Submitted to: American Veterinary Medical Association Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 18, 2007
Publication Date: July 18, 2007
Citation: Fadly, A.M., Mays, J.K., Silva, R.F., Hunt, H.D. 2007. Use of molecularly cloned avian leukosis virus to study antigenic variation following infection of meat-type chickens [abstract]. American Association of Avian Pathologists/American Veterinary Medical Association Abstract. p. 37. Technical Abstract: A molecularly cloned strain of subgroup J avian leukosis virus (ALV-J) termed R5-4 was used to study antigenic variation following infection of meat-type chickens. Chickens were inoculated with R5-4 virus at either 8 days of embryonation or at 1 week of age. Each chicken was housed in a separate isolator; chickens were sampled for ALV and antibody at 4 week intervals up to 20 weeks of age. Inoculation of R5-4 virus at 8 days of embryonation resulted in tolerant infection, as all chickens were persistently viremic with no detectable antibody. However, infection at 1 week of age induced the following infection profiles by 8 weeks post-infection: 17/30 (57%) were virus positive, antibody negative (V+A-), 5/30 (16%) were virus positive, antibody positive (V+A-), and 7/30 (23%) were virus negative, antibody positive (V- A+). Viruses isolated from the 5 chickens classed as V+A+were not neutralized by antibodies against originally inoculated virus, R5-4, suggesting development of antibody-escape mutants. These isolates are being sequenced to determine molecular differences from originally inoculated virus.