TaqMan probe-based qPCR method for specific detection and quantification of fowl adenovirus 8b challenge from chickens inoculated with live attenuated or inactivated virus

• Published in: Open Veterinary Journal Vol. 13; no. 2; pp. 171 - 178
• Main Authors: Ugwu, Chidozie C, Hair-Bejo, Mohd, Nurulfiza, Mat I, Omar, Abdul R, Aini, Ideris
• Format: Journal Article
• Language: English
• Published: Libya Faculty of Veterinary Medicine 01.02.2023; Tripoli University
• Subjects: Adenoviridae Infections - diagnosis; Adenoviridae Infections - pathology; Adenoviridae Infections - veterinary; Animals; Aviadenovirus - genetics; Chickens; fowl adenovirus 8b; Liver; Original Research; Poultry Diseases; real time pcr; Serogroup; taqman probe; virus detection; virus quantification; TaqMan probe; Virus detection; Virus quantification; Real-time PCR; Fowl adenovirus 8b
• ISSN: 2226-4485; 2218-6050
• DOI: 10.5455/OVJ.2023.v13.i2.4

Fowl adenovirus (FAdV) 8b and other serotypes cause inclusion body hepatitis (IBH) in chickens. Specific detection of aetiologic serotype in mixed infection and vaccine failure could be difficult. The objective of this study was to develop a TaqMan probe-based qPCR method for the detection and quantification of the FAdV 8b challenge virus. Forty-eight broiler chickens inoculated with live attenuated or inactivated FAdV 8b strains at day 1 of age either with or without booster at day 14 post-inoculation were used. The chickens were challenged with a pathogenic strain of FAdV 8b at day 28 of age. Liver and cloacal swabs were collected on days 7 and 14 post-challenge. Primers and probes were designed, specificity confirmed, and used to carry out qPCR amplification. The assay amplified the FAdV DNA challenge virus, but not that of the live attenuated virus. It could detect FAdV 8b DNA as low as 0.001 ng/µl in liver and cloacal swab samples. Copy numbers obtained indicate virus load and shedding. It shows that a selective detection of FAdV 8b within serotype is possible. It can be useful for rapid detection and diagnosis of the disease, virus quantification and differentiation within species, determination of vaccination failure, and efficacy especially the virus load in the target organ and shedding.