New England Biolabs Inc., have developed an innovative approach to study infectious bronchitis virus.

The new method, published in the journal PLos ONE, will allow quicker response to infectious bronchitis virus, particularly in vaccine development, curbing the spread of the contagious disease.

Infectious bronchitis virus is a coronavirus that causes the respiratory disease infectious bronchitis and is a major problem for the global poultry industry, causing significant welfare issues and economic losses. Controlling the virus is a challenge due to rapid mutation of the virus and existing vaccines offering poor cross-protection against different strains.

Enhance understanding and develop better vaccines

Research at The Pirbright Institute has focussed on studying individual infectious bronchitis virus genes to enhance our understanding of the disease and develop better vaccines. Previous methods for studying the infectious bronchitis virus genome have been slow and time-consuming, relying on recombination for the introduction of mutations and, depending on the system, can be subject to genome instability and unreliable success rates.

The research team, led by The Pirbright Institute’s Dr Sarah Keep and New England Biolabs’ Dr Greg Lohman, used a data-optimised Golden Gate Assembly process to develop a more efficient reverse genetics approach for studying infectious bronchitis virus.

The infectious bronchitis virus genome was divided into 12 fragments at high-fidelity fusion site breakpoints. All fragments were synthetically produced and propagated in E.coli plasmids, amenable to standard molecular biology techniques for DNA manipulation.

The assembly can be carried out in a single reaction, with the products used directly in subsequent viral rescue steps. The research demonstrated the use of this system for generation of point mutants and gene replacement.

A simplified, rapid approach

The system offers a simplified, rapid approach to investigate the biology of the virus. The system’s flexibility also means it can be applied rapidly to study emerging infectious bronchitis virus variants for the development of targeted vaccines.

Dr Sarah Keep, a senior molecular virologist in The Pirbright Institute’s coronaviruses group, said “This new system is a game-changer for our research on infectious bronchitis virus and will allow us to develop vaccines to control the spread of this challenging virus.”

Beyond infectious bronchitis virus, the method could potentially be used to study other coronaviruses and other large genome viruses, accelerating research and development of vaccines and treatments for various viral diseases.