Pathogenesis of H13 nephropathogenic infectious bronchitis virus

Area of Science:

• Avian Virology
• Poultry Pathology
• Veterinary Immunology

Background:

• Infectious Bronchitis Virus (IBV) is a significant pathogen in poultry.
• Nephropathogenic strains of IBV can cause substantial economic losses in the broiler industry.
• Understanding the pathogenicity of emerging IBV strains is crucial for disease management.

Purpose of the Study:

• To characterize a newly isolated nephropathogenic strain of IBV, designated H13-IBV, from commercial broilers.
• To evaluate the clinical and pathological effects of H13-IBV infection in chickens of different ages.
• To assess the impact of H13-IBV on both renal and respiratory systems.

Main Methods:

• Isolation and identification of IBV strain H13-IBV from broiler kidneys.
• Experimental infection of specific-pathogen-free chickens at different ages (1 day and 4 weeks).
• Clinical observation, gross necropsy, and histopathological examination of renal and respiratory tissues.

Main Results:

• H13-IBV induced respiratory distress, depression, and diarrhea.
• Gross renal lesions included pallor, swelling, and urate deposition; histologically, interstitial nephritis and tubular damage were observed.
• Respiratory lesions involved airsacculitis, tracheal congestion, and histological changes like deciliation and squamous metaplasia.
• The virus was highly pathogenic in 1-day-old chicks, causing severe kidney lesions, and mildly pathogenic in 4-week-old birds.

Conclusions:

• The H13-IBV strain is nephropathogenic and causes significant respiratory and renal pathology in chickens.
• Younger birds (1 day old) are more susceptible to severe clinical signs and kidney damage.
• This study identifies a distinct IBV strain with implications for poultry health and disease control strategies.