Molecular Epidemiology of Fowl Aviadenoviruses in Broiler Chickens from Vaccinated and Nonvaccinated Breeders

Bicakcioglu T., MÜŞTAK H. K., SARIÇAM İNCE S., Yoruk S., Unal G.

AVIAN DISEASES, cilt.68, sa.3, ss.209-216, 2024 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 68 Sayı: 3
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1637/aviandiseases-d-24-00017
  • Dergi Adı: AVIAN DISEASES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, CAB Abstracts, EMBASE, Veterinary Science Database
  • Sayfa Sayıları: ss.209-216
  • Ankara Üniversitesi Adresli: Evet

Özet

Fowl aviadenoviruses (FAdVs) are widely distributed among poultry populations, leading to various diseases, immunosuppression, and economic losses. Molecular characterization and phylogenetic analysis of circulating FAdV isolates play a critical role in epidemiologic studies, contributing to the control, monitoring, and prevention of related outbreaks. This study aimed to determine the serotypes of FAdV and reveal the molecular epidemiology in broiler chicken fl ocks. Samples were taken based on epidemiologically important parameters, such as vaccination status, age, and transmission route. A total of 20 vaccinated fl ocks (VF, fl ocks originated from vaccinated breeder lines) and 20 nonvaccinated fl ocks (NVF, fl ocks originated from nonvaccinated breeder lines) were randomly selected from fl ocks reporting suspected FAdV clinical symptoms and deaths. Vaccination was administered by intramuscular injection into the pectoral muscle with a commercial inactivated vaccine at 12 and 18 wk. Liver and cloacal swab samples were collected from each fl ock over two different production cycles and for three different age groups (1-day-old, 14-day-old, and 28-day-old chickens). The liver and cloacal swap samples were analyzed for FAdV using PCR targeting the hexon loop-1 gene. Molecular detection revealed that 30.0% (24/80) of all fl ocks were FAdV positive, with 50.0% (20/40) positivity in NVF and 10.0% (4/40) in VF. Sequence analysis of the hexon loop-1 gene revealed that all samples were FAdV-8b serotype (OR670689-OR670712), with 100.0% similarity. One randomly selected FAdV-8b sample was analyzed by whole-genome sequence analysis. This is the fi rst study in Turkey to deposit an FAdV whole-genome sequence (44,139 bp) into the GenBank database (PP236873). Given the significantly lower FAdV positivity rates in VF compared to NVF, the fi ndings indicate that vaccination is an effective tool for protecting against FAdV-related infections.